Aetna Cetuximab (Erbitux) Form
This procedure is not covered
Background for this Policy
U.S. Food and Drug Administration (FDA)-Approved Indications
Squamous Cell Carcinoma of the Head and Neck (SCCHN)
Erbitux is indicated:
K-Ras Wild-type, EGFR-expressing Colorectal Cancer (CRC)
Erbitux is indicated for the treatment of K-Ras wild-type, epidermal growth factor receptor (EGFR)-expressing, metastatic colorectal cancer (mCRC) as determined by an FDA-approved test:
Limitations of Use: Erbitux is not indicated for treatment of Ras-mutant colorectal cancer or when the results of the Ras mutation tests are unknown.
BRAF V600E Mutation-Positive Metastatic Colorectal Cancer (CRC)
Erbitux is indicated, in combination with encorafenib, for the treatment of adult patients with metastatic colorectal cancer (CRC) with a BRAF V600E mutation, as detected by an FDA-approved test, after prior therapy.
Compendial Uses
Erbitux (cetuximab) is a recombinant, human/mouse chimeric monoclonal antibody that binds specifically to the human epidermal growth factor receptor (EGFR). EGFR is a transmembrane glycoprotein that is constitutively expressed in many normal epithelial tissues, including the skin and hair follicle. Over expression of EGFR is also detected in many human cancers, including those of colorectal and head and neck origin. Interaction of EGFR with normal ligands leads to phosphorylation and activation of a series of intracellular tyrosine kinases, which in turn regulate transcription of molecules involved with cellular growth and survival, motility, proliferation, and transformation.
Limitations of Use: Erbitux is not indicated for treatment of Ras‐mutant colorectal cancer or when the results of the Ras mutation are unknown.
Dosage Adjustments
Black Box Warnings
KRAS: KRAS testing is recommended prior to initiating cetuximab or panitumumab therapy in metastatic colorectal cancer (mCRC) patients. KRAS is highly predictive of response to cetuximab or panitumumab in metastatic colorectal cancer setting. Due to lack of response seen in mCRC tumors with KRAS mutations—coverage will not be extended to this setting.
Crystal and Everest trials showed that cetuximab was beneficial in wild‐type mCRC tumors, but patients with KRAS mutations did not benefit from the addition of the EGFR targeted therapy. Cairo2 and Opus trials also demonstrated a lack of clinical benefit by adding the EGFR antibody, but also demonstrated a compelling decrease in progression-free survival (PFS) when EGFR targeted therapy was added. It is possible that this data reflects mCRC actually doing worse because they received EGFR targeted therapy. Amado demonstrated that KRAS wild‐type verification was also necessary prior to panitumumab therapy due to lack of response seen in tumors with KRAS mutations.
All NCI sponsored clinical trials analyzing these agents have been reevaluated to take KRAS testing into account. The EMEA already requires KRAS testing and wild‐type verification prior to initiation of cetuximab or panitumumab therapy.
Erbitux (cetuximab) should not be utilized in the following:
Colorectal Cancer
Colorectal cancer is the second-leading cause of cancer death in the United States. It is the nation's third most common cancer accounting for approximately 15 % of all new cancer cases. Metastatic disease is present at diagnosis in 30 % of the patients, and about 50 % of early-stage patients will eventually present with metastatic disease. For many years, standard treatment of colorectal cancer was 5-fluorouracil (5-FU)-based therapy. Recent availability of newer agents, including capecitabine, irinotecan and oxaliplatin, has significantly expanded the options available for the management of patients with advanced colorectal cancer, with consequent improvements in survival.
The expression of various growth factors, growth inhibitors, and their receptors contributes to the development of colorectal cancer as well as to the proliferation and survival of cancerous cells. About 65 to 70 % of human colon carcinomas have been demonstrated to express the epidermal growth factor receptor (EGFR). It has been reported that expression of EGFR correlates with tumor progression, resistance to chemotherapy and a poorer prognosis. Epidermal growth factor receptor plays an important role in initiating signal transduction, and therapeutic approaches directed towards interrupting this pathway have been shown to impair tumor cell proliferation. These strategies include anti-EGFR monoclonal antibodies, immunotoxin conjugates, and EGFR tyrosine kinase inhibitors. Cetuximab is a genetically engineered mouse monoclonal antibody that works by inhibiting the EGFR. Additionally, cetuximab has the potential to partially reverse resistance to a chemotherapy drug.
On February 12, 2004, the Food and Drug Administration (FDA) approved cetuximab (Erbitux) under its accelerated approval program as a combination treatment with irinotecan for the treatment of patients with metastatic colorectal cancer; or alone if patients cannot tolerate irinotecan. The approval of cetuximab by the FDA was largely based on the findings of a randomized, controlled study with 329 patients – 218 for cetuximab plus irinotecan combination therapy and 111 for cetuximab monotherapy. Furthermore, cetuximab was examined as a single agent in a third clinical study with 57 patients. Safety data from the 111 patients treated only with cetuximab was also assessed. All of the studies included patients with EGFR-expressing metastatic colorectal cancer, whose disease had progressed after receiving irinotecan. Results of these trials showed that the combination treatment of cetuximab and irinotecan shrank tumors in 22.9 % of patients and delayed tumor growth by 4.1 months. For patients who received cetuximab alone, the tumor response rate was 10.8 % and tumor growth was delayed by 1.5 months. However, it should be noted that although cetuximab has been reported to shrink tumors in some patients and delay tumor growth, especially when used as a combination treatment, it has not been shown to increase survival. According to guidelines from the National Comprehensive Cancer Network (NCCN, 2022), cetuximab is not recommended for use as first-line therapy as a single agent unless the patient is unable to tolerate irinotecan. NCCN guidelines and the FDA-approved labeling of Erbitux also stated that cetuximab should not be used in combination with other monoclonal antibodies.
Adverse effects associated with the use of cetuximab include difficulty in breathing and low blood pressure that usually occurs during the administration of the first treatment. Infrequent interstitial lung disease has also been reported. Other more common side effects of cetuximab treatment include acne-like rash, dry skin, tiredness or weakness, fever, constipation, and abdominal pain.
Cetuximab has also been shown to improve outcomes when used as first line therapy in combination with irinotecan-based regimens in patients with metastatic colorectal cancer. Van Cutsem et al (2007) investigated the effectiveness of cetuximab in combination with standard folinic acid (leucovorin), 5-fluorouracil and irinotecan (FOLFIRI) compared with FOLFIRI alone in the first-line treatment of patients with metastatic colorectal cancer. Patients were randomized to receive either cetuximab plus FOLFIRI (n = 608) or FOLFIRI alone (n = 609). Median progression free survival (the primary study endpoint) was significantly longer for the cetuximab plus FOLFIRI arm (8.9 months) compared to the FOLFIRI alone arm (8 months) (p = 0.036). Response rate was also significantly increased by cetuximab (46.9 % versus 38.7 %, p = 0.005). The investigators reported that treatment was generally well-tolerated with neutropenia (26.7 % in cetuximab plus FOLFIRI versus 23.3 % in FOLFIRI alone), diarrhea (15.2 % and 10.5 %, respectively) and skin reactions (18.7 % and 0.2 %, respectively) being the most common grade 3/4 adverse events. The investigators concluded that cetuximab in combination with FOLFIRI significantly increases response rate and significantly prolongs progression-free survival in the first-line treatment of patients with metastatic colorectal cancer, reducing the relative risk of progression by approximately 15 %. Treatment-related side effects of cetuximab in combination with FOLFIRI were as expected, with diarrhea being moderately and skin reactions significantly more frequent as compared to FOLFIRI alone.
Neyns et al (2008) noted that both hepatic arterial infusion (HAI) of chemotherapy and cetuximab (CET) have interesting activity for the treatment of colorectal cancer liver metastases (CRC-LM). Intravenous CET with HAI oxaliplatin (OXA) or intravenous irinotecan (IRI) followed by HAI of infusion of folic acid modulated 5-fluorouracil 5-FU/l-FA was administered to patients with CRC-LM who had failed at least 1 line of prior chemotherapy. A total of 8 patients received intravenous CET with HAI-OXA (5 patients) and intravenousIRI (3 patients) and HAI-5-FU/l-FA. Adverse events included repeated grade 3 skin toxicity (1 patient), abdominal pain with elevated liver enzymes and asthenia (2 patients), duodenal ulcer (2 patients) with catheter migration and intestinal bleeding (1 patient), reversible interstitial pneumonitis (1 patient), and cystic bile duct dilatation (2 patients) with arterio-biliary fistulization (1 patient). A partial response was documented in 5 patients (62 %). The median time to progression was 8.7 months (95 % CI: 8 to 14 months). The authors concluded that intravenous administration of CET with HAI of chemotherapy is feasible and has promising activity but is associated with specific toxicity.
Lv and colleagues (2015) estimated the safety and effectiveness of adding bevacizumab to cetuximab- or panitumumab-based therapy in the treatment of patients with mCRC, using a meta-analysis of randomized controlled trials (RCTs). These researchers performed a literature search for RCTs through PubMed, Embase, and Web of Science (up to May 22, 2014). The outcome measures were PFS, overall survival (OS), objective response rate (ORR), and adverse events (AEs). Two investigators identified eligible studies and extracted data independently. The quality of the included studies was assessed by the Jadad score. Hazard ratios (HR), RR, and 95 % Cls were calculated and pooled. A total of 4 RCTs with 2,069 patients were included in this meta-analysis. The addition of bevacizumab to cetuximab- or panitumumab-based therapy did not significantly prolonged PFS, when compared with antibody alone. The subgroup analysis of adding bevacizumab to cetuximab-based therapy also suggested no significant benefit in PFS or in OS. Patients who received the combined therapy did not have a higher ORR (RR = 0.98, 95 % CI: 0.89 to 1.07; p = 0.608). The incidence of grade 3/4 AEs was not significantly higher in the bevacizumab and cetuximab/panitumumab group. The authors concluded that the addition of bevacizumab to cetuximab- or panitumumab-based therapy did not improve PFS and OS resulting in better ORR. Thus, the combined therapy of bevacizumab with cetuximab or panitumumab is not recommended for the treatment of mCRC. However, larger-scale RCTs are needed to confirm these findings.
Moosmann et al (2011) noted that the AIO KRK-0104 randomized phase II trial investigated the safety and effectiveness of cetuximab combined with capecitabine and irinotecan (CAPIRI) or capecitabine and oxaliplatin (CAPOX) in the 1st-line treatment of metastatic colorectal cancer (mCRC). A total of 185 patients with mCRC were randomly assigned to cetuximab (400 mg/m(2) day 1, followed by 250 mg/m(2) weekly) plus CAPIRI (irinotecan 200 mg/m(2), day 1; capecitabine 800 mg/m(2) twice-daily days 1 through 14, every 3 weeks; or cetuximab plus CAPOX (oxaliplatin 130 mg/m(2) day 1; capecitabine 1,000 mg/m(2) twice-daily day 1 through 14, every 3 weeks). The primary study end-point was ORR. In the intention-to-treat patient population (n = 177), ORR was 46 % (95 % confidence interval [CI]: 35 to 57) for CAPIRI plus cetuximab versus 48 % (95 % CI: 37 to 59) for CAPOX plus cetuximab. Analysis of the KRAS gene mutation status was performed in 81.4 % of the intention-to-treat population. Patients with KRAS wild-type in the CAPIRI plus cetuximab arm showed an ORR of 50.0 %, a PFS of 6.2 months and an OS of 21.1 months. In the CAPOX plus cetuximab arm, an ORR of 44.9 %, a PFS of 7.1 months and an OS of 23.5 months were observed. While ORR and PFS were comparable in KRAS wild-type and mutant subgroups, a trend toward longer survival was associated with KRAS wild-type. Both regimens had manageable toxicity profiles and were safe. The authors concluded that this randomized trial demonstrated that the addition of cetuximab to CAPIRI or CAPOX is safe and effective in 1st-line treatment of mCRC. In the analyzed regimens, ORR and PFS did not differ according to KRAS gene mutation status. The findings of this phase II study were confounded by the concomitant use of irinotecan/oxaliplatin.
The Scottish Intercollegiate Guidelines Network (SIGN)’s clinical guideline on “Diagnosis and management of colorectal cancer” (2011) stated that “Cetuximab should be considered in combination with 5-FU/leucovorin/oxaliplatin or 5-FU/leucovorin/irinotecan chemotherapy for patients with unresectable liver metastases if patients fulfil the Scottish Medicines Consortium (SMC) criteria. The use of cetuximab in combination with oxaliplatin and capecitabine cannot currently be recommended”.
de Souza and colleagues (2012) noted that newer systemic therapies have the potential to decrease morbidity and mortality from mCRC, yet such therapies are costly and have side effects. Little is known about their non-evidence-based use. These investigators conducted a retrospective cohort study using commercial insurance claims from UnitedHealthcare, and identified incident cases of metastatic colon cancer (mCC) from July 2007 through April 2010. They evaluated the use of 3 regimens with recommendations against their use in the NCCN’s guidelines:They performed sensitivity analyses of key assumptions regarding cohort selection. Costs from a payer perspective were estimated using the average sales price for the entire duration and based on the number of claims. A total of 7,642 patients with incident colon cancer were identified, of which 1041 (14 %) had mCC. Of those, 139 (13 %) potentially received at least 1 of the 3 unsupported off-label (UOL) therapies; capecitabine was administered to 121 patients and 49 (40 %) likely received it outside of clinical guidelines, at an estimated cost of $718,000 for 218 claims. Thirty-eight patients received panitumumab and 6 patients (16 %) received it after being on cetuximab at least 2 months, at an estimated cost of $69,500 for 19 claims. Bevacizumab was administered to 884 patients. Of those, 90 (10 %) patients received it outside of clinical guidelines, at an estimated cost of $1.34 million for 636 claims. The authors concluded that in a large privately insured mCC cohort, a substantial number of patients potentially received UOL treatment. The economic costs and treatment toxicities of these therapies warrant increased efforts to stem their use in settings lacking sufficient scientific evidence.
Modest et al (2013) examined the impact of early tumor shrinkage (ETS) on PFS and OS in patients with mCRC treated within the AIO KRK 0104 trial as 1st-line therapy. Moreover, correlations of ETS with clinical characteristics and prognostic markers were evaluated. In total, 121 patients were included into this analysis. Patients were treated with cetuximab combined with either CAPIRI or CAPOX. ETS at 6 weeks was defined as a relative change of greater than or equal to 20 % in the sum of the longest diameters of target lesions compared to baseline. Survival times were compared between patients with ETS greater than or equal to 20 % versus no-ETS. ETS greater than or equal to 20 % was observed in 59 % of all patients with KRAS wild-type tumors. In these patients ETS greater than or equal to 20 % was associated with higher overall response rate (ORR) (82 % versus 19 %, p < 0.001). Also, PFS (8.9 versus 4.7 months, p < 0.001) and OS (31.6 versus 15.8 months, p = 0.005) were significantly superior in ETS greater than or equal to 20 % of patients compared to no-ETS. In patients with KRAS mutant mCRC ETS greater than or equal to 20 % neither had an effect on PFS nor OS. Cetuximab-induced skin toxicity correlated with the occurrence of ETS greater than or equal to 20 % (p = 0.002). The authors concluded that in patients with KRAS wild-type tumors treated with cetuximab plus capecitabine-based chemotherapy ETS greater than or equal to 20 % is an important predictor of favorable outcome. (This appeared to be a sub-analysis on the data of the AIO KRK-0104 study discussed above).
Hoyle et al (2013) stated that colorectal cancer is the third most commonly diagnosed cancer in the UK after breast and lung cancer. People with metastatic disease who are sufficiently fit are usually treated with active chemotherapy as 1st- or 2nd-line therapy. Recently, targeted agents have become available including anti- EGFR agents (e.g., cetuximab and panitumumab) and anti- VEGF receptor agents (e.g., bevacizumab). These researchers investigated the clinical effectiveness and cost-effectiveness of panitumumab monotherapy and cetuximab (mono- or combination chemotherapy) for Kirsten rat sarcoma (KRAS) wild-type (WT) patients, and bevacizumab in combination with non-oxaliplatin chemotherapy, for the treatment of metastatic colorectal cancer after 1st-line chemotherapy. The assessment comprised a systematic review of clinical effectiveness and cost-effectiveness studies, a review and critique of manufacturer submissions and a de-novo cohort-based economic analysis. For the assessment of effectiveness, a literature search was conducted in a range of electronic databases, including MEDLINE, EMBASE and The Cochrane Library, from 2005 to November 2010. Studies were included if they were RCTs or systematic reviews of RCTs of cetuximab, bevacizumab or panitumumab in participants with EGFR-expressing metastatic colorectal cancer with KRAS WT status that has progressed after 1st-line chemotherapy (for cetuximab and panitumumab) or participants with metastatic colorectal cancer that has progressed after 1st-line chemotherapy (bevacizumab). All steps in the review were performed by 1 reviewer and checked independently by a second. Synthesis was mainly narrative. An economic model was developed focusing on 3rd-line and subsequent lines of treatment. Costs and benefits were discounted at 3.5 % per annum. Probabilistic and uni-variate deterministic sensitivity analyses were performed. The searches identified 7,745 titles and abstracts. Two clinical trials (reported in 12 papers) were included. No data were available for bevacizumab in combination with non-oxaliplatin-based chemotherapy in previously treated patients. Neither of the included studies had KRAS status performed prospectively, but the studies did report retrospective analyses of the results for the KRAS WT subgroups. Third-line treatment with cetuximab plus best supportive care (BSC) or panitumumab plus BSC appeared to have statistically significant advantages over treatment with BSC alone in patients with KRAS WT status. For the economic evaluation, 5 studies met the inclusion criteria. The base-case incremental cost-effectiveness ratio (ICER) for KRAS WT patients for cetuximab compared with BSC is £98,000 per quality-adjusted life-year (QALY), for panitumumab compared with BSC is £150,000 per QALY and for cetuximab plus irinotecan compared with BSC is £88,000 per QALY. All ICERs are sensitive to treatment duration. The authors concluded that although cetuximab and panitumumab appeared to be clinically beneficial for KRAS WT patients compared with BSC, they are likely to represent poor value for money when judged by cost-effectiveness criteria currently used in the UK. It would be useful to conduct a RCT for patients with KRAS WT status receiving cetuximab plus irinotecan.
Furthermore, an UpToDate review on “Treatment protocols for small and large bowel cancer” (Brenner et al, 2022) does not mention the combinational use of cetuximab and capecitabine as a therapeutic option.
NCCN guidelines (2022) stated that all patients with metastatic colorectal cancer should have tumor tissue genotyped for RAS mutations (KRAS and NRAS). The guidelines stated that, at the very least, exon 2 KRAS mutation status should be determined. Whenever possible, non-exon 2 KRAS mutation status and NRAS mutation status should also be determined. Patients with any known KRAS mutation (exon 2 or non-exon 2) or NRAS mutation should not be treated with either cetuximab or panitumumab. Mutations in codons 12 and 13 in exon 2 of the coding region of the KRAS gene predict lack of response to therapy with antibodies targeted to the EGFR.The guidelines stated that testing for KRAS and NRAS mutations in codons 12 and 13 should be performed only in laboratories that are certified under the clinical laboratory improvement amendments of 1988 (CLIA-88) as qualified to perform high complexity clinical laboratory (molecular pathology) testing. No specific methodology was recommended (eg, sequencing, hybridization). The guidelines noted that testing can be performed on formalin-fixed paraffin-embedded tissue. The testing can be performed on the primary colorectal cancers and/or the metastasis, as literature has shown that the KRAS and NRAS mutations are similar in both specimen types.
A provisional clinical opinion by the American Society for Clinical Oncology (ASCO, 2009) recommended that patients with metastatic colorectal cancer receive testing for mutations in the KRAS gene to predict whether patients will benefit from treatment with cetuximab and other EGFR inhibitors.
The NCCN guidelines on colon cancer (2022) stated that "[i]nterestingly, a recent publication from de Roock et al raises the possibility that codon 13 mutations may not be absolutely predictive of non-response. However, as stated in that manuscript, these findings are hypothesis-generating only, and prospective studies will be needed to determien if patients with codon 13 mutations can, in fact, benefit from anti-EGFR therapy. At present, use of anti-EGFR agents in patients whose tumors have codon 13 mutations remains investigational, and is not endorsed by the panel for routine practice".
The FDA-approved labeling of Erbitux has the following recommendations regarding dosing in colorectal cancer:
The NCCN Guidelines (v1.2022) on "Colon cancer" states that for appendiceal adenocarcinoma, to consider systemic therapy as per NCCN guidelines for colon cancer. There are now separate NCCN guidelines for small bowel adenocarcinoma.
Head and Neck Cancer
The majority of head and neck cancers over-express the epidermal growth factor receptor (EGFR), which is associated with aggressive tumor behavior and poor clinical outcome. In a recent review, Caponigro et al (2004) noted that 3 phase II studies have evaluated the combination of cetuximab with platinum-based chemotherapy in pre-treated patients with recurrent/metastatic head and neck cancer, with a control rate ranging from 29 to 66 %. However, the authors noted that a phase III placebo-controlled trial has shown that the addition of cetuximab to cisplatin does not significantly improve median progression-free survival, despite a difference in the response rate between the two arms.
Bonner et al (2004, 2006) reported on the results of a phase III trial to examine the impact of combining cetuximab with high dose radiation on locoregional disease control and survival in patients with locally advanced squamous cell carcinoma of the head and neck. The investigators randomized 424 patients with locoregionally advanced squamous cell carcinoma of the oropharynx, hypopharynx or larynx to either radiation alone for 6-7 weeks, or radiation plus weekly cetuximab. Following completion of treatment, patients were followed by physical examination and radiographic imaging every 4 months for 2 years, and then every 6 months up to 5 years. Median survival was 54 months in subjects receiving cetuximab plus radiation therapy compared to 28 months in subjects receiving radiation therapy alone. The investigators noted that the overall toxicity profile was dominated by classic known effects of high dose head and neck radiation, although some additional toxicity was attributed to cetuximab. Significantly more subjects receiving combination therapy had grade 3/4 skin reactions (34 %) than subjects receiving radiation therapy alone (18 %). Grade 3/4 infusion reactions were seen in 3 % of subjects receiving cetuximab. The investigators concluded that the addition of cetuximab to high dose radiation in patients with locoregionally advanced squamous cell carcinoma of the head and neck demonstrated a statistically significant prolongation in overall survival. This clinical benefit was achieved with minimal enhancement in the overall toxicity profile associated with curative-intent radiation therapy. In an editorial that accompanied the 2006 article by Bonner et al, Posner and Wirth (2006) stated that "[a]t present, for patients who can tolerate it, chemoradiotherapy with cisplatin remains the standard of care. Patients who cannot tolerate platinum-based chemotherapy for any of a variety of reasons should be expected to benefit from the addition of cetuximab to radiotherapy".
Cetuximab has also been shown to be effective when combined with standard chemotherapy for locally advanced squamous cell carcinoma of the head and neck. Vermorken et al (2007) reported on the results of a multi-center phase III study to assess the efficacy and safety of cetuximab in combination with standard chemotherapy for persons with stage III/IV recurrent and/or metastatic squamous cell carcinoma of the head and neck, not suitable for local therapy. Patients from 35 European sites were randomized either to 2 groups. The chemotherapy plus cituximab arm (n = 222) received cetuximab plus cisplatin or carboplatin and 5-fluorouracil (FU). The chemotherapy arm (n = 220) received cisplatin or carboplatin with 5-FU. Median survival (the primary study endpoint) was 7.4 months in the chemotherapy alone arm compared to 10.1 months for chemotherapy plus cetuximab arm (p = 0.036). The investigators concluded that the addition of cetuximab to standard chemotherapy resulted in a clinically meaningful survival benefit. The investigators noted that the observed median survival time of 10.1 months is among the longest ever reported in a phase III trial for these patients.
In a phase 1b clinical trial, Saba et al (2014) examined the effects of everolimus in combination with cetuximab and carboplatin for recurrent/metastatic squamous cell carcinoma of the head and neck (RMSCCHN). Patients received carboplatin (area under the curve = 2 mg/ml/min; 3 weeks on, 1 week off), cetuximab (with a loading dose of 400 mg/m(2) and then 250 mg/m(2) weekly), and dose-escalating everolimus (2.5, 5.0, 7.5, and 10 mg/day) with a 3+3 design. After 4 cycles, patients without progression continued cetuximab/everolimus until progression or intolerable toxicity. Patients (age greater than or equal to 18 years) had previously untreated, unresectable RMSCCHN not amenable to radiotherapy and an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 to 2. The study enrolled 20 patients (male/female = 18/2) with RMSCCHN; the median age was 65 years (44 to 75 years). Thirteen patients received everolimus (male/female = 92 %); 2 of 6 patients receiving 2.5 mg/day experienced dose-limiting toxicity (DLT) with grade 3 hyponatremia and nausea. In 7 patients receiving de-escalated everolimus (2.5 mg every other day), grade 3 hyperglycemia produced DLT in 1 of 6 patients. The ORR was 61.5 % (all partial responses); PFS was 8.15 months. The pharmacokinetics of everolimus was described with a 2-compartment mixed-effects model. There was a significant correlation between tumor p-p44/42 staining and response (p = 0.044) and a marginally significant correlation between phosphorylated mammalian target of rapamycin and OS. The maximum tolerated dose (MTD) of everolimus with cetuximab and carboplatin was 2.5 mg every other day. The authors concluded that this regimen was associated with an encouraging RR and PFS, and this suggested possible clinical efficacy in a select group of patients with SCCHN.
Seiwert and colleagues (2020) noted that patients with cetuximab-resistant, recurrent/metastatic HNSCC have poor outcomes. In a randomized, multicenter clinical trial, these researchers hypothesized that dual blockade of mammalian target of rapamycin and EGFR would overcome cetuximab resistance on the basis of the role of phosphoinositide 3-kinase signaling in pre-clinical models of EGFR resistance. This study included patients with recurrent/metastatic HNSCC with documented progression on cetuximab (in any line in the recurrent/metastatic setting) who received 25-mg of temsirolimus weekly plus cetuximab at 400/250 mg/m2 weekly (TC) or single-agent temsirolimus (T). The primary outcome was PFS in the TC arm versus the T arm, secondary outcomes included OS, response rates, and toxicity. A total of 80 patients were randomized to therapy with TC or T alone. There was no difference for the primary outcome of median PFS (TC arm, 3.5 months; T arm, 3.5 months). The response rate was 12.5 % in the TC arm (5 responses, including 1 complete response [2.5 %]) and 2.5 % in the T arm (1 partial response; p = 0.10). Responses were clinically meaningful in the TC arm (range of 3.6 to 9.1 months) but not in the T-alone arm (1.9 months). Fatigue, electrolyte abnormalities, and leukopenia were the most common grade-3 or higher AEs and occurred in less than 20 % of patients in both arms. The authors concluded that the findings of this study did not meet its primary endpoint of improvement in PFS; however, TC induced responses in cetuximab-refractory patients with good tolerability. The post-hoc observation of activity in patients with acquired resistance (after prior benefit from cetuximab monotherapy) may warrant further investigation.
Other Tumors
Anal Cancer (Squamous Cell and Adenocarcinoma)
Czito and Willett (2009) stated that squamous cell carcinoma of the anal canal has been treated with abdomino-perineal resection, resulting in high rates of morbidity and local recurrence. Pioneering work led to the finding that radiation therapy (RT) combined with 5-FU and mitomycin results in high rates of local control as well as disease-free and colostomy-free survival without surgery. Prospective, randomized trials from Europe and the United States have shown the superiority of RT, 5-FU, and mitomycin overAt present, RT with 5-FU and mitomycin is the standard of care for anal cancer patients. Recent advances include the integration of positron emission tomography into staging, radiation treatment planning and monitoring, and the use of intensity modulated RT. European randomized trials are further evaluating the role of cisplatin in the neoadjuvant, concurrent, and adjuvant settings, as well as radiation dose escalation. Other studies are evaluating the use of capecitabine, oxaliplatin, and cetuximab with RT in this malignancy.
An UpToDate review on "Clinical features and staging of anal cancer" (Ryan and Willett, 2022) state that the management of adenocarcinomas arising in the anal canal should follow the same principles as those applied to the treatment of rectal cancer.
The NCCN Guidelines (v.2.2022) for "Anal carcinoma" states that cetuximab's anti-tumor activity is dependent on the presence of wild-type KRAS, and that "because KRAS mutations appear to be very rare in anal cancer, the use of an EGFR inhibor such as cetuximab has been considered to be a promising avenue of investigation."; however, for treatment of anal adenocarcinoma, NCCN recommends following the guidelines for rectal cancer.
Anaplastic Astrocytoma
National Comprehensive Cancer Network’s clinical practice guideline on “Central nervous system cancers” (Version 1.2022) does not list cetuximab as a therapeutic option.
Furthermore, an UpToDate review on “Initial postoperative therapy for glioblastoma and anaplastic astrocytoma” (Batchelor, 2017) does not mention cetuximab as a therapeutic option.
Biliary Tract Cancer, including Gallbladder Cancer and Cholangiocarcinoma
UpToDate reviews on "Treatment of advanced, unresectable gallbladder cancer" (Mehrotra and Bekaii-Saab, 2022) and "Adjuvant treatment for localized, resectable gallbladder cancer" (Mehrotra and Bekaii-Saab, 2018) does not mention the use of cetuximab.
UpToDate reviews on "Treatment of localized cholangiocarcinoma: Adjuvant and neoadjuvant therapy and prognosis" (Angerson and Stuart, 2022) and “Treatment options for locally advanced unersectable but nonmetastatic cholangiocarcinoma" (Anderson et al., 2022) do not mention the use of cetuximab as a therapeutic option.
An UpToDate review on "Systemic therapy for advanced cholangiocarcinoma" (Stuart, 2022) state that, "phase II trials addressing the efficacy of combined therapy with GEMOX plus either cetuximab or panitumumab have come to differing conclusions, and the role of these agents in advanced biliary tract cancer remains uncertain: In an initial phase II study of 30 patients with previously untreated locally advanced or unresectable biliary tract cancer (27 cholangiocarcinoma, 3 gallbladder cancer), 19 had objective responses to GEMOX plus cetuximab (63 percent, three complete). Nine patients with locally advanced previously unresectable disease had sufficient tumor shrinkage to permit a later potentially curative resection, although long-term outcomes were not reported. Unfortunately, benefit for the addition of cetuximab to GEMOX could not be confirmed in a randomized phase II trial in which 150 patients with advanced cholangiocarcinoma (82 percent), gallbladder cancer, or ampullary cancer were randomly assigned to GEMOX with or without cetuximab (500 mg/m
2every two weeks). Median progression-free survival was modestly (but not significantly) higher with cetuximab (6.1 versus 5.5 months), but median overall survival was shorter (11 versus 12.4 months). Serious adverse events were reported in 51 percent of the cetuximab-treated patients compared with 35 percent of the control group."
Bladder Cancer
Agarwal and Hussain (2009) stated that cancer of the urinary bladder is the 5th most prevalent solid tumor in the United States. Urothelial carcinoma is the most common form of bladder cancer, accounting for about 90 % of cases. About 25 % of patients with bladder cancer have advanced disease (muscle-invasive or metastatic disease) at presentation and are candidates for systemic chemotherapy. Urothelial carcinoma is a chemo-sensitive disease, with a high overall and complete response rate to combinational chemotherapy. In the setting of muscle-invasive urothelial carcinoma, use of neoadjuvant chemotherapy is associated with overall survival benefit. The role of adjuvant chemotherapy in this setting is yet to be validated. In the setting of metastatic disease, use of cisplatin-based regimens improves survival. However, despite initial high response rates, the responses are typically not durable leading to recurrence and death in the vast majority of these patients. Currently, there is no standard second-line therapy for patients in whom first-line chemotherapy for metastatic disease has failed. Many newer chemotherapeutic agents have shown modest activity in urothelial carcinoma. Improved understanding of molecular biology and pathogenesis of urothelial carcinoma has opened avenues for the use of molecularly targeted therapies, several of which are being tested in clinical trials. Currently, several novel drugs seem particularly promising including inhibitors of the EGFR pathway, such as cetuximab, and inhibitors of tumor angiogenesis, such as bevacizumab and sunitinib. Development of reliable molecular predictive markers is expected to improve treatment decisions, therapy development and outcomes in urothelial carcinoma. Funding of and participation in clinical trials are key to advancing the care of urothelial cancer patients.
Breast Cancer
Julia et al (2020) state triple Negative Breast Cancer (TNBC) treatment is still challenging, and immunotherapy is a potential approach in this tumor subtype. Cetuximab is an IgG1 monoclonal antibody (mAb) directed against Epidermic Growth Factor Receptor (EGFR), a protein overexpressed in a subgroup of TNBC patients and associated with poor prognosis. Previously, the authors demonstrated in vitro that Cetuximab triggers Ab-dependent cell cytotoxicity against TNBC cells. In this study, using co-cultures including TNBC cells, and NK and Dendritic Cells (DCs) from healthy donors, the authors studied the effect of Cetuximab-activated NK cells on DC function. Given that the authors previously demonstrated TNBC has an immunosuppressive effect on NK cells, they also tested Cetuximab combination with IL-15. The authors determined that Cetuximab opsonization of TNBC cells increased IFN-γ and TNF-α production by NK cells co-cultured with DCs. Moreover, the authors showed that NK cells activated by TNBC cells opsonized with Cetuximab promoted tumor material uptake and maturation of DCs, as well as their ability to produce IL-12. Furthermore, the stimulation with IL-15 increased the activation of NK cells and the maturation of DCs. These results suggest that IL-15 may enhance the efficacy of Cetuximab in the treatment of TNBC by promoting activation of both NK cells and DCs.
The NCCN Breast Cancer guidelines (v.4.2022) do not mention cetuximab treatment for breast cancer.
Bronchioloalveolar Carcinoma
In an ECOG phase-II study, Ramalingam et al (2011) evaluated cetuximab for the treatment of advanced bronchiolo-alveolar carcinoma (BAC). Patients with advanced-stage pure BAC or adenocarcinoma with BAC features, fewer than 2 prior chemotherapy regimens, and ECOG performance status of 0 to 2 were eligible. Those with prior EGFR inhibitor therapy were excluded. Cetuximab was given as a weekly intravenous infusion at 250 mg/m(2) after an initial loading dose of 400 mg/m(2) in week 1. The primary end point was determination of response rate. EGFR and KRAS mutations were evaluated by pyro-sequencing. A total of 72 patients were enrolled and 68 met eligibility requirements. Characteristics of patients included median age, 71 years; sex, 57 % females; performance status (PS) 0 or 1, 88 % of patients; and smoking status, 19 % never-smokers. Central pathology review confirmed the diagnosis in 45 of 49 available specimens. Approximately 50 % of patients received more than 2 cycles of therapy (greater than 8 weeks). Skin rash was the most common toxicity (grade 3, 15 %). The confirmed response rate was 7 %, and stable disease was observed in 35 %. The median survival and PFS were 13 and 3.3 months, respectively. Only 1 of the 6 patients with an EGFR mutation and 1 of the 7 patients with a KRAS mutation had a partial response. The authors concluded that cetuximab was associated with modest effectiveness in patients with advanced BAC, despite a low response rate. They noted that EGFR and KRAS mutations were not predictive of response to cetuximab.
Chordoma
NCCN Guidelines on bone cancer (2022) does not mention cetuximab in the clinical settting of chordoma.
Esophageal Cancer
Tian et al (2015) stated that esophageal cancer is one cause of the most common cancer death and diagnosed in approximately half a million people annually worldwide, as well as has resulted in worse status, which is responsible for an estimated 482,300 new cases and 406,800 deaths in 2008, and is the 5th highest in the mortality rate among tumor sites. Esophageal cancer mainly occurred in southern and eastern Africa, eastern Asia and some areas of China. The results of meta-analysis suggested that survival rate can be improved [relative risk (RR) 1.6; 95 % CI: 1.17 to 2.18]; objective response rate (ORR) (RR 1.47; 95 % CI: 1.05 to 2.06) and disease control rate (RR 1.21; 95 % CI: 1.03 to 1.43) in combination group are superior to that of the control group; however, the higher incidence of acne-like rash was caused (RR 9.03; 95 % CI: 1.64 to 49.63). Moreover, collated differences in OS rate and PFS remained the most common grade 3/4/5 toxicities, and quality of life after intervention revealed no evidence of a difference between the 2 groups. The authors concluded that with the present evidence, there is no role for cetuximab combined with standard approaches for esophageal cancer.
Gliomas
In a phase II study, Neyns et al (2009) evaluated the anti-tumor activity and toxicity of single-agent cetuximab in patients with recurrent high-grade glioma (HGG) after failure of surgery, radiation therapy, and chemotherapy. In this 2-arm, open-label study patients were stratified according to their EGFR gene amplification status. Cetuximab was administered intravenously at a dose of 400 mg/m(2) on week 1 followed by weekly dose of 250 mg/m(2). The primary end point for this study was the response rate in both study arms separately. A total of 55 eligible patients (28 with and 27 without EGFR amplification) tolerated cetuximab well. Three patients (5.5 %) had a partial response and 16 patients (29.6 %) had stable disease. The median time to progression was 1.9 months [95 % CI: 1.6 to 2.2 months]. Whereas the PFS was less than 6 months in the majority (n = 50/55) of patients, 5 patients (9.2 %) had a PFS on cetuximab of greater than 9 months. Median OS was 5.0 months (95 % CI: 4.2 to 5.9 months). No significant correlation was found between response, survival and EGFR amplification. The authors concluded that cetuximab was well-tolerated but had limited activity in this patient population with progressive HGG. A minority of patients may derive a more durable benefit but were not prospectively identified by EGFR gene copy number.
Loew et al (2009) stated that the EGFR is dysregulated in various tumor types such as glioblastoma multiforme (GBM), breast cancer, ovarian carcinoma, non-small cell lung cancer and other cancers. As the intracellular tyrosine kinase of the EGFR activates signaling cascades leading to cell proliferation, angiogenesis and inhibition of apoptosis, the EGFR represents an attractive target in cancer therapy. In GBM which is the most common primary central nervous system tumor in adults, the EGFR is over-expressed in about 40 to 50 % of cases, and almost half of these co-express the mutant receptor subtype EGFRvIII. This EGFR variant is constitutively activated, and thereby may contribute to the aggressive and refractory course of GBM which is associated with a median survival of only 40 to 60 weeks from diagnosis. Various trials are ongoing focusing on EGFR and EGFRvIII as new therapeutic targets in GBM. Anti-EGFR monoclonal antibodies (MAbs), e.g., cetuximab, and tyrosine kinase inhibitors (TKIs), e.g., erlotinib and gefitinib, are the most advanced in clinical development. Several trials are investigating MAbs or TKIs in combination with other agents such as inhibitors of the mammalian target of rapamycin. Other still preliminary approaches targeting the EGFR are small interfering RNA, antisense RNA and ribozymes, which lead to degradation of EGFR mRNA. The authors concluded that further studies are needed to define their clinical potential, to identify biological predictors of response and thus to characterize subgroups of patients who will benefit from treatment with these new agents.
In a phase II study, Hasselbalch et al (2010) examined the safety and effectiveness when combining cetuximab with bevacizumab and irinotecan in patients with recurrent primary GBM. Patients were included with recurrent primary GBM and progression within 6 months of ending standard treatment (radiotherapy and temozolomide). Bevacizumab and irinotecan were administered IV every 2 weeks. The first 10 patients received bevacizumab 5 mg/kg, but this was increased to 10 mg/kg after interim safety analysis. Irinotecan dose was based on whether patients were taking enzyme-inducing anti-epileptic drugs or not: 340 and 125 mg/m(2), respectively. Cetuximab 400 mg/m(2) as loading dose followed by 250 mg/m(2) weekly was administered IV. Forty-three patients were enrolled in the trial, of which 32 were available for response. Radiographical responses were noted in 34 %, of which 2 patients had complete responses and 9 patients had partial responses. The 6-month PFS probability was 30 % and median OS was 29 weeks (95 % CI: 23 to 37 weeks). One patient had lacunar infarction, 1 patient had multiple pulmonary embolisms, and 3 patients had grade 3 skin toxicity, for which 1 patient needed plastic surgery. One patient was excluded due to suspicion of interstitial lung disease. Three patients had deep-vein thrombosis; all continued on study after adequate treatment. Cetuximab in combination with bevacizumab and irinotecan in recurrent GBM is well-tolerated except for skin toxicity, with an encouraging response rate. However, the efficacy data do not seem to be superior compared with results with bevacizumab and irinotecan alone.
Hepatocellular Carcinoma
Zhu et al (2007) performed a phase 2 study with cetuximab in patients with advanced hepato-cellular carcinoma (HCC). Eligibility criteria included unresectable or metastatic measurable HCC, an Eastern Cooperative Oncology Group performance status les than or equal to 2, Cancer of the Liver Italian Program (CLIP) score less than or equal to 3, and adequate organ functions. The initial dose of cetuximab was 400 mg/m(2) given intravenously followed by weekly intravenous infusions at 250 mg/m(2). Each cycle was defined as 6 consecutive weekly treatments. Expression of EGFR was assayed by immuno-histochemistry and trough serum concentrations of cetuximab were determined during the first cycle. A total of 30 patients were enrolled and assessable for efficacy and toxicity. No responses were seen; 5 patients had stable disease (median time of 4.2 months; range of 2.8 to 4.2 months). The median overall survival (OS) was 9.6 months (95 % CI: 4.3 to 12.1 months) and the median PFS was 1.4 months (95 % CI: 1.2 to 2.6 months). The treatment was generally well-tolerated. No treatment-related grade 4 to 5 toxicities occurred. Grade 3 (according to the National Cancer Institute's Common Terminology Criteria for Adverse Events [version 3.0]) aspartate aminotransferase, hypo-magnesemia, and fever without neutropenia were noted in 1 patient (3.3 %) each. On week 6 of cycle 1, arithmetic mean serum cetuximab concentrations for patients with Child-Turcotte-Pugh (CTP) A and CTP B disease were 47.6 mcg/ml and 66.9 mcg/ml, respectively. The authors concluded that although cetuximab could be safely administered with tolerable toxicity profiles, it demonstrated no anti-tumor activity in HCC in this phase 2 study. Cetuximab trough concentrations were not notably altered in patients with mild-to-moderate hepatic dysfunction.
Asnacios and associates (2008) conducted a phase 2 trial of cetuximab in combination with the gemcitabine plus oxaliplatin (GEMOX) regimen in patients with documented progressive HCC. A total of 45 untreated patients with advanced-stage progressive HCC were prospectively enrolled. Treatment consisted of cetuximab at a dose of 400 mg/m
2initially then 250 mg/m
2weekly, plus gemcitabine at a dose of 1000 mg/m
2on day 1 and oxaliplatin at a dose of 100 mg/m
2on day 2, every 2 weeks. Treatment was continued until disease progression, unacceptable toxicity, or patient refusal. Overall, 306 cycles were administered. Grade 3 to 4 hematologic toxicity consisted of thrombocytopenia (24 %), neutropenia (20 %), and anemia (4 %). Grade 3 oxaliplatin-induced neurotoxicity occurred in 5 patients (11 %) and grade 3 cutaneous toxicity in 7 patients (16 %). There were no treatment-related deaths. The confirmed response rate was 20 % and disease stabilization was obtained in 40 % of patients. The median PFS and OS times were 4.7 months and 9.5 months, respectively. The 1-year survival rate was 40 %. The authors concluded that in poor-prognosis patients with progressive advanced-stage HCC, the GEMOX-cetuximab combination appears to be active and to have manageable toxicity. A comparative randomized trial is now being planned.
Menetrier's Disease
Fiske et al (2009) stated that Menetrier's disease is a rare pre-malignant disorder of the stomach with no proven effective medical therapy. Increased EGFR signaling has been implicated in the pathogenesis of Menetrier's disease. These investigators conducted a single-arm clinical trial with cetuximab in 9 patients (aged 29 to 79 years) with clinically and histologically documented severe Menetrier's disease that impaired quality of life to the extent that gastrectomy was being considered. Patients were treated with a loading dose of intravenous cetuximab (400 mg/m
2of body surface area), followed by 3 weekly intravenous infusions of 250 mg/m
2. Of the 7 patients who completed the 1-month course of treatment, all showed statistically significant improvement both clinically (quality-of-life indices) and biochemically (increased parietal cell mass and gastric acidity). Furthermore, all 7 patients who completed the 1-month trial elected to continue treatment (follow-up of 8 to 40 months), and 4 subsequently showed near-complete histological remission. The authors concluded that cetuximab should be considered as first-line therapy for Menetrier's disease.
An UpToDate review on "Large gastric folds: Hyperplastic and nonhyperplastic gastropathies" (Feldman and Jensen, 2018) state that Menetrier's disease is a rare acquired condition of the stomach that is characterized by giant mucosal fold in the gastric fundus and body, diminished acid secretory capactiy, and a protein losing state with hypoabluminemia. The pathogenesis is thought to be due to increased signaling of the epidermal growth factor (EGFR) which results in proliferation of epithelial cells of the mucous cell compartment. Treatment option includes cetuximab; however, controlled trials are lacking. "In small case series, cetuximab was found to be successful in treating patients with disease-related refractory symptoms. In another uncontrolled study, cetuximab was used to treat nine patients with Ménétrier's disease. Of the seven patients treated, four had almost complete reversal of foveolar hyperplasia; however, four of the seven required total gastrectomy. All seven patients demonstrated statistically significant improvement in quality-of-life indices as well as in biochemical measures (gastric acidity). The FDA has allowed cetuximab to be used on a compassionate need basis in some patients with Ménétrier's disease."
Non-Small Cell Lung Cancer
Ciardiello et al (2004) stated that 3 drugs are currently in phase II and phase III development as single agents or in combination with other anti-cancer therapies in non-small cell lung cancer (NSCLC) patients: cetuximab (Erbitux), a chimeric human-mouse monoclonal IgG1 antibody that blocks ligand binding and functional EGFR activation; and erlotinib (Tarceva) and gefitinib (Iressa), 2 orally bioavailable, small-molecule EGFR inhibitors of tyrosine kinase enzymatic activity that prevent EGFR autophosphorylation and activation. The authors concluded that anti-EGFR has shown promising anti-tumor activity in NSCLC patients with a mild toxicity profile. However, a series of important clinical issues such as selection of potentially responsive patients and optimal combination with conventional anti-cancer treatments needs to be addressed to use these drugs better in lung cancer. This is in agreement with the observation by Langer (2004) who noted that EGFR inhibitors currently under investigation for the treatment of NSCLC include gefitinib and erlotinib, as well as cetuximab. Pre-clinical models have demonstrated synergy for all these agents in combination with either chemotherapy or radiotherapy, leading to great enthusiasm regarding their ultimate contribution to lung cancer therapy. However, serious clinical challenges persist. These include the identification of the optimal dose(s); the proper integration of these agents into popular, established cytotoxic regimens; and the selection of the optimal setting(s) in which to test these compounds.
Hanna et al (2006) examined the effectiveness of cetuximab in patients with recurrent or progressive NSCLC after receiving at least one prior chemotherapy regimen. This was an open-label, phase II study of patients with EGFR-positive and EGFR-negative advanced NSCLC with Eastern Cooperative Oncology Group performance status 0 to 1. Patients received cetuximab 400 mg/m
2intravenously (IV) during 120 mins on week 1 followed by weekly doses of cetuximab 250 mg/m
2IV during 60 mins. A cycle was considered as 4 weeks of treatment and therapy was continued until disease progression or intolerable toxicities. The primary end point was to evaluate response rate. Secondary end points included an estimation of time to progression and survival. Patient and disease characteristics (n = 66) included EGFR-positive status (n = 60); EGFR-negative status (n = 6); number of prior regimens (one, n = 28; two, n = 27; greater than or equal to three, n = 11); male (n = 41); female (n = 25); adenocarcinoma (n = 36); and smoking status (never, n = 13; former, n = 45; current, n = 8). Grade 3/4 toxicities included acne-like rash (6.1 %), anaphylactic reactions (1.5 %), and diarrhea (1.5 %). The response rate for all patients (n = 66) was 4.5 % (95 % confidence interval [CI]: 0.9 % to 12.7 %) and the stable disease rate was 30.3 % (95 % CI: 19.6 % to 42.9 %). The response rate for patients with EGFR-positive tumors (n = 60) was 5 % (95 % CI: 1.0 % to 13.9 %). The median time to progression for all patients was 2.3 months (95 % CI: 2.1 to 2.6 months) and median survival time was 8.9 months (95 % CI: 6.2 to 12.6 months). The authors concluded that although the response rate with single-agent cetuximab in this heavily pretreated patient population with advanced NSCLC was only 4.5 %, the disease control rates and overall survival seem comparable to that of pemetrexed, docetaxel, and erlotinib in similar groups of patients.
Azim and Ganti (2006) stated that cytotoxic chemotherapy has helped improve the outcomes in patients with advanced NSCLC) but seemed to have reached a plateau with respect to the benefit obtained. Also, a large subset of elderly patients and those with a poor performance status cannot tolerate these drugs at recommended doses. There is a growing need to incorporate newer drugs with different mechanisms of action and better safety profile. The EGFR and vascular endothelial growth factor (VEGF) have been identified as potential targets and agents acting specifically against these targets have been developed with the hope of improving outcomes. Although recent data with the small molecule EGFR tyrosine kinase inhibitors have been disappointing, there have been instances of dramatic responses, thus raising questions regarding the ideal patient to whom these drugs should be administered. Cetuximab, the anti-EGFR antibody has shown promising results. Bevacizumab, the anti-VEGF antibody was the first drug to demonstrate a survival benefit in first line treatment when added to chemotherapy.
Butts et al (2007) reported on a randomized phase II study to evaluate the efficacy of cetuximab added to first-line gemcitabine/platinum in chemotherapy-naïve patients with advanced NSCLC. Chemotherapy-naïve patients with recurrent/metastatic NSCLC (stage IV or stage IIIB with malignant pleural effusion) received cisplatin or carboplatin, and gemcitabine plus cetuximab in arm A, or chemotherapy alone, in arm B. A total of 65 patients were randomly assigned to arm A and 66 to arm B. The investigators observed partial responses in 18 patients (27.7 %) in arm A and 12 (18.2 %) in arm B. Median progression-free survival was 5.09 months for arm A and 4.21 months in arm B. Median overall survival was 11.99 months and 9.26 months in arms A and B, respectively. The investigators noted that overall toxicity was acceptable and consistent with the profiles of the individual agents. The investigators concluded that first-line treatment with cetuximab plus gemcitabine/platinum is well-tolerated and can be administered safely in patients with advanced NSCLC. The investigators stated that differences in response rate, progression-free survival, and overall survival suggest that the addition of cetuximab to platinum/gemcitabine may improve clinical outcomes.
Rosell et al (2008) reported on the Lung Cancer Cetuximab Study, an open-label, randomized phase II pilot study of cisplatin and vinorelbine combined with cetuximab versus cisplatin and vinorelbine alone, in 83 patients with advanced EGFR-positive NSCLC. Following randomization, for a maximum of eight cycles, patients received 3-weekly cycles of cisplatin and vinorelbine alone or following cetuximab treatment. The investigators reported that response rates were 28 % in the cisplatin/vinorelbine arm (A) and 35 % in the cetuximab plus cisplatin/vinorelbine arm (B). Median PFS was 4.6 months in arm A and 5.0 months in arm B, with PFS rates at 12 months of 0 % and 15 %, respectively. Median survival was 7.3 months in arm A and 8.3 months in arm B. The 24-month survival rates were 0 % and 16 %, respectively. The investigators reported that the cetuximab combination was well-tolerated. The investigators concluded that, in the first-line treatment of advanced NSCLC, the combination of cetuximab plus cisplatin/vinorelbine demonstrated an acceptable safety profile and the potential to improve activity over cisplatin/vinorelbine alone.
In a 3-arm, randomized, phase II clinical trial, Hanna et al (2015) examined the effects of carboplatin and paclitaxel in combination with cetuximab, cixutumumab, or both for advanced NSCLC patients who will not receive bevacizumab-based therapy. Patients with chemotherapy-naive, advanced NSCLC who had an ECOG performance status of 0 or 1 were eligible. Patients were randomized to receive carboplatin intravenously at an area under the plasma drug concentration-time curve of 6.0 plus paclitaxel 200 mg/m
2intravenously on day 1 every 3 weeks combined with either intravenous cetuximab weekly (arm A), intravenous cixutumumab every 2 weeks (arm B), or both (arm C). Patients who had non-progressing disease after 12 weeks of therapy were permitted to continue on maintenance antibody therapy until they developed progressive disease. The primary end-point was PFS. The study design required 180 eligible patients and had 88 % power to detect a 60 % increase in median PFS for either comparison (arm A versus arm C or arm B versus arm C) using the log-rank test. From September 2009 to December 2010, a total of 140 patients were accrued. The study was closed to accrual early because of an excessive number of grade 5 AEs reported on arms A and C; 13 patients died during treatment (6 patients on arm A, 2 patients on arm B, and 5 patients on arm C), including 9 within approximately 1 month of starting therapy. The estimated median PFS for arms A, B, and C were similar at 3.4 months, 4.2 months, and 4 months, respectively. The authors concluded that on the basis of the apparent lack of efficacy and excessive premature deaths, the current results do not support the continued investigation of carboplatin, paclitaxel, and cixutumumab either alone or in combination with cetuximab for patients with advanced NSCLC.
In a single-arm phase II trial in NSCLC combining cetuximab with carboplatin and paclitaxel, 31 patients had EGFR IHC performed; 4 patients who tested negative for EGFR IHC had a worse survival than those who tested positive for EGFR IHC (median OS 6 versus 14 months) (Borghaei et al, 2008). Also, in the pivotal phase III FLEX trial (Pirker et al, 2009; O'Byrne et al, 2009), patients were required to express EGFR IHC in at least 1 tumor cell, whereas in another pivotal phase III trial (BMS-099) (Lynch et al, 2008), there was no biomarker requirement for enrollment. This is one suggested theory as to why the FLEX trial was statistically significant for a survival benefit and the BMS-099 trial was negative. However, a retrospective analysis of the BMS-099 trial found that neither KRAS or EGFR mutations were predictive of response to treatment with cetuximab.
EGFR FISH analysis was evaluated in the SWOG 0342 trial, a phase II trial comparing concurrent cetuximab with chemotherapy versus sequential treatment (Hirsch et al, 2008). Although there was no difference in clinical efficacy between the SWOG 0342 concurrent and sequential arms, the biomarker analyses suggested that EGFR FISH positive or gene amplification may have predictive value for cetuximab treatment, as patients with higher gene copy numbers had better survival outcomes. Patients scored as 1 to 4 or low FISH (n = 18) had a median PFS of 3 months, whereas those patients with a score of 5 to 6 or high FISH (n = 26) had a median PFS of 6 months.
Pancreatic Adenocarcinoma
Cetuximab has been shown in a phase III study to lack efficacy in the treatment of pancreatic adenocarcinoma. Philip et al (2007) tested the efficacy of cetuximab and gemcitabine combination in the phase III setting in 735 patients with locally advanced unresectable or metastatic pancreatic cancer. Patients were stratified by performance status, stage and prior pancreatectomy, and randomized to either gemcitabine alone or gemcitibine plus cetuximab. The median survival was 6 months in the gemcitabine arm and 6.5 months in the gemcitabine plus cetuximab arm for an overall hazard ratio of 1.09 (95 % CI: 0.93 to 1.27, p= 0.14). The corresponding progression free survival (the primary study endpoint) was 3 months and 3.5 months, for gemcitabine and gemcitabine plus cetuximab arms, respectively (hazard ratio = 1.13, 95 % CI: 0.97 to 1.3, p = 0.058). The confirmed response probabilities were 7 % in each arm, and inclusion of unconfirmed responses yielded 14 % in the gemcitabine arm and 12 % in the gemcitabine plus cetuximab arm. The investigators reported that 90 patients experienced at least one grade 4 toxicity; 14 % on the gemcitabine plus cetuximab, 11 % on gemcitabine alone. The investigators concluded that the study failed to demonstrate a clinically significant advantage of the addition of cetuximab to gemcitabine for overall survival, progression free survival and response in advanced pancreas cancer.
In a systematic review and meta-analysis, Forster and colleagues (2020) examined the potential benefit of adding cetuximab to neoadjuvant, adjuvant, or palliative standard therapy for pancreatic cancer. These researchers carried out a systematic literature search in Medline, Web of Science, and Cochrane Central Register of Controlled Trials (CENTRAL). Only RCTs examining the effect of adding cetuximab to standard chemotherapy in pancreatic cancer were included. Evaluated outcomes were OS, PFS, objective response, and toxicity. For OS and PFS, HR with 95 % CI were chosen as effect measure. For objective response, odds ratios (OR) with 95 % CI were used. Analysis was based on a random effects model. After screening 568 publications, a total of 4 RCTs with 924 patients were included. In all trials, patients were adequately randomized with balanced intervention and control groups. There was no significant difference in OS (HR 1.04; 95 % CI: 0.90 to 1.19; p = 0.60), PFS (HR 1.06; 95 % CI: 0.93 to 1.22; p = 0.36), or objective response (OR 0.99; 95 % CI: 0.66 to 1.49; p = 0.96) when adding cetuximab to a standard therapy. Toxicity was the same or higher in each of the included trials. According to GRADE, the certainty of the evidence was high; thus, adding cetuximab to pancreatic cancer therapy provided no clinically relevant benefit. The authors concluded that in the presence of no survival benefit, increased toxicity, and higher costs, a decreased cost-benefit ratio compared to the standard care must be suggested. These researchers stated further trials examining cetuximab in an unselected pancreatic cancer population must be viewed with a critical eye. The upper bound of the pooled effect for OS excluded a clinically relevant effect; thus, a future RCT would be unlikely to change the effect estimate or could even be unethical in light of the data presented. These investigators stated that further research in pancreatic cancer should focus on other therapeutic regimens than those including cetuximab or should examine the benefit of cetuximab in the small minority of KRAS wild-type patients, respecting the entirety of all mutations in this dire tumor.
Penile Cancer
National Comprehensive Cancer Network guidelines on penile cancer (NCCN, 2022) recommends consideration of cetuximab as single agent therapy for subsequent-line systemic therapy for metastatic or recurrent disease in certain circmumstances.
Rescigno et al (2012) stated that guidelines on the treatment of metastatic squamous cell carcinoma of the penis are limited to a few prospective trials. Cisplatin-based regimens represent the standard of treatment with promising activity of taxanes. Recently, EGFR over-expression has been shown in these patients. These researchers treated an elderly man with a docetaxel-cetuximab combination after failure of the cisplatin regimen. They observed a necrosis of the inguinal lymph nodes and a reduction of (18)F-fluorodeoxyglucose uptake at PET/CT scan. Only mild mucositis and skin toxicity had been detected. The authors concluded that this case report, the first in the literature, showed that this combination is active and well-tolerated in penile squamous cell carcinoma. These preliminary findings need to be validated by well-designed studies.
Brown et al (2014) described 3 cases of advanced refractory penile cancer treated with targeted therapy against the EGFR. These researchers identified 3 patients with advanced penile cancer who had disease progression after platinum chemotherapy refractory and who subsequently received EGFR-targeted therapy. Their tumor tissue was evaluated for expression of EGFR by immunohistochemistry and messenger RNA quantitation and was also tested for the presence of human papillomavirus DNA by line hybridization. K-ras mutation was evaluated by polymerase chain reaction for 6 mutations in codon 12 and 1 mutation in codon 13. One patient responded to cetuximab and remained disease-free 42 months after presentation. One patient responded to panitumumab, then suffered relapse. One other progressed through EGFR-targeted therapy; EGFR expression by immunohistochemistry was 1-2+ in all cases, and messenger RNA expression ranged from 4.08 to 7.33. No K-ras mutations or human papillomavirus DNA was detected. The authors reported 3 cases in which EGFR-targeted therapy was used to treat platinum-refractory penile cancer patients. The authors concluded that because 2 of the 3 had clinical benefit, future prospective trials of EGFR-targeted therapy in penile cancer are warranted.
Carthon et al (2014) evaluated the safety and effectiveness of EGFR-targeted therapy in patients with advanced penile or scrotal cancer. These investigators retrospectively reviewed the charts of patients with penile or scrotal squamous cell carcinoma who had visited their tertiary cancer center between 2002 and 2009, including their subsequent treatment and follow-up. These researchers collected details of EGFR-targeted therapy and clinical outcomes. Treatment-associated time-to-disease-progression (TTP), OS, responses to therapy and toxicity were evaluated. A total of 24 patients had received EGFR-targeted therapies, including cetuximab, erlotinib and gefitinib. The most common treatment given (to 67 % of patients) was cetuximab combined with 1 or more cytotoxic drugs. The most common adverse effect was skin rash (71 %). The median (range) TTP and OS were 11.3 (1 to 40) and 29.6 (2 to 205) weeks, respectively. The OS time for patients with visceral or bone metastases was significantly shorter than it was for those without (24.7 versus 49.9 weeks, p = 0.013). Among 17 patients treated with cetuximab alone or in combination with cisplatin, there were 4 partial responses (23.5 %) including 2 patients with apparently chemotherapy-resistant tumors. The authors concluded the findings of this study suggested that cetuximab has anti-tumor activity in metastatic penile cancer, and may enhance the effect of cisplatin-based chemotherapy. Moreover, they stated that prospective studies of EGFR-targeted therapies in men with these tumors are needed.
Post-Operative Radiotherapy Plus Cetuximab in Head and Neck Squamous Cell Carcinoma
In a systematic review and meta-analysis of RCTs, Li et al (2023) re-examined the safety and effectiveness of cetuximab versus cisplatin combined with RT in patients with HNSCC. A total of 7 RCTs were included in the final analysis. Participants treated by cetuximab plus RT showed an inferior OS and loco-regional control (LRC) compared to cisplatin plus radiotherapy. The tendency of PFS agreed with OS and LRC. Subgroup analysis showed that cetuximab had poorer OS relative to cisplatin in the absence of induction chemotherapy. The profile of severe AEs (SAEs) varied between the 2 groups, no significant difference in total SAEs was shown for the 2 arms. The authors concluded that cetuximab combined with RT showed significantly reduced therapeutic efficacy compared to cisplatin plus RT in HNSCC patients.
Marques et al (2023) stated that the use of concurrent cetuximab with post-operative RT for patients with HNSCC has been scarcely discussed in the literature. In a retrospective, single-center study, these investigators reported clinical outcomes of high-risk HNSCC patients treated by post-operative RT with cetuximab. Between January 2013 and December 2016, all medical records of patients operated for HNSCC who underwent post-operative radio-chemotherapy were analyzed. Patients who received cisplatin were excluded; only patients who received cetuximab were included in the analysis. Among 52 patients with HNSCC treated with post-operative radio-chemotherapy, 18 patients received cetuximab potentiation due to ineligibility for cisplatin. Median OS and PFS were 23 and 19.5 months and 3-year OS and PFS were 30.5 % and 25.9 %, respectively. There was a 22 % treatment discontinuation rate. The authors concluded that post-operative RT with cetuximab for patients with high-risk HNSCC ineligible for cisplatin showed similar outcomes to the literature data for exclusive post-operative RT, with a high discontinuation rate. These low-power data supported the lack of indication for cetuximab in combination with post-operative RT.
Prostate Cancer
Cathomas et al (2012) stated that the EGFR is over-expressed in the majority of metastatic castration-resistant prostate cancers (mCRPC) and might represent a valid therapeutic target. The combination of docetaxel and cetuximab, the monoclonal antibody against EGFR, has not been tested in patients with prostate cancer. Patients with mCRPC progressing during or within 90 days after at least 12 weeks of docetaxel were included in this phase II clinical trial. Treatment consisted of docetaxel (75 mg/m(2) every 3 weeks or 35 mg/m(2) on days 1, 8, 15 every 4 weeks) in combination with cetuximab (400 mg/m(2) on day 1 and then 250 mg/m(2) weekly). The primary endpoint was PFS at 12 weeks defined as the absence of prostate-specific antigen (PSA), radiographic, or clinical progression. Evaluation of known biomarkers of response and resistance to cetuximab (EGFR, PTEN, amphiregulin, epiregulin) was conducted. A total of 38 patients were enrolled at 15 Swiss centers. Median age was 68 years and median PSA was 212 ng/ml. Progression-free survival at 12 weeks was 34 % [95 % CI: 19 % to 52 %], PFS at 24 weeks was 20 %, and median OS was 13.3 months (95 % CI: 7.3 to 15.4). Seven patients (20 %) had a confirmed greater than or equal to 50 % and 11 patients (31%) a confirmed greater than or equal to 30 % PSA decline. About 47 % of enrolled patients experienced grade 3 and 8 % grade 4 toxicities. A significantly improved PFS was found in patients with over-expression of EGFR and persistent activity of PTEN. The authors concluded that EGFR inhibition with cetuximab might improve the outcome of patients with mCRPC. They stated that a potential correlation between EGFR over-expression, persistent expression of PTEN, and EGFR inhibition should be investigated further.
UpToDate reviews on "Overview of the treatment of disseminated castration-sensitive prostate cancer" (Dawson, 2018) and "Overview of the treatment of castration-resistant prostate cancer (CRPC)" (Dawson, 2022) do not mention the use of cetuximab as a therapeutic option.
Salivary Duct Carcinoma
Kawahara and colleagues (2017) noted that salivary duct carcinoma is a highly aggressive disease with a poor prognosis. Surgical resection is currently the only curative treatment, as there is no effective systemic therapy for this malignancy. Recently, trastuzumab has been shown to be effective in the treatment of salivary duct carcinoma; similarly, molecularly targeted agents, such as cetuximab, are expected to be useful for salivary duct carcinoma treatment. These researchers described the case of a 56-year old man diagnosed with salivary duct carcinoma in the left submandibular region, with ipsilateral multiple metastases to the neck lymph nodes. Radical resection of the tumor and submandibular gland with neck dissection were performed. One month after radical surgery, computed tomography (CT) scans indicated metastasis in the lower lobe of the left lung. CT-guided transthoracic fine-needle aspiration biopsy revealed a single metastasis and lung metastasectomy was immediately performed. The tumor cells of the primary lesion and those of the lung metastasis were immunohistochemically positive for EGFR. One month later, multiple right lung metastases appeared, and the patient was treated with cisplatin/5-FU chemotherapy plus cetuximab, achieving a complete radiographic response. However, multiple lung metastases developed during adjuvant weekly cetuximab monotherapy. Subsequently, treatment with S-1 and weekly cetuximab was initiated, and the multiple lung metastases have been maintained as stable disease for 5 months. The authors concluded that this was the first report of cetuximab use for the treatment of salivary duct carcinoma. They noted that although cisplatin/5-FU chemotherapy plus cetuximab was effective in treating the lung metastasis, cetuximab monotherapy was insufficient for controlling tumor growth. Moreover, they stated that prospective and larger randomized studies with longer follow-up periods are needed to confirm these findings.
Furthermore, an UpToDate review on “Malignant salivary gland tumors: Treatment of recurrent and metastatic disease” (Laurie and Schiff, 2022) states "EGFR inhibitors, such as gefitinib, cetuximab, and lapatinib, have demonstrated minimal activity, despite EGFR expression in adenoid cystoid carcinomas (ACCs) and mucoepidermoid cancers".
Skin Cancer - Non-Melanoma Skin Cancer
Wollina and colleagues (2017) stated that non-melanoma skin cancer (NMSC) is the most common malignancy in humans. These investigators discussed the use of cetuximab in NMSC searching PubMed from 2011 to 2017 using the following items: "Non-melanoma skin cancer and cetuximab", "cutaneous squamous cell carcinoma and cetuximab", and "basal cell carcinoma and cetuximab", and "cetuximab and skin toxicity". Available data were analyzed including case reports. Current evidence of cetuximab efficacy in NMSC was mainly obtained in cutaneous SCC and to a lesser extend in basal cell carcinoma (BCC). Response rates varied for neoadjuvant, adjuvant, mono- and combined therapy with cetuximab. Management of cutaneous toxicities is necessary. The authors concluded that cetuximab is an option for recurrent or advanced NMSC of the skin. It appeared to be justified particularly in very high-risk tumors. Moreover, they stated that there is a need for phase-III clinical trials.
Skin Cancer - Squamous Cell Carcinoma of Skin
Jalili and colleagues (2008) stated that cutaneous squamous cell carcinoma (SCC) is one of the most common cancers worldwide. Epidermal growth factor receptor is expressed at the cell surface by more than 90 % of SCCs and its activation is responsible for cell cycle progression, proliferation, survival, angiogenesis and metastasis. Cyclooxygenase-2 (COX-2) is an enzyme up-regulated through EGFR signaling and responsible for some of the EGFR-dependent biological effects. These researchers presented the case of an 88-year old man with a recurrent, locoregionally meta-static SCC of the right parietal region, which was resistant to radiotherapy. With a combination therapy of cetuximab and celecoxib, the tumor regressed partially and the patient's Karnofsky index improved. These investigators speculated that the combined use of cetuximab and COX-2 inhibitors can be a new and effective therapy for advanced and recurrent cutaneous SCCs.
Maubec et al (2011) evaluated the safety and effectiveness of cetuximab as a first-line monotherapy in patients with unresectable squamous cell carcinoma of the skin (SCCS). A total of 36 patients received cetuximab (initial dose of 400 mg/m(2) followed by subsequent weekly doses of 250 mg/m(2)) for at least 6 weeks with a 48-week follow-up. The primary end point was the disease control rate (DCR) at 6 weeks (according to Response Evaluation Criteria in Solid Tumors [RECIST] criteria). Secondary end points included best response rate, OS, PFS, and toxicity assessment. Association of treatment efficacy with RAS mutations or FcγR genotypes was investigated. Median age of the study population was 79 years. Disease control rate at 6 weeks was obtained in 25 of 36 patients (69 %; 95 % CI: 52 % to 84 %) of the intention-to-treat population. The best responses were 8 partial responses and 2 complete responses. There were no cetuximab-related deaths. There were 3 related serious adverse events: 2 grade 4 infusion reactions and 1 grade 3 interstitial pneumopathy. Grade 1 to 2 acne-like rash occurred in 78 % of patients and was associated with prolonged PFS. One HRAS mutation was identified. Combined FcγRIIa-131H/H and/or FcγRIIIa-158V/V polymorphisms were not associated with the clinical outcomes. The authors concluded that as a first-line treatment in patients with unresectable SCCS, cetuximab achieved 69 % DCR.
Thyroid Cancer
Wiseman et al (2007) noted that anaplastic thyroid cancer is an endocrine malignancy. Its rare and rapidly lethal disease course has made it challenging to study. Little is known regarding the expression by anaplastic tumors of molecular targets for new human anti-cancer agents that have been studied in the pre-clinical or clinical setting. These investigators evaluated the expression profile of anaplastic thyroid tumors for molecular targets for treatment. Of the 94 cases of anaplastic thyroid cancers diagnosed and treated in British Columbia, Canada over a 20-year period (1984 to 2004), 32 cases (34 %) had adequate archival tissue available for evaluation. A tissue microarray was constructed from these anaplastic thyroid tumors and immuno-histochemistry was utilized to evaluate expression of 31 molecular markers. The markers evaluated were: EGFR, HER2, HER3, HER4, ER, PR, uPA-R, clusterin, E-cadherin, beta-catenin, AMF-R, c-kit, VEGF, ILK, aurora A, aurora B, aurora C, RET, CA-IX, IGF1-R, p53, MDM2, p21, Bcl-2, cyclin D1, cyclin E, p27, calcitonin, MIB-1, TTF-1, and thyroglobulin. A single tumor with strong calcitonin expression was identified as a poorly differentiated medullary carcinoma and excluded from the study cohort. The mean age of the anaplastic cohort was 66 years; 16 patients (51 %) were females, and the median patient survival was 23 weeks. A wide range in molecular marker expression was observed by the anaplastic thyroid cancer tumors (0 to 100 %). The therapeutic targets most frequently and most strongly over-expressed by the anaplastic tumors were: beta-catenin (41 %), aurora A (41 %), cyclin E (67 %), cyclin D1 (77 %), and EGFR (84 %). The authors concluded that anaplastic thyroid tumors exhibit considerable derangement of their cell cycle and multiple signal transduction pathways that leads to uncontrolled cellular proliferation and the development of genomic instability. This report was the first to comprehensively evaluate a panel of molecular targets for therapy of anaplastic thyroid cancer and supported the development of clinical trials with agents such as cetuximab, small-molecule tyrosine kinase inhibitors, and aurora kinase inhibitors, which may offer new hope for individuals diagnosed with this fatal thyroid malignancy.
Urothelial Carcinoma
In a randomized phase II clinical trial, Hussain and colleagues (2014) examined the effectiveness of gemcitabine/cisplatin (GC) with or without cetuximab (CTX) in patients with advanced urothelial carcinoma (UC). Patients with advanced UC, measurable disease, and adequate organ function were randomized 1:2 to cisplatin (70 mg/m(2) ) on day 1 plus gemcitabine (1,000 mg/m(2) ) on days 1, 8, and 15 (arm A) or GC plus CTX (500 mg/m(2) ) on days 1 and 15 (arm B). The primary end-point was the ORR. The secondary end-points were the response duration, safety, PFS, OS, determination of whether or not CTX sensitized non-responders to GC, and exploratory biomarker analysis. The accrual targets were 27 and 54 patients for the 2 arms, respectively. The ORR was reported by arm with binomial CIs. Kaplan-Meier methods were used for time-to-event end-points. A total of 88 eligible patients were randomized; 87 were toxicity-evaluable, and 85 were response-evaluable. The ORRs were 57.1 % for arm A (95 % CI: 37 % to 76 %) and 61.4 % for arm B (95 % CI: 48 % to 74 %). The median PFS times were 8.5 months for arm A (95 % CI: 5.7 to 10.4 months) and 7.6 months for arm B (95 % CI: 6.1 to 8.7 months). The median OS times were 17.4 months for arm A (95 % CI: 12.8 months to unreached) and 14.3 months for arm B (95 % CI: 11.6 to 22.2 months). The most common grade 3/grade 4 AEs in both arms were myelosuppression and nausea. Thromboembolism, acneiform rash, fatigue, pain, hypersensitivity reactions, elevated transaminases, hyponatremia, and hypomagnesemia were more common in arm B; 3 grade 5 AEs occurred in arm B. The presence of primary disease significantly correlated with thromboembolism. An increased soluble E-cadherin level after cycle 2 correlated with a higher risk of death. The authors concluded that GC plus CTX was feasible but was associated with more AEs and no improvements in outcomes.
Combined Therapies
Combination Cetuximab and Lapatinib for Solid Tumors
In a phase I clinical trial, Deeken et al (2015) evaluated the safety, DLTs, and MTDs of cetuximab and lapatinib in patients with solid tumors. Patients received standard weekly cetuximab with escalating lapatinib doses of 750 mg, 1,000 mg, or 1,250 mg daily in 3-week cycles; DLTs were monitored through the end of cycle 2. Pre-treatment and post-treatment tumor biopsies and germline DNA samples were obtained for correlative studies. A total of 22 patients were enrolled, and 18 patients each were evaluable for toxicity and response; 59 % of patients had received prior anti-EGFR therapy. Common toxicities included rash and diarrhea. No patient experienced a DLT at the highest dose level, and no grade 4 toxicity was observed. Response included no complete responses, 3 partial responses, 9 patients with stable disease, and 6 patients with disease progression, for an ORR of 17 % and a clinical benefit rate of 67 %. The clinical benefit rate in patients who had previously received anti-EGFR therapy was 70 %. The mean treatment duration was 4.7 cycles (range of 1 to 14 cycles). Decreased expression of EGFR/ErbB2 pathway components after treatment was correlated with response, whereas increased expression in the PI3K, Jak/Stat, and MAPK pathways occurred in non-responders. The authors concluded that the combination of cetuximab and lapatinib was well-tolerated, had the expected toxicities, and exhibited notable clinical activity, including in patients who had received previous anti-EGFR therapy. Moreover, they stated that further clinical study of this combination is needed.
Combination of Cetuximab and Encorafenib for the Treatment of Colorectal Cancer
van Geel and colleagues (2017) performed a phase-Ib, dose-escalation study of encorafenib and cetuximab with or without alpelisib in patients with metastatic BRAF-mutant metastatic colorectal cancer (mCRC). Patients with refractory BRAF-mutant mCRC were treated with encorafenib plus a cetuximab, with (n = 28) or without (n = 26) a PI3Kα inhibitor (alpelisib). The primary objective was to determine the MTD or a recommended phase-II dose; DLT were reported in 3 patients receiving dual treatment and 2 patients receiving triple treatment. The MTD was not reached for either group and the phase-II doses were selected as 200 mg encorafenib (both groups) and 300 mg alpelisib. Combinations of cetuximab and encorafenib showed promising clinical activity and tolerability in patients with BRAF-mutant mCRC; confirmed overall response rates of 19 % and 18 % were observed and median PFS was 3.7 and 4.2 months for the dual- and triple-therapy groups, respectively. The authors demonstrated that dual (encorafenib plus cetuximab) and triple (encorafenib plus cetuximab and alpelisib) combination treatments are tolerable and provide promising clinical activity in the difficult-to-treat patient population with BRAF-mutant mCRC.
Combination of Cetuximab and Natural Killer Cells Therapy for the Treatment of Non-Small Cell Lung Cancer
Liang and colleagues (2018) stated that natural killer (NK) cells therapy has the potential to prolong survival in patients with advanced NSCLC. These researchers conducted a clinical trial to examine the safety and efficacy of cetuximab plus NK cells therapy in patients with advanced NSCLC. Between June 2015 and August 2016, a total of 54 patients with advanced EGFR-expressing NSCLC were randomly assigned to the cetuximab plus NK cells therapy group (A; n = 27) or cetuximab alone group (B; n = 27). Patients in group A received 2 courses of NK cells therapy continuously. Cetuximab was administered intravenously and the weekly maintenance dose was continued until tumor progression. All AEs were manageable and no significant difference was noted between the 2 groups (p > 0.05). Levels of CEA, NSE and circulating tumor cells (CTCs) in group A were significantly lower than those before treatment (p < 0.05). Patients in group A had a significant improvement in immune function and quality of life (QOL) (p < 0.05). Patients in group A survived longer than those in group B (median PFS: 6 months versus 4.5 months; median OS: 9.5 months versus 7.5 months; p < 0.05). The authors concluded that the findings of this study showed that combination therapy of cetuximab and NK cell therapy yielded better outcomes in patients with advanced EGFR-overexpressing NSCLC. This was the first clinical trial to examine the safety and efficacy of a combination of cetuximab and NK cells therapy. However, this study was not powered to adequately demonstrate its clinical benefit due to the small sample size. These investigators noted that the encouraging survival results observed suggested that additional long-term follow-up on a larger cohort of patients merits consideration to further define the benefits of this combination therapy and to provide an alternative to chemo-radiotherapy for patients with advanced EGFR-overexpressing NSCLC.
Combination of Cetuximab and Natural Killer Cells Therapy for the Treatment of Liver Metastases of Gastro-Intestinal Carcinoma
In a phase-I clinical trial, Adotevi and associates (2018) examined the safety and efficacy of in-situ delivery of allogeneic NK cells combined with cetuximab in liver metastasis of gastro-intestinal (GI) origin. The conditioning chemotherapy was administrated before the allogeneic NK cells injection via hepatic artery. Three escalating doses were tested (3.106, 8.106 and 12.106 NK cells/kg) following by a high-dose interleukin-2 (IL-2). Cetuximab was administered intravenously every week for 7 weeks. A total of 9 patients with liver metastases of CRC or pancreatic cancers were included, 3 per dose-level. Hepatic artery injection was successfully performed in all patients with no report of DLT; 2 patients had febrile aplasia requiring a short-term anti-biotherapy. Grade 3/4 anemia and thrombopenia were also observed related to the chemotherapy. Objective clinical responses were documented in 3 patients and among them 2 occurred in patients injected with cell products harboring 2 KIR ligand mismatches and 1 in a patient with 1 KIR ligand mismatch. Immune monitoring revealed that most patients presented an increase but transient of IL-15 and IL-7 cytokines levels 1 week after chemotherapy. Furthermore, a high expansion of FoxP3+regulatory T cells and PD-1+ T cells was observed in all patients, related to IL-2 administration. The authors concluded that these findings demonstrated that combining allogeneic NK cells transfer via intra-hepatic artery, cetuximab and a high-dose IL-2 was feasible, well-tolerated and may result in clinical responses. These preliminary findings need to be validated by well-designed studies.
Combination Cetuximab Plus Interleukin-12 for Unresectable Primary or Recurrent Head and Neck Squamous Cell Carcinoma (HNSCC)
McMichael and colleagues (2019) stated that monoclonal antibodies including cetuximab can induce antibody-dependent cellular cytotoxicity (ADCC) and cytokine production mediated via innate immune cells with the ability to recognize mAb-coated tumors. Pre-clinical modeling has shown that co-stimulation of natural killer (NK) cells via the Fc receptor and the interleukin-12 (IL-12) receptor promotes NK cell-mediated ADCC and production of cytokines. In a phase-I/II clinical trial, these researchers examined the combination of cetuximab with IL-12 for the treatment of EGFR-expressing head and neck cancer (HNC). Treatment consisted of intravenous cetuximab 500 mg/m
2every 2 weeks with either 0.2 ug/kg or 0.3 ug/kg subcutaneous IL-12 days 2 and 5 of the 2-week cycle, beginning with cycle 2. Correlative studies from blood draws obtained prior to treatment and during therapy included measurement of ADCC, serum cytokine and chemokine analysis, determination of NK cell FcγRIIIa polymorphisms and an analysis of myeloid derived suppressor cell (MDSC) frequency in peripheral blood. The combination of cetuximab and IL-12 was well-tolerated. No clinical responses were observed, however, 48 % of patients exhibited prolonged PFS (average of 6.5 months). Compared to patients who did not exhibit clinical benefit, patients with PFS greater than 100 days exhibited increased ADCC as therapy continued compared to baseline, greater production of IFN-gamma, IP-10, and TNF-alpha at the beginning of cycle 8 compared to baseline values and had a predominance of monocytic MDSCs versus granulocytic MDSCs prior to therapy. The authors concluded that further investigation of IL-12 as an immunomodulatory agent in combination with cetuximab in HNSCC is needed.
Combination Cetuximab Plus Pazopanib for Recurrent or Metastatic HNSCC
Adkins and colleagues (2018) noted that angiogenesis is a hallmark of HNSCC, and a mechanism of resistance to EGFR inhibition. In an open-label, single-center, dose-escalation, phase-Ib clinical trial using a standard 3 + 3 design, these investigators examined the safety and potential activity of pazopanib, an angiogenesis inhibitor, plus cetuximab, an EGFR inhibitor, in patients with recurrent or metastatic HNSCC. Eligible participants were patients with histologically or cytologically confirmed recurrent or metastatic HNSCC, aged at least 18 years, had measurable disease as per RECIST version 1.1, and an ECOG PS of 0 to 1. During dose-escalation, pazopanib oral suspension was administered daily in 8-week cycles at doses of 200 mg/day, 400 mg/day, 600 mg/day, or 800 mg/day, with cetuximab given intravenously once-weekly (400 mg/m
21st dose and 250 mg/m
2in consecutive cycles). The primary end-point was to determine the MTD or recommended phase-II dose of pazopanib in combination with cetuximab. Analyses were done per protocol. Between June 5, 2013, and April 4, 2017, these researchers enrolled 22 patients into the phase-Ib, dose-escalation phase of the trial. A MTD of pazopanib in combination with cetuximab was not reached. Single DLT events (all grade-3) during dose-escalation occurred with pazopanib 400 mg/day (neutropenia with infection), 600 mg/day (proteinuria), and 800 mg/day (fatigue). The established recommended phase-II dose for the combination was 800 mg/day of pazopanib during cycles of 8 weeks each, plus cetuximab 400 mg/m
2on day 1 of cycle 1, then cetuximab 250 mg/m
2weekly. A further 9 patients were enrolled into the expansion cohort and treated with the established recommended phase-II dose. The most common (grade-3 to grade-4) AEs for all patients were hypertension (10 [32 %] of 31), lymphocyte count decrease (7 [23 %]), and dysphagia (7 [23 %]). There were no treatment-related deaths; 11 (35 %; 95 % CI: 19.2 to 54.6) of 31 patients achieved an overall response, as assessed by the investigator; 2 (6 %) had a CR, and 9 (29 %) a PR. Tumor responses were also observed in 6 (55 %) of 11 patients with platinum-naive and cetuximab-naive disease, 3 (25 %) of 12 patients with cetuximab-resistant disease, and 5(28 %) of 18 patients with platinum-resistant disease. The authors concluded that pazopanib oral suspension at a dose of 800 mg/day was feasible to administer in combination with standard weekly cetuximab for patients with recurrent or metastatic HNSCC. These researchers noted that encouraging preliminary anti-tumor activity was observed with this combination therapy and warrants further validation in large randomized trials with more homogeneous patient data-sets.
The authors stated that this study had several drawbacks. The small number of patients treated did not allow for detection of rare AEs or AEs specific to certain populations. For example, in a previous study, an Asian population of patients treated with pazopanib tablets had plasma drug concentrations at least 20 % higher than those reported in white populations; higher drug concentrations might increase AEs.
Combination Cetuximab Plus Regorafenib for Advanced Solid Tumors
Weekes and colleagues (2019) noted that oral regorafenib 160-mg once-daily (QD) 3 weeks on/1 week off is approved in CRC, GI stromal tumors (GISTs) and HCC. In a phase-I, open-label, dose-escalation study, these researchers established the safety and pharmacokinetics (PK) of regorafenib combined with cetuximab in advanced refractory solid tumors. Patients with advanced/metastatic solid tumors who progressed after standard therapy were enrolled in this trial. Regorafenib was administered at various dose levels QD continuously or intermittently (3 weeks on/1 week off) combined with intravenous cetuximab 250 mg/m
2weekly. The primary objectives were safety, PK and MTD. The secondary objective was tumor response; and DLTs were evaluated in Cycle 1. Of 42 treated patients, 31 received regorafenib intermittently (120-mg, n = 8; 160-mg, n = 23) and 11 continuously (60-mg, n = 5; 100-mg, n = 6) plus cetuximab. The continuous arm was terminated due to low tolerable dose. In the intermittent arm, 1 DLT (grade-3 hand-foot skin reaction) was observed at 120-mg, but none at 160-mg, thus, 160 mg/day was declared as the MTD in combination with cetuximab. The most common all-grade treatment-emergent AEs were fatigue (52 %), hypophosphatemia (48 %) and diarrhea (40 %); 1 grade-3 cetuximab-related dermatitis acneiform was observed. No clinically relevant drug-drug interactions were observed; 5 patients (21 %) had a partial response. The authors concluded that regorafenib 160-mg QD (3 weeks on/1 week off) plus standard dose of cetuximab was well-tolerated with no unexpected toxicities and promising initial signs of efficacy. However, they noted that interpretation of efficacy should be viewed with caution since the trial enrolled a highly heterogeneous group of patients, only a limited number of patients were evaluable for efficacy; and efficacy was only evaluated as a secondary objective. These researchers stated that in case of further development, the recommended phase-II dose for the combination will be the standard dose for either drug.
Combinaton Cetuximab Plus Zoledronic Acid for Metastatic Rectal Cancer
Tokumaru and colleagues (2019) noted that the combination of cetuximab (CTX) and chemotherapy, such as FOLFOX or FOLFIRI, is currently the standard treatment for metastatic colorectal cancer (mCRC). Zoledronic acid (ZOL) is used in patients with bone metastasis. These investigators reported their experience in the case of a 58-year old man with metastatic rectal cancer who was treated with CTX + ZOL as 3rd-line therapy, and in whom this combination appeared to be effective. These researchers stated that although the patient developed bone metastasis and cardiac tamponade due to the recurrence of rectal cancer, he survived for approximately 10 months following the initiation of CTX and ZOL treatment. The authors concluded that these findings demonstrated that combination therapy of CTX and ZOL inhibited the growth of metastatic rectal cancer; moreover, they stated that the efficacy of this combination therapy should be proven in future clinical trials.
Combination Cetuximab Plus Carboplatin and Paclitaxel for Advanced or Recurrent Cervical Cancer
Pignata and colleagues (2019) noted that cervical cancer cells often express EGFR; and CTX can be safely combined with carboplatin (C) and paclitaxel (P), a standard treatment for advanced/recurrent cervical cancer (ARCC) patients. In a phase -II clinical trial, these investigators examine the effects of CTX plus C and P in ARCC patients. Participants with ECOG PS of less than or equal to 1 were randomized to CP for 6 cycles with or without CXT (400 mg/m
21 week before starting CP, then 250 mg/m
2weekly) until disease progression or unacceptable toxicity. Event-free survival (EFS) was the primary end-point. With a 4.5 months expected median EFS and a 6.4 months predicted EFS (HR 0.70), 0.20 1-tailed α and 80 % power, 89 events were required for the final intent-to-treat (ITT) analysis. A total of 108 patients were assigned to CP (n = 53) or CP-CTX (n = 55). Median age was 50, 69 % were PS0, 76 % had recurrent disease, 91 % had distant metastasis and 57 % had received previous chemotherapy. After a median follow-up of 23 months, 102 patients had an event, 97 progressed and 61 died. Median EFS was 4.7 and 6.0 months (1-tail, p = 0.43), median PFS was 5.2 and 7.6 months (1-tail, p = 0.20) and median OS was 17.7 and 17 months (1-tail, p = 0.27), with CP and CP-CTX, respectively. There was no difference in the occurrence of severe AEs, except for skin toxicity. Biomarker analysis, in a small subgroup of patients, suggested that PIK3CA mutation might be predictive of CTX resistance. The authors concluded that CP-CTX was not more active than CP alone in unselected ARCC patients.
Combination Cetuximab Plus Modified FOLFIRI for Metastatic Gastric Cancer
Liu et al (2017) evaluated the efficacy of cetuximab combined with modified FOLFIRI (mFOLFIRI) as a second-line treatment in metastatic gastric cancer patients and to identify potential biomarkers of clinical outcomes. All 61 patients received an initial intravenous (IV) dose of cetuximab (400 mg/m
2) and weekly doses (250 mg/m
2) thereafter, starting on day 1. On day 2 of each 14-day period, patients received IV irinotecan (180 mg/m
2), leucovorin (200 mg/m
2), and an IV bolus dose of 5-FU (400 mg/m
2) followed by a continuous infusion of 5-FU (2400 mg/m
2) for 46 h. The primary endpoint was time-to-progression (TTP). The response rate (RR) was 33.3% among 54 evaluable patients. In the intention-to-treat analysis, median TTP was 4.6 months (95% confidential interval [CI]: 3.6-5.6 months) and median overall survival (OS) was 8.6 months (95% CI: 7.3-9.9 months). In univariate analyses, plasma vascular endothelial growth factor (VEGF) levels were correlated with clinical outcome. In patients with low (≤12.6 pg/ml) and high (>12.6 pg/ml) baseline plasma VEGF levels, RR values were 55.0% and 5.3%, respectively (P = 0.001); median TTP values were 6.9 months and 2.8 months, respectively (P = 0.0005); and median OS values were 12 months and 5 months, respectively (P <0.0001). None of these patients exhibited KRAS, BRAF, or PIK3CA mutations. The authors concluded that combination therapy comprising cetuximab and mFOLFIRI was well tolerated and active as a second-line treatment for patients with metastatic gastric cancer. Patients with low baseline plasma VEGF levels were associated with better clinical outcomes.
The NCCN Gastric Cancer guidelines (v.2.2022) do not mention cetuximab treatment for gastric cancer.
: Requires Precertification:
Precertification of cetuximab (Erbitux) is required of all Aetna participating providers and members in applicable plan designs. For precertification of cetuximab (Erbitux), call (866) 752-7021 (Commercial), or fax (888) 267-3277. For Statement of Medical Necessity (SMN) precertification forms, see
Specialty Pharmacy Precertification.
For Medicare Part B plans, call (866) 503-0857 or fax (844) 268-7263.Criteria for Initial Approval
Aetna considers cetuximab (Erbitux) medically necessary for the treatment of members with the following diseases:
Colorectal cancer - for treatment of colorectal cancer, including appendiceal adenocarcinoma and anal adenocarcinoma, for unresectable/inoperable, advanced, or metastatic disease and the member has not previously experienced clinical failure on panitumumab when
allof the following criteria are met:
Squamous cell carcinoma of the head and neck - for treatment of squamous cell carcinoma of the head and neck when
anyof the following criteria is met:
Aetna considers all other indications as experimental and investigational (for additional information, see Experimental and Investigational and Background sections).
Continuation of Therapy
Aetna considers continuation of cetuximab (Erbitux) therapy medically necessary in members requesting reauthorization for an indication listed in Section I when there is no evidence of unacceptable toxicity or disease progression while on the current regimen.