Understanding Plaque Psoriasis and Its Treatments

Plaque psoriasis is a chronic autoimmune skin condition that affects approximately 2-3% of the global population. It is characterized by red, raised, scaly plaques on the skin, which can cause itching, pain, and significant psychological distress. Moderate to severe plaque psoriasis is typically defined as affecting more than 10% of the body surface area or having a significant impact on a patient's quality of life.

Drug Treatment Options

Drug treatment options for moderate to severe plaque psoriasis fall into several categories, including topical treatments, phototherapy, and systemic therapies.

• Topical treatments include treatment options such as vitamin D analogues, calcineurin inhibitors, keratolytics, and corticosteroids. These medications are applied directly to the skin and can help reduce inflammation and improve symptoms. However, they are generally only effective for mild to moderate psoriasis and may not be sufficient for patients with more severe disease.
• Phototherapy involves exposing the skin to ultraviolet light, which can help slow down the production of skin cells and reduce inflammation. This treatment can be effective for patients with moderate to severe plaque psoriasis, but it may require multiple sessions and can increase the risk of skin cancer.
• Systemic therapies include biologic agents, non-biologic agents, and oral medications. Biologic agents, such as tumor necrosis factor (TNF) inhibitors (e.g., ustekinumab, secukinumab, ixekizumab, brodalumab, guselkumab, tildrakizumab, and risankizumab) and interleukin (IL) inhibitors (e.g., guselkumab, risankizumab, and tildrakizumab), are targeted therapies that work by blocking specific molecules in the immune system that are involved in the development of psoriasis. Non-biologic agents, such as apremilast and tofacitinib, also work by targeting specific molecules in the immune system. Oral medications, such as methotrexate and acitretin, are systemic therapies that can help reduce inflammation and slow down the production of skin cells.

Ilumya (tildrakizumab-asmn) is FDA-approved for the treatment of adults with moderate-to-severe plaque psoriasis who are candidates for systemic therapy or phototherapy. Ilumya must be administered as a subcutaneous injection by a healthcare professional. The recommended dosage is 100 mg at Weeks 0, 4, and every 12 weeks thereafter. The medication works as an IgG1 kappa monoclonal antibody to decrease the immune/inflammatory response that leads to the symptoms seen with plaque psoriasis.

Definitions

• Body surface area (BSA) is a measure of the total area involved by plaques in relation to the total body surface area. There are a number of different methods, however most clinical trials on plaque psoriasis use the "handprint method", where the patient’s actual palm/hand size is estimated as 1% of BSA.
• Immune modulator refers to the class of medications that function by inhibiting or activating various pathways of the immune system in an effort to reduce inflammatory/immune reactions.
• Monoclonal Antibody is a type of drug that consists of a single clone of antibodies aimed against a specific target. Ilumya, for example, is a monoclonal antibody against IL-23.
• Plaque psoriasis is a chronic skin disorder characterized by the formation of cutaneous plaques, which appear as scaly, raised lesions on the surface of the skin. These plaques can occur anywhere on the body and typically fluctuate in their location and severity.
• Systemic Therapy refers to the broad category of agents infused for the treatment of plaque psoriasis.
• Phototherapy is the use of ultraviolet light to treat the symptoms of plaque psoriasis. It can be performed as phototherapy alone with UVB or as photochemotherapy using UVA in combination with a photosensitizing drug (PUVA).
• PASI score is the Psoriasis Area and Severity Index (PASI), which is the gold-standard for measurement of psoriasis severity. It combines a measure of the severity of lesions and the area affected into a single score, ranging from 0 (no disease) to 72 (maximal disease).

Medical Necessity Criteria for Initial Authorization

The Plan considers initial therapy for Ilumya (tildrakizumab-asmn) medically necessary when ALL of the following criteria are met:

1. The medication is being prescribed by or in consultation with a dermatologist; AND
2. The member is 18 years of age or older; AND
3. The member has a diagnosis of moderate to severe plaque psoriasis as defined by ONE of the following:
   • a. PASI score >12 or greater; or
   • b. Body Surface Area (BSA) is >10%; or
   • c. Body Surface Area (BSA) is >3% and plaques involve a sensitive region (e.g. face, head/neck/scalp, genitalia, palms, soles) or limit functional ability; AND
4. The member is unable to use, or has adequately tried and failed BOTH of the following:
   • a. phototherapy (e.g., UVB, PUVA) OR topical treatments (e.g., anthralin, calcipotriene, coal tars, corticosteroids, and/or tazarotene); and
   • b. at least 3 months of a conventional systemic therapy (e.g., methotrexate, cyclosporine, or acitretin) at maximally indicated doses; AND
5. The member does NOT have documented evidence of ANY of the following:
   • a. active serious infection; or
   • b. active TB infection; or
   • c. concurrent use of a biologic or targeted synthetic DMARD in combination with Ilumya; AND
6. The member has a documented negative tuberculosis skin test within the last 12 months; and

Medical Necessity Criteria for Reauthorization

Reauthorization for 12 months will be granted if BOTH of the following are met:

1. the member still meets the applicable initial criteria; AND
2. chart documentation shows ONE of the following:
   • a. At least 75% improvement in PASI score compared to baseline; or
   • b. A reduction in body surface area (BSA) affected since starting treatment; or

Chart documentation showing improvement or maintenance of disease activity.

Experimental or Investigational / Not Medically Necessary

Ilumya (tildrakizumab-asmn) for any other indication is not considered medically necessary by the Plan, or it is considered experimental or investigational and include, but are not limited to, the following:

• Use in pediatric populations (<18 years old), as the safety and efficacy of Ilumya has not been evaluated in this patient population; or
• In combination with any of the following medications, as there is limited evidence to support this:
  • Biologic Disease-modifying antirheumatic drugs (DMARDs); or
  • Janus kinase inhibitors; or
  • Phosphodiesterase 4 (PDE4) inhibitors; or
• In patients needing or expected to receive a live vaccine; or
• In patients with latent or active TB; or
• In patients with a current active infection, including infections of the skin; or
• To treat any other condition besides chronic plaque psoriasis.