Cemiplimab is an immunotherapy for basal cell carcinoma (BCC). It is a targeted immunotherapy that works by modulating the immune system to recognize and combat cancer cells. Its development addresses a need for effective treatments in advanced cases of BCC, where traditional approaches may be insufficient.
Understanding Basal Cell Carcinoma
Basal cell carcinoma (BCC) is the most common form of skin cancer, originating from basal cells found in the lower part of the epidermis. These cells produce new skin cells. BCC typically develops on sun-exposed areas of the body, such as the face, head, and neck, due to DNA damage primarily from ultraviolet (UV) radiation.
While BCC is generally slow-growing and rarely spreads to other parts of the body, it can be destructive to local tissues if left untreated. BCCs can manifest in various ways, often appearing as shiny, pearly bumps with visible blood vessels, open sores that do not heal, or reddish patches that may bleed or crust. Early detection and traditional treatments like surgery are usually effective for localized BCC, but advanced cases sometimes require more specialized therapies.
How Cemiplimab Works
Cemiplimab is a PD-1 (Programmed Death-1) inhibitor. Cancer cells can develop ways to evade the immune system, often by exploiting a pathway involving the PD-1 protein on immune cells and its ligands, PD-L1 and PD-L2, found on cancer cells. When PD-L1 or PD-L2 binds to PD-1, it sends an inhibitory signal that essentially “turns off” the T-cells, immune cells that attack abnormal cells.
Cemiplimab works by binding to the PD-1 receptor on T-cells, blocking its interaction with PD-L1 and PD-L2. By preventing this binding, cemiplimab removes the “brakes” that cancer cells place on the immune system. This action reactivates the T-cells, allowing them to recognize and attack the cancer cells more effectively.
Who Cemiplimab Is For
Cemiplimab is indicated for specific advanced forms of basal cell carcinoma. It is approved for adult patients with locally advanced BCC who are not candidates for curative surgery or curative radiation. Cemiplimab is also approved for patients with metastatic BCC.
The medication is generally considered for patients who have previously been treated with a hedgehog pathway inhibitor (HHI) and whose disease has progressed, or for whom HHI therapy is not appropriate due to intolerance or lack of response. It is not typically used for early-stage or easily treatable BCC. A medical professional’s assessment is necessary to determine if a patient is eligible for cemiplimab treatment, considering the specific characteristics of their cancer and overall health.
Administering Cemiplimab and Expected Outcomes
Cemiplimab is administered intravenously. The typical recommended dosage is 350 mg, infused over approximately 30 minutes, every three weeks. Treatment with cemiplimab usually continues until the disease progresses or until unacceptable side effects occur.
Clinical trials have shown promising outcomes for patients receiving cemiplimab for advanced BCC. In a study of patients with locally advanced BCC, the objective response rate (tumor shrinkage or disappearance) was 29%, with 79% of responders maintaining their response for at least six months. For patients with metastatic BCC, the objective response rate was 21%, and all responders maintained their responses for at least six months. While individual responses can vary, these results indicate that cemiplimab can lead to meaningful tumor shrinkage and disease control in selected patients.
Potential Side Effects and Management
Cemiplimab, like other immunotherapies, can cause side effects. Common side effects reported in clinical trials include fatigue, musculoskeletal pain, diarrhea, rash, and pruritus (itching). Other common reactions include nausea, decreased appetite, and upper respiratory tract infections.
More serious side effects, known as “immune-related adverse events” (irAEs), can occur when the activated immune system mistakenly attacks healthy tissues. These can affect various organ systems and may include conditions such as pneumonitis (inflammation of the lungs), colitis (inflammation of the colon), hepatitis (inflammation of the liver), and endocrinopathies (disorders of hormone-producing glands like the thyroid or adrenal glands). Patients are closely monitored for signs and symptoms of these adverse events, and reporting any new or worsening symptoms to healthcare providers promptly is important. Management of irAEs often involves the temporary withholding or permanent discontinuation of cemiplimab, along with the administration of corticosteroids or other immunosuppressants to reduce the immune response.