On February 9, the U.S. Food and Drug Administration (FDA) granted regular approval to cemiplimab-rwlc (Libtayo) for patients with locally advanced basal cell carcinoma (BCC) previously treated with a hedgehog pathway inhibitor (HHI) or for whom an HHI is not appropriate. The FDA also granted accelerated approval to cemiplimab for patients with metastatic BCC previously treated with an HHI or for whom an HHI is not appropriate.
Efficacy was evaluated in Study 1620, an ongoing, open-label, multicenter, nonrandomized trial in patients with advanced BCC (locally advanced or metastatic) whose disease had progressed on HHI therapy, who had not had an objective response after 9 months on HHI therapy, or were intolerant of prior HHI therapy. Eligibility required that patients with locally advanced BCC were not candidates for curative surgery or curative radiotherapy, per multidisciplinary assessment. All patients received cemiplimab at 350 mg every 3 weeks for up to 93 weeks until disease progression, unacceptable toxicity, or completion of planned treatment.
The main efficacy outcome measures were confirmed objective response rate and duration of response as assessed by independent central review. For patients without externally visible target lesions, confirmed objective response rate was assessed according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. A composite response assessment incorporating clinical response criteria using digital medical photography together with RECIST 1.1, was used for those with externally visible target lesions.
Among 84 patients with locally advanced BCC, the confirmed objective response rate was 29% (95% confidence interval [CI] = 19%–40%) with a median duration of response not being reached (range = 2.1–21.4+ months) and 79% of responders maintaining their response for at least 6 months. Among 28 patients with metastatic BCC, the confirmed objective response rate was 21% (95% CI = 8%–41%) with a median duration of response not being reached (range = 9–23.0+ months), and all responders maintaining their responses for at least 6 months.
Severe adverse reactions included immune-mediated adverse reactions (eg, pneumonitis, hepatitis, colitis, adrenal insufficiency, hypo- and hyperthyroidism, diabetes mellitus, and nephritis) and infusion reactions. The most common adverse reactions (incidence ≥ 20%) were fatigue, musculoskeletal pain, diarrhea, rash, and pruritis.
The recommended dosage of cemiplimab is 350 mg as an intravenous infusion over 30 minutes every 3 weeks until disease progression or unacceptable toxicity.