Patients with metastatic, locally advanced cutaneous SCC respond well to cemiplimab

Key takeaways:

• The objective response rate among groups 1 to 3 and group 6 were 47.2% and 44.8%, respectively.
• Serious adverse events were reported in 31.1% to 34.5% of patients.

Cemiplimab provided clinically meaningful responses for patients with metastatic and locally advanced cutaneous squamous cell carcinoma, according to a study.

“Cutaneous squamous cell carcinoma (CSCC) is the second most common nonmelanoma skin cancer, with an estimated 2.4 million cases diagnosed in 2019 worldwide,” Brett G. M. Hughes, MBBS, of the department of cancer care services at Royal Brisbane and Women’s Hospital and the faculty of medicine at the University of Queensland in Australia, and colleagues wrote. “Cemiplimab, a high-affinity PD-1 antibody, demonstrated antitumor activity in a phase 1 advanced CSCC expansion cohort and a pivotal phase 2 study.”

In this phase 2 study, four groups of patients were treated with varying doses of cemiplimab. In group 1, 59 patients with metastatic CSCC (mCSCC) received a weight-based dose of cemiplimab intravenously at 3 mg/kg every 2 weeks. In group 2, 78 patients with locally advanced CSCC (laCSCC) also received the same weight-based dose. In group 3, 56 patients with mCSCC received a fixed-dose of cemiplimab at 350 mg intravenously every 3 weeks.

All patients were treated for 54 weeks or less except for a group 6 (n = 167), which received the same treatment as group 3 but for 108 weeks or less.

After 42.5 months of follow-up, the objective response rate (ORR) among groups 1 to 3, collectively, was 47.2%, the estimated 12-month duration of response (DOR) was 88.3% and the median progression-free survival (PFS) was 26 months.

Similarly, the 8.7-month follow-up results for group 6 showed an ORR of 44.8%, however, the DOR and median PFS endpoints were not met.

Adverse events were experienced by nearly all patients in all groups with the most common events being fatigue, diarrhea and pruritus in groups 1 to 3 and fatigue, diarrhea and nausea in group 6.

Serious treatment-emergent adverse event rates were 31.1% and 34.5% for groups 1 to 3 and group 6, respectively.

“These results confirm that cemiplimab provides clinically meaningful activity in both mCSCC and laCSCC, as evidenced by ORR, DOR and PFS,” the authors wrote. “Due to the advanced age of this patient population, close monitoring for [adverse events] is imperative so that immune-suppressive therapy can be promptly initiated when needed.”