ABSTRACT 818P, Phase 2 confirmatory study of cemiplimab

ESMO 2022

ABSTRACT 818P: Phase 2 confirmatory study of cemiplimab (350mg IV Q3W) in patients with locally

advanced or metastatic cutaneous squamous cell carcinoma (CSCC): Study 1540 Group 6

Speaker: Brett G. Hughes

Background

While most patients diagnosed with CSCC are cured with local therapies, for the small percentage

developing advanced CSCC the disease is life threatening with dismal prognosis. In a phase 1 trial

and a pivotal phase 2 clinical trial, cemiplimab, an anti–programmed cell death receptor-1 [anti–PD-1],

was the first systemic therapy to demonstrate significant antitumor activity in patients with

advanced CSCC. Here, we report results from Group 6 of the pivotal phase 2 trial, providing additional

efficacy and safety data for cemiplimab monotherapy [350 mg every 3 weeks (Q3W)] up to 104 weeks,

in patients with advanced CSCC.

Methods

Patients with advanced CSCC (metastatic [nodal or distant] or locally advanced) were treated with

cemiplimab for up to 108 weeks. The primary endpoint was objective response rate (ORR; complete

response + partial response) per independent central review (ICR). Secondary endpoints included

duration of response (DOR), progression-free survival (PFS), and overall survival (OS) by central and

investigator review as well as safety and tolerability of cemiplimab.

Results

At data cut-off date of 25 October 2021, 167 patients were enrolled, of whom 165 received at least

one dose of cemiplimab and were followed-up for a median of 8.7 months (range: 0 to 19.5).

Their average age was 76 years (range, 40 to 68), and most had cancer of the head and neck (68%).

Five of these 167 patients had received prior systemic therapies for CSCC.

Per ICR, ORR was 45.1% (95% CI: 37.4% to 53.1%) with complete responses in 5.5% and partial

responses in 39.6%. The DOR was not reached (95% CI: 13.0 months to evaluable [NE]). Among treated

patients, median PFS was 14.7 months (95% CI: 10.4 to NE) and median OS was not reached (95% CI:

17.6 months to NE).

The most common treatment-emergent adverse events (TEAEs) of any grade were fatigue (26%),

diarrhea (21%), pruritus (21%), and nausea (17%). The most common grade ≥ 3 TEAEs were constipation and decreased appetite (each 3.6%), and maculo-papular rash (3%).

Conclusion

The Group 6 primary analysis demonstrates a safety and efficacy profile for cemiplimab that is

consistent with that of the earlier groups of Study 1540. Cemiplimab remains a standard-of-care option

in patients with advanced CSCC who are not candidates for curative surgery or radiation.

Funding: Regeneron Pharmaceuticals and Sanofi