789O - Neoadjuvant cemiplimab in patients (pts) with stage II–IV (M0) cutaneous squamous cell carcinoma (CSCC): Primary analysis of a phase II study

Background

CSCC is highly immune-responsive; a prior pilot study demonstrated a high rate of pathologic complete response (pCR) or major pathologic response (MPR, ≤10% viable tumor), using cemiplimab anti-programmed death 1 (PD-1) therapy in the neoadjuvant setting. Here, we present the primary analysis of a confirmatory, open-label, multicenter, Phase 2, single-arm trial of neoadjuvant cemiplimab in pts with resectable Stage II–IV (M0) CSCC.

Methods

Pts received cemiplimab 350 mg IV q3W for up to 4 doses before surgery. The primary endpoint was pCR rate per independent central pathologic review (ICPR). Key secondary endpoints included MPR rate per ICPR, objective response rate (ORR; complete response [CR] + partial response [PR]) per RECIST v1.1, investigator-assessed pCR and MPR, safety and tolerability.

Results

At data cutoff date of 01 Dec 2021, 79 pts were enrolled (67 male; median age 73.0 yrs [range, 66.0–81.0]; ECOG performance status 0 (n=60) and 1 (n=19) with stage II (n=5), III (n=38), or IV(M0) (n =36) disease; 62 pts received all 4 doses (median number of doses given (Q1:Q3), 4 (4:4); 70 pts underwent surgery. The study met its primary endpoint: pCR was observed in 40 (50.6%) pts (95% confidence interval [CI], 39.1–62.1%). MPR was observed in an additional 10 (12.7%) pts (95% CI, 6.2–22.0%). ORR was 68.4% (95% CI, 56.9–78.4) (5 CR, 49 PR, 16 stable disease, 8 progressive disease (PD), 1 non evaluable. Reasons 9 pts did not have surgery: 3 responders declined surgery, 2 lost to follow-up or noncompliance, 2 had inoperable PD, 2 due to AE. Fourteen (17.7%) pts experienced Grade ≥3 AE. Four pts died due to AEs: 1 exacerbation of cardiac failure, 2 myocardial infarctions, and 1 COVID-19 pneumonia. The most common AEs regardless of attribution (all grades) were fatigue (30.4%), rash maculo-papular (13.9%), diarrhea (13.9%) and nausea (13.9%).

Conclusions

The pCR + MPR of 63.3% by ICPR in pts with Stage II–IV (M0) CSCC is the highest observed in a multicenter anti-PD-1 neoadjuvant monotherapy study for any solid tumor type. The safety profile of neoadjuvant cemiplimab is consistent with previous anti-PD-1 monotherapy experience. Ongoing follow-up will describe disease-free survival.

Clinical trial identification

NCT04154943.

Editorial acknowledgement

Medical writing support was provided by John G Facciponte, PhD, of Prime, Knutsford, UK, funded by Regeneron Pharmaceuticals, Inc., and Sanofi.

Legal entity responsible for the study

Regeneron Pharmaceuticals, Inc., and Sanofi.

Funding

Regeneron Pharmaceuticals, Inc., and Sanofi.

Disclosure

N. Gross: Financial Interests, Personal, Research Grant: Regeneron Pharmaceuticals, Inc.; Financial Interests, Personal, Advisory Board: PDS Biotechnology, Shattuck Labs and Genzyme; Financial Interests, Personal, Advisory Role: PDS Biotechnology, Shattuck Labs and Genzyme. D.M. Miller: Financial Interests, Personal, Advisory Role: Castle Biosciences, EMD Serono, Merck KGaA, Merck Sharpe & Dome, Pfizer, Regeneron, Sanofi Genzyme; Financial Interests, Personal, Ownership Interest: Checkpoint Therapeutics; Financial Interests, Personal, Research Grant: Kartos Therapeutics, NeoImmune Tech, Inc., Regeneron Pharmaceuticals, Inc. N. Khushanlani: Financial Interests, Personal, Research Grant: Regeneron Pharmaceuticals, Inc., Bristol Myers Squibb, HUYA Bioscience International, Merck, Novartis, GlaxoSmithKline, Celgene, Amgen; Financial Interests, Personal, Advisory Board: EMD Serono, Regeneron Pharmaceuticals, Inc., Genentech, AstraZeneca (data safety monitoring committee), Merck, Array Biopharma, Jounce Therapeutics, Immunocore, Bristol Myers Squibb, HUYA Bioscience International; Financial Interests, Personal, Other, honoraria: Sanofi; Financial Interests, Personal, Stocks/Shares: Bellicum Pharmaceuticals, Mazor Robotics, Amarin, Transenetrix. V. Divi: Financial Interests, Institutional, Research Grant: Genentech. E.S. Ruiz: Financial Interests, Personal, Advisory Board: Genentech, Leo Pharmaceuticals, Regeneron Pharmaceuticals, Inc., Sanofi; Financial Interests, Personal, Advisory Role, consulting fees: Genentech, Leo Pharmaceuticals, Regeneron Pharmaceuticals, Inc., Sanofi; Financial Interests, Personal, Member of the Board of Directors: Checkpoint Therapeutics. E.J. Lipson: Financial Interests, Personal, Other, Advisory board and consulting fees: Bristol Myers-Squibb, Eisai, Genentech, Immunocore, Instil Bio, MacroGenics, Merck, Natera, Nektar Therapeutics, Odonate Therapeutics, OncoSec, Pfizer, Rain Therapeutics, Regeneron, Sanofi; Financial Interests, Institutional, Research Grant: Bristol Myers Squibb, Merck, Regeneron. F. Meier: Financial Interests, Personal, Other, Travel support, speaker’s fees or advisor’s honoraria: Bristol Myers Squibb, Merck Sharp & Dohme, Novartis, Pierre Fabre, Roche and Sanofi; Financial Interests, Personal, Research Grant: Novartis and Roche. P.L. Swiecicki: Financial Interests, Institutional, Research Grant: Ascentage Pharma, Pfizer; Financial Interests, Personal, Advisory Board: Prelude Therapeutics, Elevar Therapeutics, Regeneron Pharmaceuticals. J.L. Atlas: Financial Interests, Personal, Advisory Role: Regeneron Pharmaceuticals, Inc., Sanofi, and Bristol Myers Squibb. J.L. Geiger: Financial Interests, Institutional, Research Grant: Alkermes, Debio, Merck, Regeneron Pharmaceuticals, Inc., and Roche/Genentech; Financial Interests, Personal, Advisory Role: Exelixis, Merck and Regeneron Pharmaceuticals, Inc. A. Hauschild: Financial Interests, Personal and Institutional, Other, Institutional grants, speaker’s honoraria and consultancy fees: Amgen, Bristol Myers Squibb, Merck Sharp & Dohme, Novartis, Pierre Fabre, Provectus and Roche; Financial Interests, Institutional, Other, Institutional grants and consultancy fees: EMD Serono, Philogen and Regeneron Pharmaceuticals, Inc.; Financial Interests, Personal, Advisory Role: OncoSec Medical. J.H. Choe: Financial Interests, Personal, Advisory Role: Exelixis, Coherus Biosciences, Regeneron Pharmaceuticals, Inc. B.G.M. Hughes: Financial Interests, Personal, Advisory Role: AstraZeneca, Bristol Myers Squibb, Eisai, Merck Sharp & Dohme, Pfizer and Roche; Financial Interests, Institutional, Research Grant: Amgen. S. Yoo: Financial Interests, Personal, Full or part-time Employment: Regeneron Pharmaceuticals, Inc.; Financial Interests, Personal, Stocks/Shares: Regeneron Pharmaceuticals, Inc. K. Fenech: Financial Interests, Personal, Full or part-time Employment: Regeneron Pharmaceuticals, Inc.; Financial Interests, Personal, Stocks/Shares: Regeneron Pharmaceuticals, Inc. M.D. Mathias: Financial Interests, Personal, Full or part-time Employment: Regeneron Pharmaceuticals, Inc.; Financial Interests, Personal, Stocks/Shares: Regeneron Pharmaceuticals, Inc. H. Han: Financial Interests, Personal, Full or part-time Employment: Regeneron Pharmaceuticals, Inc.; Financial Interests, Personal, Stocks/Shares: Regeneron Pharmaceuticals, Inc. M.G. Fury: Financial Interests, Personal, Full or part-time Employment: Regeneron Pharmaceuticals, Inc.; Financial Interests, Personal, Stocks/Shares: Regeneron Pharmaceuticals, Inc. D. Rischin: Financial Interests, Institutional, Research Grant: Regeneron Pharmaceuticals, Inc., Genentech, Sanofi, Kura Oncology, Roche, Merck Sharp & Dohme, Merck KGaA, Bristol Myers Squibb, GlaxoSmithKline, ALX Oncology; Financial Interests, Personal, Advisory Role: Merck Sharp & Dohme, Regeneron Pharmaceuticals, Inc., Sanofi, GlaxoSmithKline, Bristol Myers Squibb; Financial Interests, Personal, Advisory Board: Merck Sharp & Dohme, Regeneron Pharmaceuticals, Inc., Sanofi, GlaxoSmithKline, Bristol Myers Squibb. All other authors have declared no conflicts of interest.