Phase II study of the safety and efficacy of the anti-PD-1 antibody balstilimab in patients with recurrent and/or metastatic cervical cancer

Abstract

Objective: This phase II clinical trial evaluated the safety and antitumor activity of balstilimab, an anti-PD-1 antibody, in patients with previously-treated, recurrent/metastatic cervical cancer.

Methods: Eligible patients were 18 years or older with recurrent and/or metastatic cervical cancer and who had relapsed after a prior platinum-based treatment regimen for advanced disease. Balstilimab was administered intravenously at 3 mg/kg once every two weeks, for up to 24 months. The primary endpoint was objective response rate (ORR, RECIST v1.1) as assessed by an independent review committee.

Results: At data cutoff, 161 women (median age, 53 years [range 25-81]) were enrolled and treated with balstilimab. Of these, 140 had measurable disease at baseline and one prior line of platinum-based therapy in the metastatic, persistent, or recurrent setting; these patients were included in the efficacy analyses. The ORR was 15% (95% CI, 10.0%-21.8%) and included 5 patients with a complete response and 16 with a partial response. The median duration of response was 15.4 months. In patients with PD-L1-positive tumors the ORR was 20%, however patients with PD-L1-negative tumors also responded to balstilimab (ORR, 7.9%). Responses were not restricted to tumors of squamous cell histology, and an ORR of 12.5% was seen in the subset of patients with cervical adenocarcinoma. The disease control rate was 49.3% (95% CI, 41.1%-57.5%). Immune-mediated enterocolitis (3.1%) and diarrhea (1.9%) were the most common grade 3 or higher treatment-related adverse events.

Conclusion: Balstilimab demonstrated meaningful and durable clinical activity, with manageable safety, in patients with previously-treated, recurrent/metastatic cervical cancer.

Keywords: Cervical cancer; Checkpoint inhibitor; Immunotherapy; PD-1; Phase II.

Conflict of interest statement

Declaration of Competing Interest DMO reports personal fees and institutional grants from AstraZeneca, GSK/Tesaro, ImmunoGen, Janssen/Johnson & Johnson, Abbvie, Regeneron, Amgen, Clovis Oncology, Novocure, Genentech/Roche, Iovance, Eisai, Agenus, Merck, SeaGen, Novartis, Mersana; personal fees from Ambry, GOG Foundation, Myriad Genetics, Tarveda, Rubis, and Elevar; additional institutional funding from VentiRx Array Biopharma, EMD Serono, Ergomed, Ajinomoto Inc., Ludwig Cancer Research Stemcentrx, Inc., CERULEAN Pharma, Bristol-Myers Squibb, Serono, TRACON Pharmaceuticals, INC Research, Inc., inVentiv Health Clinical, PRA Intl and GenMab. AO reports personal fees from AstraZeneca, PharmaMar, Roche, Clinical Care Options, Clovis Oncology, Deciphera Pharmaceuticals, ImmunoGen, GenMab, Mersana, prIME Oncology, GlaxoSmithKline, and Tesaro; funding from AstraZeneca, Daiichi Sankyo, Eli Lilly and Company, Genentech, Immunomedics, Macrogenics, Merck Sharp & Dohme, Novartis, Pfizer, Piqur Therapeutics, Roche, Synthon, and Zenith Pharmaceuticals. BJM reports personal fees from Agenus, Akeso Bio, AstraZeneca, Genmab/Seattle Genetics, Iovance, Merck, Puma, Roche/Genentech, GOG Foundation, and GSK/Tesaro. FS reports personal fees and travel support from AstraZeneca, GSK/Tesaro, Merck Sharp & Dohme, Sandoz (Novartis), and Clovis Oncology, and Roche. CR reports personal fees from Merck, BMS, Roche, AstraZeneca, and Pfizer. LG reports personal fees from AstraZeneca, Clovis Oncology, GlaxoSmithKline, Merck Sharp & Dohme, and Roche; travel support from AstraZeneca and PharmaMar. AL reports personal fees from AstraZeneca, Tesaro, Clovis Oncology, Merck Sharp & Dohme, BIOCAD, AbilityPharma, Seattle Genetics, and Zentalis; institutional fees, grant and travel support from GlaxoSmithKline and Merck Serono. KNM reports personal fees from Aravive, AstraZeneca, Bristol Myers Squibb, Eisai, Elevar, GSK/Tesaro, Genentech/Roche, ImmunoGen, Merck, Mersana, Myriad, OncXerna, Sorrento, and VBL Therapeutics; funding from PTC Therapeutics, Lilly, and Merck. ACHB reports personal fees from AstraZeneca, Clovis Oncology, GlaxoSmithKline, Novartis, Pfizer, Roche, and Seagen. JA reports personal fees from AstraZeneca, GlaxoSmithKline, Roche, Merck Sharp & Dohme, PharmaMar; funding from Janssen and Merck Sharp & Dohme; travel support from Janssen, GlaxoSmithKline, and Novartis. CPO reports personal fees from Abbvie, AstraZeneca, Bristol Myers Squibb, Clovis Oncology, Genmab, GlaxoSmithKline, Tesaro, Mersana, PharmaMar; funding from Lilly, Roche, and Sanofi. CRdA reports personal fees from Merck Sharp & Dohme. LMR reports personal fees from AstraZeneca, Clovis Oncology, Eisai, EMD Serono, Genentech/Roche, GlaxoSmithKline, GOG Foundation, Mersana Therapeutics, Merck, Myriad Genetics, OnTarget, Rubius, BluPrint Oncology, Products in Knowledge; grant funding from Akeso Bio, Genentech, and Merck; travel support from GlaxoSmithKline. WOF reports employment by, and stock ownership in, Agenus Inc. MA reports employment by Agenus Inc. IRC reports personal fees from Abbvie, AstraZeneca, Bristol Myers Squibb, Clovis Oncology, Genmab, GlaxoSmithKline, Tesaro, Mersana, PharmaMar, and Roche; research funding from Bristol Myers Squibb, GlaxoSmithKline, and Merck Sharp & Dohme. All remaining authors have declared no conflicts of interest.

Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.