Abstract CT123: IMvoke010: Randomized Phase III study of atezolizumab as adjuvant monotherapy after definitive therapy of squamous cell carcinoma of the head and neck (SCCHN)

Abstract

Background: Locally advanced SCCHN is associated with a high risk for local recurrence and distant metastases. Current treatment options include a combination of surgery, radiation therapy and chemotherapy to optimize the chances for long-term disease control and improved survival. As standard of care, patients are monitored after definitive local therapy for local recurrence and/or distant metastases. No effective systemic adjuvant treatment has been identified. Atezolizumab (atezo) is an anti-programmed death-ligand 1 (PD-L1) monoclonal antibody that restores anti-tumor immunity by preventing PD-L1 from binding to its receptors. Efficacy results from a cohort of 32 patients with recurrent/metastatic SCCHN in the Phase I PCD4989g study suggested that atezo offers promising clinical benefit in SCCHN. The objective of IMvoke010 (NCT03452137) is to evaluate the efficacy and safety of adjuvant treatment with atezo in comparison to placebo in patients with locally advanced SCCHN who are at high risk for disease recurrence or progression following definitive curative therapy. Trial design: IMvoke010 is a global, double-blind, placebo-controlled, randomized Phase III trial currently enrolling patients who have completed definitive local/regional therapy for Stage III human papillomavirus (HPV)-positive oropharyngeal carcinoma or Stage IVA or IVB HPV-negative SCCHN involving the oral cavity, oropharynx, larynx or hypopharynx and are at high risk for disease recurrence or progression. Approximately 400 patients will be randomized 1:1 to receive placebo or atezo 1200 mg every 3 weeks for up to a year (≤ 16 cycles) or until unacceptable toxicity, disease recurrence or progression. Patients with nasopharyngeal carcinoma, metastatic disease or progressive disease during or at completion of definitive local therapy will be excluded. Primary endpoints are independent review facility-assessed event-free survival (EFS) and overall survival. Key secondary endpoints include investigator-assessed EFS, safety and patient reported outcomes. Exploratory biomarkers will also be assessed. Citation Format: Deborah J. Wong, Jerome Fayette, Ye Guo, Matthew Kowgier, Ezra Cohen, Ricard Mesia Nin, Arunee Dechaphunkul, Kumar Prabhash, Jessica Geiger, Sarwan Bishnoi, Henning Schafer, Christina Matheny, Fairooz Kabbinavar, Alan Sandler, David Raben, Robert Haddad. IMvoke010: Randomized Phase III study of atezolizumab as adjuvant monotherapy after definitive therapy of squamous cell carcinoma of the head and neck (SCCHN) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT123.