Phase I and expansion cohort study of adjuvant cisplatin, intensity-modulated radiation therapy (IMRT), and MK-3475 (Pembrolizumab) in high-risk head and neck squamous cell carcinoma (HNSCC)
Bauman JE, Harris J, Uppaluri R, Yao M, Ferris RL, Chen J, Jordan RC, Joshi NP, Jujjuvaparu S, Blakaj D, Razaq M, Sheqwara J, Mell LK, Sen N, Clump DA, Garg M, Yilmaz E, and Le QT. Phase I and expansion cohort study of adjuvant cisplatin, intensity-modulated radiation therapy (IMRT), and MK-3475 (Pembrolizumab) in high-risk head and neck squamous cell carcinoma (HNSCC). J Clin Oncol 2019; 37.
J Clin Oncol
Background: Pembrolizumab, an anti-PDI monoclonal antibody, improves survival in advanced HNSCC. Patients with pathologic high risk, HPV-negative HNSCC have a high recurrence rate despite adjuvant cisplatin-IMRT (CRT), the current standard. Immunosuppression is induced by HNSCC and CRT, and may be reversible by targeting PD1. Methods: We conducted a phase I trial with expansion cohort to determine the recommended phase II schedule (RP2S) for adding fixed-dose pembrolizumab to adjuvant CRT (NCT02775812). Eligibility: oral cavity, pharynx, or larynx primary; HPV-negative; pathologic high risk (positive margin or extranodal extension [ENE]); Zubrod 0-1. During phase I, patients enrolled in descending cohorts of 12 (Table). RP2S was declared if < 3 dose-limiting toxicities (DLT) occurred. DLT was defined as > Grade 3 non-hematologic adverse event (AE) related to pembrolizumab, immune-related (ir)AE requiring > 2 weeks of systemic steroids, or unacceptable delay in IMRT. The expansion cohort enrolled 20. Results: From Nov 2016-Oct 2018, 34 eligible patients enrolled at 22 NRG institutions. During the first cohort, 1 DLT was observed (Grade 3 fever). RP2S was declared as Schedule 3 and the expansion cohort triggered. Among all 34 patients, median age was 60 years (26-83); 68% were male; 74% had Zubrod 1; 85% had oral cavity; 88% had ENE; 21% had positive margin. During expansion, 3 additional patients with DLT were observed: wound infection; diverticulitis; nausea. No DLT unacceptably delayed IMRT Twenty-eight of 34 (82%) received > 5 doses of pembrolizumab; 17 (50%) got all 8 doses. Thirty-one of 32 (97%) DLT-evaluable patients received all adjuvant RT; 1 withdrew consent after starting protocol.Conclusions: The RP2S is pembrolizumab 200 mg IV q 3 weeks for 8 doses, starting the week before adjuvant CRT This regimen was safe and feasible in a cooperative group setting. irAE were rare in this population. (Table Presented).