INTERLINK-1: A Phase III, Randomized, Placebo-Controlled Study of Monalizumab plus Cetuximab in Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma

Purpose: Treatment options for recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) after failure of immune checkpoint inhibitor treatment and platinum-based chemotherapy are limited. Preliminary data suggested that monalizumab plus cetuximab had clinical activity in R/M HNSCC. Patients and Methods: INTERLINK-1 (NCT04590963) was a double-blind, phase III study. Participants with R/M HNSCC who had received immune checkpoint inhibitor therapy and progressed despite platinum-based chemotherapy were randomized 2:1 to monalizumab (750 mg, every 2 weeks) or placebo, plus cetuximab (400 mg/m2 loading dose, then 250 mg/m2, weekly). The primary endpoint was overall survival (OS) in participants with non-oropharyngeal cancer or human papillomavirus (HPV)-negative oropharyngeal cancer (HPV-unrelated analysis set). Secondary endpoints included progression-free survival and objective response rate. Results: At data cutoff, 216 participants were randomized in the HPV-unrelated analysis set: 145 to monalizumab plus cetuximab and 71 to placebo plus cetuximab. Median OS was 8.8 months for monalizumab plus cetuximab versus 8.6 months for placebo plus cetuximab (HR, 1.00; 95% confidence interval, 0.66–1.54); median progression-free survival was 3.6 versus 3.8 months, respectively (HR, 1.11; 95% confidence interval, 0.79–1.57); and the objective response rate was 15.2% versus 23.9%, respectively. INTERLINK-1 was terminated after a preplanned interim analysis showed that futility criteria were met (predetermined futility HR >0.874). Grade 3/4 treatment–related adverse events were reported in 18.3% and 17.2% of participants treated in the monalizumab and placebo arms, respectively. Conclusions: Monalizumab plus cetuximab did not improve OS compared with placebo plus cetuximab. The safety profile of the combination was consistent with safety observations for cetuximab monotherapy.