Aim: To determine whether EMD 1201081, a TLR9 agonist, added to cetuximab had antitumor activity in second-line recurrent/metastatic squamous cell carcinoma of the head and neck (R/M SCCHN).
Methods: This was a phase 2, open-label, randomized trial of EMD 1201081 0.32 mg/kg subcutaneously weekly plus cetuximab (combination) vs cetuximab monotherapy (control) in cetuximab-naïve patients with R/M SCCHN who progressed on 1 cytotoxic regimen. Crossover to combination was permitted after progression.
Results: Objective response rate in both arms was 5.7% (95% CI 1.2-15.7%) by independent assessment. Disease control was 37.7% for patients on combination (24.8-52.1%) and 43.4% on control (29.8-57.7%). Neither independent nor investigator assessments showed significant differences between study arms. Median progression-free survival was 1.5 months (1.3-2.6) for patients on combination, and 1.9 months (1.5-2.9) on control. The most frequent adverse events in the combination arm were rash (29.6%), acneiform dermatitis (22.2%), and injection site reactions (20.4%). Grade 3/4 dyspnea and hypokalemia were more frequent with cetuximab monotherapy (7.5% and 5.7% vs 1.9% each, respectively), and grade 3/4 respiratory failure and disease progression were more frequent with combination (5.6% each vs 1.9% each).
Conclusion: EMD 1201081 was well tolerated combined with cetuximab, but there was no incremental clinical efficacy.
Trial registration: ClinicalTrials.gov NCT01040832.