Merck says 3475A-D77 Phase 3 trial met primary endpoints

Merck (MRK) announced the first data presentation from the pivotal 3475A-D77 Phase 3 trial, evaluating the subcutaneous administration of pembrolizumab, together with berahyaluronidase alfa. Berahyaluronidase alfa is a variant of human hyaluronidase developed and manufactured by Alteogen Inc. These results are being presented today at the European Lung Cancer Congress 2025 and published simultaneously in Annals of Oncology. The study met its primary endpoints, demonstrating noninferior pharmacokinetics for subcutaneous pembrolizumab administered with chemotherapy with a median injection time of two minutes, versus intravenous KEYTRUDA administered with chemotherapy for the first-line treatment of adult patients with metastatic non-small cell lung cancer. The secondary endpoints of objective response rate, progression-free survival and duration of response and safety were consistent for subcutaneous pembrolizumab with chemotherapy compared to IV KEYTRUDA with chemotherapy. Median overall survival was not reached in either arm. Based on these data, the U.S. Food and Drug Administration has accepted for review a Biologics License. In addition, results of a prospective, observational time and motion descriptive analysis conducted alongside study 3475A-D77 show that, compared to IV KEYTRUDA, subcutaneous pembrolizumab reduced time for patients spent in-chair and in the treatment room by 49.7% and 47.4%, respectively, and reduced the total active time spent by healthcare professionals on treatment preparation, administration process and patient monitoring by 45.7%.