A Study of Subcutaneous (SC) Pembrolizumab Coformulated With Berahyaluronidase Alfa (MK-3475A) vs Intravenous Pembrolizumab in Adult Participants With Metastatic Non-small Cell Lung Cancer (NSCLC) (MK-3475A-D77)-Japan Extension

This study is to assess the pharmacokinetics (PK) and safety of SC pembrolizumab (+) berahyaluronidase alfa vs intravenous (IV) pembrolizumab, administered with chemotherapy in first line treatment of adult Japanese participants with metastatic non-small cell lung cancer. The primary hypotheses of this study are pembrolizumab (+) berahyaluronidase alfa subcutaneous (SC) is noninferior to pembrolizumab IV with respect to PK parameters.

Japan extension study will require approximately six years which includes one additional year (beyond the global study's last participant last study related contact) from the time the first participant (or their legally acceptable representative) provides informed consent until the last participant's last study related contact to complete. The Japan extension study will include participants previously enrolled in Japan in the global study for MK-3475A-D77 (NCT05722015) plus the study will continue to enroll participants in Japan until the sample size for participants in Japan reaches approximately 39. As of Amendment 1 of the supplemental statistical analysis plan (effective date: 23 Aug 2024), patient reported outcomes will no longer be the secondary outcome measures of the study.