Merck Announces Interim Results From Cohort A Of KEYNOTE-427

(RTTNews) - Merck & Co Inc. (MRK) announced interim results from Cohort A of KEYNOTE-427, a Phase 2 trial evaluating KEYTRUDA, Merck's anti-PD-1 therapy, as first-line treatment for advanced clear cell renal cell carcinoma (RCC). Interim data showed an overall response rate (ORR) of 38.2 percent (95% CI, 29.1-47.9) in patients who received KEYTRUDA monotherapy as first-line therapy, the primary endpoint of the study.

In a pre-specified, exploratory sub-group analysis based on PD-L1 status, ORR was 50.0 percent (95% CI, 34.9-65.1) in patients whose tumors expressed PD-L1 (CPS =1). In a pre-specified exploratory sub-group analysis based on the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk model, ORR was 42.0 percent (95% CI, 30.2-54.5) in patients with intermediate/poor prognostic risk. This is the first presentation of Phase 2 data for an anti-PD-1 monotherapy as first-line treatment for advanced clear cell RCC.

Merck has an extensive clinical development program across RCC and is advancing multiple potential registration-enabling studies with KEYTRUDA, as monotherapy and in combination with other treatments, including KEYNOTE-564, KEYNOTE-426 and KEYNOTE-581.

KEYNOTE-427 is a single-arm, open-label, non-randomized, multi-cohort, Phase 2 study evaluating the safety and efficacy of KEYTRUDA as monotherapy in patients with advanced RCC who have not received prior systemic therapy. Data being presented at ASCO are from Cohort A, which includes patients with advanced clear cell RCC (n=110). The primary endpoint is ORR, according to RECIST v1.1, as assessed by independent central review. Secondary endpoints include duration of response (DOR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and safety and tolerability.