Mural Oncology provides update on ARTISTRY-7 at Investor Day

ARTISTRY-7 is a potentially registrational phase 3 trial comparing the combination of nemvaleukin and pembrolizumab versus investigator’s choice single agent chemotherapy in heavily pre-treated patients with platinum-resistant ovarian cancer, with a primary endpoint of overall survival. Secondary endpoints include progression free survival, overall response rate, disease control rate, duration of response, time to response, CA-125 response, and treatment emergent adverse events. This four-arm trial also contains two smaller monotherapy arms to assess contribution of components. PROC is an area of high unmet need, with few effective treatment options and poor survival. Nemvaleukin for the treatment of PROC has received Food & Drug Administration Fast Track Designation. Enrollment is complete, with a total of 456 patients, and approximately 187 patients in each of the two experimental arms. Futility analyses are complete for both monotherapy arms: Pembrolizumab: Predetermined analysis criteria were based on Keynote-100 trial, where single agent pembrolizumab was evaluated in 376 patients with PROC with a response rate of 8%. Futility in this arm of ARTISTRY-7 was defined as fewer than two confirmed complete or partial responses in the first 12 patients enrolled. This arm was closed to further enrollment for futility in August 2023 after enrolling 27 patients. Nemvaleukin: Predetermined futility criteria were based on two historical phase 2 trials using different doses and schedules of aldesleukin, an approved high-dose IL-2, that showed consistent response rates of approximately 25%, including some patients with durable complete responses. Futility criteria for this nemvaleukin single arm required at least one patient among the first 24 enrolled to achieve an objective response or stable disease for at least three months to continue enrollment. The nemvaleukin single arm met this threshold to continue and ultimately enrolled 55 patients. No statistical comparisons will be performed on the pembrolizumab and nemvaleukin monotherapy arms; all analyses of these two arms will be descriptive. Based on benchmarking against prior phase 3 trials in PROC, which had different eligibility criteria regarding the number of prior therapies, and the eligibility criteria of ARTISTRY-7 which allow for up to five prior lines of therapy in the platinum-resistant or refractory setting, protocol assumptions are: A median Overall Survival of 10 months for the chemotherapy control arm. A median OS of 14.3 months for the nemvaleukin plus pembrolizumab experimental arm. Protocol specific interim analysis for OS will occur at 75% of OS events.Cumulative alpha spend at interim analysis is 1-sided, 0.0096. Maximum hazard ratio for success at the interim analysis is 0.727, assuming exactly 215 OS events. With enrollment complete, the OS events required for interim analysis are estimated to occur by late Q4 2024 or early Q1 2025. Mural expects the interim analysis data readout to be available in late Q1 or early Q2 2025. If the hazard ratio meets the bar for success, the study will be declared positive and the company will plan to file a Biologics License Application in 2025. If the target hazard ratio is not met, the company may decide to continue to final analysis at approximately 286 OS events, or it may decide to terminate the study.