eFFECTOR Therapeutics to Resume Trading at 9 a.m. Following Disappointing Tomivosertib Data in NSCLC

eFFECTOR Therapeutics (EFTR) to Resume Trading at 9 a.m.

• eFFECTOR Therapeutics, Inc. (EFTR), a leader in the development of selective translation regulator inhibitors (STRIs) for the treatment of cancer, today announced topline results from the primary analysis of the randomized Phase 2 KICKSTART trial which tested tomivosertib or placebo, each combined with pembrolizumab, as frontline treatment for patients with non-small cell lung cancer (NSCLC) with PD-L1 ≥50%. Based on 36 events, the hazard ratio for progression free survival (PFS, the primary endpoint of the study) using a stratified Cox proportional hazards model was 0.62 (95% confidence intervals 0.3 to 1.3) in favor of tomivosertib. The two-sided p value for PFS, based on a stratified log rank test, was 0.21, which did not meet the pre-specified threshold of p≤0.2. The median PFS was 13.0 weeks in the tomivosertib plus pembrolizumab arm and 11.7 weeks in the placebo plus pembrolizumab arm, respectively. Overall survival results remain immature, however no trend favoring tomivosertib was observed. There were 67% Grade 3 or higher treatment emergent adverse events in the tomivosertib plus pembrolizumab arm versus 37% in the placebo plus pembrolizumab arm.
• “While there was evidence of modest tomivosertib activity in the trial, based on the totality of the data currently available we do not see an obvious path forward to continue developing tomivosertib in frontline NSCLC,” said Steve Worland, Ph.D., president and chief executive officer of eFFECTOR. “We sincerely appreciate the contributions of all the patients, their families, and trial site professionals who contributed to the execution of the trial. We will continue to analyze trial data and hope to present our findings at a future medical conference.”
• Dr. Worland continued: “While we’re disappointed that tomivosertib won’t be moving forward in frontline NSCLC, our strategy to maximize the value of all assets in our pipeline remains unchanged. Zotatifin, with its novel mechanism distinct from that of tomivosertib’s, is a drug candidate that is poised to enter a randomized, potentially registrational trial in estrogen receptor positive (ER+) breast cancer later this year. Our focus is now further sharpened towards advancing zotatifin through development as efficiently as possible, building on the recent positive updates of median PFS (mPFS) and safety data at last year’s San Antonio Breast Cancer Symposium (SABCS®). As a next step for the zotatifin program, we expect to report additional data, including the recommended phase 2 dose (RP2D), for zotatifin combined with fulvestrant and abemaciclib in the second half of 2024. In addition, as part of our strategy to leverage investigator-sponsored trials to conserve capital, a separate, investigator-sponsored trial of tomivosertib in acute myeloid leukemia (AML) will continue unchanged. The mechanistic rationale to test tomivosertib in AML is entirely distinct from the rationale in NSCLC and relies on tomivosertib’s potential to inhibit production of survival proteins Mcl-1 and Bcl-2, which are required for leukemia cell survival.”