お知らせ • Dec 08
eFFECTOR Therapeutics, Inc. Announces New Positive Interim Data from Dose Escalation and Phase 2 Expansion Cohorts of Zotatifin in Er+ Metastatic Breast Cancer Patients
eFFECTOR Therapeutics, Inc. announced new positive interim data from dose escalation and Phase 2 expansion cohorts of a Phase 1/2 clinical study of zotatifin in patients with estrogen receptor positive (ER+) metastatic breast cancer (mBC). The data, reflecting a cutoff date of Nov. 17, 2023, is being presented by Ezra Rosen, M.D., Ph.D., Medical Oncologist and Early Drug Development Specialist, Memorial Sloan Kettering Cancer Center, at the 2023 San Antonio Breast Cancer Symposium (SABCS®), held from December 5 – 9, 2023 in San Antonio, Texas. In the ZFA triplet cohort, wherein patients with a median of four prior lines of therapy for metastatic disease received 0.07 mg/kg zotatifin dosed on Days 1 and 8 of 21-day cycles, combined with fulvestrant and abemaciclib, the mPFS was 7.4 months (95% confidence intervals 2.8 to non-estimable). As previously reported, five of 19 (26%) RECIST-evaluable patients had partial responses, including four confirmed and one unconfirmed. The ZFA triplet was generally well tolerated, with the large majority of zotatifin-related treatment-emergent adverse events (TEAEs) being Grade 1 or 2. The most common zotatifin-related TEAEs were nausea, vomiting and fatigue, all Grade 1 or 2. The most common Grade 3 or higher zotatifin-related TEAEs were anemia and blood creatinine phosphokinase increase, each in two of 20 (10%) patients. Four of 20 (20%) of patients discontinued treatment due to adverse events of any cause. In the new ZF dose escalation cohorts, three patients were enrolled at each dose level of 0.1, 0.14 and 0.2 mg/kg zotatifin administered once every two weeks, combined with fulvestrant. The patients were heavily pretreated, with a median of four prior lines of treatment for metastatic disease. There were no dose-limiting toxicities (DLTs) or serious adverse events (SAEs) observed in these nine patients and enrollment is ongoing now at 0.28 mg/kg zotatifin combined with fulvestrant. There was one confirmed partial response in the 0.1 mg/kg cohort, two instances of stable disease in the 0.14 mg/kg cohort and one instance of stable disease in the 0.2 mg/kg cohort. Based on the safety and tolerability of the ZF doublet, dose escalation has been reopened in the ZFA triplet, with enrollment ongoing at 0.1 mg/kg zotatifin dosed once every two weeks, combined with fulvestrant and abemaciclib. The company expects to report additional data from dose escalation in the first half of 2024. The Phase 1/2 trial (NCT04092673) is an open-label randomized dose-escalation and cohort-expansion study evaluating eIF4A inhibitor, zotatifin, in patients with advanced solid tumors. The primary objectives of part one of the trial are to evaluate the safety and tolerability of zotatifin as a monotherapy in patients with defined, advanced solid tumors, determine the recommended Phase 2 dose for zotatifin as a monotherapy and to evaluate the pharmacokinetics profile. In part two of the trial, the primary objective is to evaluate the preliminary antitumor activity of zotatifin as a monotherapy and as a combination therapy in patients with defined, advanced solid tumors. Zotatifin is a potent and sequence-selective small molecule inhibitor of the RNA helicase eIF4A that is designed to suppress expression of a network of cancer driving proteins, including Cyclins D and E, CDKs 2, 4 and 6 and select RTKs as well as KRAS. are currently investigating zotatifin in ongoing clinical trials for solid tumors.