Salarius Pharmaceuticals, Inc. announced that investigators at the University of Texas MD Anderson Cancer Center?s Leukemia department presented clinical data on seclidemstat in patients with MDS and CMML at the 2024 European Hematology Association (EHA) Hybrid Congress. The meeting was held in Madrid and virtually from June 13-16, 2024. The objective of this investigator-initiated Phase 1/2 dose-escalation study is to evaluate the safety, tolerability, maximum tolerated dose and overall response of seclidemstat in combination with azacitidine in adult patients with higher-risk MDS or CMML who previously failed or relapsed after hypomethylating agent therapy.

As of May 2024, 16 patients were enrolled in this study with 14 patients evaluable for efficacy. As presented at EHA, of the 14 evaluable patients for efficacy, 6 (43%) had an objective response including 1 complete response, 3 marrow complete responses, 1 marrow complete response plus hematological improvement and 1 hematologic improvement. The median overall survival was 18.5 months (95% CI, range 6.1-30.9 months), median event-free survival was 7.2 months (95% CI, range 6.3-8.2 months) and median follow-up time was 18.9 months (95% CI, range 0-48 months) from treatment initiation.

As reported, overall survival after failing therapy with hypomethylating agents typically is 4-6 months. 15 patients were evaluable for toxicity, with a dose-limiting toxicity observed in 1 patient in the 750mg BID cohort. Per protocol, the cohort was expanded to 3 additional patients.

Based upon reported data, Salarius believes adverse events observed were manageable. The Phase 1 dose-escalation portion of this study will evaluate up to six dose levels of seclidemstat. Cohort 5 (dose level 750mg BID seclidemstat in combination with azacitidine) is currently enrolling and cohort 6, the final cohort, will receive 900mg BID seclidemstat in combination with azacitidine.

The maximum tolerated dose, which will inform the Phase 2 portion of the study, has not yet been reached.