Evaluate Ofirnoflast in Adults With Very Low- to Intermediate-risk Myelodysplastic Syndromes Requiring Transfusions

Overview

The primary objective of this study is to evaluate the efficacy and safety of ofirnoflast administered orally once daily in adults with very low- to intermediate-risk myelodysplastic syndromes (MDS) who are transfusion-dependent and have failed one to three prior therapies, in order to identify the optimal dose for continuation into a Phase 3 study. The secondary objectives of this study are to evaluate the extended hematologic response to ofirnoflast, to assess the safety and tolerability of ofirnoflast during the dose-selection phase, and to evaluate hematologic improvement with ofirnoflast treatment.

* Ofirnoflast (HT-6184) is a first-in-class, orally administered small-molecule allosteric inhibitor of the NIMA-related protein kinase 7 (NEK7)-NLRP3 inflammasome, developed to address the inflammatory mechanisms implicated in ineffective hematopoiesis in myelodysplastic syndromes (MDS). Chronic activation of the NLRP3 inflammasome in MDS triggers pyroptosis, driving the ineffective hematopoiesis and cytopenias that define the disease. By selectively targeting NEK7, an essential mediator of NLRP3 assembly, ofirnoflast disrupts this inflammatory cascade without broadly suppressing innate immunity, with the goal of restoring hematopoiesis. * Participants with very low- to intermediate-risk MDS who have failed one or more prior lines of therapy face limited treatment options and often develop chronic, symptomatic cytopenias requiring ongoing red blood cell (RBC) transfusions, which are associated with iron overload, reduced quality of life, and increased healthcare utilization. This study is designed to evaluate ofirnoflast in this defined, multiply-relapsed population and to identify the optimal dose to advance into a Phase 3 study. * Enrollment will proceed in two sequential phases. Phase A (Safety Lead-in) will open with five participants administered ofirnoflast, observed for a minimum of 4 weeks. Following this observation period, the Safety Review Committee (SRC) will conduct a formal safety review; if no more than 1 of the 5 participants experiences a dose-limiting toxicity (DLT), enrollment will proceed to Phase B. Phase B (Randomized Enrollment) will dose arms concurrently with an additional formal safety review conducted by the SRC after the first 10 participants randomized. * For all participants, the study consists of four periods. A Screening Period of up to 28 days prior to first dose will be used to confirm eligibility. A 24-Week Initial Treatment Period begins on Day 1 with administration of the first dose and continues for 24 weeks; all participants receive study intervention for a minimum of 24 weeks to allow complete assessment of hematologic response, with the primary endpoint evaluated during Weeks 1-24 using a landmark assessment at Week 24 to ensure comparability across the population. An Extension Period begins after Week 24 for participants who demonstrate clinical benefit as determined by the investigator; these participants may continue ofirnoflast at their established dose until disease progression. * The SRC will conduct a dose-selection analysis after enrollment is complete and the last enrolled participant has completed 8 weeks of dosing, with final analysis following completion of the 24-week Initial Treatment Period. Dose selection will be based on a pre-specified composite assessment incorporating RBC transfusion-independence and hematologic improvement response rates by arm, incidence and severity of treatment-emergent adverse events, dose modifications and discontinuations due to toxicity, and pharmacokinetic exposure parameters. * The SRC will monitor participant safety, including safety signal detection, throughout the study, with the frequency of routine safety reviews subject to adjustment based on observed enrollment rate. All participants will receive best supportive care throughout the study.