Imbria's ninerafaxstat heads toward FORTITUDE-HCM data with no rival on its mechanism
The Phase 2b trial testing ninerafaxstat against placebo in non-obstructive HCM has no direct mechanistic comparator, leaving prior Phase 2a signals as the only benchmark for late-2026 topline data.
Executive Summary
- A placebo-controlled Phase 2b trial is testing whether ninerafaxstat's cardiac energetics mechanism improves patient-reported symptoms in non-obstructive HCM, a subset of the disease with no approved targeted therapy.
- No competing program in the indication shares ninerafaxstat's mechanism, so the trial's outcome will stand alone rather than read against a rival's data in the same pathway.
- Enrollment and protocol history show no destabilizing changes, and the trial's completion timeline has held steady since it opened, shifting the open question from execution risk to what the data will show.
- A recent orphan designation signals recognized unmet need in this population without speaking to whether the trial's endpoint will be met.
The trial
FORTITUDE-HCM (NCT07023614) is a randomized, double-blind, placebo-controlled Phase 2b trial evaluating ninerafaxstat in patients with symptomatic non-obstructive hypertrophic cardiomyopathy (nHCM). The trial targets 165 patients across the United States and ten other countries including Spain, Italy, the United Kingdom, and Germany. Its primary endpoint is change in the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS), a patient-reported measure of symptoms and physical function, with four secondary endpoints covering ventilatory efficiency during exercise testing and additional KCCQ subscales. Imbria Pharmaceuticals, Inc. guided topline data to late 2026 when it closed a $57.5 million Series B financing in April 2025, led by Deep Track Capital with participation from Cytokinetics. NCT07023614+1A Trial to Evaluate the Efficacy and Safety of Ninerafaxstat in Patients With Symptomatic Non-obstructive Hypertrophic CardiomyopathyNCT07023614MA-IMBRIAApr 10, 2025
Probability of SuccessBased on the AppliedXL Probability of Success model. For more information about the methodology, read the research here.
The prior signal
Ninerafaxstat has already produced open-label Phase 2a data in the same indication. The IMPROVE-HCM trial's results were presented at a late-breaking session at the American College of Cardiology's 2024 meeting and published simultaneously in the Journal of the American College of Cardiology. A separate Phase 2a trial, IMPROVE-DiCE, tested ninerafaxstat in heart failure with preserved ejection fraction and reported the drug was well tolerated over 12 weeks, with results published in Circulation. FORTITUDE-HCM is the first randomized, placebo-controlled trial of the drug in nHCM, making it the test of whether the open-label signal holds under blinding and against a comparator arm. MA-IMBRIAMA-IMBRIAApr 10, 2025
The competitive field
No trial identified in the nHCM or broader hypertrophic cardiomyopathy landscape shares ninerafaxstat's target or mechanism. The closest active programs in the same indication family, Cytokinetics' aficamten and Lexicon Pharmaceuticals' sotagliflozin, work through different mechanisms and both have Phase 3 trials nearing completion around mid-2026, ahead of FORTITUDE-HCM's own primary completion date. Other named comparators in the broader cardiomyopathy space, including tafamidis, acoramidis, and eplontersen, treat transthyretin amyloid cardiomyopathy, a distinct disease with a different mechanism, and are not comparators to ninerafaxstat's pathway. With no direct mechanistic precedent to benchmark against, FORTITUDE-HCM's result will stand as an isolated data point on cardiac energetics modulation as a therapeutic approach in this population, rather than one measured against a rival program's outcome.
Operational read
The trial moved from Not yet recruiting to Recruiting in October 2025, on the timeline the sponsor guided, and its primary completion date has held at December 1, 2026 without amendment. Enrollment target has stayed flat at 165 patients since the record was created. The trial's protocol-change history shows a single endpoint amendment and no primary-completion-date changes, consistent with a stable registry record. In June 2026, the FDA granted ninerafaxstat Orphan Drug Designation for symptomatic nHCM, a designation tied to unmet need in a rare population rather than a predictor of trial outcome. NCT07023614A Trial to Evaluate the Efficacy and Safety of Ninerafaxstat in Patients With Symptomatic Non-obstructive Hypertrophic CardiomyopathyNCT07023614
This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.