FDA Grants Fast Track Designation to HTX-001 for Symptomatic Nonobstructive Hypertrophic Cardiomyopathy

The US Food and Drug Administration (FDA) has granted Fast Track designation to HTX-001, an investigational antisense oligonucleotide, for the treatment of symptomatic nonobstructive hypertrophic cardiomyopathy (nHCM), according to HAYA Therapeutics SA.¹

“Patients with nonobstructive HCM are seeking treatments that go beyond management of symptoms. This designation reflects the urgency of delivering better therapeutic options,” Jordan Shin, MD, PhD, CMO of HAYA Therapeutics, said in a statement. “With our Phase 1 clinical trial already underway, Fast Track designation allows us to work more closely with the FDA as we advance HTX-001, our investigational precision RNA-guided therapy designed to reprogram disease-driving cardiac fibroblasts – the sentinel effector cells which act to drive fibrosis and remodeling in the myocardium.”

FDA Grants Fast Track Status to lncRNA-Targeting Cardiac Therapy

HTX-001 targets WISPER, a heart stress-specific long non-coding RNA (lncRNA) overexpressed in hypertrophic cardiomyopathy, with the goal of reprogramming disease-driving cardiac myofibroblasts toward a healthier phenotype. The designation follows dosing of the first cohort in an ongoing Phase 1a/b trial in May 2026.²

Nonobstructive HCM accounts for an estimated 30% to 60% of all hypertrophic cardiomyopathy cases, yet current therapeutic approaches do not directly target the fibrotic pathology or diastolic dysfunction driving the disease. Existing management remains largely symptomatic, leaving a gap for therapies aimed at the underlying myocardial fibrosis. HTX-001 is designed to address this gap by acting on cardiac fibroblasts, the cells HAYA identifies as central drivers of fibrosis and remodeling in the myocardium.

HTX-001 is a first-in-class ASO engineered to downregulate WISPER, a lncRNA specifically upregulated under cardiac stress and implicated in the fibrotic remodeling seen in HCM. By targeting WISPER in cardiac myofibroblasts, the therapy is intended to shift these disease-driving cells away from a fibrotic, pathological state and toward a healthier phenotype, according to HAYA Therapeutics. This mechanism distinguishes HTX-001 from existing HCM therapies, which primarily manage symptoms such as outflow obstruction or diastolic dysfunction rather than targeting the cellular biology underlying fibrosis.

The therapy is being evaluated in an ongoing Phase 1a/b clinical trial, with the first patient cohort dosed in May 2026, per the company.²

What FDA Fast Track Designation Means for HTX-001

FDA Fast Track designation is intended to expedite the development and review of therapies addressing serious conditions and unmet medical needs.³ The designation may allow more frequent interactions between HAYA Therapeutics and the FDA throughout development and could make HTX-001 eligible for accelerated approval, priority review, and rolling review, according to the company.

Fast Track status does not indicate the FDA has reviewed clinical efficacy or safety data for HTX-001, as the therapy remains in early-phase testing and has not been approved by the FDA or any other regulatory authority. The designation instead reflects the FDA's recognition of the unmet need in nHCM, a population for which no therapies directly target the underlying fibrotic pathology, according to HAYA Therapeutics leadership.

“HAYA was founded on the belief that the regulatory genome offers a new way to address the underlying biology of disease,” said Samir Ounzain, PhD, CEO and co-founder of HAYA Therapeutics. “This regulatory designation recognizes the potential of HTX-001 to offer a differentiated therapeutic approach for patients with nHCM.”

References:

1. HAYA Therapeutics SA. HAYA Therapeutics receives FDA Fast Track designation for HTX-001. Published July 28, 2026. Accessed July 28, 2026. https://www.businesswire.com/news/home/20260728393451/en/HAYA-Therapeutics-Receives-FDA-Fast-Track-Designation-for-HTX-001

2. HAYA Therapeutics SA. HAYA Therapeutics announces first cohort dosed in Phase 1 clinical trial of HTX-001, an investigational precision cellular reprogramming therapy for cardiac fibrosis. Accessed July 28, 2026. https://www.hayatx.com/haya-therapeutics-announces-first-cohort-dosed-in-phase-1-clinical-trial-of-htx-001-an-investigational-precision-cellular-reprogramming-therapy-for-cardiac-fibrosis/

3. US Food and Drug Administration. Fast track. Accessed July 28, 2026. https://www.fda.gov/patients/fast-track-breakthrough-therapy-accelerated-approval-priority-review/fast-track