GV101 Gains FDA Fast Track Status for Friedreich Ataxia Ahead of Phase 2 Trial

The FDA has granted fast track designation to GV101, an investigational oral, selective Rho-associated coiled-coil containing protein kinase 2 (ROCK2) inhibitor from Graviton BioScience, for the treatment of Friedreich ataxia (FA).¹ The designation follows FDA clearance of the company’s investigational new drug application for the agent in FA. Graviton announced that it plans to launch a phase 2 study, with US enrollment expected to begin in the fourth quarter of 2026.

"Receiving Fast Track Designation from the FDA is an important milestone for GV101 and underscores the significant unmet need for therapies that address the underlying biology of Friedreich's ataxia," Samuel Waksal, PhD, founder and chief executive officer at Graviton BioScience, said in a statement.¹

"We believe GV101 has the potential to provide a differentiated treatment approach by increasing frataxin, the protein that is deficient in individuals living with Friedreich's ataxia,” Waksal added in a statement.¹ “Together with our recent IND clearance, Fast Track Designation provides important momentum as we move forward with preparations for our Phase 2 study and work closely with the FDA to efficiently advance the development of GV101 for patients”

Phase 2 Development and Safety

The phase 2a trial is a dose-ranging, randomized, double-blind, placebo-controlled study with an open-label extension evaluating the safety, pharmacodynamics, and efficacy of GV101.² Participants will be sequentially randomized 3:1 to GV101 or matching placebo once daily for 12 weeks in 3 parallel dose groups (200, 300, and 400 mg), following a loading-dose period of up to 2 weeks, with a target of 16 participants per group.

READ MORE: FDA Investigates Confirmed Insertional Oncogenesis With Spinal Muscular Atrophy Gene Therapy

Patients currently receiving omaveloxolone (Skyclarys; Biogen), the only FDA-approved therapy for FA, are excluded. Global sites are expected to follow US enrollment. Graviton described GV101’s safety and tolerability profile as favorable, reporting exposure in more than 500 clinical study participants for periods of up to 24 weeks, with extension studies exceeding 1 year.

Biological Rationale and Clinical Context

FA is an autosomal recessive neurodegenerative disease caused by GAA trinucleotide repeat expansions in FXN that reduce production of frataxin, a mitochondrial protein essential for cellular energy production. It affects approximately 5000 patients in the US, typically begins in childhood or adolescence, and causes progressive ataxia, dysarthria, dysphagia, and loss of ambulation. Cardiac complications, including hypertrophic cardiomyopathy, account for more than half of FA-related deaths.

Omaveloxolone, an Nrf2 activator, remains the only FDA-approved FA therapy, indicated for patients aged 16 years and older. In the 48-week, placebo-controlled MOXIe part 2 trial, omaveloxolone 150 mg daily reduced modified Friedreich Ataxia Rating Scale scores by 2.41 points vs placebo.³ Omaveloxolone does not directly restore frataxin; GV101 instead aims to upregulate endogenous frataxin expression.

GV101 Mechanism and Development History

ROCK2 regulates pathways involved in inflammation, fibrosis, metabolism, and gene expression. Graviton reports that selective ROCK2 inhibition increases frataxin transcription and translation and that GV101 raised FXN messenger RNA and frataxin protein in preclinical studies.¹

GV101, formally known as TDI01, was previously studied in an open-label phase 1b/2 trial (NCT06169722) of 60 patients with pretreated moderate to severe chronic graft-vs-host disease. The 24-week best overall response rate was 86.2% (95% CI, 68.3%-96.1%) at 400 mg and 67.9% (95% CI, 47.6%-84.1%) at 200 mg.⁴ The only grade 3 or higher adverse event in at least 5% of participants was bilirubin elevation without transaminase elevation, which Graviton attributed to reversible UGT1A1 and OATP1B3 inhibition.

Click here to view more of our FDA coverage.

REFERENCES
1. Graviton BioScience. Graviton BioScience announces FDA fast track designation for GV101 for the treatment of Friedreich’s ataxia. PR Newswire. Published November 3, 2026. November 11, 2026. https://www.prnewswire.com/news-releases/graviton-bioscience-announces-fda-fast-track-designation-for-gv101-for-the-treatment-of-friedreichs-ataxia-302926880.html
2. GV101 for Friedreich’s Ataxia (FA) Treatment. ClinicalTrials.gov identifier: NCT07870590. Accessed November 11, 2026. https://clinicaltrials.gov/study/NCT07870590
3. Lynch DR, Chin MP, Delatycki MB, et al. Safety and Efficacy of Omaveloxolone in Friedreich Ataxia (MOXIe Study). Ann Neurol. 2021;89(2):212-225. doi:10.1002/ana.25934
4. Mo X, Zhang X, Guo R, et al. Novel highly selective ROCK2 inhibitor (TDI01) for the treatment of chronic graft-versus-host disease: a multicenter, open-label phase Ib/II study. Signal Transduct Target Ther. 2026;11(1):313. Published 2026 Aug 6. doi:10.1038/s41392-026-02889-w