On April 17, Cycle Pharmaceuticals announced it is halting all clinical studies of govorestat. This includes the ongoing Open Label Extension of the INSPIRE Phase III trial for CMT-SORD as well as all Early Access Programs. The company said it is stopping current studies to determine what other data is needed for regulatory approval.
In 2025, the company announced the phase 3 clinical trial in SORD did not meet its primary endpoint, and it was in discussions with the FDA to understand what additional data the agency needed to decide on drug approval.
Cycle Group Holdings bought Applied Therapeutics – the company that first developed govorestat – earlier this year.
What is govorestat?
Govorestat is an “investigational” therapy, which means that it is being tested for safety and efficacy in people. In 2025, it was in development for CMT-SORD, as well as another disease.
CMT-SORD (sorbitol dehydrogenase deficiency) is a subtype of CMT. Mutations in the SORD gene lead to the buildup of a type of sugar called sorbitol. Over time, the sorbitol buildup becomes toxic to peripheral nerves, causing muscle weakness and sensory loss. Govorestat is made to curb this buildup by blocking an enzyme called aldose reductase.
Expanded Access Program discontinued
To focus on redesigning the program for FDA approval, Cycle is ending its Expanded Access Program, or EAP. An EAP is a way for patients to get a drug while it is still being studied, before drug approval.
The company requests trial participants with CMT-SORD, contact the clinician at their trial site to determine next steps for care, which may include clinical monitoring and consideration for future clinical studies.
Stopping therapy
Cycle reports no new safety concerns related to stopping the drug. Govorestat leaves the body over a few days and there is no known physical dependence. In CMT-SORD patients, blood levels of sorbitol may slowly return to where they were before treatment.
The future of govorestat
According to Cycle, it still plans to develop govorestat for CMT-SORD. The company says it is reviewing trial data, talking with the FDA, and deciding what studies or steps are needed to gain approval.
For patients and families
Study pauses, missed goals and regulatory setbacks are common in rare disease drug development. Many drugs that people take today went through several rounds of clinical trials, data review, and talks with regulators before they were approved.
As the leading organization representing people with CMT, CMTA is working directly with Cycle leadership, trial researchers, and CMT-SORD patients to determine the way forward. While much is still unknown, we are committed to identifying the best possible outcome in this situation for people with CMT-SORD and their families.
On April 29, from 1-2 pm EST, CMTA held a virtual meeting for CMT-SORD patients to share the latest updates. CMTA CEO Sue Bruhn and Mike Shy, M.D., principal investigator for the INSPIRE Phase III trials, answered questions and offered insight on Cycle’s decision to end this program.
CMTA will share updates on our website and by email as new information comes in.
Read more about the end of the INSPIRE Phase III trial for CMT-SORD.
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