In a recent press release, Prilenia Therapeutics and the Huntington’s Study Group (HSG) announced the completion of participant enrollment in PROOF-HD, a global phase III clinical trial of pridopidine’s impact on total functional capacity (TFC) in Huntington’s disease (HD). As HD Buzz reported in June of this year, pridopidine is a highly selective sigma 1 receptor (S1R) agonist. S1R proteins are found in brain regions affected by HD, and help nerve cells survive under stress. Pridopidine targets S1R proteins to help improve the brain’s response to stress brought on by HD.

FDA grants orphan drug status to SOM Biotech for development of SOM 3355 for HD 

Earlier this week, SOM Biotech announced that the U.S. FDA has granted orphan drug designation (ODD) to SOM 3355, a drug currently in clinical development for treatment of chorea in HD. SOM uses AI-based computational technology to identify drugs that have already been developed and researched and repurpose them for treatment of rare diseases. SOM3355—or bevantolol hydrochloride, a drug commonly used to treat hypertension—is a VMAT2 inhibitor that acts similarly to tetrabenazine by interfering with how dopamine messages are passed between neurons, but is reported to have a better side-effect profile than current standards of care. ODD is granted to support the development of drugs for safe and effective treatment of orphan diseases. For updates on the statues of SOM3355 and other drugs in the HD research pipeline, keep your eye on the therapies in the pipeline page on HDSA’s website. 

Dr. Ed Wild talks HD Clarity and the importance of observational research on Help4HD Podcast  

As researchers forge ahead in search of treatments and cures for HD, there is still much to be learned about the biology of the disease. Last week, Dr. Ed Wild, a decorated neurologist and professor, Associate Director of UCL Huntington’s Disease Centre, and founder of HD Buzz, joined Help4HD podcast host Lauren Holder to discuss the importance of observational research studies. After sharing his perspectives of the halt of dosing of tominersen in Roche’s GENERATION-HD1 trial and the value of the data the trial provided despite the emotional toll it placed on the HD community, the focus shifted to where we go from here. While clinical trials provide critical information on whether an interventional strategy for a disease will be successful, they are not the only way to get involved in research. Observational trials, like ENROLL-HD or HD-Clarity, are like the foundation upon which a clinical trial gets built; they improve how we understand the biology of HD, support validation of new biomarkers for the disease, and provide valuable insights that can speed up the clinical trials process. To learn more about Dr. Wild’s perspectives on observational trials and the HD research pipeline, listen to the full podcast episode here. To find observational research sites near you, visit