FDA approval is a major milestone, but for patients with rare diseases, it is only the beginning. In this episode of The CheckRare Brief, we look at two new rare disease approvals, ongoing drug supply problems affecting patients, and a major acquisition that illustrates how rare disease therapies move from small biotech companies into the hands of larger pharmaceutical companies. The US Food and Drug Administration (FDA) granted accelerated approval to Ultragenyx’s Genglycos for the treatment of GSD1a. GSD1a is a rare metabolic disorder, caused by mutations in the G6PC gene, that impairs glucose production. The dietary standard of care, uncooked cornstarch every three to six hours, nocturnal feeds, and strict exclusion of fructose, galactose, and sucrose, has sustained life but cannot correct the underlying enzymatic deficiency and is a major burden on patients and caregivers. However, the gene therapy showed a reduction in cornstarch consumption by 30%. Ultragenyx also received a Priority Review Voucher alongside the drug’s approval. The FDA also approved Pasatru to treat patients with FOP, a disorder in which skeletal muscle and connective tissue are gradually ossified. The approval is based on safety and efficacy data from the phase 3 OPTIMA clinical trial in which Pasatru was found to reduce FOP flare ups by 90%. This marks the second FDA approved treatment for the indication, giving patients and physicians options in their management. Sanofi is currently facing supply chain issues, including in their treatments for Pompe disease and hemophilia. An FDA inspection in January highlighted several quality control concerns at a manufacturing plant in Ireland, and in June the FDA followed up with a letter stating that these concerns had not been addressed. While the plant is still open, they are making significant changes to the site to be compliant. Sanofi is doing its best to get therapies back to patients, but the patients are very frustrated about the lack of transparency and the lack of a back up manufacturing plant. Finally, the pharmaceutical company Biomarin bought Alesta, a small biotech company that is developing a treatment for hypophosphatasia. Hypophosphatasia is a rare metabolic disorder that leads to poor mineralization in teeth and bones. Currently, Stensiz is available as an enzyme replacement therapy but there is always a need for patients to have treatment options. The drug Biomarin just bought, ALE1, is in a phase 1/2 study. Details on the trial are currently unknown, but it would appear the data was compelling enough for Biomarin to buy it. This partnership between small biotech and big pharma is seen often in rare diseases. Small biotechs can be very good at discovering and developing a promising drug, but eventually capital, regulatory expertise, manufacturing, and commercial infrastructure are necessary to get these treatments to patients. References FDA approves Ultragenyx drug for GSD1a https://www.fda.gov/news-events/press-announcements/fda-approves-first-therapy-patients-aged-8-years-and-older-glycogen-storage-disease-type-ia FDA approves Regeneron drug for FOP https://www.globenewswire.com/news-release/2026/08/19/3347919/0/en/pasatru-garetosmab-grts-first-and-only-fda-approved-treatment-demonstrating-reduction-in-new-heterotopic-ossification-ho-lesions-and-clinician-assessed-flare-ups-in-a-placebo-contr.html Sanofi drug supply shortage Sanofi letter to Pompe group FDA letter to Genzyme Ireland Sanofi letter to Hemophilia Foundation Sanofi press release (Aug 17) about shortage - BioMarin buys third rare disease company in a year https://www.prnewswire.com/news-releases/biomarin-to-acquire-alesta-therapeutics-to-gain-ale1-a-potential-first-oral-therapy-for-hypophosphatasia-adding-an-important-clinical-program-to-biomarins-pipeline-302854068.html FDA Extends Review of Capricor’s Deramiocel for DMD https://www.capricor.com/investors/news-events/press-releases/detail/354/capricor-therapeutics-announces-extension-of-pdufa-target Produced by CheckRare. Explore additional CME activities, physician interviews, podcasts, and rare disease resources at CheckRare.com. Subscribe to the CheckRare Podcast Network for the latest rare disease education, expert interviews, and weekly news. Part of the CheckRare Podcast Network: Trusted conversations, news, education, and expert insights across the rare disease community.
