- BridgeBio said an experimental muscular dystrophy drug it's developing showed signs of helping patients, reporting Monday that once- or twice-daily oral doses improved mobility and biological markers of disease in a 14-patient trial. No serious side effects were reported, according to the company, and no participants stopped treatment because of side effects.
- The trial didn't compare BridgeBio's drug, called BBP-418, against a placebo, making it harder to determine how patients taking it compare to those whose disease is untreated. BridgeBio said it plans on beginning a Phase 3 clinical trial in the second half of 2022, and will soon begin discussing that study's design with the Food and Drug Administration and other regulators.
- News of trial success was welcome for BridgeBio, which suffered a major late-stage setback in December for another rare disease treatment. Since then, the California-based biotech has sold off one of its two approved drugs and signed over U.S. commercialization rights for its other one.
BridgeBio is one of about six companies aiming to treat limb-girdle muscular dystrophy, a disorder of several subtypes caused by specific genetic mutations. BBP-418 treats a type called 2i that results from a mutation in a gene called FKRP and affects a protein essential for stabilizing muscle cells. Around 7,000 people in the U.S. and European Union are thought to have the condition.
In the Phase 2 trial, treatment with BridgeBio's drug led to slight improvements on a commonly used measure of mobility known as the 10-meter walk test. Participants were able to complete the test by 3% faster after 90 days and, among those who were in the first two dose groups, by 4% after 180 days. Over the six months leading up to enrollment, the walking speed of those same participants had declined.
Trial investigators also found that study enrollees had, on average, a 43% increase in the healthy version of the protein affected by the FKRP mutation, as well as decreased levels of creatine kinase, an enzyme that's associated with muscle breakdown.
The preliminary study data were included in a poster presented at the Muscular Dystrophy Association meeting in Nasvhille.
In addition to the efficacy data, BridgeBio also outlined safety results for its drug. The company said that, among healthy volunteers, BBP-418 was well tolerated at doses higher than the the planned therapeutic dose. Researchers also didn't find any side effects that would require them to lower dose.
BBP-418 wouldn't compete directly with a gene therapy being developed by Sarepta Therapeutics, which already reported data following two years of treatment, nor any of that company's other gene therapies for limb-girdle muscular dystrophy.
BridgeBio's shares rose about 2% in morning trading Monday. However, the company is far from regaining losses after negative data in December for its rare heart disease drug acoramidis, which spurred a 72% one-day plunge in its stock price.