BridgeBio Pharma anticipates it could seek accelerated approval for an experimental muscular dystrophy drug it’s developing, outlining in a statement Monday a path to U.S. regulators in the coming years.
An affiliate of BridgeBio, ML Bio Solutions, is currently enrolling patients with the disease limb-girdle muscular dystrophy into a Phase 3 clinical trial of the drug. According to BridgeBio, the Food and Drug Administration is open to assessing the treatment on the basis of biomarker data that could become available late next year or early in 2025.
In the case of BridgeBio’s treatment, that data would involve measuring levels of a shock-absorbing protein, which, when dysfunctional, leads to the progressive leg and arm weakness that’s seen with limb-girdle muscular dystrophy.
ML Bio Solutions plans to assess levels of this protein, alpha-dystroglycan or αDG, when it’s in a specific “glyosylated” state that’s important to how the disease unfolds. This interim analysis will occur one year into the trial, which will also test the drug’s effect on patients’ function after three years.
“The meeting with the U.S. FDA was both positive and productive in discussing the potential use of glycosylated αDG levels as a surrogate endpoint in our clinical trial,” said Douglas Sproule, ML Bio’s chief medical officer, in BridgeBio’s statement.
The discussions between BridgeBio, ML Bio and the FDA are another example of the balance being struck between regulators and industry over how to speed to market new treatments for deadly diseases, while ensuring they’re still properly vetted for safety and efficacy. Accelerated approval has proven an important tool, but has also attracted criticism from some who feel the balance has swung to far in favor of drugmakers.
The FDA uses accelerated approval most often to clear new medicines for cancer, but has also applied it to therapies for Alzheimer’s, ALS and, most recently, a gene therapy for a different kind of muscular dystrophy.
BridgeBio and ML’s treatment, known as BBP-418, is an oral drug that supplies a “substrate” to boost the activity of an enzyme involved in glycosylating, or adding a carbohydrate to, αDG.
Results from a small Phase 2 study last year showed signs the treatment might help people with a certain form of limb-girdle muscular dystrophy called Type 2I, for which there are no approved medicines in the U.S.
The first patient has already been dosed in the Phase 3 trial testing BBP-418, and BridgeBio is continuing to open new sites in the U.S., Europe and Australia.
The company recently got a boost from positive data in a Phase 3 trial of another of its rare disease drugs, called acoramidis. Its shares have more than doubled since, and traded at over $35 apiece on Monday.