Boston Pharma highlights fibrosis, MASH reversal with monthly drug

Boston Pharmaceuticals announced promising mid-stage results for its FGF21 analogue, efimosfermin alfa (BOS-580), suggesting its potential to improve liver fibrosis and resolve metabolic dysfunction-associated steatohepatitis (MASH). Notably, the drug offers the advantage of a monthly dosing regimen. The company intends to advance the programme to late-stage trials by 2025.

In the Phase II study, 84 patients with biopsy-confirmed F2 or F3 MASH were randomized to receive either a once-monthly subcutaneous injection of 300 mg efimosfermin or a placebo. After 24 weeks, results from 65 patients showed that nearly half (45.2%) of those treated with efimosfermin experienced an improvement in liver fibrosis by at least one stage without worsening their MASH condition, compared to 20.6% in the placebo group. Additionally, over two-thirds (67.7%) of patients on efimosfermin saw their MASH resolve with no further liver damage, in contrast to 29.4% in the placebo group. When evaluating both fibrosis improvement and MASH resolution, 38.7% of efimosfermin-treated patients achieved these combined goals, more than double the 17.6% observed in the placebo group.

Boston Pharma highlighted that the drug also led to "rapid and significant" improvements in key cardiometabolic markers. Participants exhibited significant reductions in liver fat content, markers of liver injury, and enhancements in glycaemic control. The topline results are scheduled to be presented next week at the American Association for the Study of Liver Diseases (AASLD) annual meeting. "We believe these data, along with upcoming results from our extension study and advanced fibrosis study, will allow us to compile a comprehensive package for discussions with regulatory authorities ahead of our entry into pivotal studies," stated CEO Sophie Kornowski.

Earlier this year, Akero Therapeutics reported that its lead asset, efruxifermin, also designed to mimic FGF21's biological activity, achieved at least a one-stage improvement in fibrosis without worsening MASH in 41% of patients on the 50 mg dose and 39% on the 28 mg dose after 24 weeks. Meanwhile, 89bio's FGF21 analogue, pegozafermin, demonstrated 27% and 26% rates of fibrosis improvement without worsening MASH in its 44 mg every-two-week and 30 mg weekly doses, respectively, in the Phase IIb ENLIVEN trial. The company commenced a Phase III study in May to evaluate pegozafermin in MASH patients with compensated cirrhosis, which could potentially support expedited approval in the US and conditional approval in Europe.