Boston Pharmaceuticals Announces Positive Phase 2a Results from Monthly and Bi-weekly Dosing with Investigational BOS-580 NASH Program at EASL 2023

– Low discontinuation rate due to treatment emergent adverse events was observed in the study

–Twelve-week monthly and bi-weekly treatment with BOS-580 resulted in statistically significant reductions in liver fat content and biomarkers of liver injury and fibrosis

CAMBRIDGE, Mass.–(BUSINESS WIRE)–Boston Pharmaceuticals today announced positive Phase 2a results for BOS-580, its investigational, proprietary, long-acting fibroblast growth factor 21 (FGF21) analog for the treatment of non-alcoholic steatohepatitis (NASH). The study suggested promising results for monthly and bi-weekly doses of BOS-580, which achieved statistically significant reduction in liver fat content, an exploratory endpoint in the trial of phenotypic NASH patients. Statistically significant reductions in additional exploratory endpoints, including biomarkers of liver injury and fibrosis, were also observed. In the trial, a low discontinuation rate due to treatment-emergent adverse events was observed. The most common adverse events in patients treated with BOS-580 were gastrointestinal in nature, mild to moderate, and transient. These and other results from the study were presented in a late-breaking poster at the European Association for the Study of the Liver (EASL 2023) International Liver Congress in Vienna, Austria.

“Today’s findings strengthen our belief that BOS-580 has the potential to play an important role as a once monthly treatment available to physicians who treat patients suffering from NASH. We are looking forward to further accelerate the development of our molecule towards pivotal trials and ultimately registration,” said Sophie Kornowski, PharmD, CEO of Boston Pharmaceuticals.

BOS-580 is a genetically engineered variant of FGF21 with an extended half-life enabling the potential for once-monthly dosing.

“The need for safe and effective treatment options for NASH continues to be acute and may be heightened as its prevalence is expected to increase by 63% in the United States alone by 2030,” said Rohit Loomba, MD, MHSc, chief of the Division of Gastroenterology and Hepatology at University of California San Diego School of Medicine. “There is a growing body of evidence demonstrating that FGF21 analogs can potentially increase NASH resolution and improve fibrosis.”

Key Study Findings

The Phase 2a study was designed to evaluate the safety, tolerability and dose-response relationship of BOS-580 in phenotypic NASH patients. Participants (n=102) were randomized to receive once-monthly or bi-weekly subcutaneous doses of BOS-580 or placebo over 12 weeks, at 75mg, 150mg, or 300mg. Within each cohort, patients were randomized 4:1 (BOS-580 vs. placebo) to identify dose levels and regimens for further development.

Monthly and bi-weekly subcutaneous treatment with BOS-580 resulted in a statistically significant reduction from baseline of liver fat content and markers of liver injury and fibrosis, which were exploratory endpoints in the Phase 2a trial:

• ≥70% of patients treated with a ≥150mg total monthly dose of BOS-580 showed a reduction in liver fat by ≥50%, compared to only 3% of placebo-treated patients.
• Patients treated with a 300mg total monthly dose of BOS-580 had a ≥45% reduction in alanine transaminase from baseline; similar reductions in aspartate aminotransferase were observed.
• The soluble marker of fibrosis PRO-C3 was decreased by approximately 30% in patients treated with 300mg total monthly dose of BOS-580, compared to a 5% reduction among placebo-treated patients.
• Suggestions of improvement in metabolic health was manifested by reductions in serum triglycerides.

Low discontinuation rate due to treatment emergent adverse events (4.6% in treated patients vs. 5.4% in the placebo group) was observed in the study. The most common adverse events in this Phase 2a trial were gastrointestinal, and included nausea, vomiting, and diarrhea.

About BOS-580

BOS-580 is an investigational, genetically engineered analog of human FGF21, stabilized through novel disulfide bonds, uniquely manufactured from a CHO cell line resulting in an extended half-life. BOS-580, in clinical development for the treatment of non-alcoholic steatohepatitis, has the potential to regulate various metabolic pathways to decrease liver fat and ameliorate liver inflammation and injury.

About Boston Pharmaceuticals

Boston Pharmaceuticals is a clinical stage biopharmaceutical company that leverages an experienced drug development team to advance a portfolio of highly differentiated therapies that may address important unmet medical needs in serious liver diseases, with NASH as the focus of its lead asset. The Company acquired promising drug development candidates through partnerships with proven innovative biotechnology and pharmaceutical companies. Boston Pharmaceuticals applies rigorous decision making to advance programs to deliver differentiated medicines to patients in need of new options, while creating value for all parties involved in the journey. For more information, please visit www.bostonpharmaceuticals.com or follow on Twitter @BosPharma and LinkedIn.

About B-Flexion

Boston Pharmaceuticals is a portfolio company of B-Flexion, a private entrepreneurial investment firm that partners with sophisticated capital to deliver exceptional value over the generations, while also contributing positively to society. Chaired by Ernesto Bertarelli and with offices across Europe and the United States, B-Flexion seeds, acquires and builds investment partnerships, principally in the fields of Private Equity, Venture & Growth Capital, Real Assets, Hedge Funds, Credit, and Public Securities. As well as these partnerships, B-Flexion makes principal investments in operating businesses in transformative industries with a focus on Healthcare, Planet, Consumer and Technology.

For more information, please visit www.bflexion.com.

Contacts

Amelia Marosek

[email protected]