Why BioAge Labs’ promising obesity drug trial of azelaprag came to an abrupt halt

BioAge Labs, a clinical-stage biopharmaceutical company focused on metabolic disease research, has announced the discontinuation of its STRIDES Phase 2 obesity drug trial. The decision came after a subset of participants receiving azelaprag exhibited liver safety concerns, specifically elevated liver enzymes known as liver transaminitis.

The trial, aimed at assessing azelaprag as a treatment for obesity, was designed to evaluate the drug both as a standalone therapy and in combination with tirzepatide. While the tirzepatide-only group showed no liver safety concerns, 11 patients in the azelaprag treatment arms experienced transaminase elevations.

Liver safety concerns prompt halt in obesity drug trial

The STRIDES Phase 2 study enrolled 204 participants out of a planned 220, targeting individuals aged 55 and older. Its primary goal was to test the efficacy and safety of azelaprag in reducing body weight. However, as CEO Kristen Fortney explained, liver safety concerns meant that continuing the study would conflict with BioAge Labs’ commitment to patient safety.

In a statement, Fortney remarked that while the findings are disappointing, azelaprag’s earlier preclinical and Phase 1b results demonstrated encouraging efficacy. Despite discontinuing the trial, BioAge will continue monitoring patients already enrolled and analyze the available data to guide the program’s next steps. The company plans to update stakeholders on its azelaprag strategy in the first quarter of 2025.

Shifting focus to metabolic disease research

Although the obesity drug trial was halted, BioAge remains focused on its broader pipeline, particularly its metabolic disease research efforts. A key area of focus is its brain-penetrant NLRP3 inhibitors, which target neuroinflammation—a critical factor in both metabolic and neurodegenerative diseases. This program is on track for an Investigational New Drug (IND) application in the second half of 2025.

BioAge’s proprietary platform, built on over 50 years of human aging data, underpins its development strategy. By identifying pathways linked to aging and metabolism, the company has developed promising candidates like azelaprag, which earlier trials suggested could promote metabolism and prevent muscle atrophy.

Impact on the obesity drug landscape

The discontinuation of the STRIDES Phase 2 study highlights the challenges of balancing efficacy and safety in metabolic disease research. Experts believe that while azelaprag’s mechanism of action shows potential, addressing its liver safety concerns is essential for the drug’s future.

BioAge Labs’ decision to shift focus to other therapeutic programs reflects the importance of a diversified pipeline in biopharmaceutical innovation. Fortney stressed that while the trial’s outcome was a setback, BioAge remains committed to its mission of advancing therapies that target the biology of aging.

By maintaining its focus on metabolic disease research and addressing safety challenges, BioAge aims to continue contributing to breakthroughs in aging-related treatments.