BioAge Labs Halts STRIDES Phase 2 Trial of Azelaprag-Tirzepatide Combo

BioAge Labs, which recently raised upwards of $198 million through an upsized IPO in September 2024 to fund its clinical trials, has announced the discontinuation of its STRIDES Phase 2 trial.

The trial aimed to evaluate azelaprag, an orally available apelin receptor agonist, both as a monotherapy and in combination with tirzepatide for obesity treatment. This follows earlier milestones, including a $170 million fundraising round in February 2024 and promising preclinical data that positioned azelaprag as a potential best-in-class oral obesity therapy.

The decision to halt the trial comes after liver transaminitis—elevated liver enzymes—was observed in some participants receiving azelaprag, though no clinically significant symptoms were reported. No such elevations were noted in the tirzepatide-only treatment group.

Kristen Fortney, CEO and co-founder of BioAge Labs, stated:

“Patient safety is our top priority in the conduct of our clinical studies. We made the difficult decision to discontinue the STRIDES Phase 2 study of azelaprag because it became clear that the emerging safety profile of the current doses tested is not consistent with our goal of a best-in-class oral obesity therapy. While this outcome is a significant disappointment, we remain encouraged by azelaprag’s promising preclinical and Ph1b efficacy profile. We remain committed to our focus on developing therapies for metabolic aging. In parallel to assessing the next steps for the azelaprag program, we will continue to advance our NLRP3 inhibitor program as well as additional research programs with novel mechanisms emerging from our platform.”

The STRIDES trial, designed to enroll 220 participants aged 55 and older, sought to assess the efficacy, safety, and tolerability of azelaprag. Of the 204 participants enrolled, 11 experienced transaminase elevations, prompting the discontinuation of dosing and enrollment. BioAge plans to analyze the trial data and provide updates on azelaprag’s future in Q1 2025.

Meanwhile, BioAge continues to focus on its broader pipeline. The company’s brain-penetrant NLRP3 inhibitor program, targeting neuroinflammation and its links to metabolic and neurodegenerative diseases, is advancing toward an IND submission in the second half of 2025.

Cover image: SteveLuker

Topics: Clinical Trials