Resalis Therapeutics has dosed the first participant in a Phase 1b clinical trial evaluating its lead candidate, RES-010, an investigational RNA-based therapy for overweight and obesity.

The study will assess the safety, tolerability, pharmacokinetics and pharmacodynamic effects of RES-010 over 12 weeks of treatment, while also investigating its impact on body weight and metabolic biomarkers.

RES-010 is an antisense oligonucleotide designed to inhibit microRNA-22 (miR-22), a regulator of metabolic dysfunction associated with obesity. The company is developing the therapy to investigate whether targeting the pathway can support fat-selective weight loss while preserving lean body mass.

The randomised, placebo-controlled multiple ascending dose study is expected to enrol up to 36 healthy overweight and moderately obese adults at a single clinical site in Australia. Participants will receive once-weekly subcutaneous injections for 12 weeks, with an optional safety follow-up period of up to six months.

Primary endpoints include safety, tolerability and pharmacokinetics. The study will also evaluate changes in body weight, pharmacodynamic markers, lipid metabolism and inflammatory biomarkers to better understand the therapy’s effects on metabolic health.

Topline data are expected later in 2026.

The Phase 1b study follows a first-in-human trial in which RES-010 was reported to be well tolerated. According to the company, the earlier study also demonstrated dose-dependent target engagement and reductions in body weight, supporting further clinical evaluation over a longer treatment period.

Almut Nitsche, chief medical and development officer of Resalis Therapeutics, said: “Data from the first-in-human study show that RES-010 was well tolerated and delivers early pharmacodynamic activity, with dose-dependent target engagement and reductions in body weight. These results provide a strong rationale for further evaluating the RES-010 profile over extended treatment durations.”

The obesity treatment landscape has evolved rapidly with the introduction of GLP-1 receptor agonists and related therapies. However, researchers continue to explore alternative approaches that target the biological mechanisms underlying metabolic dysfunction, with the aim of improving long-term outcomes and preserving lean body mass during weight loss.

Resalis believes inhibition of miR-22 may offer a differentiated approach by targeting metabolic pathways associated with obesity rather than appetite regulation alone.

Alessandro Toniolo, chief executive officer of Resalis Therapeutics, added: “The future of obesity treatment lies not only in reducing weight, but in restoring a healthier metabolic balance to achieve more durable outcomes for patients.”

If successful, RES-010 could add to a growing pipeline of RNA-based medicines being investigated for metabolic disorders. The study is expected to provide early insights into the therapy’s safety profile and biological activity before progression into later-stage clinical development.