Hanmi Pharm's obesity drug candidate aims to overcome GLP-1 muscle loss limitation

Hanmi Pharm said Wednesday that it showcased preclinical research on its novel obesity treatment, HM17321, at the Obesity Society’s ObesityWeek conference, highlighting its potential to simultaneously promote weight loss and muscle gain.

The drug, which the company claimed could be a “game changer,” is designed to simultaneously reduce fat and increase muscle mass, addressing a key limitation of existing glucagon-like peptide-1 (GLP-1) based obesity treatments, which often result in muscle loss.

Choi In-young, head of Hanmi’s R&D Center, presented the drug as an innovative obesity solution developed using advanced AI and structural modeling technologies. HM17321, she explained, “selectively targets fat while boosting muscle mass, offering a new treatment paradigm.” 

When used in combination with current therapies, it also demonstrates superior weight loss in both quantity and quality, he added. He also noted that, being peptide-based, HM17321 is expected to be “more cost-effective than antibody-based muscle-preserving therapies.”

During the conference, which was held in San Antonio, Texas, from Sunday to Wednesday, Hanmi Pharm presented two preclinical studies that demonstrated HM17321’s ability to provide effective weight loss while preserving muscle mass, a feature not seen in traditional GLP-1 drugs.

Unlike GLP-1 treatments, which target incretin receptors, HM17321 works by targeting the CRF2 (corticotropin-releasing factor 2) receptor.

While GLP-1-based obesity drugs are effective in promoting weight loss, with up to 40 percent of the lost weight being muscle, they often cause side effects such as reduced basal metabolic rate and fat regain once treatment is stopped. In contrast, Hanmi’s studies showed that HM17321 achieved weight loss similar to the GLP-1 drug semaglutide but also increased lean mass, including muscle, without the associated muscle loss.

In one animal study, HM17321 restored muscle function to levels seen in healthy animals, as measured by a wire-hanging test. The treatment also promoted lipolysis and normalized fat cell phenotypes in obesity models.

In another presentation, Hanmi Pharm presented results showing that HM17321, when combined with the company’s next-generation triple therapy (LA-GLP/GIP/GCG, code name: HM15275) and semaglutide, resulted in significant reductions in weight and fat mass compared to their respective monotherapies. The combination therapy also preserved lean mass, a common issue with many weight-loss treatments.

A Hanmi official emphasized the potential of HM17321 to become a “first-in-class” drug by specifically targeting fat, increasing muscle mass, and improving muscle function. 

In addition, Hanmi presented a preclinical study of HM15275, which was first revealed at the American Diabetes Association (ADA) conference in June. HM15275 is a triple-action obesity treatment expected to achieve more than 25 percent weight loss while minimizing muscle loss. 

The Hanmi official added that HM15275 improves metabolic phenotypes and enhances energy metabolism through dietary regulation and its optimized triple-action mechanism. The treatment is progressing through phase 1 clinical trials in the U.S., with plans for phase 2 trials in 2025.