A South Korean pharmaceutical company has secured one of the largest licensing deals in the booming obesity treatment market, partnering with biotech giant Genentech to develop a drug that could reshape how doctors approach weight loss.

Hanmi Pharmaceutical announced Monday that Genentech, a member of the Roche Group, will pay $190 million upfront for worldwide rights to HM17321, an experimental therapy designed to help patients lose fat while preserving muscle mass. The total value of the agreement could reach $2.3 billion when development milestones, regulatory approvals, and sales-based royalties are included.

The deal reflects pharmaceutical companies' intense focus on next-generation obesity treatments as they race to improve upon blockbuster drugs like Ozempic and Wegovy. While those medications have transformed weight management, they carry a significant drawback: patients typically lose both fat and lean muscle mass during treatment, which can affect metabolism and physical function.

A Different Approach to Weight Loss

HM17321 works through what researchers call a "non-incretin mechanism," setting it apart from the GLP-1 receptor agonists that currently dominate the obesity market. The drug is a synthetic version of urocortin-2, a naturally occurring peptide that regulates metabolism and energy balance.

In preclinical studies, the compound demonstrated what Hanmi describes as "quantitative and qualitative improvements" in weight reduction compared to existing therapies. More importantly, it appeared to selectively target fat tissue while maintaining or even building muscle mass.

"The paradigm of obesity treatment is evolving beyond simple weight reduction toward improving body composition and restoring metabolic health," said In-Young Choi, senior executive vice president of Hanmi's research and development division. "We are very pleased that the differentiated scientific mechanism and development potential of HM17321 have been recognized by the global market."

The therapy's unique mechanism could make it valuable both as a standalone treatment and in combination with GLP-1 drugs, according to company statements. Hanmi has suggested the peptide-based drug might eventually be developed as a fixed-dose combination product alongside incretin therapies.

Early Stage Development With Global Ambitions

HM17321 remains in the earliest stages of human testing. The U.S. Food and Drug Administration granted investigational new drug clearance last November, allowing Hanmi to begin a Phase 1 clinical trial evaluating safety, tolerability, and how the body processes the drug in healthy volunteers and people with obesity.

Under the licensing agreement, Hanmi will complete this initial study before handing development responsibilities to Genentech, which will conduct the larger Phase 2 and Phase 3 trials needed for regulatory approval. The deal covers all territories except South Korea, where Hanmi retains commercial rights.

Boris L. Zaïtra, head of corporate business development at Roche, framed the acquisition as part of a broader strategy to address obesity and related metabolic conditions through multiple therapeutic approaches. "By licensing this next-generation investigational therapy with first-in-class potential from Hanmi, Roche and Genentech will pursue a differentiated approach to selectively reduce fat mass while improving both muscle mass and muscle function," he said in a statement.

The Muscle Mass Problem

The muscle preservation aspect of HM17321 addresses what has emerged as a significant concern among physicians prescribing current obesity medications. Studies have shown that patients on GLP-1 drugs typically lose 25-40% of their total weight reduction from lean tissue rather than fat.

This matters because muscle mass plays crucial roles beyond physical strength. Skeletal muscle helps regulate blood sugar, supports metabolic health, and protects against age-related decline. Losing significant muscle during weight loss can make it harder to maintain that weight loss long-term and may increase health risks, particularly in older adults.

The issue has prompted researchers to emphasize the importance of resistance training and adequate protein intake for patients taking weight-loss medications, but a pharmaceutical solution that addresses the problem directly would represent a significant advance.

Joining a Crowded Field

The deal positions Hanmi and Genentech in an increasingly competitive landscape. Pharmaceutical companies worldwide are investing billions in obesity research, seeking to capture a share of what analysts project could become a $100 billion annual market within the next decade.

Beyond improved versions of GLP-1 drugs, companies are exploring combinations of multiple hormone pathways, oral formulations that would eliminate weekly injections, and therapies targeting different aspects of metabolism and appetite regulation.

For Hanmi, a mid-sized Korean pharmaceutical company, the Genentech partnership represents validation of its research capabilities and a potential financial windfall that could fund further drug development. The $190 million upfront payment alone exceeds the company's total research and development budget in recent years.

Whether HM17321 will ultimately prove safe and effective in humans remains to be seen. The drug must still navigate years of clinical trials before reaching patients. But in a field where the standard of care has shifted dramatically in just a few years, pharmaceutical companies are betting that the next breakthrough in obesity treatment may be just around the corner.