Kailera's HRS9531 Shows Strong Phase II Weight Loss, Pfizer Cautious on Danuglipron

• Kailera Therapeutics' HRS9531, a dual GLP-1/GIP receptor agonist, demonstrated a 21.1% placebo-adjusted weight reduction in Phase II trials over 36 weeks.
• Pfizer CEO Albert Bourla expressed caution regarding their oral obesity candidate, danuglipron, despite plans for late-stage studies of the once-daily formulation.
• Kailera reported that 59% of patients on HRS9531 achieved at least 20% body weight loss, with no plateau observed, suggesting potential for greater efficacy with longer use.
• Pfizer abandoned a twice-daily danuglipron formulation due to toxicities, focusing on a once-daily version, but analysts remain divided on its prospects in the competitive obesity market.

Kailera Therapeutics has announced positive topline Phase II data for HRS9531, a subcutaneous dual agonist of the GLP-1 and GIP receptors, while Pfizer remains cautiously optimistic about its oral obesity candidate, danuglipron. The developments highlight the intensifying competition in the obesity treatment landscape.

Kailera's HRS9531 Demonstrates Significant Weight Loss

Kailera's HRS9531 showed a mean placebo-adjusted weight reduction of 21.1% at 36 weeks in a Phase II trial. The company reported that 59% of patients achieved at least a 20% reduction in body weight, with no plateau observed, suggesting potential for increased efficacy with prolonged use. The dual GLP-1 and GIP receptor mechanism is shared by Eli Lilly's tirzepatide. Kailera CEO Ron Renaud called the findings "compelling," emphasizing the potential impact of HRS9531 on obesity and related conditions. The company is now focusing on building its clinical and manufacturing capabilities to advance HRS9531 into Phase III development.

Pfizer's Danuglipron Strategy

Pfizer CEO Albert Bourla expressed caution regarding the company's plans for danuglipron, an oral GLP-1 receptor agonist. While Pfizer intends to initiate a late-stage study for a once-daily formulation later this year, Bourla acknowledged the need for better decision-making, especially after abandoning a twice-daily formulation due to toxicity issues in Phase IIb trials in December 2023. Analysts are split on Pfizer's strategy, with some questioning whether pursuing danuglipron is the right decision. BMO Capital Markets analysts noted that Pfizer seems "hesitant to expand on danuglipron expectations" following the mid-stage readout. Despite this, Pfizer appears committed to the oral route, with Bourla stating that entering the injectable market might be "a little bit too late."

Competitive Landscape

The obesity market is becoming increasingly competitive, with Novo Nordisk's semaglutide and Eli Lilly's tirzepatide already approved and gaining traction. Danuglipron, designed for oral availability, aims to offer a more convenient treatment option. HRS9531, with its strong Phase II results, poses a potential challenge to existing injectable treatments. The success of these and other emerging therapies will depend on efficacy, safety, and patient convenience.