Pfizer has terminated the development of its oral obesity candidate danuglipron after a patient on a clinical trial with the drug suffered a liver injury.
The oral glucagon-like peptide-1 receptor agonist (GLP-1RA) was being investigated in chronic weight management in several Phase I and Phase II trials.
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Two Phase I studies (NCT06567327 and NCT06568731) met pharmacokinetic (PK) endpoints and determined a formulation and dose for danuglipron. In one of these studies, an asymptomatic patient experienced a potential drug-induced liver injury. The injury resolved after drug discontinuation; however, Pfizer has decided, based on this event, available clinical data, and recent input from regulators to discontinue the development of the drug. The therapy has been investigated in a total of 1,400 patients.
Chief scientific officer and president of R&D at Pfizer, Dr. Chris Boshoff said: “While we are disappointed to discontinue the development of danuglipron, we remain committed to evaluating and advancing promising programs in an effort to bring innovative new medicines to patients.”
Pfizer will be presenting data from the studies at an upcoming medical conference and peer-reviewed journal.
Pfizer still pushing in obesity space
Unlike some of its big pharma competitors, Pfizer has not had much luck in the obesity pill space. In December 2023, the company stopped the development of the twice-daily version of danuglipron due to high rates of gastrointestinal side effects. This came six months after the company had culled another oral GLP-1-RA candidate, lotiglipron, due to associated high transaminase levels.
The company still has another oral obesity candidate in trials, a once daily glucose-dependent insulinotropic polypeptide (GIP) receptor antagonist, PF-07976016. The therapy is being investigated in a Phase IIa trial (NCT06717425), which was initiated in December 2024.
Pfizer faces fierce competition in the obesity space, especially from Novo Nordisk and Eli Lilly, both of which have cemented a reputation with their subcutaneous GLP-1RA therapies Wegovy (semaglutide) and Zepbound (tirzepatide), respectively.
Eli Lilly is also looking to enter the oral obesity space and is running a Phase III programme of its daily pill orforglipron. GlobalData predicts sales of orforglipron to reach $11.8bn in 2030.
GlobalData is the parent company of Clinical Trials Arena.
Biotechs are also making headway in the obesity arena. Viking Therapeutics is studying an oral version of the weight loss therapy VK2735 in an ongoing Phase II study (NCT06828055), and its subcutaneous formulation is set to enter a Phase III trial in Q2 2025.
Pfizer’s stock, listed on the New York Stock Exchange (NYSE), remains stable despite the danuglipron announcement. Meanwhile, Viking’s stock, listed on the Nasdaq exchange, jumped by 21% at market open today (14 April).
