Pfizer rocked by failure of weight-loss pill set to compete with lucrative rivals Ozempic and Mounjaro

More than half of patients in a mid-stage study had to stop taking twice-daily danuglipron due to nausea and vomiting, according to a statement Friday. The shares fell 3.9% in trading before US markets opened. 

Weight-loss shots made by Eli Lilly & Co. and rival Novo Nordisk A/S are a gold mine that’s propelled them to dizzying valuations and lured other drugmakers into the field. Pfizer and UK drugmaker AstraZeneca Plc see pills as a way to make inroads into a market projected to reach $100 billion within seven years.

Patients in the trial lost up to 13% of their body weight in 32 weeks. Analysts were looking for body-weight reduction in at least a mid-teens percentage for the drug to compete with Lilly’s experimental weight-loss pill, which helped patients with diabetes and obesity lose almost 15% in 36 weeks.

“The data highlights the very competitive nature of the obesity category,” with Lilly and Novo way ahead, Mizuho analyst Jared Holz said in a note. Pfizer’s pill “does not appear too competitive with the leading drugs,” he said. 

Path forward

While the most common adverse events in the study were mild, nausea was seen in up to 73% of patients, vomiting in up to 47% and diarrhea in up to 25%. Pfizer said it will continue developing a once-daily version of the pill that may improve be more tolerable. More data from that version is expected in the first half of next year. 

The outcome of those studies will “inform a path forward,” Pfizer said.

The drugmaker is looking for new products to make up for the huge gap left by the fading pandemic. Pfizer slashed its annual sales forecast range by $9 billion on Oct. 13, citing falling sales of Covid-19 shots and the company’s Paxlovid pill.

Pfizer has said that oral weight-loss drugs will capture a third of the obesity market. The company had pinned its weight-loss hopes on danuglipron after discontinuing another experimental obesity drug in June due to safety concerns.

The study enrolled 630 patients with obesity across the US, Canada, Japan and Taiwan, who received the experimental drug for as long as 10 months.