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Pfizer said Tuesday that its experimental obesity drug, acquired through Metsera, produced solid weight loss when taken once a month in a mid-term trial.
“The data is very good and we are saying one thing clear: We have a monthly product that has a very competitive profile in terms of safety and effectiveness,” Pfizer CEO Albert Bourla told CNBC on Tuesday.
Obese or overweight patients lost up to 12.3% of their weight compared to placebo at week 28 in the ongoing phase two study. Weight loss due to the injection reached 10.5% when analyzing all patients, regardless of discontinuations.
The company said no plateaus were observed after patients transitioned to monthly dosing, suggesting continued weight loss is expected as the study continues through week 64.
The data offers preliminary evidence that the shot can be administered less frequently than existing drugs without sacrificing effectiveness, which could be a major advantage for Pfizer after facing several setbacks in developing obesity drugs. It is trying to enter a market dominated by Elie Lilly And Novo NordiskNovo’s weekly injections, with an important new addition to the Novo daily pill.
While it’s unclear how much Pfizer could reduce its market share once the vaccine becomes available, monthly dosing could offer a more convenient option for patients.
Pfizer executives told CNBC that patients already using injectable GLP-1 drugs are unlikely to switch to daily oral treatments, arguing that those patients would be more comfortable opting for less frequent injections to maintain their weight loss.
Dr. Jim List, Pfizer’s director of internal medicine, told CNBC that “one week doesn’t work for everyone” because some patients have to travel and can’t keep their shots refrigerated.
The Pfizer shot “is going to help expand the market, democratize weight loss, which is what we need, and give patients a more convenient option for many of them when it comes to maintenance,” List said. But he added that Pfizer’s philosophy is that patients will benefit from several different offerings in the obesity drug market, whether weekly or monthly injections or oral options.
Pfizer plans to advance 10 phase three trials of the shot, called PF’3944, this year. During Pfizer’s earnings conference call later Tuesday, the company’s chief scientific officer, Chris Boshoff, said modeling predicts that a higher monthly dose of the shot that Pfizer plans to use in a late-stage trial could result in a 16% weight loss by week 28.
Bourla told CNBC that the higher dose of the drug will produce efficacy and tolerability data that are “perhaps best in class, so better than anything else.”
Pfizer announced its results on the same day it reported fourth-quarter earnings and revenue that beat expectations. Pfizer shares closed down nearly 3% on Tuesday.
The company’s injection is an ultra-long-acting GLP-1 drug, meaning it is designed to stay active in the body longer than existing treatments like Novo’s Wegovy. Pfizer is developing it as a weekly and monthly injection, as well as in combination with other treatments targeting different gut hormones.
During the trial, patients began receiving weekly injections of the drug for 12 weeks before progressing to once-a-month dosing.
The study was designed to test whether different doses of the drug could help patients continue their weight loss after switching from weekly to monthly injections. She also examined whether higher doses of the drug could be given monthly and still be tolerable for patients.
The drug was generally well tolerated by patients, with most gastrointestinal side effects being mild or moderate. This corresponds to other GLP-1 drugs.
Pfizer said there were no new safety concerns.
The company said it has selected two dosing regimens – low and medium monthly maintenance dose – to test in phase three trials. Among the two dosing regimens in the phase two trial, five patients stopped treatment due to side effects during the weekly phase of the trial, while five more stopped the drug during the monthly phase.
In a separate mid-stage trial last year, Metsera said the highest dose of the shot resulted in weight loss of up to 14.1% on average after 28 weekly doses.
