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Pfizer on Tuesday said its experimental obesity drug, which it acquired through Metsera, drove solid weight loss when taken once a month in a mid-stage trial.
“The data are very good, and we are saying one clear thing, that we have a monthly product that has a very competitive profile in tolerability and efficacy,” Pfizer CEO Albert Bourla told CNBC in an interview on Tuesday.
Patients with obesity or who are overweight lost up to 12.3% of their weight compared with placebo at week 28 in the ongoing phase two study. The injection’s weight loss was up to 10.5% when analyzing all patients regardless of discontinuations.
The company said no plateau was observed after patients transitioned to monthly dosing, which suggests that continued weight loss is expected as the study continues through week 64.
The data offer early evidence that the injection can be administered less frequently than existing drugs without sacrificing efficacy, which could be a major boost for Pfizer after it faced several setbacks in developing obesity drugs. It’s trying to enter a market dominated by Eli Lilly and Novo Nordisk‘s weekly injections, with a strong new entrant in Novo’s daily pill.
While it’s unclear how much Pfizer could cut into their market share once the shot is available, monthly dosing could offer a more convenient option for patients.
Pfizer executives told CNBC that patients who are already using injectable GLP-1 drugs are unlikely to switch to daily oral treatments, arguing that those patients would be more comfortable with opting for less frequent injections to maintain weight loss.
Dr. Jim List, Pfizer’s chief internal medicine officer, told CNBC that “weekly doesn’t work for everybody,” since some patients need to travel and can’t keep their injections refrigerated.
Pfizer’s injection is “going to help expand the market, to help democratize weight loss, which is what we need, as well as enable patients to have an option that’s more convenient for a lot of them for maintenance,” List said. But he added that Pfizer’s philosophy is that patients will benefit from having several different offerings in the obesity drug market, whether it’s weekly or monthly injections or oral options.
Pfizer plans to advance 10 phase three trials on the injection, called PF’3944, this year. During Pfizer’s earnings call later Tuesday, the company’s Chief Scientific Officer Chris Boshoff said that modeling predicts that a higher monthly dose of the injection that Pfizer plans to use in late-stage trial could result in 16% weight loss at week 28.
Bourla told CNBC that the higher dose of the drug will produce efficacy and tolerability data that is “maybe best in class, so better than anything else.”
Pfizer announced the results on the same day it posted fourth-quarter earnings and revenue that topped expectations. Shares of Pfizer closed nearly 3% lower on Tuesday.
The company’s injection is an ultra-long-acting GLP-1 drug, meaning it is engineered to remain active in the body for longer than existing treatments like Novo’s Wegovy. Pfizer is developing it as both a weekly and a once-monthly injection, as well as in combination with other treatments that target different gut hormones.
In the trial, patients started on weekly injections of the drug for 12 weeks before switching to once-monthly 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. It also examined whether higher doses of the drug could be given monthly while remaining tolerable for patients.
The drug was generally well tolerated by patients, with most gastrointestinal side effects reported as mild or moderate. That’s consistent with other GLP-1 drugs.
Pfizer said there were no new safety issues.
The company said it had selected two dosing regimens β a low and medium monthly maintenance dose β to be tested in phase three trials. Across the two dosing regimens in the phase two trial, five patients discontinued treatment due to side effects during the weekly phase of the trial, while another five stopped the drug during the monthly phase.Β
In a separate mid-stage trial last year, Metsera said the highest dose of the injection demonstrated weight loss of up to 14.1% on average after 28 weekly doses.
