Breaking News

Pfizer to acquire Metsera, developer of obesity drugs

September 22, 2025
Biotech Correspondent

Morning. Today, we read about a big acquisition fueled by obesity, doctors shifting their views on biopharma marketing, see a rare disease drug win approval after a long stretch of uncertainty, and more.

M&A 

Pfizer to acquire Metsera, developer of obesity drugs

Pfizer is paying $47.50 a share in cash for Metsera, a 43% premium on the startup's closing price on Friday that gives the deal an enterprise value of $4.9 billion. The pact also includes a contingent value right worth up to $22.50 a share based on potential clinical and regulatory milestones for Metsera's medicines. 

Pfizer has struggled in the obesity drug race. By acquiring Metsera, the pharma giant gets revamped pipeline of both oral and injectable treatments with different targets that Metsera had picked up through its own licensing and acquisition deals. 

Founded in 2022, New York-based Metsera launched publicly just last year, with $290 million in early financing deals led by ARCH and Population Health Partners. 

Read more from my colleague Andrew Joseph.


Rare Disease

MBX hormone replacement shows efficacy in mid-stage study

A once-weekly drug from MBX Biosciences achieved the primary goal of a mid-stage clinical trial for patients with chronic hypoparathyroidism, a type of hormonal disorder. The results reported this morning, however, were less impressive when compared to the benefits of an approved treatment. 

In the 12-week study, the MBX drug, called canvuparatide, posted a 63% response rate compared to a placebo response of 31%. The treatment effect was statistically significant but narrower than hoped, due partly to a high placebo response rate. 

The outcome may leave investors questioning the potential benefit of canvuparatide relative to Yorvipath, a competing medicine from Ascendis Pharma approved last year.

But MBX shares doubled in pre-market trading, likely due to the company's relatively low enterprise value of around $100 million heading into Monday's study readout. Ascendis is worth $10 billion.

Read more from my colleague Adam Feuerstein. 


rare disease

FDA grants approval to ultra-rare disease drug

After months of back-and-forth with regulators, the Food and Drug Administration has granted accelerated approval to the first treatment for Barth syndrome, an ultra-rare mitochondrial disorder that affects just 150 people in the U.S. The decision follows years of fraught debate over trial design with the maker of the drug, Stealth BioTherapeutics, FDA divisions over data standards, and a looming threat that the company would collapse before a verdict, STAT's Ed Silverman writes.

The medicine, to be marketed as Forzinity, was approved based on gains in muscle strength and comes with the usual condition: Stealth must verify clinical benefit in confirmatory trials.

Patient advocates, who had campaigned fiercely as the company warned it might end its expanded access program, hailed the move as a lifeline — though they stressed the urgency of expanding eligibility to the youngest patients, many of whom may not reach the 66-pound weight cutoff in time.

Read more.


marketing

Doctors are more tied to pharma as trust erodes

A decade-long follow-up survey of nearly 300 physicians finds their views on pharmaceutical marketing have shifted in complicated ways: More are strongly convinced that meetings with sales reps undermine public trust in medicine. That said, doctors are increasingly comfortable accepting small gifts or paid speaking gigs, STAT's Ed Silverman writes.

The findings, published in JAMA Health Forum, show that doctors do say they find industry reps a valuable source of education on new treatments, even as they note that the practice likely leads to unnecessary prescribing. The findings land as the FDA cracks down on direct-to-consumer ads — a move cheered by critics like HHS Secretary Robert F. Kennedy Jr. — and as the $35 billion spent yearly by pharma on is increasingly scrutinized.

Read more.



vaccines

RFK Jr.'s ACIP advisers begin altering childhood vaccine guidance

A newly reconstituted vaccine advisory panel under HHS Secretary Robert F. Kennedy Jr. veered from the CDC's data-driven approach at its inaugural meeting late last week, STAT reports. Members questioned safety and effectiveness evidence, revived long-settled vaccine policy debates, and voted to restrict the use of the MMRV shot to children over 4. 

The members even flirted with delaying the hepatitis B birth dose, though that move was tabled after many hours of heated discussion. The proceedings alarmed medical groups like the AMA, which warned of "erosion of the committee's integrity," while outside experts cautioned that Kennedy's handpicked panel risks undermining confidence in decades of immunization policy at a moment of already fragile public trust.

Read more.


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More reads

  • Winner of mRNA Nobel Prize says ACIP member's claim that Covid vaccines persist is 'absolutely impossible,' STAT
  • Japan biotech inks research pact in effort to develop new RNA meds, FierceBiotech

Thanks for reading! Until tomorrow,


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