AstraZeneca has completed its acquisition of SixPeaks Bio, an obesity drug startup focused on developing treatments that preserve muscle mass during weight loss, for a total deal value of up to $300 million. The British pharmaceutical giant exercised its option to acquire the remaining shares of SixPeaks on October 22, paying $170 million upfront for the shares it didn't already own.
The deal structure includes an additional $30 million payment in two years and potential milestone payments of up to $100 million based on achieving certain regulatory milestones, according to AstraZeneca's third-quarter earnings report released Wednesday.
Targeting Muscle Preservation in Obesity Treatment
SixPeaks Bio is advancing a bispecific antibody that targets both activin type IIA and IIB receptors, an approach designed to improve the quality of weight loss by helping patients reduce fat while maintaining muscle mass. This addresses a significant limitation of current obesity medications like Wegovy and Zepbound, which can lead to muscle loss alongside fat reduction.
"The SixPeaks acquisition is part of" AstraZeneca's overall obesity strategy, CEO Pascal Soriot explained during a media call Thursday. "It's really looking for new mechanisms that will help patients lose fat but not so much muscle."
The acquisition represents the culmination of a "build-to-buy" strategy initiated by Versant Ventures, which launched SixPeaks in 2024 with $30 million in funding and a collaboration agreement that gave AstraZeneca the option to acquire the company at a predetermined price.
Medical Focus Over Aesthetic Approach
AstraZeneca is positioning itself in the competitive obesity market by emphasizing medical outcomes rather than cosmetic weight loss. Soriot articulated this philosophy during the earnings call, stating his personal discomfort with focusing purely on aesthetic aspects of obesity treatment.
"What is really fundamental is the so-called visceral fat," Soriot explained, referring to fat that accumulates around internal organs including the liver and heart. "This is what we need to drive down."
The company views muscle preservation as "a fundamental aspect of keeping people healthy," according to Soriot, who emphasized that AstraZeneca's approach focuses "not the aesthetic aspect" but "really the medical aspect" of obesity treatment.
Expanding Obesity Pipeline
The SixPeaks acquisition adds to AstraZeneca's growing obesity portfolio, which includes three drugs currently in Phase 2 testing for obesity and weight management. The company has been building its presence in this space through strategic partnerships, including a November 2023 deal with China-based Eccogene for oral GLP-1 therapy ECC5004, valued at $185 million upfront plus up to $1.83 billion in milestone payments.
AstraZeneca already has experience in the incretin drug class through its GLP-1 medicine Bydureon, and has identified obesity as a key area for expansion. The company has also established partnerships with Regeneron Pharmaceuticals as part of its obesity strategy.
Alex Mayweg, a managing director at Versant who chaired SixPeaks' board, noted at the startup's launch that AstraZeneca's "drive, interest, capability and motivation to win in this race was extremely strong."
Strong Financial Performance
The acquisition comes as AstraZeneca reported robust third-quarter results, with product revenue reaching nearly $15.2 billion, representing a 10% year-on-year increase at constant exchange rates and exceeding analyst estimates by approximately 2%. The company's oncology franchise remained its strongest performer, contributing more than $6.6 billion to quarterly revenue with 18% growth.
AstraZeneca maintained its full-year guidance, expecting revenue growth in the high-single digit percentage range and core earnings-per-share increases in the low double-digit percentage range.
