AstraZeneca buys back its own startup for a new take on weight loss

AstraZeneca acquired SixPeaks Bio, a biotech startup it co-founded in 2024, for $170M upfront, plus up to $130M in future payments, to expand its footprint in the competitive obesity drug market.

Why it matters: Obesity drugs are a booming market—but current leaders like Wegovy and Zepbound cause muscle loss. SixPeaks aims to change that with a therapy that preserves muscle during weight loss, offering a next-gen solution.

Backstory: SixPeaks Bio launched last year with $30M in funding and a “build-to-buy” model developed with Versant Ventures, allowing AstraZeneca to secure a purchase option early. SixPeaks' focus on drugs targeting activin receptors to combat muscle loss during weight loss.

Big picture: Pharma giants are racing to develop obesity drugs beyond current blockbusters like Wegovy and Zepbound. AstraZeneca, which already has a GLP-1 drug and three weight management candidates in Phase 2 trials, now joins peers like Eli Lilly in expanding their pipelines through strategic acquisitions.

Zoom in: FDA is tightening requirements to ensure that muscle-preserving drugs must also show weight loss results, a fact that favors SixPeaks’ approach. Let´s see if their approach fares better than that of Eli Lilly and BioAge Labs, which have both recently faced safety and efficacy hurdles.