Retro Biosciences raises at $1.8B as Alzheimer's trial advances
Altman-backed longevity firm marks down from a mooted $5B but its first pill clears early safety; data due ~August
Summary
Retro Biosciences, the cellular-rejuvenation company backed by OpenAI CEO Sam Altman, announced on 22 May 2026 a funding round valuing it at $1.8B, a markdown from the ~$5B figure floated in late 2025. Its first clinical trial, a pill designed to help clear protein aggregates in Alzheimer's patients, has shown no dose-limiting toxicities; CEO Joe Betts-LaCroix said data should come around August. Retro pursues a mix of in-vivo gene therapies, cell-replacement and aggregate-clearance approaches toward a goal of adding 10 healthy years to human lifespan. Altman's ~$180M investment carried a ~$258M stake value in May 2026 court filings. Retro competes with Altos Labs in longevity biology.
By the numbers
- $1.8B, new valuation (down from a ~$5B figure floated late 2025).
- ~$180M, Sam Altman's cumulative investment; ~$258M stake value (May 2026 filings).
- ~August 2026, expected first Alzheimer's trial data.
- 10 years, healthy-lifespan extension target.
- 0, dose-limiting toxicities reported so far.
Why it matters
Retro's markdown is a barometer for the longevity sector after 2025's hype: capital is still flowing but at sober prices. A clinical Alzheimer's signal from an aging-focused firm would be the field's first real human-efficacy data point, and would reset valuations again, up or down.
What to watch
- The ~August Alzheimer's trial readout.
- Whether the markdown spreads to peers (Altos, NewLimit) or stays Retro-specific.
- Progress of Retro's in-vivo gene-therapy and cell-replacement programs.