# Scorpion Therapeutics

Source: https://onco.cc/companies/scorpion-therapeutics/  
OnCo record `scorpion-therapeutics` (Company). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Scorpion Therapeutics was a Boston start-up that designed a cancer pill, STX-478, aimed only at the mutated form of a growth protein called PI3K-alpha, sparing the normal form. Eli Lilly bought the programme in 2025.

## Summary

Scorpion Therapeutics was a Boston precision oncology company founded in 2020 whose lead asset, STX-478, is a mutant-selective, allosteric PI3K-alpha inhibitor intended to avoid the hyperglycaemia and other toxicities of wild-type PI3K-alpha inhibition. In January 2025 Eli Lilly agreed to acquire the STX-478 programme; Lilly's first-quarter 2025 results describe the acquisition as the main driver of a 1.57 billion US dollar acquired in-process research and development charge, and the Scorpion website now redirects to Lilly's announcement. SEC Form D filings show roughly 172 million US dollars sold in 2020 offerings and a further 125.7 million US dollars sold in a 2024 offering before the sale to Lilly.

## Fields

- Kind: Company
- Last checked: 2026-09-10
- HQ: Boston, MA
- Type: biotech
- Website: https://www.scorpiontx.com/

## Notes

- scorpiontx.com redirects to a Lilly investor page that returned HTTP 403, so the acquisition press release itself could not be fetched; the deal is confirmed via Lilly's SEC-filed earnings releases. Headline deal value (reported in press as up to 2.5 billion US dollars) and the reported spin-out of non-PI3K assets were not verified. Series labels for the Form D rounds are not stated in the filings.

## Sources

- Official website: https://www.scorpiontx.com/
- Lilly Q1 2025 results mentioning the acquisition (SEC exhibit): https://www.sec.gov/Archives/edgar/data/59478/000005947825000129/q125lillysalesandearningsp.htm
- Form D (July 2024): https://www.sec.gov/Archives/edgar/data/1811858/000095012324006593/primary_doc.xml

## Connected records

- fronts: [Targeted Therapy](https://onco.cc/fronts/targeted-therapy/)
- technologies: [Small-molecule kinase inhibitors](https://onco.cc/technologies/kinase-inhibitors/)
- targets: [PIK3CA / PI3K-alpha](https://onco.cc/targets/pik3ca/)
- companies: [Casdin Capital](https://onco.cc/companies/casdin-capital/), [Eli Lilly (incl. Loxo)](https://onco.cc/companies/eli-lilly/)

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