Company Profile · Precision Oncology · Boston, MA
Scorpion Therapeutics
The clinical-stage biotech that set out to "put the sting in cancer" - and sold its lead drug to Eli Lilly for up to $2.5 billion.
The clinical-stage biotech that set out to "put the sting in cancer" - and sold its lead drug to Eli Lilly for up to $2.5 billion.
Most biotechs are born around a single molecule. Scorpion Therapeutics was born around a method. Launched in Boston in October 2020 with a $108 million Series A, the company pitched something it called "Precision Oncology 2.0" - a promise to widen the reach of targeted cancer drugs to the mutations and patient groups that the first generation of precision medicines never managed to serve.
The idea rested on an engine rather than an asset. Scorpion pulled together target discovery, cancer biology, medicinal and computational chemistry, cancer genomics and translational medicine under one roof, then let the drug candidates emerge from that pipeline. The bet was that cancer's hardest targets are not hard because no one has tried, but because the available drugs hit healthy cells as well as diseased ones. Design a molecule that discriminates - that is mutant-selective - and a "difficult" target becomes a tractable one.
By January 2025 that thesis had a price tag. Eli Lilly agreed to acquire Scorpion and its lead program in a deal worth up to $2.5 billion. It is a compressed arc for a drug company: from launch to a multi-billion-dollar exit in a little over four years.
"Scorpion set out to 'put the sting in cancer' - to broaden precision oncology beyond the targets first-generation medicines could reach."
Scorpion designed small-molecule cancer drugs - pills, not biologics - against targets that earlier precision approaches struggled with. Its work centered on two well-known cancer pathways: PI3K-alpha, one of the most frequently mutated genes in cancer, and EGFR, a common driver of non-small cell lung cancer.
The direct beneficiaries were patients: people with hormone-positive breast cancer and EGFR-mutant lung cancer enrolled in its trials. Its commercial counterparts were pharmaceutical partners - Pierre Fabre on the lung-cancer programs, and ultimately Eli Lilly as acquirer.
The problem it targeted is a familiar one in oncology: existing PI3K-alpha inhibitors work, but they also suppress the pathway in healthy tissue, producing side effects severe enough that many patients stop treatment. Scorpion's lead drug, STX-478, was engineered to inhibit the mutant pathway while largely sparing normal cells - the difference between a drug that works on paper and one a patient can actually stay on.
That tolerability angle is exactly what made the lead program attractive to a large pharma buyer.
An oral, once-daily, mutant-selective PI3K-alpha inhibitor in a Phase 1/2 trial for hormone-positive breast cancer and other solid tumors. Designed to spare healthy tissue for better tolerability. This was the program Eli Lilly acquired.
A potentially best-in-class fourth-generation EGFR inhibitor targeting exon 19/21 mutations with the resistance-driving C797S mutation in lung cancer. First patient dosed October 2024; co-developed with Pierre Fabre as PFL-241.
A mutant-selective EGFR inhibitor aimed at EGFR exon 20 insertion non-small cell lung cancer, part of the EGFR franchise licensed to and co-developed with Pierre Fabre Laboratories.
The discovery engine itself: target discovery, cancer biology, computational and medicinal chemistry, genomics and translational medicine integrated to design molecules against hard-to-drug targets.
Scorpion ran the classic venture-backed R&D model: raise equity to fund a platform and pipeline, then monetize through partnerships, milestones and, ultimately, an acquisition. It never sold a product. Its value came from the science - and buyers paid for it.
Bars are scaled for illustration. Series A (2020) investors included Atlas Venture, Omega Funds, Vida Ventures, Abingworth and Partners HealthCare Innovation.
Scorpion competed in a crowded field of precision-oncology developers - Relay Therapeutics, Nuvalent, Blueprint Medicines, Kymera and Loxo@Lilly among them. Its differentiation was less a single molecule than an approach: mutant-selectivity as a design principle, and a platform built to catalog cancer's resistance mechanisms before drawing a chemical structure.
The founding team gave that claim credibility. It included Gary Glick, a serial biotech founder who served as founding CEO; Keith Flaherty of the Mass General Cancer Center and a Loxo Oncology co-founder; Gad Getz of the Broad Institute; and Liron Bar-Peled of Harvard and Mass General.
The company also chose partnership over solo development where it made sense. Rather than carry its EGFR lung-cancer programs alone, it struck a co-development and license deal with France's Pierre Fabre - a way to move drugs toward patients faster than a young company could on its own.
When Lilly bought only the lead PI3K-alpha program, the rest of the pipeline and the team were not wound down. They were spun into a new independent company, Antares Therapeutics, backed by a $177 million Series A and led by former CEO Axel Hoos - with Lilly holding a minority stake.
Founded in Boston by Glick, Flaherty, Getz and Bar-Peled to advance "Precision Oncology 2.0."
A $162 million financing broadened the discovery platform and pipeline ambitions.
Agreed to co-develop and commercialize EGFR inhibitors STX-721 and STX-241 for lung cancer.
Raised $150 million in July; first patient dosed in the STX-241 Phase 1/2 trial in October.
Eli Lilly agreed to acquire Scorpion and STX-478 for up to $2.5 billion; remaining assets became Antares Therapeutics.
"STX-478 was designed to hit the mutant PI3K-alpha pathway in cancer cells - but not healthy ones. That distinction is the whole point."
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It was a Boston-based, clinical-stage precision oncology company that designed mutant-selective small-molecule cancer drugs using an integrated discovery platform it called "Precision Oncology 2.0."
Eli Lilly agreed in January 2025 to acquire Scorpion and its PI3K-alpha inhibitor program (STX-478) in a deal worth up to $2.5 billion.
An oral, once-daily, mutant-selective PI3K-alpha inhibitor developed for hormone-positive breast cancer and other solid tumors, designed to spare healthy cells for better tolerability. It was Scorpion's lead program.
The non-PI3K-alpha pipeline and staff were spun into a new independent company, Antares Therapeutics, backed by a $177 million Series A and led by former CEO Axel Hoos. Its EGFR programs are advanced by partner Pierre Fabre.
More than $440 million in venture funding across three rounds, including a $108 million Series A in 2020 and a $150 million Series C in 2024, before its acquisition.
Profile compiled from public sources including company releases, Fierce Biotech, BioSpace, Crunchbase and Eli Lilly investor materials.