KymaThera raises $80M Series B to move cancer drug into the clinic
What's the deal? KymaTheraDealroom has a profile for this one. Try Dealroom →, a San Diego biotech developing precision medicines for genetically defined diseases, has closed an $80 million Series B. Alta PartnersDealroom has a profile for this one. Try Dealroom → led the round, with participation from Series A co-leads Venrock and Foresite Capital, new investor J. Wood Capital, and others.
What's the endgame? The money will primarily fund K-1728, KymaThera's oral, pan-mutant selective PI3Kα inhibitor. The drug is designed to target both kinase and helical domain PI3Kα mutations while sparing wild-type PI3Kα — the source of toxicity that has limited earlier efforts against the target.
The company is developing K-1728 for HR+/HER2- breast cancer, as a monotherapy and in combination regimens, and as a monotherapy for PI3Kα-driven vascular malformations. Both areas, it says, have limited treatment options.
Why now? KymaThera expects to begin patient dosing in a Phase 1 study in the fourth quarter of 2026. The financing follows a 2024 Series A co-led by Foresite and Venrock, bringing total capital raised to more than $100 million, and is expected to fund development through initial clinical proof-of-concept.
Chief executive officer Rob Kania said PI3Kα's potential has been "constrained by wild-type PI3Kα-mediated toxicity and incomplete coverage of clinically relevant mutations." He said K-1728 has "class-leading potency with helical mutant selectivity windows wider than any reported to date."
In preclinical and IND-enabling studies, the drug drove tumour regressions at low, once-daily doses against both mutation classes, with a wide window between effective exposures and those tied to hyperglycemia, the company said.
What investors say: "I invest in people, and KymaThera has assembled an outstanding team with deep experience in drug discovery and development," said Bob More, partner at Alta Partners. Foresite managing director Michael Rome called K-1728, which is internally discovered and wholly owned, "an impressive result."
The signal: At $80 million, the round sits near the top of US Series B health deals — above roughly 90% of such rounds all-time. That scale reflects investor appetite for differentiated oncology assets aimed at well-validated but hard-to-drug targets.
Read more: prnewswire.com
Image credit: KymaThera
