KymaThera Raises $80M to Advance PI3Kα Cancer Drug

KymaThera has raised $80 million in a Series B financing to advance the development of its investigational cancer drug K-1728, an oral PI3Kα inhibitor designed to target multiple disease-causing mutations.

The financing was led by Alta Partners, with participation from existing and new investors including Venrock, Foresite Capital and J. Wood Capital. The latest funding brings KymaThera’s total capital raised to more than $100 million.

The biotechnology company plans to use the new funding mainly to advance K-1728 into clinical development. KymaThera expects to begin dosing patients in a Phase 1 clinical trial in the fourth quarter of 2026. The financing is expected to support the program through initial clinical proof-of-concept.

KymaThera is initially developing K-1728 for hormone receptor-positive, HER2-negative (HR+/HER2-) breast cancer. The company is also exploring the drug as a treatment for PI3Kα-driven vascular malformations, a group of conditions that can cause serious and disabling symptoms and have limited systemic treatment options.

PI3Kα is an important target in cancer research, but developing drugs against it has been challenging because blocking normal PI3Kα activity can lead to side effects such as high blood sugar. KymaThera says K-1728 was designed to selectively target mutant forms of PI3Kα while maintaining a wider therapeutic window.

In preclinical and IND-enabling studies, K-1728 showed activity against both kinase and helical domain PI3Kα mutations. The drug produced tumor regressions at low, once-daily doses in preclinical cancer models carrying these mutations.

The company also reported a wide separation between drug exposure levels linked to tumor regression and those associated with hyperglycemia. According to KymaThera, these findings support the potential of K-1728 as a pan-mutant PI3Kα inhibitor.

“We designed K-1728 from the outset to address key limitations of earlier PI3Kα approaches,” said Rob Kania, Ph.D., CEO of KymaThera. He added that the new financing will allow the company to move the drug into clinical development and explore its potential in both cancer and vascular malformations.

Alta Partners’ Bob More said the investment reflects confidence in KymaThera’s team and its ability to advance K-1728 into the clinic.

The Series B follows KymaThera’s 2024 Series A financing, which was co-led by Foresite Capital and Venrock. The company said the latest investment will support its transition from preclinical research to human clinical trials.