Boundless Bio has wrapped a $105 million series B financing to launch the company’s extrachromosomal DNA (ecDNA) programs for aggressive cancers into the clinic.
The financing was co-led by RA Capital Management and Nextech Invest and also included Fidelity Management & Research Company LLC, Redmile Group, Wellington Management and others.
Launched in 2019, Boundless is developing precision oncology drugs targeting ecDNA cancers that have resisted treatment. Since raising $46 million in a Series A, Boundless has quietly been working on its tech and has singled out three targets through a custom platform called Spyglass.
ecDNA cancers are characterized by rapid replication of cancer-promoting genes. Patients with these types of aggressive, difficult-to-treat cancers have a high rate of relapse and poor prognosis. Boundless’ ecDNA approach differs from other precision medicines that target specific cell mutations that lead to cancer. Those treatments don’t typically work against rapidly reproducing cancers, the company said.
Drug discovery is now underway for the three targets. The company also plans to use the new funding to develop companion diagnostic tests called Echo that will help identify patients with ecDNA-driven tumors.
“This financing round and stellar investor syndicate reflects the investment community’s appreciation for the high unmet clinical need of patients with oncogene amplified cancers and the promise of our innovative approach to targeting ecDNA to improve and prolong the lives of these patients,” Zachary Hornby, president and CEO of Boundless, said in a statement.
As part of the financing, Nextech Invest Partner Jakob Loven, Ph.D., will join Boundless’ board of directors.
“We invest in oncology companies with compelling science,” Loven said. “ecDNA is a transformative new area of cancer biology, and Boundless Bio is the clear leader in the rapidly emerging field.”