Boundless Bio’s transformational approach to solving one of the great unmet needs in fighting cancer has received some added – and hefty – validation.
On May 16, the clinical stage, precision oncology company announced the closing of a $100 million Series C financing co-led by Leaps by Bayer, the impact investment arm of Bayer AG, and RA Capital Management, as well as participation from additional new investors Sectoral Asset Management and Piper Heartland Healthcare Capital.
“We’re pleased with the amount, it’s a nice indicator in this market,” said Boundless Bio CEO Zachary Hornby. “What’s nice and unique about this Series C is we’re adding for the first time a strategic investor, Leaps by Bayer, that brings a new composition to our investor syndicate. It also shows that pharma is aware of what we’re doing, sees value in what we’re doing and deemed this sufficiently rigorous science to put money into.”
The Series C round adds $100 million to previous funding rounds, including a $46 million Series A in 2019 that was led by ARCH Ventures and an oversubscribed $105 million Series B in 2021 led by Nextech Invest and RA Capital.
This latest funding round will provide Boundless Bio runway into the second half of 2025 and allow the company to advance the first-in-human clinical study of its lead compound, BBI-335, from first patient dosed earlier this month through important clinical data readouts, Hornby said.
“We should be able to enroll and generate meaningful data on a significant number of patients in this timeframe that this capital provides,” he added.
Disrupting Cancer’s ‘Little Circles’
Boundless Bio is developing innovative therapeutics directed against extrachromosomal DNA (ecDNA) – fragments of chromosomes that lead to oncogene amplified cancer. The fragments are absent in normal healthy tissue and are observed in 14% of early-stage cancers and up to 40% of metastatic cancers, driving both tumor development as well as resistance to current therapeutics. Roughly
400,000 patients are newly diagnosed in the U.S. each year with oncogene amplified cancer.
“In some cancer cells, little pieces of chromosomes break off and turn into little circles and those circles can start duplicating over and over again,” Hornby explained. “This is the scientific premise on which our company is formed – that there’s these unique properties of cancer cells, when they have these little circles, and our therapeutics can destroy their functionality so that cancer cells can no longer rely on them to do their dirty work.”
BBI-335 and other ecDNA-directed therapies (ecDTx) under development in Boundless’ pipeline can target the ecDNA in cancers with oncogene amplifications across multiple different solid tumor types. Cancers with oncogene amplifications occur in about a quarter of patients and “remain one of the largest unmet needs in the cancer industry,” Hornby said. “We’re going after a big population with a big idea. It’s cutting-edge biology and we’re hoping we can make a meaningful impact in these patients.”
Investing in “Fundamental Breakthroughs’
In addition to financing BBI-335’s clinical trial, the new funds will also support advancement of Boundless Bio’s preclinical pipeline of differentiated ecDTx candidates and its proprietary ecDNA diagnostic clinical trial assay ECHO (ecDNA Harboring Oncogenes), which is being developed in partnership with SOPHiA GENETICS to detect presence of ecDNA in patients.
“At Leaps by Bayer, we invest in fundamental breakthroughs in healthcare,” said Juergen Eckhardt, M.D., executive vice president and global head of Leaps by Bayer. “The ability to address oncogene amplified cancers has remained one of the industry’s greatest challenges in the treatment of cancer. We are thrilled to support Boundless Bio, a company whose innovations have the potential to impact the lives of patients who currently have no effective standard of care.”
In addition to Leaps by Bayer and RA Capital co-leading the round alongside new investors Sectoral Asset Management and Piper Heartland Healthcare Capital joining, the Series C financing included participation from existing investors Fidelity Management & Research Company LLC, ARCH Venture Partners, Nextech, Wellington Management, Vertex Ventures HC, Redmile Group, Surveyor Capital (a Citadel company), GT Healthcare Capital Partners, Alexandria Venture Investments, PFM Health Sciences, Logos Capital, and City Hill Ventures.
In conjunction with the financing, Fabio Pucci, Ph.D., senior director of Venture Investments Health at Leaps by Bayer, will join the Boundless Bio board of directors.
“We are excited to have Leaps by Bayer join our world-class investor syndicate and to welcome Fabio Pucci to our Board of Directors,” Hornby said. “The support from new investors along with the continued commitment of our existing investors emphasizes our momentum and progress in bringing the first ecDNA-directed therapies to patients with oncogene amplified cancers.”
CEO: Zachary Hornby
Headquarters: San Diego, UTC
Business: Next-generation precision oncology company dedicated to the discovery and development of new drugs targeting ecDNA
Notable: Boundless Bio is the only company dedicated to treating oncogene amplified cancers and is the leading precision oncology company in the burgeoning field of ecDNA.