Start-Up Targets Extra DNA in Cancer, Raises $46.4M

Paul Mischel (Ludwig Institute for Cancer Research)

19 Sept. 2019. A new biotechnology enterprise is developing treatments for aggressive solid tumor cancers that block the effects of DNA residing outside of chromosomes. Boundless Bio Inc. in San Diego formed earlier this year and raised more than $46 million in its first venture financing.

Boundless Bio says it’s designing a new type of cancer therapy addressing extrachromosomal DNA, strands of DNA that are not part of normal chromosomes in the genome or found in typical cells. Instead, the circular pieces of DNA reside within the nucleus of oncogenes, mutated genes responsible for cancer. These extrachromosomal DNA occurrences are associated with nearly half of all solid tumor cancers, says Boundless Bio, particularly aggressive, fast-growing cancers.

The biotechnology company is founded by six researchers from the fields of cancer biology, but also computer science and biomedical engineering. The scientific founders are led by Paul Mischel, a researcher in cancer genetics at the Ludwig Institute for Cancer Research, affiliated with University of California in San Diego. Mischel studies extrachromosomal DNA in oncogene amplification, a process where genes make multiple extra copies that contribute to cancer cell multiplication. These copy number variations code for proteins that evade normal regulatory functions and encourage tumor growth.

Boundless Bio says its technology aims to address the role of extrachromosomal DNA, or ecDNA, in cancer, leading to new cancer treatments. “Guided by our developing understanding of ecDNA,” says Mischel in a company statement released through BusinessWire, “our scientific founders have created a new architectural map of the cancer genome to demonstrate why some cancers aggressively evolve and resist existing treatment approaches. We have developed technology capable of identifying, characterizing, and ultimately, drugging, ecDNA-driven tumors.”

The company formed earlier this year and began operations in stealth mode. Zachary Hornby, who became Boundless Bio’s president and CEO in May 2019 notes, “Boundless Bio aims to improve cancer care by bringing a whole new class of weapons to the cancer-fighting armamentarium that exploit the emerging field of ecDNA biology.” He adds, “We are creating powerful medicines that counterattack this ecDNA phenomenon by eliminating cancer cells’ ability to employ ecDNA to survive.”

Boundless Bio is raising $46.4 million in its first venture funding round, led by health care and life science venture investors ARCH Venture Partners in Chicago and City Hill Ventures in San Diego. Taking part in the financing are Vertex Ventures, GT Healthcare Capital Partners, Boxer Capital of the Tavistock Group, Alexandria Venture Investments, and other undisclosed investors.

The company expects to apply the funds to building its technology to identify and describe tumors that result from extrachromosomal DNA. The first treatments will aim for solid tumor cancers caused by high copy number mutations.

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