Boundless Bio Raises Oversubscribed $105 Million Series B Financing to Advance Next-Generation Precision Oncology Therapies Directed Against Extrachromosomal DNA (ecDNA)

Led by Nextech Invest and RA Capital Management, with participation from new investors Fidelity Management & Research Company LLC, Redmile Group, Wellington Management, Surveyor Capital, PFM Health Sciences, and Logos Capital and existing investors

Funding will support development of ecDNA directed therapeutic programs and ecDNA companion diagnostic to address oncogene amplified cancers

SAN DIEGO--()--Boundless Bio, a next-generation precision oncology company developing innovative therapeutics directed against extrachromosomal DNA (ecDNA) in aggressive cancers, today announced the closing of an oversubscribed $105 Million Series B financing. With the proceeds of the financing, the company will advance into the clinic multiple ecDNA-directed therapeutic programs and the accompanying ecDNA Harboring Oncogenes (ECHO™) companion diagnostic and expand its pipeline of novel cancer therapies targeting ecDNA.

RA Capital Management and Nextech Invest co-led the financing, with participation from a top-tier syndicate of funds, including Fidelity Management & Research Company LLC, Redmile Group, Wellington Management, Surveyor Capital (a Citadel company), PFM Health Sciences, and Logos Capital. Current investors ARCH Venture Partners, City Hill Ventures, Vertex Ventures HC, GT Healthcare Capital Partners, Boxer Capital of Tavistock Group, and Alexandria Venture Investments also participated in the Series B. In conjunction with the financing, Jakob Loven, Ph.D., Partner at Nextech Invest, will join the Boundless Bio Board of Directors.

“Boundless Bio has made tremendous progress since launching in 2019,” said Zachary Hornby, President and Chief Executive Officer of Boundless Bio. “Over the past two years our team has custom built a platform, called Spyglass, that enables us to interrogate ecDNA in cancer and reveal key therapeutically targetable liabilities in ecDNA-driven, gene amplified tumors. From these efforts, we have discovered and validated three ecDNA-essential targets and have initiated drug discovery against each. In addition, we are developing the ECHO companion diagnostic assay to 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.”

ecDNA are circular units of DNA that contain functional genes and are highly transcriptionally active. ecDNA constitute a primary driver of gene amplification and copy number heterogeneity in cancer. ecDNA are present in many solid tumor cancers but generally not in healthy cells. Boundless Bio’s Spyglass™ platform combines proprietary ecDNA model systems with bespoke analytical tools to enable Boundless Bio scientists to interrogate ecDNA cancer biology to discover new cancer targets that are synthetically lethal in ecDNA-driven cancers. Boundless Bio is leveraging these insights to discover and develop innovative new precision medicines targeting the underlying cellular machinery that enables ecDNA to function in cancer.

“We invest in oncology companies with compelling science,” said Jakob Loven, Ph.D., Partner at Nextech Invest. “ecDNA is a transformative new area of cancer biology, and Boundless Bio is the clear leader in the rapidly emerging field. The Boundless team has made remarkable progress since the company formation, demonstrating that ecDNA biology is tractable as a therapeutic approach and advancing a powerful platform, exciting early drug programs and a promising companion diagnostic approach. We are eager to work with the experienced Boundless team to transform cancer care for underserved patients with gene amplified cancers.”

“RA Capital has been following the Boundless Bio story for some time now and believes that the team has developed industry-leading expertise in the biology that underlies high unmet need, gene amplified tumors,” said Zach Scheiner, Ph.D., Principal at RA Capital Management. “Boundless Bio has shown ecDNA to be a driver of both tumor growth and resistance to targeted therapies, and the team is poised to make significant therapeutic advances in this exciting new field. We are pleased to support their efforts to help bring these potentially transformative therapies to patients in need.”

About Boundless Bio

Boundless Bio is a next-generation precision oncology company interrogating a novel area of cancer biology, extrachromosomal DNA (ecDNA), to deliver transformative therapies to patients with previously intractable cancers.

For more information, visit www.boundlessbio.com.

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About ecDNA

Extrachromosomal DNA, or ecDNA, are distinct circular units of DNA lacking centromeres but containing functional genes, including oncogenes, that are separated from tumor cell chromosomes. ecDNA replicate within cancer cells and can be passed to daughter cells asymmetrically during cell division, thereby constituting a primary driver of focal gene amplification and copy number heterogeneity in cancer. By leveraging the plasticity afforded by ecDNA, cancer has the ability to increase or decrease copy number of select oncogenes located on ecDNA to enable survival under selective pressures, including chemotherapy, targeted therapy, immunotherapy, or radiation, making ecDNA one of cancer cells’ primary mechanisms of recurrence and treatment resistance. ecDNA are not found in healthy cells but are present in many solid tumor cancers. They are a key driver of the most aggressive and difficult-to-treat cancers, specifically those characterized by high copy number amplification of oncogenes.

About Boundless Bio’s Spyglass™ Platform

Boundless Bio’s Spyglass™ platform is a comprehensive suite of proprietary ecDNA-driven and pair-matched tumor models along with proprietary imaging and molecular analytical tools that enables Boundless Bio’s researchers to interrogate ecDNA biology and maintain a robust pipeline of novel oncology targets essential to the function of cancer cells that are enabled by ecDNA. The Spyglass platform facilitates innovation in the development of precision therapeutics specifically targeting ecDNA-driven tumors, thus enabling selective treatments for patients whose tumor genetic profiles make them most likely to benefit from our novel therapeutic candidates.

Contacts

Sarah Sutton
Finsbury Glover Hering
sarah.sutton@fgh.com
202-337-0808

Danielle Cantey
Finsbury Glover Hering
danielle.cantey@fgh.com
202-337-0808

Contacts

Sarah Sutton
Finsbury Glover Hering
sarah.sutton@fgh.com
202-337-0808

Danielle Cantey
Finsbury Glover Hering
danielle.cantey@fgh.com
202-337-0808