BOLD Boundless Bio Inc

Boundless Bio (Nasdaq: BOLD), a clinical-stage oncology company interrogating extrachromosomal DNA (ecDNA) biology to deliver transformative therapies to patients with previously intractable oncogene amplified cancers, today announced that Robert (“Bob”) Doebele, M.D., Ph.D., has been appointed as Chief Medical Officer.

“We are excited to have Bob join Boundless at this pivotal time as we continue to advance the BBI-355 Phase 1/2 POTENTIATE trial and approach the selection of a development candidate for our Kinesin program,” said Zachary Hornby, President and Chief Executive Officer of Boundless Bio. “Bob has been a driving force behind precision oncology drug development throughout his career. His leadership in clinical development will be instrumental in advancing our ecDTx programs and, most importantly, in delivering novel treatment options to patients with oncogene amplified cancers.”

Dr. Doebele was the co-founder of Rain Oncology, Inc., (acquired by Pathos AI), a precision oncology company, where he served as Chief Scientific and Medical Officer, directing the research and development of innovative therapies targeting oncogenic drivers in tumor-agnostic, biomarker-driven trials. Specifically, he led the clinical development plans for milademetan, a small molecule MDM2 inhibitor, Phase 2 planning for tarloxotinib, a hypoxia-activated pan-HER kinase inhibitor, and the development of a preclinical program focused on inducing synthetic lethality by inhibiting RAD52. Dr. Doebele previously led the research and clinical trials at the University of Colorado that launched the TRK inhibitor field by demonstrating that NTRK1/2/3 gene fusions represent a novel tumor agnostic target in cancer, a strategy that ultimately led to the approval of Vitrakvi® (larotrectinib) and Rozlytrek® (entrectinib). He also served as the director of the Thoracic Oncology Research Initiative at the University of Colorado Cancer Center and co-founded and co-directed the University of Colorado Molecular Tumor Board. Dr. Doebele received his M.D. and Ph.D. in Immunology from the University of Pennsylvania School of Medicine and an A.B. in Molecular Biology from Princeton University.

“I am thrilled to join Boundless Bio, a company focused on interrogating novel biology to develop treatments for patients with oncogene amplified cancers,” said Dr. Doebele. “In my career as a biotech executive, scientist, and clinician, I have witnessed the potential of precision oncology to deliver meaningful outcomes for patients. Despite these advancements, there are very few treatments that effectively treat patients with oncogene amplifications, and I look forward to joining Boundless’ mission to develop life-improving therapies for these patients.”

About Boundless BioBoundless Bio is a clinical-stage oncology company dedicated to unlocking a new paradigm in cancer therapeutics to address the significant unmet need of patients with oncogene amplified tumors by targeting extrachromosomal DNA (ecDNA), a root cause of oncogene amplification observed in more than 14% of cancer patients. Boundless Bio is developing the first ecDNA-directed therapeutic candidate (ecDTx), BBI-355, which is an oral inhibitor of checkpoint kinase 1 (CHK1) being evaluated in a Phase 1/2 clinical trial in patients with oncogene amplified cancers. Leveraging its Spyglass platform, Boundless Bio has additional programs advancing through preclinical development and discovery. Boundless Bio is headquartered in San Diego, CA. For more information, visit www.boundlessbio.com and follow us on LinkedIn and X.

Forward-Looking StatementsBoundless Bio cautions you that statements contained in this press release regarding matters that are not historical facts are forward-looking statements. The forward-looking statements are based on our current beliefs and expectations and include but are not limited to: our ability to advance our ecDTx programs, and deliver novel, life-improving treatment options to patients. Actual results may differ from those set forth in this press release due to the risks and uncertainties inherent in our business, including, without limitation: we are early in our development efforts and our approach to discover and develop ecDTx directed against ecDNA in oncogene amplified cancers is novel and unproven; and other risks described in our filings with the Securities and Exchange Commission (SEC), including under the heading “Risk Factors” in our quarterly report on Form 10-Q for the quarter ended March 31, 2024 and any subsequent filings with the SEC. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof, and we undertake no obligation to update such statements to reflect events that occur or circumstances that exist after the date hereof. All forward-looking statements are qualified in their entirety by this cautionary statement, which is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.

Contacts:

InvestorsRenee LeckTHRUST Strategic Communicationsrenee@thrustsc.com

MediaCarly Scadutocarly@carlyscadutoconsulting.com