Boundless Bio (BOLD) and Serapha Bio Announce Merger, $230M Private Placement

Boundless Bio (BOLD) announced a definitive merger agreement with Serapha Bio on June 23, 2026, alongside a $230 million private placement. The deal is expected to create a combined oncology company focused on ecDNA-driven cancers, driving Boundless Bio's stock higher following the announcement. The private placement, led by RA Capital Management and new investors, will fund the combined entity. Boundless Bio's lead candidate, BBI-355, is currently in a Phase 1/2 clinical trial for ecDNA-driven cancers. Serapha Bio contributes an AI-powered platform for oncology drug discovery. Dr. Jared Gollob, Boundless Bio's current CEO, will lead the new company. The merger is anticipated to close in the fourth quarter of 2026.