Dren Bio, a privately held clinical stage company in San Carlos, California, closed a $350 million private financing on October 29, its first disclosed venture round in more than four years and a step change from the $65 million Series B it raised in 2022. The round was co led by Juvia Group and Lightspeed Venture Partners, with new investors including Mirae Asset Capital Life Science, General Catalyst, Cormorant Asset Management and OrbiMed, alongside existing backers. Juvia’s Sujal Shah and Lightspeed’s Shelley Chu join the board. The company did not disclose the round’s designation or its valuation.
The money is earmarked for one drug. Dibotatug, also called DR-01, is a first in class monoclonal antibody targeting CD94, designed to selectively deplete pathogenic cytotoxic T and natural killer cells while preserving the broader immune system. Its most advanced studies are in cytotoxic T cell lymphoma and large granular lymphocytic leukemia, two rare blood cancers for which the company says there are no approved therapies. Proceeds will fund continued late stage development, regulatory submission and the planned commercial launch, plus expansion into aplastic anemia, other bone marrow failure syndromes and autoimmune diseases, and the wider pipeline built on its Targeted Myeloid Engager and Phagocytosis platform.
The clinical evidence disclosed so far is directional rather than quantified. More than 300 patients have been dosed in the Phase 1/2 study of the two lead indications, and the company says overall and complete responses have been observed in patients whose disease had relapsed or was refractory, without publishing response rates in the financing announcement. BioSpace noted the study’s primary readout is slated for December on ClinicalTrials.gov, and that the programme is listed by the company as being in registrational development. Endpoints News framed the ambition as reaching the market by the end of 2027.
Context explains both the size and the structure. Dren’s platform has already been validated by partners on other assets: Novartis committed $150 million upfront in 2024 for cancer antibody research, and Sanofi paid $600 million upfront for the separate DR-0201 programme, which it acquired in May 2025 as SAR448501. Keeping dibotatug in house is therefore a choice, not a necessity, and $350 million is roughly the cost of running registrational trials in two rare cancers and building a first commercial organization to sell into them. Whether the December readout supports that build is the next event, and it arrives within weeks of the cheque.