Bambusa Therapeutics Announces Completion of Series A-2 Financing to Accelerate Next-Generation Bispecific Programs

BOSTON, Nov. 17, 2025 /PRNewswire/ -- Bambusa Therapeutics, Inc. ("Bambusa"), a clinical-stage biotechnology company pioneering next-generation bispecific antibodies for immunology and inflammation (I&I), today announced the completion of its oversubscribed Series A-2 financing, closed at a substantial valuation step-up over the prior round.

This Series A-2 financing reflects strong participation from Bambusa's existing investors, including Athos KG, RA Capital Management, INCE Capital, Redmile Group, BVF Partners L.P., Salvia GmbH, Janus Henderson Investors, Invus, ADAR1 Capital Management, and Dawn Biopharma (an investment platform controlled by KKR). Their continued commitment highlights growing confidence in Bambusa's highly differentiated bispecific platform, rapid execution, and clinical momentum.

Proceeds will accelerate the development of BBT003 and BBT004, extending the company's proven capability to move programs swiftly from concept to the clinic.

"In just 18 months, our team has advanced two bispecific programs, BBT001 and BBT002, from development candidate to clinical proof-of-concept, an unprecedented pace in I&I biologics, demonstrating what a small, highly coordinated team can achieve in a short period of time," said Dr. Shanshan Xu, Founder and Chief Executive Officer of Bambusa Therapeutics. "This new financing enables us to apply that same momentum to BBT003 and BBT004. Closing the round at a significantly increased valuation is a clear reflection of the strength of our data, the speed and quality of our execution, and the deep conviction from our investors. 2026 will be a catalyst-rich year for Bambusa with more than 10 clinical readouts across multiple I&I indications."

BBT001 and BBT002 — both built on Bambusa's half-life-extended bispecific architecture — have progressed into Phase I studies in dermatology and respiratory indications, realizing the founding ambition to create transformative medicines that reshape the I&I landscape. BBT003 and BBT004 will be developed in gastroenterology and rheumatology, leveraging the same development engine that has driven Bambusa's early clinical velocity.

Dr. Derek DiRocco, Partner at RA Capital Management, commented: "RA Capital Management is delighted to continue to support Bambusa as they progress their portfolio of potentially best-in-disease bispecific antibodies for various I&I indications deeper into the clinic. In the nine months since we led the Series A-1 financing, we have been thrilled with the rapid and flawless execution delivered by the Bambusa team. Over the next year we eagerly look forward to the extensive clinical data sets that will highlight the immense value across the Bambusa portfolio."   

Key uses of proceeds:

• Advance BBT003 and BBT004 through IND-enabling studies and into early clinical development, maintaining Bambusa's pace of advancement.
• Broaden Bambusa's bispecific antibody platform into new I&I indications and deepen the pipeline.
• Strengthen core development infrastructure to support rapid progression through upcoming clinical and regulatory milestones.

About Bambusa Therapeutics

Bambusa Therapeutics is a clinical-stage biotechnology company developing a portfolio designed to transform care across a wide spectrum of chronic diseases. Powered by an innovative antibody engineering platform featuring half-life extension and high-concentration subcutaneous delivery, Bambusa's vision is to deliver transformative medicines for patients across every stage of life — setting a new pace for the next era of I&I therapeutics. For more information, visit www.bambusatx.com.

• BBT001 is a first-in-class half-life-extended bispecific antibody targeting IL-4Rα and IL-31 with best-in-disease potential. It is currently in Phase I development for atopic dermatitis and other Type 2 inflammatory skin diseases.
• BBT002 is a first-in-class half-life-extended bispecific antibody targeting IL-4Rα and IL-5 with best-in-disease potential. It is currently in Phase I development for Type 2 inflammatory disorders including COPD, asthma, CRSwNP, eosinophilic esophagitis, and food allergy.
• BBT003 and BBT004 are preclinical programs focused on gastroenterology and rheumatology, respectively.

SOURCE Bambusa Therapeutics, Inc.