NEW YORK and VIENNA – October 31, 2025 — HOOKIPA Pharma Inc. (OTC: HOOK) announced the completion of the sale of its hepatitis B (HB-400) and human immunodeficiency virus (HB-500) programs to Gilead Sciences, Inc., a global leader in antiviral therapeutics. The closing, finalized on October 30, 2025, marks a strategic realignment of HOOKIPA’s pipeline and strengthens Gilead’s position in advancing next-generation viral immunotherapies. Both assets were originally developed in collaboration under an existing licensing and co-development agreement between the two companies.
Science Significance
The HB-400 and HB-500 programs represent innovative immunotherapy platforms targeting chronic viral infections that remain significant global health challenges. HB-400, a therapeutic vaccine candidate for hepatitis B virus (HBV), leverages HOOKIPA’s arenavirus-based immunotherapy technology to stimulate durable immune responses that could achieve functional cures. HB-500, aimed at HIV treatment, applies the same viral vector platform to generate T-cell immunity capable of controlling infection without continuous antiretroviral therapy. By transferring these programs, Gilead gains access to promising pre-clinical and early-stage clinical data that align with its long-standing expertise in antiviral drug development.
Regulatory Significance
The transaction is structured to enable Gilead to oversee ongoing regulatory submissions and clinical trial activities for both programs, ensuring continuity in compliance with global Good Clinical Practice (GCP) and Good Manufacturing Practice (GMP) standards. The programs’ ongoing clinical development phases — including studies under U.S. FDA and European regulatory oversight — will now proceed under Gilead’s operational control. This transition supports a seamless regulatory handover, minimizing disruption to existing or planned investigational activities in viral immunotherapy.
Business Significance
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The asset sale underscores HOOKIPA’s strategic focus on oncology immunotherapies, particularly in human papillomavirus-positive cancers and other solid tumors, while reinforcing its balance sheet and operational efficiency. For Gilead, the acquisition strengthens its infectious disease portfolio, adding next-generation immunotherapeutic modalities to complement its antiviral franchise. This move expands Gilead’s innovation pipeline while allowing HOOKIPA to concentrate resources on late-stage cancer immunotherapy development, thereby maximizing shareholder value and scientific impact through focused execution.
Patients’ Significance
Patients affected by chronic hepatitis B and HIV infection stand to benefit from the continuation and acceleration of clinical development under Gilead’s global infrastructure. Gilead’s proven track record in delivering life-changing antiviral therapies ensures sustained investment and expertise to advance these candidates toward clinical validation and potential approval. The transaction ensures patients enrolled in ongoing studies experience continuity of care and sustained access to investigational therapies under established ethical and regulatory safeguards.
Policy Significance
This transaction reflects the broader policy emphasis on public-private collaboration to combat global infectious diseases. By enabling specialized biotech firms like HOOKIPA to innovate early and partner with established pharmaceutical leaders, such asset transfers foster an ecosystem of efficient R&D translation and resource optimization. The deal aligns with international health objectives targeting hepatitis B elimination by 2030 and sustained HIV epidemic control, as endorsed by the World Health Organization and leading regulatory agencies worldwide.
The completion of the HBV and HIV asset sale marks a transformative milestone for both HOOKIPA Pharma and Gilead Sciences. It reinforces Gilead’s commitment to expanding its antiviral leadership through cutting-edge immunotherapy, while empowering HOOKIPA to sharpen its oncology focus and capitalize on its arenavirus platform’s therapeutic potential. As both companies pursue their specialized missions, the transaction exemplifies the strategic collaboration model driving innovation, regulatory progress, and patient impact in the global biopharmaceutical industry.
Source: HOOKIPA Pharma Inc. press release
