Gilead Acquires Full Rights to HBV and HIV Therapeutic Vaccines from Hookipa for $10 Million

On May 22, according to the report by the well-known industry media Fierce Biotech,Gilead Sciences Pays $10 Million to Acquire Full Ownership of Sandfly Virus Immunotherapy for Hepatitis B (HBV) and Human Immunodeficiency Virus (HIV) Developed in Long-Term Collaboration with Hookipa Pharma。

Hookipa Pharma, Inc. was founded in 2011, with its headquarters located in New York and Vienna. It is a biotechnology company focused on developing immunotherapies. The company’s self-developed arenavirus platform helps the human body recognize and eliminate viruses or tumor cells by "reprogramming" the immune system, with applications covering infectious diseases and cancer treatment.

Figure1: Hookipa Pharma's R&D Pipeline

The Two Products Involved in This TransactionTherapeutic VaccineRespectively:

1、HB-400

A treatment for chronicHBV Arenavirus Therapeutic Vaccine。GS-2829 + GS-6779 are two vaccine components based on viral vectors., is based on Hookipa's non-replicating arenavirus vector（arenavirus vector）Vaccine delivery technology platform development, using Lymphocytic Choriomeningitis Virus (LCMV) and Vesicular Stomatitis Virus (VSV) vectors. These vectors are engineered to express HBV antigens, thereby activating the host's immune response.

Figure2：HB-400

As early asIn 2023, Hookipa initiated the Phase 1a/1b trial of HB-400. At the 2025 European Association for the Study of the Liver (EASL2025) Annual Meeting held in Amsterdam, Netherlands, researchers announcedGS-2829 + GS-6779These two therapeutic vaccines are currently undergoing trials aimed at evaluating the safety, tolerability, and immunogenicity of the drugs.Phase 1a Study (NCT05770895) Results.

The results showed that both single and alternating administration of the viral vector were safe and well-tolerated. The immune response triggered by the vaccine was dose-dependent; in several participants (C8) The increase in the 5th and 6th doses further enhanced the magnitude of the T-cell response. Participants generated HBV-specific T-cells against all vaccine-encoded HBV antigens, accompanied by a sustained high level of anti-HBsAg.

2、HB-500

A treatment forHIV Arenavirus Therapeutic Vaccine。The vaccineUsing arenavirus-basedTwo replication vectors of Pichinde virus and lymphocytic choriomeningitis virus. These vectors deliver HIV antigens from immunogenic regions of HIV-1 proteins, which are highly conserved in the HIV-1 subtype B variant. The amino acid sequences differ between immunogens, allowing coverage of more than 80% of circulating HIV-1 viral variants.

January 2025,HookipaAnnounced the completion of its evaluationRecruitment for the Phase Ib Clinical Trial of HB-500 in the Treatment of HIV.The trial involves 30 participants and is expected to complete its primary endpoint in the second half of 2025.According to recentSignTransaction Agreement, will involveHookipa Gradually Phases Out Phase 1 Study of HB-500 Instead of Handing Over to GileadAdvance。

Gilead Sciences andThe partnership with Hookipa dates back to 2018.At that time, the company was authorized for the first time to use arenavirus immune technology to combat HBV and HIV. In 2021, Gilead decided not to advance the resulting HIV immunotherapy into the clinical stage, but reconsidered in 2022 and updated the collaboration.

At that time, Gilead Sciences paidA $15 million upfront payment and a $5 million equity investment. The terms of the original agreement include a potential $10 million project completion fee by Gilead, along with an additional $162.5 million in development milestone payments and up to $65 million in commercialization milestone payments.

Now, Gilead Sciences decidesTranslate thisTwo candidate vaccines are fully under our control.According toSubmitted on May 22ToA document from the U.S. Securities and Exchange Commission,Gilead Sciences willThisTotal Payment$10 million,Of which 3 million US dollars will be paid at the closing of the transaction, and the remaining 7 million US dollars will be paid in three phases., corresponding to the steps of advancing the technology transfer plan.

Last year, Gilead Sciences' sales revenue from HIV-related products totaled$19.6 billion, among which antiretroviralDrugBiktarvy (Biktarvy) and antiviral drug Descovy (Main Product. Although the company has not yet brought a therapeutic vaccine to market, withCompanyPrepare to launch its already approvedLong-Acting HIV Prevention Drug Lenacapavir Enters the Pre-Exposure Prophylaxis (PrEP) Market，This situation seems likely to change in the coming weeks.

InIn terms of HBV, Gilead Sciences is already sellingAntiviral DrugsVemlidy，AndHB-400 Therapeutic VaccineOrWill be for the companyDouble down in this field，Provide Alternative Products。So far this year,Vir Biotechnology and GSK have both abandoned the proposed "functional cure" for the virus, although GSK is still developing another drug.

Notably, in recent months,Hookipa Continues to Face Setbacks: In February, the company canceled its merger plan with Poolbeg Pharma. This followed a tough 2024, which included a 30% layoff after Roche exited its collaboration on the KRAS-mutant cancer project HB-700. Despite these challenges, Gilead’s decision to purchase full rights to HB-400 and HB-500 reflects strong confidence in Hookipa's two therapeutic vaccine programs.

References:

[1]Gilead pays partner Hookipa $10M to take over HBV, HIV therapeutic vaccine programs.By James Waldron.May 22, 2025 10:10am.

[2]Gilead Sciences、Hookipa Pharma Official Website.

[3]The Dawn of Functional Cure for Chronic Hepatitis B| Gilead Sciences' Therapeutic Vaccine for Chronic Hepatitis B (GS-2829 + GS-6779) is Currently Undergoing Phase 1 Clinical Trials. PharmaResearchPath. April 25, 2025.

[4]EASL2025: Gilead's Therapeutic Hepatitis B Vaccine GS-2829/GS-6779 First-in-Human Clinical Data Released. Liver Time. May 19, 2025.

[5]A wave of low-profile new biotech companies plansHIV Conquered in 2025. Latest HIV Developments by Wen Dao. April 17, 2025.