Highlights:

ILA signs agreement to acquire Galidesivir antiviral program from NASDAQ-listed BioCryst

Island Pharmaceuticals may pursue FDA Animal Rule for Marburg virus drug approval

ILA shares close 13.79% higher at AUD 0.16 on 9 July 2025 following acquisition news

Island Pharmaceuticals Limited (ASX:ILA) has entered into a binding asset purchase agreement to acquire the Galidesivir antiviral program from BioCryst Pharmaceuticals Inc. The acquisition follows a previously announced Letter of Intent in September 2024 and will add a second clinical-stage antiviral asset to Island’s portfolio.

Galidesivir is a broad-spectrum antiviral compound with demonstrated activity against more than 20 RNA viruses, including several high-priority global health threats such as Ebola, Marburg, Zika, Yellow Fever, and MERS. The compound is a nucleoside analog that mimics ATP and inhibits viral RNA synthesis. Its prior development was backed by more than AUD 70 million in U.S. government funding, targeting emerging infectious diseases and biodefense threats.

Island Pharmaceuticals has completed its due diligence on the program and expects to close the transaction within 30 days. The company will now move forward with regulatory planning to leverage the U.S. Food & Drug Administration’s (FDA) Animal Rule, which allows for approval of drugs based on animal efficacy studies when human trials are not ethical or feasible.

According to Island, a successful additional non-human primate study targeting Marburg virus disease could potentially support a New Drug Application (NDA). If approved, the NDA may also qualify the company for a Priority Review Voucher (PRV). These PRVs have previously traded for between AUD 100 million and AUD 150 million on the open market, though the company noted that further validation is required before any submission.

Island CEO and Managing Director Dr David Foster stated that the due diligence process included an extensive review of clinical and preclinical data, including prior collaboration with consultants to identify a potential regulatory pathway. The company will now focus on pre-submission engagement with the FDA to determine specific requirements under the Animal Rule.

The Galidesivir data package includes completed Phase 1 clinical trials in healthy volunteers, covering both intramuscular and intravenous dosing regimens. In addition, the program includes a previously conducted successful non-human primate study in Marburg virus, which may support further regulatory filings under the Animal Rule framework.

Island Pharmaceuticals Chairman Jason Carroll said the acquisition of Galidesivir represents a key expansion of the company’s pipeline and reinforces its focus on antiviral drug development for high-consequence diseases. He also noted the relevance of Galidesivir’s activity against Category A bioterrorism agents, as defined by the U.S. Centers for Disease Control and Prevention (CDC), including Filoviruses such as Ebola and Marburg, which carry mortality rates between 25% and 90% and currently lack approved treatments.

With the acquisition, Island now holds two antiviral assets:

Galidesivir, which targets multiple RNA viruses and is advancing toward potential regulatory submission under the FDA Animal Rule; and
ISLA-101, which is being evaluated for dengue and other mosquito-borne diseases.

Following the announcement, Island Pharmaceuticals shares closed 13.79% higher at AUD 0.16 on 9 July 2025.