This nucleoside RNA polymerase inhibitor disrupts the viral replication process and has the potential to fight multiple viral threats at once.
Galidesivir (BCX4430) is a broad-spectrum antiviral in advanced development under the Animal Rule for the treatment of viruses that pose a threat to health and national security. A Phase 1 clinical safety and pharmacokinetics study in healthy subjects has been completed, and in animal studies, galidesivir has demonstrated survival benefits against a variety of serious pathogens, including Ebola, Marburg, Yellow Fever and Zika viruses. Galidesivir has also demonstrated broad-spectrum activity in vitro against more than 20 ribonucleic acid (RNA) viruses in nine different families, including filoviruses, togaviruses, bunyaviruses, arenaviruses, paramyxoviruses, coronaviruses and flaviviruses.
BioCryst is developing galidesivir in collaboration with U.S. Government Agencies and other institutions. In September 2013, the National Institute of Allergy and Infectious Diseases (NIAID) contracted with BioCryst for the development of galidesivir as a treatment for Marburg virus disease and potentially for other filoviruses, including Ebola virus. The total funding from NIAID could be up to $39.5 million if all contract options are exercised.
In March 2015, BioCryst announced that the Biomedical Advanced Research and Development Authority (BARDA) within the U.S. Department of Health & Human Services’ Office of the Assistant Secretary for Preparedness and Response (ASPR) has awarded BioCryst a contract for the continued development of galidesivir as a potential treatment for diseases caused by RNA pathogens, including filoviruses.
This includes a base ASPR/BARDA contract of $16.3 million to support galidesivir drug manufacturing, as well as $22.8 million in additional development options that can be exercised by the government, bringing the potential value of the contract to $39.1 million.
BioCryst intends to develop one or more small-molecule antiviral drugs directed against viral RNA polymerase, a common and essential component of RNA viruses. This approach could allow a single drug to address gaps in the U.S. government’s medical countermeasure plan such as treatments for viral hemorrhagic fevers, and to possibly replace multiple, pathogen-specific drugs for use in response to both natural outbreaks and bioterrorist threats.
RNA polymerase plays a crucial role in viral replication process; transcription and replication of the virus genome. Nucleoside RNA polymerase inhibitors, such as galidesivir, are metabolized to the active triphosphate (nucleotide) form by cellular kinases. The drug nucleotide binds to the viral enzyme active site and becomes incorporated into the growing viral RNA strand, leading to premature chain termination.
Interfering with the replication process is a well-established antiviral strategy that has been successfully exploited in developing such life-saving drugs as the nucleoside inhibitors of HIV and acyclovir for herpes simplex complex. Galidesivir may be suitable for administration by intravenous, intramuscular, and oral routes.