Gilead has partnered with Gritstone to develop an HIV-specific therapeutic vaccine in a deal worth up to $725 million. 

Gilead will pay $60 million when the deal closes, but could pay Gritstone up to $725 million if the option is exercised and commercial, clinical and regulatory milestones are achieved.  

“Gilead and Gritstone are partnering together to test the ability of Gritstone’s vaccine platform to stimulate T cell (immune) responses against HIV,” a spokesperson for Gilead told BioProcess Insider. “This approach may have the potential to complement Gilead’s overall HIV cure research strategy.” 

Image/iStock: Janka Dharmasena

Gilead will use its antigens and Gritstone’s vaccine platform compromised of self-amplifying mRNA and adenoviral vectors to develop the therapeutic vaccine. 

Self-amplifying mRNA (SAM) produces target antigens to stimulate adaptive immunity. Adenoviral vectors are engineered to deliver genetic material to stimulate immune response against disease targets, HIV in this case. 

“Adenoviral vectors will be administered separately from the SAM platform in a sequential vaccine regimen aimed at priming and boosting anti-HIV immune responses,” we were told.  

The firm will be responsible for conducting a Phase I study for the HIV-specific therapeutic vaccine and has the option to develop and commercialize the vaccine beyond Phase I.  

Gritstone will manufacture the vaccine. Gilead did not divulge where this will take place. However, the firm has key facilities located in Cambridge, Massachusetts and Pleasanton, California and is headquartered in Emeryville, California.  

COVID-19 a catalyst?  

Despite the coronavirus pandemic highlighting the use of mRNA platforms through the success of Moderna and Pfizer’s COVID-19 mRNA vaccines, Gilead said this has not influenced its deal with Gritstone.  

“The potential of an mRNA platform for HIV has been of interest for several years, prior to COVID-19. The COVID-19 vaccine experience is likely to add to the scientific knowledge base that may be relevant for many diseases” said Gilead.  

While the firm could not disclose an expected timeline for the production, a spokesperson told us “Our goal is to initiate regulatory and research activities this year.”