Gilead partners with cancer biotech Gritstone on HIV immunotherapy

 

• Gilead will partner with a small Californian biotech to develop an immunotherapy for HIV, announcing Monday a collaboration-and-option deal with the company, Gritstone Oncology, that could be worth hundreds of millions of dollars.
• Per deal terms, Gilead will pay Gritstone $30 million upfront and invest another $30 million in the smaller company's stock. Gritstone could receive as much as $725 million more, should Gilead exercise an option to take the treatment forward following early clinical tests, and if other, unspecified milestones are met. All or some of that money may never materialize, however, if development doesn't go as planned.
• Gilead and Gritstone envision the immunotherapy working much like a vaccine to teach the immune system which targets to attack and destroy, except they plan for it to be used as treatment rather than for prevention.

Gritstone, as its full name suggests, was started as a cancer drug developer. Since launching a little more than five years ago, the biotech's chief focus has been advancing research into personalized and donor-based cancer immunotherapy.

Lately, though, Gritstone is making headlines for its efforts in infectious disease. Two weeks ago, the company announced plans to develop a coronavirus vaccine together with the U.S. National Institutes of Health and the Bill and Melinda Gates Foundation. Borrowing from its cancer work, Gritstone believes it can design a vaccine capable of eliciting a stronger response from virus-killing T cells than current candidates and will soon start a Phase 1 clinical trial.

Shares in Gritstone more than tripled following the coronavirus vaccine announcement.

Monday's deal with Gilead calls more attention to the infectious disease applications of Gritstone's cancer research.

Some of the preclinical testing underpinning Gritstone's immunotherapies used model proteins derived from simian immunodeficiency virus, the monkey version of HIV. These proteins functioned as stand-ins for the cancer proteins Gritstone aims to teach the body to target with immunotherapy.  

The T cell response in monkeys treated by Gritstone "captured the attention of Gilead's virology team," said Karin Jooss, head of research and development at Gritstone, in a Feb. 1 statement.

Gilead sells more than half a dozen HIV therapies, which combined earn the company billions of dollars each year. But while all are potent drugs, capable of keeping the deadly virus in check, none are curative and must be taken chronically.

Like other companies in HIV research, Gilead has worked to develop longer- and longer-lasting treatments, including an experimental drug called lenacapavir now in late-stage testing. The biotech also has four drugs in earlier stages that are designed to be steps toward the broader goal of an HIV cure.

Gilead and Gritstone have similarly high hopes for the vaccine-based approach they plan to take under Monday's collaboration deal. Gilead will use Gritstone's vaccine-like technology, which combines an adenovirus vector with self-amplifying messenger RNA, to target HIV-specific "antigens," or target proteins, that it's developing. The idea, according to Gilead and Gritstone, is to train the immune system to destroy HIV-infected cells.

The idea of a "T cell vaccine" for HIV is not new, however, and past efforts using different approaches have come up short, too.

Gilead will be responsible for a Phase 1 study of the therapeutic vaccine, after which it has the choice to obtain an exclusive license for further development.

https://www.biopharmadive.com/news/gilead-gritstone-hiv-vaccine-immunotherapy/594258/