Gilead Sciences pens early-stage HIV vaccine pact with Gritstone Oncology

Gilead
(Gilead China)

Initially known as a machine learning biotech focused on cancer, Gritstone Oncology has been broadening its scope to include a very early look at treatments for COVID-19 and, now, another infectious disease.

In a $60 million upfront equity split payment, Big Pharma Gilead Sciences is pairing up with Gritstone for an HIV therapeutic vaccine the pair believes could be curative for the disease.

Under the deal, Gilead will run a phase 1 study for the vaccine and hold on to an option to obtain an exclusive license to work and sell the therapy, should it pass muster, after the early trial.

As part of the deal, Gritstone is in line for $725 million in biobucks should Gilead hit that go button, as well as other milestones, and is on the hook for mid-single-digit to low-double-digit tiered royalties on net sales, should it gain approval.

In the biotech’s release, Gritstone was sparse on details of the HIV therapeutic and its technology, but we know it taps simian immunodeficiency virus (SIV)-derived antigens as model antigens, which are very similar to HIV-1.

“The resulting strong, durable and broad anti-SIV CD8+ T cell responses and T cell memory data captured the attention of Gilead’s virology team,” the biotech said in a statement.

RELATED: Gritstone adds COVID-19 to the pipeline with NIAID-supported vaccine

“We jointly performed further experiments that generated additional compelling data, which was also complemented by our exciting clinical data with neoantigens in cancer patients. We are delighted to now advance our partnership and product candidates for the treatment of patients with HIV infection.”

Gilead is now a global leader in HIV/AIDS and infectious disease in general, using antiretroviral therapies for the former and becoming the sole player in hepatitis C a few years ago when its single and cocktail therapies essentially came out with the capacity to cure the disease.

It is now more focused on cancer when it comes to R&D, but, clearly, infectious disease remains a focal point for its business; it recently repurposed its once-failed Ebola drug remdesivir as a treatment for some patients with COVID-19.

Gritstone, a 2017 Fierce 15 winner, has a similar arc though on a much, much smaller scale: It too focuses on cancer but also infectious disease with recent early work also zeroing in on a potential COVID-19 vaccine with the National Institute of Allergy and Infectious Diseases.

While its tech originally focused on neoantigens and a machine learning approach for cancer vaccines, it also has a second focus on infectious disease. For COVID-19, and under a license agreement with the La Jolla Institute for Immunology, Gritstone has access to epitopes of the SARS-CoV-2 virus—a part of the virus to which antibodies bind—identified in its studies.

Like the first generation of COVID-19 vaccines, Gritstone’s candidate targets the spike protein of the new coronavirus, but it also contains other targets that could help boost T-cell immunity. It is still early days here, however.

“Curing HIV remains the ultimate aspiration for Gilead’s HIV research and development efforts. Gritstone’s vaccine technology has the potential to educate the immune system to specifically recognize and destroy HIV-infected cells by leveraging SAM and adenoviral vectors,” said Diana Brainard, M.D., senior vice president and virology therapeutic area head at Gilead. “This, along with our other partnerships and internal programs, reflects Gilead’s commitment to continuing innovation to discover a cure for HIV and bring about an end to the HIV epidemic.”

RELATED: J&J gears up for clinical test of HIV vaccine efficacy

Gilead Sciences already sells a drug designed to stop people becoming infected, but it is taken daily, creating a compliance burden and putting the price of protection beyond the reach of many people, particularly in the parts of Africa where HIV is most prevalent. A HIV vaccine would be a holy grail in the fight against the disease.

Johnson & Johnson is one of the very few companies working on a vaccine, with its candidate featuring four components designed to provide protection against multiple strains.

“It is well-established that CD8+ T cells are critical for the elimination of virally infected cells, and we have built a highly differentiated vaccine platform that has been shown to generate large numbers of antigen-specific T cells, including CD8+ T cells, even in advanced and immunocompromised cancer patients,” said Andrew Allen, M.D., Ph.D., co-founder, president and CEO of Gritstone.

“On the heels of our recent COVID-19 program initiation in partnership with the NIH, this program adds to our growing infectious disease pipeline supported by collaborations with leading biopharma and renowned institutions.”