Big science: Upstart Gritstone bags $102M to go after a new immuno-oncology target

Gritstone CEO Andrew Allen

All hail neoantigens, the new, big science idea in cancer vaccines.

This morning a group of marquee venture backers put up $102 million to bankroll a startup--Gritstone Oncology--that plans to develop personalized cancer vaccines that can specifically spur an immune system assault on antigens that are created by tumors. Working under the direction of a group of high-profile biotech execs, Gritstone plans to initially go after lung cancer as it sets out to succeed in a field that has so far been largely a colossal disappointment.

As is often the case these days, Gritstone won't be the only upstart to spotlight the same goal. Third Rock and SR One provided a $55 million Series A just a few weeks ago to fund Neon Therapeutics, which has gathered together a group of scientific leaders in neoantigens to launch a company with a multifaceted approach to immuno-oncology. And more startups may be in the works as well as VCs funnel cash into one of the hottest fields in biotech.

Gritstone is being helmed by Andrew Allen, a co-founder and former chief medical officer at Clovis Oncology ($CLVS), which is now going head-to-head against AstraZeneca ($AZN) in a late-stage race on two cancer drug programs. Allen left Clovis back in June to start Gritstone and Patrick Mahaffy, the CEO at Clovis, is stepping in as chairman of the startup, with Rich Heyman, who launched and sold Aragon and Seragon in blockbuster deals with Big Pharmas, on the board.

Allen started working in immuno-oncology years before he tackled the job at Clovis. And when he came across a paper from Tim Chan on neoantigens, it struck him as a "beautiful opportunity around what feels like and looks like a big science idea."

Chan's paper focused on the higher likelihood of a patient's response to the checkpoint inhibitor Yervoy based on the proliferation of tumor neoantigens. "If we could predict the right neoantigens," says Allen, "we could improve the response rate."

The next step in the company's evolution will be to identify vaccine partners who can bring the right kind of technology--perhaps using tech like virus-like particles--to the table. And then he wants to head straight into the clinic as soon as possible, well aware that the company has plenty to learn from each new patient who receives a personalized therapeutic cancer vaccine.

Allen's first hire at the company was Roman Yelensky, the newly named executive vice president and head of sequencing and informatics. The CEO met his new EVP when Yelensky went to work on a companion diagnostic for Clovis, and he's the reason why the company will split its operations between San Francisco and Cambridge, MA.

Versant Ventures and The Column Group led the round, joined by Clarus Ventures, Frazier Healthcare Partners, Redmile Group, Casdin Capital, and Transformational Healthcare Opportunity, a "special-purpose vehicle" for private investors.

Gritstone--as well as Neon--are acutely aware of the failures that have preceded them in cancer vaccines. While not dangerous, the notion of amping up an immune system assault that could extinguish cancer cells has generally proven to be ineffective. Merck KGaA tried two late-stage efforts and threw in the towel each time. And others, like Aduro, are pursuing cancer vaccines as part of a combination strategy, where the synergies may be more apparent than their effectiveness as a monotherapy.

Gritstone co-founders Chan and Naiyer Rizvi have been pursuing this work at Memorial Sloan Kettering Cancer Center. Other scientific founders include Professor Jean-Charles Soria of the Institut Gustave Roussy, Professor Graham Lord of King's College London and Dr. Mark Cobbold of Massachusetts General Hospital.

"The scientific community doesn't yet know how to transition from individual tumor-mutation data to a short list of neoantigens that are therapeutically relevant to each patient, but the Gritstone team's expertise and approach made us confident that they will be the ones to successfully tackle this scientific challenge," said Peter Svennilson, founder and managing partner of The Column Group.

- here's the release