Akrevia no more, Xilio Therapeutics bags $101M for I-O programs

As it gears up to move its immuno-oncology programs into the clinic, Akrevia Therapeutics has reeled in a $100.5 million series B and changed its name to Xilio Therapeutics to mark its transition from a research-focused company to an R&D-stage one. 

With technology licensed from City of Hope and Thomas Jefferson University, Xilio is creating tumor-selective treatments that stay “turned off” or “dark” in the body until they reach the tumor microenvironment, where they “turn on,” Xilio CEO Rene Russo told FierceBiotech. The company is keeping how the platform works, exactly, under wraps, but the hope is to cut down on the toxic side effects that prevent many patients from taking certain immunotherapies or from finishing a full course of treatment. 

“The problem we see is that immunotherapy has incredible potential and has demonstrated really meaningful benefits for some patients. But there is a huge remaining set of patients outside of that fraction who are not able to benefit,” said Tim Clackson, Ph.D., Xilio’s president and R&D chief. “There are molecules known to have potential for huge benefit, but we can’t get it to patients at the right dose, or at all, because of side effects.” 

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Take IL-2 (interleukin-2), a cytokine discovered decades ago but that has seen limited use. It has a short half-life, necessitating multiple doses per day, and tamps the immune system down before activating it, requiring high doses to work. Xilio is among several players working to deliver IL-2’s power without its side effects. These include Synthorx, which Sanofi snapped up for $2.5 billion in December.

With its new funding, Xilio will push its lead programs, XTX101, a CTLA-4-targeting antibody, and XTX201, the IL-2 drug, through IND-enabling studies and into phase 1. It plans to bring XTX101 into the clinic first, with an IND for XTX201 to follow in 2021.

“We have now demonstrated tumor-selective activity in preclinical models for both our lead programs. In the case of XTX101, we have shown clearly improved tumor inhibition in models compared to ipilimumab [Yervoy], the current standard of care,” Clackson said.

And these programs are just the beginning. The proceeds will also bankroll the development of earlier-stage candidates to broaden the company’s pipeline. 

“We are excited about the potential with this raise not only to bring the first two therapies into the clinic, but to continue to tap an untapped area of high-potential immunotherapies,” said Russo.

“Each time we advance one of these molecules with this technology, we’re learning more and we will be able to expand and move to other molecules more efficiently and effectively,” she added.

Takeda Ventures led the round, joining Xilio’s series A backers F-Prime Capital and Atlas Venture. SV Health Investors, MRL Ventures Fund, RiverVest Venture Partners, Bay City Capital, Solasta Ventures, M Ventures and Ipsen Ventures also chipped in.