Affini-T Therapeutics launches with $175 million for cancer treatments

The startup, based in Boston and Seattle, will make T cell therapies for infamously tough-to-treat conditions.

Affini-T Therapeutics is engineering cell therapies for cancers that are traditionally tough to treat.Affini-T Therapeutics

Affini-T Therapeutics has raised $175 million to develop engineered T cell therapies for tough-to-treat cancers. It’s one of the largest launches for a biotech startup so far this year.

The company, based in Boston and Seattle, hopes that cell therapies — which have so far only been approved for treating blood cancers — can help people with tumors caused by the notorious protein KRAS.

More than 30 percent of cancers have mutations in KRAS or one of the protein’s close cousins, according to the National Cancer Institute. “It is what allows some cancer cells to grow and divide very quickly,” said Dr. Jak Knowles, cofounder, president, and chief executive of Affini-T.

Affini-T Therapeutics chief executive Dr. Jak Knowles.Affini-T Therapeutics

Oncologists have known about KRAS for decades, but drug designers have struggled to find molecules that can selectivity target mutant versions of the protein. “Everyone recognizes it is a fundamental basis of cancer, but it is hard to get at,” Knowles said.

That’s starting to change. Last year, the Food and Drug Administration approved the first KRAS inhibitor, a pill called Lumakras, for a form of lung cancer. But that drug only targets KRAS proteins with a mutation called G12C. Affini-T is focusing on two different KRAS mutations called G12V and G12D, which are common in pancreatic, colorectal, and lung cancers. There are no approved therapies for tumors with these mutations.

Affini-T plans to tackle those tumors with help from T cells, the immune system sentinels that can recognize infections or tumors with a homing beacon called a T cell receptor.

Dr. Philip Greenberg, an immunologist at the Fred Hutchinson Cancer Research Center in Seattle, found T cell receptors that target mutant forms of KRAS in healthy young people. Affini-T, which was cofounded by Greenberg and his colleagues, will add those homing beacons to the T cells of people with cancers caused by KRAS.

“We plan to have the programs active in the clinic next year,” Knowles said.

Affini-T is leasing lab space from the gene therapy company Dyno Therapeutics in Watertown, but will be moving into a 40,000-square-foot lab in a new nine-story life sciences building in Watertown’s Arsenal Yards later this year.

Vida Ventures, a Boston-based venture capital firm, and Leaps by Bayer, the early-stage investment arm of the German pharma company, co-led the $175 million financing.

“Everyone knows Boston for biotech, but not necessarily cell therapy. When investors think of cell therapy, they think of Philadelphia or the West Coast,” said Dr. Arjun Goyal, managing director of Vida and cofounder of Affini-T. “But it was a very conscious decision to base this company in Boston.”

“It is where the talent is,” Knowles said. “The management teams are really exceptional in Boston.”