3T Biosciences, a San Francisco-based biotechnology startup, came out of stealth mode Thursday with $40 million in funding from the investment firms Westlake Village BioPartners and Lightspeed Venture Partners.
3T, which was initially formed in 2017, aims to harness the body’s immune system to fight cancer. It’s a goal shared by many other biotechs, but one that, for complex biological and scientific reasons, has proven challenging nonetheless. 3T believes it’s in a position to succeed, though, thanks to a suite of technologies it claims can help overcome two obstacles in immunotherapy development.
Specifically, the company’s research focuses on a kind of receptor found on the surface of T cells. As T cells circulate through the body, these “TCR” proteins put the immune system on alert, as they’re able to recognize threats like foreign pathogens and malignant cells. While TCRs have attracted researchers’ attention for years, the first approval for a TCR-based therapy came just this past January.
3T’s technology is designed to identify proteins that could be new targets for TCRs, and use them to create new treatments for solid tumors as well as diseases tied to the immune system. Additionally, it’s meant to screen TCRs — and antibodies that act like them — to find those that are the most highly selective and can avoid reacting with off-target proteins. In theory, this technology would give rise to therapies that are safer, more specific, and capable of being given at larger doses.
“This is a field that's been of interest to us for some time,” said Sean Harper, a co-founding managing director at Westlake and, now, board chair for 3T. “But we've not made an investment in this area before, because nothing that we had seen convincingly had the capabilities, the integrated set of tools and technologies to effectively de-risk these targets from cross-reacting with normal tissues.”
“To go forward with these targets without that de-risking process is sort of version 1.0 of TCR-based therapies,” added Harper, who was previously head of research and development at Amgen. “And we're always looking for version 2.0 or 3.0 when we invest in these things.”
3T — with its technology and the expertise of its scientific co-founders, including K. Christopher Garcia, who runs an eponymous lab at Stanford University — represented such a version, according to Harper.
For example, one of the company’s purported advantages is that it employs information from cancer patients who have strongly benefited from a kind of immunotherapy known as checkpoint inhibitors. This information is then used to uncover what TCR targets the patients have in common.
The company’s platform can also display billions of synthetic peptides, and has so far pinpointed more than a dozen possible new targets for TCRs that are now in the preclinical evaluation stage, according to Stefan Scherer, an industry veteran who’s taking on the roles of president and CEO. Previously, Scherer has held leadership positions at GSK, Novartis, Roche and Cellectis, a biotech researching a certain type of cellular immunotherapy.
3T’s most advanced program, however, is not built around one of these new targets, but rather a publicly known cancer-tested antigen. Harper said that program is meant to give 3T a “fast start,” and is on track to enter human testing in either late 2023 or early 2024. The novel programs would then follow suit, with the current aim of getting the most advanced into the clinic by late 2024.
In announcing its launch, 3T also disclosed that it has exclusively in-licensed from Stanford a platform for discovering antibody-based, therapeutic proteins, as well as development-stage TCR assets targeting MAGE-A3, an antigen that has also been of interest to other cancer drugmakers. Prior attempts to develop therapies around this target have hit setbacks, however.
3T previously received seed funding from the Parker Institute for Cancer Immunotherapy, among other investors.