Connecticut biotech Halda Therapeutics, created by Arvinas founder Craig Crews, has reeled in another $126 million to start clinical testing of its oral molecules for solid tumors.
With the new money, the startup said Monday it will enter the clinic in the first half of next year for metastatic, castration-resistant prostate cancer with its first experimental medicine, dubbed HLD-0915. The New Haven-based drug developer then plans to test a second candidate for breast cancer at a later, undisclosed date.
Craig CrewsAs radiopharmaceuticals and antibody-drug conjugates pick up steam in oncology, including in the prostate cancer field, Halda hopes to give patients an orally available option that could potentially be easier to take, chief scientific officer Kat Kayser-Bricker said in an interview.
Halda is working on so-called RIPTAC drugs, an abbreviation for regulated induced proximity targeting chimeras. The biotech hopes its small molecules will hold proteins together in a dumbbell shape to “hug and smother” tumor cells and block critical functions of the targeted protein for longer durations, Crews previously told Endpoints News. The “hold” mechanism is the genesis of Halda’s name.
“This pharmacology with the RIPTACs is really designed to be efficacious across these resistance mechanisms similar to what you see with a biologic like ADCs or radioisotopes, where you leverage a protein’s expression to deliver the cell-killing mechanism,” Kayser-Bricker said. “But this is with an orally bioavailable small molecule, which is incredibly exciting for this space, because primarily prostate cancer patients are treated with their urologists inside the community and they start on oral therapies.”
The Phase 1 will test HLD-0915 as a monotherapy, the CSO said.
The financing marks the 63rd megaround of the year, as investors pour larger sums into more concentrated bets amid a long-running market downturn. The industry is on pace for a record year for nine-figure private funding rounds, SVB said in a mid-year report earlier this month.
Halda emerged with $76 million in February 2023 to build on work out of Crews’ lab at Yale. Research in his lab previously led to the formation of Arvinas, a Phase 3 public biotech partnered with Pfizer and Novartis.
Another heterobifunctional biotech from the professor’s lab, Siduma Therapeutics, shuttered earlier this year due to the “challenging funding environment.” Siduma had received funds from Sequoia Capital China, Andreessen Horowitz, Casdin Capital, Connecticut Innovations, Elm Street Ventures and EQRx.
Siduma and Halda appear to have different investors. A group of high-profile biotech firms invested in Halda for the first time as part of its Series B extension, including Deep Track Capital, Frazier Life Sciences, RA Capital Management, Vida Ventures, Boxer Capital and Taiho Ventures. Existing backers returned, including Canaan Partners, Access Biotechnology, Elm Street Ventures and Connecticut Innovations.
Tim Shannon, Halda’s executive chair and Canaan’s general partner, leads the company. With the new financing, Halda will eventually find a full-time CEO, Kayser-Bricker said. As part of the financing, four people joined Halda’s board: Deep Track’s Rebecca Luse, Frazier’s Joe Cabral, RA’s Nandita Shangari and Vida’s Arjun Goyal.