Turnstone narrows cell therapy focus to 'high unmet need' tumor indications

Turnstone Biologics is narrowing the focus of phase 1 trials of its lead tumor-infiltrating lymphocyte (TIL) therapy, with cutaneous melanoma and breast cancer no longer in the mix.

The program, dubbed TIDAL-01, has been undergoing two phase 1 trials, including the STARLING study evaluating the therapy for the treatment of breast cancer, colorectal cancer and uveal melanoma. Meanwhile, an investigator-sponsored trial with the H. Lee Moffitt Cancer Center and Research Institute has been focused on cutaneous and non-cutaneous melanomas.

In a second-quarter earnings release yesterday, Turnstone said its clinical development strategy for TIDAL-01 is now focused on “three high unmet medical need indications including colorectal cancer, head and neck cancer and uveal melanoma.”

“In doing so, [we] have deprioritized cutaneous melanoma and breast cancer,” the company said.

Alongside the company’s earnings, Turnstone reported some initial data from the first four colorectal cancer patients in the STARLING trial, including one of the patients demonstrating “a deep and durable ongoing complete response.”

“The clinical signals from these initial data, including a remarkable complete response in one of the first four patients, demonstrated deep and durable anti-tumor activity along with corresponding biological data, which support our fundamental hypothesis of enriching for tumor-reactive T cells in our Selected TIL therapies,” CEO Sammy Farah, Ph.D., said in the earnings release.

“As the competitive profile of TIDAL-01 strengthens with this initial clinical data, we are prioritizing development in solid tumor indications, including metastatic colorectal cancer, where we believe we can differentiate our TIL technology and provide the most benefit to patients,” Farah added.

Turnstone, which went public via an $80 million IPO last year, ended June with $62.4 million at hand, which it expects to last into the third quarter of 2025.