Turnstone Biologics reports initial data from STARLING trial of TIDAL-01

Turnstone Biologics reported initial data from its Phase 1 STARLING trial of TIDAL-01 in metastatic microsatellite stable colorectal cancer, or MSS mCRC. Turnstone’s Phase 1 STARLING trial is an ongoing muti-site, first-in-human, non-randomized, open label, single-dose study, and is evaluating the safety, tolerability, and clinical activity of TIDAL-01. The trial is currently enrolling patients with colorectal cancer, head and neck squamous cell carcinoma, and uveal melanoma. As of the cutoff date of July 15, key takeaways from the initial data include the following: Among the four evaluable MSS mCRC patients included in the study, Turnstone observed a 25% overall response rate, or ORR, and 50% disease control rate, or DCR. One patient demonstrated a deep and durable ongoing complete response, or CR. Overall, 50% of patients showed sustained clinical benefit, with notable progression free survival of over one year in the patient with ongoing complete response and six months for a patient with stable disease. The TIDAL-01 process demonstrated the ability to generate high titer, polyclonal and multi-epitope tumor neoantigen-reactive T cells that expanded in the patient, persisted in the blood and correlated with an increase in CD8 T cell tumor infiltration. TIDAL-01 was generally well-tolerated and safety events observed were consistent with known AEs associated with the lymphodepletion regimen, and IL-2 and pembrolizumab administration. The manufacturing success rate for TIDAL-01 in CRC for patients with sufficient starting material was 80%, which is consistent with other early clinical-stage cell therapy processes. The target dose total T cells was exceeded in all manufactured CRC products.