Turnstone Biologics, a Phase 1 biotech developing selected TIL therapies for solid tumors, raised $80 million by offering 6.7 million shares at $12, the low end of the range of $12 to $14. The company offered 0.9 million more shares than anticipated. Takeda had agreed to submit a non-binding indication of interest on $8 million worth of shares in the offering (10% of the deal); if Takeda did not submit an indication of interest, then the company had planned to sell $8 million worth of shares to Takeda in a concurrent private placement.
Utilizing a differentiated approach to tumor infiltrating lymphocytes (TILs), Turnstone's selected TILs are designed to extend clinical benefit across the majority of solid tumors. The company's lead candidate, TIDAL-01, is undergoing a Phase 1 trial for the treatment of breast cancer, colorectal cancer, and uveal melanoma. It is also conducting an investigator sponsored trial with Moffitt, in both cutaneous and non-cutaneous melanomas. Non-clinical studies in multiple tumor samples have achieved tumor-reactive T cell frequencies in Selected TIL drug product of up to 62% (targeting >70%), with a median frequency of 23%. Turnstone intends to provide an initial clinical update across these two trials in mid-2024.
Turnstone Biologics plans to list on the Nasdaq under the symbol TSBX. BofA Securities, Leerink Partners, and Piper Sandler acted as joint bookrunners on the deal.
