Turnstone Biologics Corp.

General Information

We are a clinical stage biotechnology company focused on developing new medicines to treat and cure patients with solid tumors. (Incorporated in Delaware)

Approved immunotherapies represent a significant advancement in the treatment of solid tumors, but many patients either do not respond or experience relapsed disease following an initial response. We believe the most significant challenge to creating curative immunotherapies in these patients is the low numbers of T cells that can recognize and attack the tumor, which we refer to as tumor-reactive T cells. To address this problem, we are pioneering a differentiated approach to tumor infiltrating lymphocytes, or TILs.


TILs are a type of cell therapy that harness the patient’s own immune cells to target their own tumors. TIL therapy involves the isolation of lymphocytes from the patient’s tumor, expansion of the isolated cells outside the body, and then infusion of the cells back into the patient. TILs have the ability to penetrate, recognize, and kill cancer cells and offer potential to treat or cure solid tumors. Because TILs include an expansive breadth of lymphocytes that are specific to the patient’s tumor antigens, we believe they have the potential to overcome tumor heterogeneity which often presents a significant challenge for other therapies. Clinical trials with standard “bulk TILs,” the first generation of TIL therapy that involves isolation and expansion of all of the TILs in the tumor sample, have shown objective responses in clinical trials in limited solid tumor types.


We are developing next-generation TIL therapies by selecting the most potent (meaning able to mediate an anti-tumor response) and tumor-reactive T cells, which we refer to as Selected TILs. Unlike other approaches that rely on standard “bulk TILs” that have demonstrated objective responses in clinical trials only in limited tumor types, we are developing our Selected TILs for potential treatment across the majority of solid tumors.

We have initiated two Phase 1 clinical trials for our lead candidate, TIDAL-01, including a multi-site trial for the treatment of breast cancer, colorectal cancer and uveal melanoma, and an investigator-sponsored trial with H. Lee Moffitt Cancer Center and Research Institute, Inc., or Moffitt, in both cutaneous and non-cutaneous melanomas. We discuss the nature of this investigator-sponsored trial, including how this trial differs from a clinical trial sponsored by our company, as well as our roles and responsibilities in the trial, in more detail in the prospectus. We intend to provide an initial clinical update across these two trials in mid-2024.

We are also actively advancing our preclinical pipeline programs including TIDAL-02, our next Selected TIL program, and our TIDAL-01 viral immunotherapy combination program. We define objective response as a patient experiencing a partial response or complete response to any given therapy.

(Note: Turnstone Biologics Corp. upsized its IPO at pricing – to 6.67 million shares – up from 5.8 million shares in the prospectus – and priced the IPO at $12.00 – the low end of its $12.00-to-$14.00 price range – to raise $80.04 million. Turnstone Biologics Corp. filed an S-1/A on July 17, 2023, in which it disclosed terms for its IPO: 5.8 million shares at $12.00 to $14.00 to raise $75.4 million. Turnstone Biologics Corp. filed its S-1 on June 12, 2023.


Employees: 112
Founded: 2014
Contact Information
Address 9310 Athena Circle, Suite 300 La Jolla, California 92037
Phone Number (347) 897-5988
Web Address http://www.turnstonebio.com/
View Prospectus: Turnstone Biologics Corp.
Financial Information
Market Cap $266.26mil
Revenues $81.89 mil (last 12 months)
Net Income $-18.5 mil (last 12 months)
IPO Profile
Symbol TSBX
Exchange NASDAQ
Shares (millions): 6.7
Price range $12.00 - $12.00
Est. $ Volume $80.0 mil
Manager / Joint Managers BofA Securities/ Leerink/ Piper Sandler
Expected To Trade: 7/21/2023
Status: Priced
Quiet Period Expiration Date:
Lock-Up Period Expiration Date:
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