IO Biotech Completes Enrollment of 380 Patients in Pivotal Phase 3 Trial in Advanced Melanoma

• Trial expected to reach the primary endpoint of progression free survival in the second half of 2025
• Per-protocol interim analysis expected in mid-2024

NEW YORK, Nov. 10, 2023 (GLOBE NEWSWIRE) -- IO Biotech (Nasdaq: IOBT), a clinical-stage biopharmaceutical company developing novel, immune-modulating therapeutic cancer vaccines, announced today that it has completed enrollment in the pivotal Phase 3 clinical trial for IO102-IO103, in combination with KEYTRUDA^® (pembrolizumab), Merck’s anti-PD-1 therapy, in patients with advanced melanoma. As of today, 380 patients have been randomized in the trial.

“The Phase 1/2 data of IO102-IO103 in combination with a PD-1 inhibitor in patients with first-line advanced melanoma demonstrated approximately double the effect than would have been expected with PD-1 inhibitor monotherapy in this patient population – with 80% of patients achieving a response, 50% of patients achieving a complete response, and no additional systemic toxicity than that typically seen with a PD-1 inhibitor alone,” said Mai-Britt Zocca, PhD, President and CEO of IO Biotech. “Completion of enrollment in this pivotal Phase 3 trial marks a significant milestone for our company and is a testament to the enthusiasm for this study among our investigators and the patient community. We would like to extend our gratitude to the patients, caregivers, investigators, and study staff whose commitment to this trial is helping bring us closer to potentially changing the treatment paradigm for patients with advanced melanoma.”

“Metastatic melanoma is a life-threatening cancer and although many new treatments have been introduced over the last decade that have significantly improved the outcomes for patients, there still remains a high unmet need for more efficacious options with low treatment-induced toxicity for people battling advanced melanoma,” said Laurent Mortier, MD, Principal Investigator at the Centre Hospitalier Universitaire de Lille in France. “The interest from patients to enter this study is a testament to the need for better treatment options, and we are all eager to see the results.”

Andrew Poklepovic, MD, Principal Investigator at the VCU Massey Comprehensive Cancer Center in Richmond, Virginia, commented, “I am very excited to see the successful completion of accrual to this important Phase 3 trial and eagerly await reported outcomes. The Phase 1/2 trial previously reported showed outstanding preliminary data on efficacy and safety. Phase 3 validation of this novel immune modulatory approach combined with standard of care anti-PD-1 has the potential to transform the field of melanoma and illuminate new ways to approach the treatment of cancers with immunotherapy.”

About Trial Endpoints

The primary endpoint of the IOB-013/KN-D18 trial is progression free survival (PFS). The PFS analysis is event-driven and will be conducted when 226 events have occurred in the trial, which the company estimates will take place in the second half of 2025. Additionally, there is a planned per-protocol interim analysis of overall response rate when the first 225 randomized patients reach one year of treatment in mid-2024. The outcome of this analysis is expected in the third quarter of 2024. There is a high statistical bar for the Phase 3 interim analysis (p≤0.005), which was set to preserve most of the alpha for the primary endpoint of PFS. Regardless of the outcome of the interim analysis, the trial is designed to continue to the primary PFS endpoint.

About the IOB-013/KN-D18 Pivotal Phase 3 Clinical Trial

IOB-013/KN-D18 (Clinical Trials.gov: NCT05155254) is an open label, randomized Phase 3 clinical trial of IO102-IO103 in combination with pembrolizumab versus pembrolizumab alone in patients with previously untreated, unresectable or metastatic (advanced) melanoma, being conducted in collaboration with Merck. Patients have been enrolled from centers across the United States, Europe, Australia, Turkey, Israel and South Africa. The primary endpoint of the study is progression free survival. Biomarker analyses will also be conducted. IO Biotech is sponsoring the Phase 3 trial and Merck is supplying pembrolizumab. IO Biotech maintains global commercial rights to IO102-IO103.

About IO102-IO103

IO102-IO103 is an investigational immune-modulating therapeutic cancer vaccine designed to target the immunosuppressive mechanisms mediated by the proteins indoleamine 2,3-dioxygenase (IDO) and programmed death-ligand 1 (PD-L1). The company is currently conducting a pivotal Phase 3 trial (IOB-013/KN-D18; NCT05155254) evaluating IO102-IO103 in combination with pembrolizumab in first-line advanced melanoma patients, a Phase 2 basket trial (IOB-022/KN-D38; NCT05077709) evaluating IO102-IO103 in combination with pembrolizumab in first-line advanced non-small cell lung cancer and head and neck cancer (SCCHN), and a Phase 2 basket trial (IOB-032/PN-E40; NCT05280314) evaluating IO102-IO103 plus pembrolizumab as a perioperative treatment in solid tumors including melanoma and SCCHN.

The clinical trials are sponsored by IO Biotech and conducted in collaboration with Merck and Merck is supplying pembrolizumab. IO Biotech maintains global commercial rights to IO102-IO103.

KEYTRUDA^® is a registered trademark of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.

About IO Biotech

IO Biotech is a clinical-stage biopharmaceutical company developing novel, immune-modulating therapeutic cancer vaccines based on its T-win^® vaccine platform. The T-win platform is a novel approach to cancer vaccines designed to activate T cells to target tumor cells and immunosuppressive cells in the tumor microenvironment. IO Biotech is advancing its lead cancer vaccine candidate, IO102-IO103, in clinical trials, and additional pipeline candidates through preclinical development. Based on positive Phase 1/2 first line advanced melanoma data, IO102-IO103, in combination with pembrolizumab, has been granted a breakthrough therapy designation for the treatment of unresectable/metastatic melanoma by the US Food and Drug Administration. IO Biotech is headquartered in Copenhagen, Denmark and has US headquarters in New York, New York.

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Forward-Looking Statement

This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking statements, including regarding the timing of the interim analysis of our Phase 3 trial, current or future clinical trials, their progress, enrollment or results, or the company’s financial position or cash runway, are based on IO Biotech’s current assumptions and expectations of future events and trends, which affect or may affect its business, strategy, operations or financial performance, and actual results and other events may differ materially from those expressed or implied in such statements due to numerous risks and uncertainties. Forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified. Because forward-looking statements are inherently subject to risks and uncertainties, you should not rely on these forward-looking statements as predictions of future events. These forward-looking statements speak only as of the date hereof and should not be unduly relied upon. Except to the extent required by law, IO Biotech undertakes no obligation to update these statements, whether as a result of any new information, future developments or otherwise.

Company Contact:

Maryann Cimino, Director of Investor Relations

IO Biotech, Inc.

617-710-7305