IO Biotech, Inc.
Key statistics
from XBRL data in SEC filingsAI briefing
from the latest 10-K, 10-Q and 8-K eventsIO Biotech is a clinical-stage biopharmaceutical company developing off-the-shelf therapeutic cancer vaccines based on its T-win platform, with its lead candidate Cylembio (imsapepimut and etimupepimut, adjuvanted) in late-stage development for advanced melanoma.
What they do
IO Biotech develops immune-modulatory therapeutic cancer vaccines designed to kill tumor cells and immune-suppressive cells in the tumor microenvironment. Its lead candidate, IO102-IO103, known in the U.S. as Cylembio, targets IDO and PD-L1 expressing cells and is being tested in combination with anti-PD-1 therapies. The company also has preclinical candidates IO112 targeting arginase 1 and IO170 targeting TGF-beta.
Revenue drivers
- Cylembio (IO102-IO103) — Lead therapeutic cancer vaccine candidate; no revenue generated to date as it remains in clinical development. A Phase 3 trial in advanced melanoma narrowly missed its primary PFS endpoint in August 2025.
- IO112 — Preclinical T-win vaccine candidate targeting arginase 1; no revenue generated. Preclinical data presented at SITC 2025 showed anti-tumor activity.
- IO170 — Preclinical T-win vaccine candidate targeting TGF-beta; no revenue generated. Preclinical data showed induction of immune responses that could inhibit tumor growth.
Recent performance
In Q3 2025, IO Biotech reported a net loss and ended the quarter with approximately $31 million in cash and cash equivalents, which is expected to support operations through the first quarter of 2026. The company's Phase 3 IOB-013 trial of Cylembio plus pembrolizumab in advanced melanoma showed a median PFS of 19.4 months versus 11.0 months for pembrolizumab alone, but narrowly missed statistical significance (HR 0.77, p=0.056). Overall survival data are not yet mature, with a trend favoring the combination (HR 0.79). The company also presented final Phase 2 basket trial data for IO102-IO103 in NSCLC and SCCHN and preclinical data for IO112 and IO170.
Strategy
IO Biotech is focusing on aligning with the FDA on a potential new Phase 3 registrational trial for Cylembio in advanced melanoma, with a meeting scheduled for December 2025. The company is also advancing its T-win pipeline, with IO112 expected to enter clinical development next. It plans to continue presenting data at medical conferences and engaging with investors. The company's goal is to bring Cylembio to cancer patients as quickly as possible.
Risks
- Clinical and regulatory risk — The Phase 3 IOB-013 trial narrowly missed its primary PFS endpoint, and future trials may not achieve statistical significance or receive regulatory approval.
- Funding risk — The company has incurred net losses since inception and will need substantial additional funding; cash is expected to last only through Q1 2026.
- Manufacturing and supply chain risk — IO Biotech relies on third-party CMOs for manufacturing its product candidates, and production difficulties could delay clinical trials or commercialization.
- Competition risk — The oncology space is highly competitive, and competitors may develop or commercialize products more quickly or successfully.
Outlook
Management expects overall survival data from the Phase 3 IOB-013 trial in 2026. The company has a meeting with the FDA in December 2025 to align on a potential new Phase 3 registrational trial for Cylembio in advanced melanoma. IO Biotech also plans to advance IO112 into clinical development and continue presenting data for its T-win pipeline.