IO Biotech said it will seek bankruptcy protection after a late-stage cancer vaccine effort failed and FDA interactions tightened the path forward. The Danish developer filed an SEC notice stating it intends to shut down operations, following workforce reductions and a Phase 3 miss for its melanoma vaccine Cylembio. The company’s troubles escalated after regulators advised it not to submit the vaccine for approval in the wake of the Phase 3 result, and subsequent interactions did not reverse course. IO’s remaining cash position, outlined in earlier reporting, was expected to be insufficient to sustain the company beyond early 2026. Under the bankruptcy process, a trustee would take control and liquidate remaining assets. The shutdown also follows a broader pattern of early-stage biotech attrition after clinical setbacks. For stakeholders, the key signal is how quickly late-stage failures and regulatory stances can force liquidation rather than restructuring—especially when development strategies require additional capital to meet updated requirements.