IO Biotech enrols 380 patients with advanced melanoma in phase 3 trial

The trial is evaluating an investigational cancer vaccine in combination with Keytruda

IO Biotech has announced that it has completed the enrolment of 380 patients in a phase 3 clinical trial of its investigational immune-modulating therapeutic cancer vaccine in advanced melanoma.

The open-label, randomised clinical study being conducted in collaboration with Merck & Co – known as MSD outside the US and Canada – is comparing the candidate IO102-IO103 in combination with Merck’s anti-PD-1 therapy Keytruda (pembrolizumab) versus Keytruda alone in patients with previously untreated, unresectable or metastatic melanoma.

The cancer vaccine in combination with a PD-1 inhibitor has already demonstrated “approximately double the effect than would have been expected with PD-1 inhibitor monotherapy in this patient population,” said Mai-Britt Zocca, president and chief executive officer of IO Biotech, with results from a phase 1/2 study showing that 80% of patients achieved a response and 50% achieved a complete response.

Furthermore, there were no additional systematic toxicity responses other than those typically recognised with a PD-1 inhibitor alone.

Metastatic melanoma is a type of skin cancer that is often caused by too much sun exposure, which accounts for around 1.7% of global cancer diagnoses.

So far, patients have been enrolled from centres across the US, EU, Australia, Turkey, Israel and South Africa.

The primary endpoint of the phase 3 trial is progression free survival (PFS) and a PFS analysis is estimated to be conducted in the second half of 2025 after 226 events have occurred in the trial.

Andrew Poklepovic, principal investigator at the VCU Massey Comprehensive Cancer Center in Richmond, Virginia, said: “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.”

Merck’s Keytruda has already received approvals from the European Commission and the US Food and Drug Administration and has been undergoing several clinical studies to treat cancer, including gastric, bladder and lung cancer.

Most recently, Merck shared positive results for adjuvant Keytruda in a late-stage trial in certain kidney cancer patients.