NY-ESO-1 Vaccine in Combination With Ipilimumab in Patients With Unresectable or Metastatic Melanoma

Patients were enrolled sequentially, alternating among 3 treatment arms. Study treatment comprised ipilimumab 3 mg/kg administered intravenously (IV) over 90 minutes every 3 weeks for 4 doses followed by the NY-ESO-1 vaccine administered subcutaneously (SC). Arm A received the NY-ESO-1 recombinant protein mixed with polyinosinic-polycytidylic acid-poly-L-lysine carboxymethylcellulose (Poly-ICLC) and Montanide; Arm B received NY-ESO-1 overlapping long peptides 4 (OLP4) mixed with Poly-ICLC and Montanide; and Arm C received NY-ESO-1 OLP4 mixed with Poly-ICLC (without Montanide). The vaccine was administered immediately following the ipilimumab infusion, and patients were observed for 1 hour following administration. No dose adjustments or delays were permitted. Because the study treatment regimens had not been previously investigated in humans, the first patient in each treatment arm was followed for 28 days and evaluated for any regimen-limiting toxicity (RLT), defined as any dose-limiting toxicity (DLT) that could not be attributed solely to either the vaccine or ipilimumab and was therefore considered to be related to the combination. If an RLT was observed in the first patient, the second patient was to be evaluated for 28 days before the third patient was enrolled. If at any point ≥ 2 RLTs were observed in a treatment arm, accrual to that arm was to be terminated and the combination in that arm was to be declared unsafe. Patients were monitored for safety, immune and tumor response, and immunological changes in the tumor microenvironment for the duration of study participation, which may have been up to 6 months.