Phase I/II study of multipeptide cancer vaccine IMA901 after single‐dose cyclophosphamide in Japanese patients with advanced renal cell cancer with long‐term follow up

Abstract Background IMA901 is the first therapeutic vaccine for renal cell cancer (RCC). It contains multiple tumor‐associated peptides (TUMAPs) that are naturally present in human cancers. Methods In a phase I/II study , we treated a total of 10 Japanese patients with advanced RCC who were human leukocyte antigen A (HLA‐A)*02 +. Vaccination involved i.d. injection of GM‐CSF (75 μg), followed within 15–30 min by i.d. injection of IMA901 (containing 413 μg of each peptide). No treatment with either anticancer agents or immunosuppressants was allowed within 4 weeks before entering the trial. Patients were scheduled to receive 7 vaccinations during the first 5 weeks of treatment (induction period), followed by 10 further vaccinations at 3‐week intervals for up to 30 weeks (maintenance period). The primary endpoints were safety and tolerability, while the secondary endpoints were PFS, OS, and immunogenicity. Results There were no treatment‐related serious adverse events or deaths during the study period. When the response was assessed after 4 months, 10% of patients showed a partial response, 80% had stable disease, and 10% had progressive disease. Among patients in whom the T‐cell response was analyzed, five patients showed a vaccine‐induced T‐cell response against at least one HLA class I‐restricted TUMAP and two patients had T‐cell responses to multiple TUMAPs. PFS was 5.5 months and OS was 18 months. Conclusions This study demonstrated the safety and tolerability of IMA901 vaccine in Japanese RCC patients, and also showed that vaccination elicited an immune response.