Phase I clinical trial of human vascular endothelial growth factor receptor 1 peptide vaccines for patients with metastatic renal cell carcinoma

Background: It is well known that renal cell carcinoma (RCC) represents one of the most immune-responsive cancers. Although the lack of defined antigens in RCC has hindered more specific vaccine development, research regarding vaccination therapy has been of special interest for the treatment of RCC for more than 30 years. Methods: To evaluate the safety of the vascular endothelial growth factor receptor 1 (VEGFR1) peptide vaccination and its clinical outcomes, data from 18 metastatic RCC (mRCC) patients treated with VEGFR1 vaccine were collected. Toxicity assessments were performed. Clinical outcomes included assessment using CT scanning, magnetic resonance imaging or X-ray examination in accordance with the WHO Response Evaluation Criteria in Solid Tumors. Results: No patient showed any toxicities of grade 3 or greater. Of the 18 patients, 2 patients showed a partial response during treatment. Stable disease for more than 5 months was observed in eight patients with a median duration of 16.5 months (4-32 months). At the time of the analysis in this study, six patients were alive with a median follow-up of 30 months (26-36 months). Conclusion: These results suggest that VEGFR1 peptide vaccine is safe and is recommended for further trials for patients with mRCC.