Ninth international conference on progress in vaccination against cancer (PIVAC 9), 8–10 October 2009, Sofia, Bulgaria

Excerpt

Progress in Vaccination Against Cancer 9 (PIVAC-9) was held on 8–10 October 2009, Sofia, Bulgaria, the ninth in an annual series of meetings to pinpoint the year’s advances in cancer immunology and immunotherapy. The talks presented were grouped into five main areas including a session on Cancer Immunity and Ageing for the first time at PIVAC. The other sessions were on aspects of tolerance, immunosuppression and tumour escape; interactions between chemotherapy and immunotherapy; ways to improve cancer vaccines; and the continuing debate on immune monitoring and its standardisation. The meeting opened with a keynote presentation by G. Gaudernack (Oslo) focussing on the approach to cancer vaccines based not on individualised vaccines but a universal vaccine; in this case, human telomerase reverse transcriptase (hTERT). After testing a large number of candidate peptides from hTERT for immunogenicity in vitro, a sequence which potentially represented a good general cancer vaccine was selected. Findings from the latest Norwegian clinical trial of telomerase vaccination for NSCLC (using the GV1001 vaccine consisting of a long telomerase-derived class II-binding peptide EARPALLTSRLRFIPK and one HLA-A2 peptide (hTERT I540-548) together with GM-CSF) were encouraging. Monitoring these patients determined that mixed Th1/Th2 cytokine profiles were observed in the majority of patients, with the concurrent production of IFN-γ, TNF-α, IL-4, and IL-13. Interestingly, CD4+ responses correlated better than CD8 with clinical responses. It was also intriguing that whereas DTH responses were consistent in the NSCLC trial, no DTH response was observed in the melanoma trial, where GV1001 had been combined with temozolomide. Very long-term immunological memory was demonstrated even after vaccination with a single amino acid substitution peptide (mutant ras), and this was confirmed with the GV1001 peptide. Interestingly, in some patients the response was delayed up to several months after vaccination. Furthermore, the results on 26 patients with metastatic, treatment-resistant NSCLC stage III/I showed that 54% of 24 evaluable patients mounted an immune response against GV1001 and one complete regression in a patient with inoperable lung cancer after GV1001 vaccination was achieved (7 years follow-up). A 78% immune response rate in 25 patients with stage IV of metastatic malignant melanoma was observed as well after combining temozolomide with GV1001. Of these patients, long-term T cell responses were seen in ten, and a clinical tumour response was demonstrated in five. After these encouraging results, the main part of the meeting began with the session dedicated to Cancer Immunity and Ageing. This was considered in light of the fact that most clinical trials of experimental cancer therapy, including immunotherapy, do not include elderly patients, despite most solid cancers being diseases of older age. …