Survival improved with personalized tumor vaccines added to IL-2 for melanoma
Combining high-dose interleukin-2 (IL-2) and personalized vaccines to activate patients' immune systems improves survival of metastatic melanoma even more than IL-2 alone.
Metastatic melanoma has a poor prognosis, but treatment with IL-2 can extend survival. This study tested the hypothesis that adding active specific immunotherapy (ASI) with patient-specific tumor stem cell vaccines derived from autologous tumor cell lines would improve outcomes. The study was published in Cancer Biotherapy & Radiopharmaceuticals (2014; doi:10.1089/cbr.2013.1565).
IL-2 has been a standard therapy for melanoma since it was approved for metastatic renal cell cancer in 1992, and it has been approved for melanoma since 1998. Despite the recent introduction of oral enzyme inhibitors, such as vemurafinib, dabrafenib, trametinib, and ipilimumab, the authors stated that IL-2 is still recommended for patients who are medically fit enough for such treatment. They based this suggestion on the 20% 5-year survival rate for 150 patients who were treated with inpatient IL-2 regimens from 1987 to 2010, and on the lack of long-term follow-up data for the new therapies.
This study of existing databases found that, of 149 patients who were treated with IL-2, 32 also received ASI, with 19 of them receiving the ASI within 12 months of the IL-2 therapy. The patients who received IL-2 plus ASI had a longer median survival of 39.5 months than the 12.0 months of those who received only IL-2. The 5-year survival rate was 39% for those who received IL-2 and ASI versus 13% for those who received only IL-2. Further analysis found that ASI based on dendritic cells and tumor cell lines led to longer survival than ASI with irradiated tumor cells.
Overall, this retrospective study suggested that those who receive IL-2 followed by a patient-specific melanoma stem cell vaccine have better survival than those who receive IL-2 alone.