Immunothérapie des cancers : Succès récents et perspectives

Abstract

L’immunothérapie des cancers a longtemps été considérée comme une approche thérapeutique séduisante mais peu efficace. Deux nouvelles approches d’immunothérapie, l’une vaccinale chez des patients atteints de cancers de la prostate ou de mélanomes, et l’autre utilisant un anticorps anti-CTLA4 qui cible les lymphocytes T de patients atteints de mélanomes, ont démontré leur efficacité dans des essais cliniques de phase III. La prise en compte de l’immunosuppression associée au cancer et la combinaison de l’immunothérapie avec les traitements conventionnels (chimiothérapie, traitement antiangiogénique) devraient encore améliorer cette approche, aussi bien dans son efficacité que dans ses indications cliniques.

Immunotherapy of cancer has long been considered as an attractive therapeutic approach but with no impact on clinical practice. Two clinical protocols of immunotherapy, one based on a cancer vaccine in patients with prostate cancer or melanoma and the other using an immunomodulator targeting T cells (anti-CTLA4 mAb) in melanoma patients, have demonstrated clinical efficacy in two phase III clinical trials. To improve these encouraging clinical results, biomarkers to better select patients which may benefit from this therapy are actively searched. In addition, immunosuppression associated with cancer has to be overcome to allow a better immunostimulation. In contrast to chemotherapy, clinical variables to monitor the efficacy of immunotherapy has to be revisited and overall survival appears to be a better endpoint than clinical response defined by the RECIST criteria. Combination of immunotherapy with conventional treatments (chemotherapy, anti-angiogenic, etc.) should further improve this approach both in its effectiveness and in its clinical indications.