Immunotherapy comes of age for blood cancers
The recent approval of nivolumab for the treatment of relapsed classical Hodgkin Lymphoma (cHL) has brought the tumor micro environment into the limelight and has focused attention specifically on the recruitment of host immunity in the treatment of blood cancers. The approval was based on an impressive 87% response rate in cHL patients who had failed both autologous stem cell transplant as well as brentuximab vedotin . Pembrolizumab and other similar agents are also showing activity in cHL and several other hematologic malignancies. By way of side effects, patients have suffered from a wide plethora of autoimmune issues especially regarding the endocrine system but autoimmune pneumonitis and colitis have led to termination of therapy in 2–5 % of patients. Some responses have persisted in spite of termination, but there is no consensus on when to stop these agents and if the responses are durable in most patients.