There is a new set of drugs called PD-1 (programmed T cell death 1) and PDL-1 (programmed T cell death ligand) inhibitors that unleash the immune system to attack cancer and in so doing are causing great excitement in oncology as potent new therapies. There have been FDA approvals to use these types of agents (fully human anti-PD-1 monoclonal antibodies) to treat melanoma, non-small cell lung cancer (pembrolizumab and nivolumab) and renal cancer (nivolumab). How effective they will be in chronic lymphocytic leukemia (CLL) is still to be determined.
Take Away Points:
- CLL is very effective at hiding from the immune system.
- New therapies that improve the immune system’s ability to find and kill the CLL cells should offer the promise of better results.
- Trials using these approaches can be found, including these three on the website Clinicaltrials.gov and one interesting trial we mentioned here on our website lead by Dr. Nitin Jain from MD Anderson Cancer Center.
Since CLL is a disease of the immune system and the only cure for CLL has been accomplished by importing a new immune system through a high-risk allogeneic (genetically dissimilar because the cells are from someone else and hence immunologically incompatible) hematopoietic (blood-forming) stem cell (or bone marrow) transplant, it makes good sense to explore using these new drugs in CLL, as they already have had success in solid tumors.
Keep in mind that these trials are very early in development and the very early data presented at ASCO 2015 demonstrated good results in Hodgkin’s Lymphoma, but not so much in other lymphomas.
Dr. John Pagel with the Swedish Hospital in Seattle, WA is both a transplanter and a CLL expert, so he understands the immune risks and benefits of this type of therapy.