Experimental treatment offers hope for CAR-T leukemia patients
- Some of the chronic lymphocytic leukemia patients in a small-scale University of Pennsylvania study of Novartis' CTL 109 have experienced sustained remission benefit from having the modified cells in their bodies for years after initial infusions.
- Four of 14 patients in the five-year study had complete remissions, but six did not respond to therapy at all. The remaining four had partial responses to treatment.
- The important takeaway from this study is that patients who have experienced sustained remission benefit from having the modified cells in their bodies for years after initial infusions. This means that in some patients, the re-engineered CTL019 cells retain their ability to target and destroy cancerous cells for a long period of time.
Despite the fact that this study is small, its power lies in the fact that some of the results have been long-lasting. This is yet another positive development in the world of immuno-oncology, because it demonstrates the ability of chimeric antigen receptor therapy (CAR-T) treatments to create long-term immnologic responses to specific cancers.
Nonetheless, there was a notable downside in this study, highlighting a problem that has emerged with CAR-T in general---the occurence of cytokine release syndrome (CRS) in response to treatment. CRS is an extreme inflammatory response to CAR-T, which leads to flu-like symptoms and can be fatal.
Researchers have been investigating ways to manage CRS without compromising treatment goals. One method that has worked is giving patients the antibody drug tocilizumab combined with steroids.
So what was the difference between patients who survived and patients who died? One development researchers discovered was that in patients who did not respond to treatment, the re-engineered, customized T-cells did not expand as aggressively as they did in patients who had a big response, which led them to develop CRS early on, but also benefit more from the treatment.
Novartis is continuing to move forward with its research, with the goal of tackling CRS and eventually gaining a CLL approval for CTL019.