Among 108 patients with fast-growing and refractory aggressive non-Hodgkin lymphoma (NHL), more than half were still alive at least a year after receiving a single infusion of a CAR T-cell therapy, axicabtagene ciloleucel (axi-cel), that targets the CD-19 protein frequently found on cancerous lymphoma cells, researchers reported. This latest analysis of ZUMA-1, which combines Phase I and II trial data, assessed the rate and durability of responses and survival among these patients after a median follow-up of 15.4 months. More than one year after a single infusion of axi-cel, 42 percent of patients remain in remission and 40 percent of patients exhibit no evidence of cancer.
“Long-term follow-up of ZUMA-1 confirms that these responses can be durable and the ongoing responses at 24 months suggest that late relapses are uncommon. Patients who are in remission at 6 months tend to stay in remission,” said lead study author Sattva Neelapu, MD, professor at The University of Texas MD Anderson Cancer Center. “With existing therapy, the median survival for people with this disease is only 6 months. Here, we see more than half of patients — 59 percent — are still alive over a year after treatment.”
The study also provides some of the first clues as to why some patients relapse or do not respond to CAR T-cell therapy After analyzing tumor tissue from before and after treatment in patients who relapsed, the researchers found that in a third of patients the CD19 protein was no longer present on cancer cells. Secondly, more than two-thirds of tumors showed evidence of another protein, PD-L1, likely helping the cancer cells survive by inhibiting the function of the infused T cells. Follow-up studies are now underway to identify possible approaches to overcoming these problems.