A long-term follow-up study of immunotherapy with CAR T-cells in patients with B-cell non-Hodgkin’s lymphoma with CD20-carrying B-cells show the approach is similar in effectiveness and safety to the more common CAR T-cell therapy.
The study, published in the journal Signal Transduction and Targeted Therapy, accounted for the fate of patients included in a Phase 1/2 trial (NCT01735604) of the treatment.
Most studies to date have focused on a type of CAR T-cells that recognize and fight another type of cancerous B-cell — those carrying a CD19 molecule. The recently approved Kymriah (tisagenlecleucel) belonged to those.
But lymphomas can also be caused by a CD20 type of B-cell, and researchers at the Chinese PLA General Hospital in Beijing, China have developed CAR T-cells targeting this specific non-Hodgkin’s lymphoma type.
Their study, “Long-term safety and efficacy of CART-20 cells in patients with refractory or relapsed B-cell non-Hodgkin lymphoma: 5-years follow-up results of the phase I and IIa trials,” showed that response rates were similar to those seen with CD19 type CAR T-cells.
The two studies enrolled 17 patients who had relapsed or did not respond to earlier treatment.
Researchers could evaluate responses in 11 of these in the Phase 2a trial. Data showed that a single treatment had eradicated tumors in 54.5%, or six of the patients. In addition, 27.3% saw their tumors shrink, making the objective response rate 81.8%. Two more patients had a complete response after an additional radiotherapy course.
In the Phase 1 study, the tumors in five of six patients regressed.
Researchers followed 12 patients who responded to the treatment for 20 months, with one patient followed up for 60 months after the first CAR T-cell infusion. These patients had a median progression-free survival of 10 months, but progression-free time ranged from two to 57 months.
Researchers reported that the treatment was rather well-tolerated, with no patients experiencing the most severe type of adverse reactions. Four patients had milder forms of cytokine release syndrome.
Among grade 3 side effects were rigor, shingles, and abnormally low numbers of immune cells called neutrophils and antibodies. The patients were given injections of antibodies during the treatment to prevent viral infections, and researchers did not observe an increased infection risk.
Although the number of included patients was small, the study demonstrated that CD20 type CAR T-cells may be a viable treatment option for relapsed or refractory patients with this type of non-Hodgkin’s lymphoma.
