Researchers have devised a way to program T cells to target a different protein present on tumor cells, the New York Times reports.
The two recently approved gene therapies for cancer — Novartis' Kymriah for leukemia and Kite Pharmaceutical's Yescarta for lymphoma — both rely on removing cancer patients' T cells and engineering them to attack cells presenting CD19, which is found on most malignant leukemia and lymphoma cells, the Times adds.
Researchers at the National Cancer Institute and Stanford University have now tried getting T cells to instead focus on CD22, which cancer cells tend to still express after they've become resistant to CD19 therapy. As Stanford's Crystal Mackall and her colleagues report in Nature Medicine this week, they conducted a phase 1 trial of 21 adults and children with B cell acute lymphoblastic leukemia, some of whom had already been treated with CD19 immunotherapy. Nearly three quarters of patients who received the higher of the doses tested went into remission, the researchers report.
Mackall and her colleagues say their findings suggest that immunotherapy targeting both CD19 and CD22 could be more effective than each alone.
"The best way to go is to treat up front with a combination of 19 and 22," adds the University of Pennsylvania's Carl June at the Times. "That should make it 'game over' for the leukemia. I think that will paint it into a corner, and we'll no longer see that kind of relapse. I'm really excited about it." He adds that he'll be studying the treatment.
Mackall tells the Times that they are now testing that the combination treatment at Stanford.