The promise of immune cell therapies is to direct the incredible sophistication of the immune system to the medical targets we want to hit. In the case of CAR-T cells, we take a patient’s own immune T-cells and “program” them through genetic modification to go after cancer cells. While the process of the genetic modification to create those cells is still incredibly expensive and challenging, we’ve seen amazing progress with CAR-T in liquid tumors (e.g., leukemias, lymphomas, etc).
But, when it comes to solid tumors, it’s been far more challenging. Enter this Phase II clinical trial from China (summarized in Nature News). The researchers performed a random controlled trial on 266 patients with gastric or gastro-esophageal cancer who resisted previous treatment and assigned 2/3 to receive CAR-T or best-medical-care (the control) otherwise. The results (see the survival curve below) are impressive — while the median progression-free survival is only about 1.5 months different, it’s very clear that by month 8 there are no progression-free patients in the control group but something like ~25% of the CAR-T group.
The side effect profile is still challenging (with 99% of patients in CAR-T group experiencing moderately severe side effects) but this is (sadly) to be expected with CAR-T treatments.
While it remains to be seen how this scales up in a Phase III study with a larger population, this is incredibly promising finding — giving clinicians a new tool in their arsenal for dealing with a wider range of cancer targets as well as suggesting that cell therapies still have more tricks up their sleeves
The phase II clinical trial in China tested chimeric antigen receptor (CAR) T cells in people with advanced gastric cancer or gastro-oesophageal junction cancer, which are solid tumours. To create CAR-T-cell therapies, T cells are collected from a person with cancer and tweaked to produce proteins that target cancer cells. The T cells are then infused back into the same person. CAR-T-cell therapy has revolutionized cancer treatment but has been most successful against blood cancers.
“Solid tumours generally don’t respond well to CAR-T-cell therapy,” says Lisa Mielke, a cancer researcher at the Olivia Newton John Cancer Research Institute in Heidelberg, Australia. The trials are among the first in which CAR-T-cell therapy has had promising results against solid tumours. They provide “evidence that there is potential for CAR T cells to be further optimized for future treatment of patients with solid tumours”, adds Mielke.
Cancer-fighting CAR T cells show promising results for hard-to-treat tumours
Rachel Fieldhouse | Nature News