When treated with their own nonengineered T cells plus chemotherapy, six of seven patients with inoperable or metastatic pancreatic cancer showed objective responses or stable disease, according to the results of a study reported at the American Association for Cancer Research’s Immune Cell Therapies for Cancer conference in July 2019.
Unlike CAR T-cell therapy, the T cells used for the study were not genetically modified to target a specific antigen. Instead, they were naturally modified by being exposed to foreign proteins. Researchers used patients’ autologous CD3+, CD4+, and CD8+ T cells, expanded them in a culture that included peptides from five tumor-associated antigens, then infused them back into the patients.
They administered the treatment to 18 patients with pancreatic cancer: 9 who were responding to concurrent chemotherapy, 6 with disease that had progressed with chemotherapy, and 3 with resectable cancer. Only 7 of the 9 responders were evaluable, but 6 of those showed stable disease. Of the 6 patients who progressed with chemotherapy, 1 showed disease stabilization with the T cells and 2 showed symptom stabilization. The 3 patients receiving surgery had only one T-cell infusion before surgery and were not yet evaluable.
The researchers reported that postinfusion tumor-reactive T cells were detected in all patients who showed clinical benefit and that they demonstrated activity against all five tumor-associated antigens plus additional nontargeted antigens.