Marker Therapeutics reports interim results of MultiTAA T Cell Therapy
Marker Therapeutics announced interim data from an ongoing investigator-sponsored clinical trial led by Baylor College of Medicine, evaluating the company's MultiTAA T cell therapy in patients with pancreatic adenocarcinoma. The trial plans to enroll a total of 45 patients with advanced or borderline resectable pancreatic adenocarcinoma in a three-arm trial. Arm A is for patients with unresectable/metastatic disease who are responding to standard first-line chemotherapy. Arm B is for patients with progressive disease or therapy intolerance. Arm C is an exploratory arm for patients with surgically resectable disease. To date, a total of 19 patients have been administered infusions of MultiTAA T cell therapy. Arm A: This arm was designed to evaluate the safety and potential efficacy of using MultiTAA cells as part of first-line treatment for patients with pancreatic cancer. These patients in the chemo-responsive arm have completed or will complete at least three months of standard-of-care chemotherapy - the period during which a response to chemotherapy would typically occur - before receiving up to six administrations of MultiTAA T cells in conjunction with chemotherapy. Overall tumor volume shrinkage was observed in six out of the eight patients with a measurable tumor after administration of MultiTAA cells. One evaluable patient did not have tumor measurements for analysis. Of the 9 evaluable patients, over half have survived to or beyond the historical median overall survival associated with their respective chemotherapy regimens, and 7 of the 9 patients remain alive. In patients responding to therapy, significant expansion of the infused MultiTAA cells was observed, along with broad-based epitope spreading, with significant expansion of endogenous T cells specific for other tumor specific antigens. Arm B: This arm was designed to evaluate the use of MultiTAA cells as a second-line therapy for patients who have failed first-line chemotherapy. The patients in this chemo-refractory arm are either ineligible for chemotherapy or have progressed on chemotherapy and have received or are receiving up to six doses of MultiTAA T cells as a monotherapy. Among the patients who saw clinical disease stabilization, significant expansion of the infused MultiTAA cells was observed, along with broad-based epitope spreading, with significant expansion of endogenous T cells specific for other tumor specific antigens. Arm C: This arm was designed to assess T cell infiltration and expansion. These patients with borderline surgically resectable disease received or will receive a dose of T cells following chemotherapy, radiotherapy or combination prior to surgical resection and up to five additional doses of T cells after surgery. In these patients, MultiTAA T cells were measurable in meaningful numbers as detected by correlative analysis of resected tumor, and significant expansion of the infused MultiTAA cells was observed, along with broad-based epitope spreading, with significant expansion of endogenous T cells specific for other tumor specific antigens. Overall, investigators observed a clinical benefit correlated with the detection of tumor-reactive T cells in patient peripheral blood and within tumor biopsy samples post-infusion. T cells exhibited activity against both targeted antigens as well as non-targeted TAAs including WT-1, AFP, MART-1 and numerous antigens of the MAGE family, indicating induction of antigen/epitope spreading. No infusion-related systemic- or neurotoxicity was observed, and patients continue to be evaluated and enrolled in the trial.