In a recent study presented at the American Association for Cancer Research conference on Pancreatic Cancer: Innovation in Research and Treatment, researchers reported that a combination therapy of gemcitabine and radioimmunotherapy (fractionated doses of (90Y-clivatuzumab tetraxetan) given to metastatic pancreatic ductal cancer patients improved survival times over patients who received only radioimmunotherapy. The study was a randomized phase Ib study of patients who had received at least two prior systemic therapies.
A total of 58 patients with median age of 63.5 years were randomly split into two cohorts of 29. Both groups received the radioimmunotherapy of 90Y-clivatuzumab tetraxetan for three-week cycles. In addition, group A patients received low-dose gemcitabine for 1 week and then in combination with the radioimmunotherapy for 3 weeks per cycle. With 4-week breaks between cycles, patients were administered up to 9 cycles. Twenty-seven patients in the combination therapy group A and 26 patients in group B completed at least one cycle. A total of 12 patients (group A) and 11 patients (group B) completed two or more cycles. The others terminated treatment due to disease progression or clinical deterioration.
Researchers found that the combination therapy patients were 45% more likely to live longer relative to the patients receiving only radioimmunotherapy. For patients receiving multiple cycles, the median survival time for group A was 7.9 months, compared to 3.4 months for those in group B. There was no significant difference in survival times between cohorts for patients who received only one cycle of treatment. Three patients in group A are still being observed (11-17 months). Side effects of the treatments were reported as minimal.
Authors of the study concluded, first, that clinical study and treatment is possible in this population of cancer patients for whom there is no standard of care. Second, for patients receiving multiple cycles, the median overall survival time for combination therapy patients was 7.9 months versus 3.4 months for those receiving only radioimmunotherapy. Third, researchers concluded that treatment side effects were minimal. The only clinically significant side effect was reduced blood counts.
Picozzi, Vincent J., et al. Presented at the, American Association for Cancer Research (AACR) conference on Pancreatic Cancer: Innovation in Research and Treatment, May 18 – 21, 2014, New Orleans, LA.