The objective response rate in the study was 50%, with efficacy observed in rituximab-refractory patients, Dr. Advani said. With a median follow-up of greater than 6 months, just 1 of 11 responders had progressed. The median duration of response was not reached, with the longest complete remission lasting more than 14 months.
5F9 is able to selectively eliminate cancer cells through blockade of CD47, while rituximab enhances 5F9’s activity via antibody-dependent cellular phagocytosis, according to Dr. Advani.
“CD47 blockade takes the foot off the brakes, while rituximab puts the foot on the accelerator, leading to maximal tumor phagocytosis,” she said.
The Food and Drug Administration recently granted 5F9 a fast track designation for both diffuse large B-cell lymphoma and follicular lymphoma. Phase 2 investigations of 5F9 in these lymphomas are ongoing, Dr. Advani said.