Among 27 patients refractory to rituximab monotherapy, the overall response rate was 22%. The median progression-free survival was 5.8 months. Forty-six percent of patients demonstrated tumor reduction 3 months after therapy initiation, and the median progression-free survival for these patients was 9.1 months.
The most common adverse events included infections, rash, urticaria, fatigue, and pruritus.
Three patients experienced grade 3 infusion-related reactions, none of which were considered serious events.
Grade 3-4 neutropenia, leukopenia, anemia, and thrombocytopenia occurred in a subset of patients.
Ofatumumab was well tolerated and modestly active in this heavily pretreated, rituximab-refractory population and is therefore now being studied in less refractory FL and in combination with other agents in various B-cell neoplasms.
The present study was registered at www.clinicaltrials.gov as NCT00394836.