Despite the recent advances in treatment of CLL with targeted agents such as ibrutinib, availability of nonchemotherapy based therapies is desired. Given the 58% response rate (1996 NCI-WG criteria) of single agent ofatumumab in CLL refractory to fludarabine and alemtuzumab, we initiated a phase II trial examining response, safety, and progression-free survival (PFS) of ofatumumab as front-line monotherapy. Patients enrolled included untreated, symptomatic CLL patients over the age of 65 or those who were inappropriate/did not desire chemotherapy. Two cohorts were enrolled sequentially examining either 1 g (33 patients) or 2 g (44 patients) weekly for 8 weeks followed by maintenance dosing every 2 months for a total of 24 months. Patients receiving 1 g were older than those receiving 2 g, but there were no significant differences in other clinical characteristics. The best overall response rates in the 1 and 2 g patient cohorts were 72 and 89% (1996 NCI-WG criteria), respectively (54 and 68%, respectively, using 2008 IWCLL criteria). All but two responses were partial. The 24-month estimated PFS rates were 46 and 78%, respectively. Response and PFS was lower in del(17p) and del(11q) CLL patients. Differences in PFS between dose cohorts were statistically significant and remained so when adjusting for age or high-risk cytogenetics. Toxicity of this treatment was mild with only six patients not completing therapy due to toxicity. Ofatumumab induction followed by maintenance therapy in untreated CLL represents a well-tolerated and active regimen, particularly with the 2 g of ofatumumab. Am. J. Hematol. 91:1020-1025, 2016. © 2016 Wiley Periodicals, Inc.
© 2016 Wiley Periodicals, Inc.