Ofatumumab-based chemoimmunotherapy is effective and well tolerated in patients with previously untreated chronic lymphocytic leukemia (CLL)
Article first published online: 6 AUG 2013
© 2013 American Cancer Society
Volume 119, Issue 21, pages 3788–3796, 1 November 2013
How to Cite
Shanafelt, T., Lanasa, M. C., Call, T. G., Beaven, A. W., Leis, J. F., LaPlant, B., Bowen, D., Conte, M., Jelinek, D. F., Hanson, C. A., Kay, N. E. and Zent, C. S. (2013), Ofatumumab-based chemoimmunotherapy is effective and well tolerated in patients with previously untreated chronic lymphocytic leukemia (CLL). Cancer, 119: 3788–3796. doi: 10.1002/cncr.28292
- Issue published online: 18 OCT 2013
- Article first published online: 6 AUG 2013
- Manuscript Accepted: 2 JUL 2013
- Manuscript Revised: 12 JUN 2013
- Manuscript Received: 6 MAY 2013
- chronic lymphocytic leukemia;
- small lymphocytic lymphoma;
Although rituximab-based chemoimmunotherapy (CIT) has substantially improved clinical outcomes in chronic lymphocytic leukemia (CLL), only 40% to 50% of patients achieve a complete remission (CR). There remains interest in identifying new approaches to improve the effectiveness of CIT. Ofatumumab is a fully human anti-CD20 monoclonal antibody with greater apparent single-agent activity than rituximab in CLL patients.
Previously untreated CLL patients in need of therapy received 6 cycles of CIT induction with pentostatin, cyclophosphamide, and ofatumumab (PCO) followed by response assessment.
Of the 48 patients enrolled, 77% completed PCO induction. Adverse events during induction included grade 3+ hematologic toxicity (27%) and grade 3+ nonhematologic toxicity (23%). Median CD4 count after induction and 6 months later were 186 × 106/L and 272 × 106/L. The overall response rate was 96% (46 of 48 patients), and the CR rate was 46% (22 of 48 patients). Among the 38 patients who underwent minimal residual disease evaluation, 7 (18%) were negative for minimal residual disease. After median follow-up of 24 months, 10 (21%) patients have progressed and 8 (17%) have required retreatment. The efficacy and toxicity of ofatumumab-based CIT compare favorably to our historical trials of rituximab-based CIT using an identical chemotherapy backbone (n = 64). Time to retreatment also appeared longer for ofatumumab-based CIT (free of retreatment at 24 months: 86% [95% confidence interval = 75-99] versus 68% [95% confidence interval = 56-81] for rituximab-based CIT).
Ofatumumab-based CIT is well tolerated in patients with previously untreated CLL. The efficacy of ofatumumab-based CIT compares favorably to historical trials of rituximab-based CIT, suggesting randomized trials comparing ofatumumab-based CIT and rituximab-based CIT should be considered. Cancer 2013;119:3788–3796. © 2013 American Cancer Society.