Response to Induction Therapy and Ofatumumab Consolidation in Patients With CLL
Posted: Friday, April 9, 2021
In patients with chronic lymphocytic leukemia (CLL) who are treated with chemoimmunotherapy, high-risk cytogenetics and minimal residual disease (MRD, also known as measurable residual disease) positivity are predictive of unfavorable outcomes. A phase II study reported that risk-adapted chemoimmunotherapy may be feasible for patients with treatment-naive CLL. Ofatumumab consolidation, however, did not seem to improve the depth of response for patients who remained MRD-positive after induction therapy. The study team noted that the loss of targetable CD20 antigens among MRD-positive patients may have reduced the efficacy of consolidation therapy. The report was published in Leukemia & Lymphoma.
“Future studies are needed to investigate effectiveness of anti-CD20 monoclonal antibody in the context of targeted agents,” Inhye E. Ahn, MD, of the National Institutes of Health, Bethesda, Maryland, and colleagues concluded.
The research team evaluated how 28 patients with treatment-naive CLL responded to risk-adapted chemoimmunotherapy. Patients with high-risk cytogenetics received induction therapy with fludarabine, cyclophosphamide, and ofatumumab. Those who did not have high-risk cytogenetics received fludarabine and ofatumumab as induction therapy. If patients were MRD-positive following induction, they were treated with four doses of ofatumumab consolidation. No intervention was made if patients were MRD-negative.
The 2-year progression-free survival rate among all patients was 71.4%. No significant differences in progression-free survival were found between high- and standard-risk patients. All of the patients responded to induction therapy, and 10 patients (36%) achieved MRD negativity. None of the patients who received ofatumumab consolidation achieved MRD negativity. The study group observed a selective loss of CD20 antigens during therapy in the MRD-positive group.
Disclosure: The study authors reported no conflicts of interest.