Ofatumumab is safe and effective as front-line treatment in older patients with chronic lymphocytic leukemia and severe co-morbidities, including other malignancies.

ABSTRACT

BACKGROUND: The majority of patients with chronic lymphocytic leukemia (CLL) are older and have multiple comorbidities, including other cancer diagnoses. These patients are routinely excluded from participation in clinical trials. OBJECTIVE: In this phase II study, we determined the activity and toxicity of ofatumumab, a fully human anti-CD20 monoclonal antibody, in older patients with CLL, poor performance status and comorbidities. METHODS: Treatment-naïve patients with CLL aged ≥65 years with an ECOG performance status of 2-3 or Charlson comorbidity index ≥2 were eligible. Ofatumumab was administered intravenously weekly for the first month, then monthly for a total of 12 months. RESULTS: Thirty-four patients were enrolled. Median age was 73 years, and 29% had another cancer diagnosis. Among 32 patients evaluable for response, the overall response rate was 72%. We observed complete responses in 19% of patients and partial responses in 53%. The median progression-free survival duration was 21 months, and the estimated proportion of patients alive at 36 months was 87%. All 34 patients were evaluable for toxicity. Treatment was well tolerated, with infusion-related reactions being the most common treatment-related adverse event. Only one patient had a grade 3 infection. Additional grade 3 adverse events that may have been related to ofatumumab were diarrhea, nausea/vomiting, hyperglycemia, pulmonary embolism, and hypersensitivity reaction, each in one patient. No grade 4 adverse events were observed. CONCLUSION: Single-agent ofatumumab is a well-tolerated and effective therapeutic approach for treatment-naïve older patients with CLL; it can be safely administered to patients with significant comorbidities and other cancer diagnoses.