Ofatumumab and High-Dose Methylprednisolone Is An Effective Salvage Treatment for Heavily Pretreated, Unfit or Refractory Patients with Chronic Lymphocytic Leukemia: Single Institution Experience

Abstract 4638

High-dose methylprednisolone (HDMP) and the fully human monoclonal anti-CD 20 Ofatumumab each can produce partial responses in CLL, even though complete remissions are not often observed following treatment with either agent alone.

Previously we have reported that the combination of Rituximab and HDMP is an effective non-myelosuppressive treatment combination for previously untreated CLL patients as well as in patients that are fludarabine refractory. We report here our single institution experience of treatment using the combination of HDMP and Ofatumumab in CLL patients that were not considered to be good candidates for chemotherapy treatment due to comorbidities, poor performance status, profound cytopenias or because refractory status to fludarabine and/or alemtuzumab.

Eight patients with progressive, symptomatic CLL were treated with HDMP 1 g/m² IV daily × 3 every 28 days for three consecutive cycles, and ofatumumab administered based on package insert instructions (300 mg dose # 1 followed by 11 doses of 2,000 mg over a 6 month period) along with prophylactic antimicrobial therapy. The main objectives were to determine the safety, toxicity and clinical efficacy of this regimen.

All of the patients were males with a median age of 69 years (range 49–78). The median of prior treatments was 4.5 including 4 patients that have received previously HDMP and rituximab and two patients that underwent matched unrelated donor stem cell transplant. All patients have been previously treated with rituximab, 75% of the patients failed or were intolerant to fludarabine and/or aletuzumab and 88% had high-risk disease by the modified Rai classification. Most of the patients had bulky disease with median lymph node product of 42 cms² and median splenomegaly of 6. 5 cm (range 0–17) below the left costal margin. The median lymphocyte count was 28,000 cells/mm³. 75% of the patients had high-risk prognostic markers including unfavorable cytogenetics, unmutated IgV_H region genes or high expression levels of ZAP-70.

All patients completed the planned therapy with no major side effects or toxicities. There was no evidence of marrow suppression and even patients with pancytopenia improved their peripheral blood counts with this salvage regimen. During treatment patients experience significant decrease in peripheral white blood cell counts, increase in hemoglobin, elevation of platelets and a dramatic reduction in lymphadenopathy and splenomegaly. Response assessment based on the IW-CLL 2008 criteria showed that the overall response rate was 50% (4 partial remissions), 25% of patients had stable disease and the remainder showed progressive disease.

Overall, these data suggest that the combination of HDMP and Ofatumumab is a safe and effective salvage regimen for high-risk CLL patients that otherwise were not candidates for additional treatment. The response rates observed for the combination of HDMP and Ofatumumab in this group of patients appear to be favorable with the majority of patients achieving a response to therapy or experiencing disease stabilization. Moreover, HDMP and Ofatumumab treatment was not associated with bone marrow suppression, which is a major limiting factor for treatment administration, making this regimen a potential valid alternative for high-risk CLL patients. Additional clinical studies of this combination are warranted.