We hypothesized that ofatumumab with sequential methylprednisolone - alemtuzumab would be an effective and tolerable regimen for patients with high-risk chronic lymphocytic leukemia (CLL) with TP53 dysfunction. Thirty CLL patients with TP53 dysfunction (15 treatment naive (TN), 15 relapsed/refractory (R/R)) were enrolled in this phase II study. Therapy included ofatumumab with methylprednisolone for 2-4 monthly cycles, then ofatumumab with alemtuzumab for 4-24 weeks, then allogeneic transplantation or maintenance. The rate of overall response, complete response, marrow minimal residual disease (MRD) negativity, 3-year progression-free survival and overall survival were 80, 13, 80, 53, and 66%, respectively, in TN patients and 68, 0, 54, 25, and 53%, respectively, in R/R patients. Notable grade 3/4 toxicities included neutropenia and infection in 43 and 40% of patients, respectively. At median follow-up of 45 months, 13 patients died, and 10 patients are alive posttransplant. Overall, we observed high rates of MRD-negativity and acceptable tolerability in high-risk CLL.
Keywords: CLL; MRD; TP53; alloHSCT; deletion 17p.