A Multicenter, Phase 4 Observational Study of Ofatumumab in Chronic Lymphocytic Leukemia: A European Research Initiative on CLL (ERIC) Study

In this observational, retrospective study that was conducted in Europe, the primary objective was to understand the safety profile of ofatumumab when it was administered outside of clinical trials to patients with previously treated chronic lymphocytic leukemia (CLL). The secondary end points included progression-free survival (PFS) and overall survival (OS).

Patients were eligible regardless of treatment history or disease status as long as they were not participating in ofatumumab-based clinical trials. Data on patients’ characteristics at diagnosis, previous treatments, adverse events (AEs), response rate, PFS, and OS were recorded.
           
Of the 120 patients screened, 103 were eligible for the study. Most patients were male and in advanced clinical stages of CLL. The patients’ median age was 64 years. The median number of previous lines of therapy was 4, and most patients (81%) had received previous rituximab combination regimens.

Patients received a median of 9 cycles of ofatumumab. A total of 161 AEs were reported in 68 patients, with 17% of AEs that were considered ofatumumab-related. Infusion related-reactions, neurotropenia, thrombocytopenia, and anemia were the most common hematologic AEs. These hematologic AEs correlated with the number of previous lines of therapy. Nonhematologic AEs included infection, fatigue, fever, rash, cough, diarrhea, and nausea.

The overall response rate (ORR) was 23%. The median PFS and OS were 5 and 12 months, respectively. The main causes of death were disease progression (61%) and infection (28%).
Moreno and colleagues concluded that the safety profile of ofatumumab given outside of clinical trials to patients with poor-prognosis and with heavily pretreated CLL was consistent with that observed in clinical trials. Expectedly, the ORR was lower in this study. However, the PFS and OS were comparable to data reported in phase 2 trials.  

References

Moreno C, Montillo M, Panayiotis P, et al. A multicenter, phase IV observational study of ofatumumab in chronic lymphocytic leukemia (CLL): a European Research Initiative on CLL: (ERIC) study. Blood. 2013;122(21). Abstract 1645.