According to research published early online in the Journal of Clinical Oncology, cladribine and fludarabine in combination with cyclophosphamide are equally effective and safe first-line regimens for progressive chronic lymphocytic leukaemia (CLL).

The PALG-CLL3 study involved a total of 423 patients and was conducted to compare the efficacy and safety of cladribine and fludarabine, each combined with cyclophosphamide, in previously untreated progressive CLL. Patients were randomised to receive cladribine at 0.12 mg/kg combined with cyclophosphamide at 250 mg/m2 for 3 days intravenously (CC regimen, n=211) or fludarabine at 25 mg/m2 combined with cyclophosphamide at 250 mg/m2 for 3 days intravenously (FC regimen, n=212), every 28 days for up to six cycles. The primary end point was complete response (CR) rate. Secondary end points included overall response rate (ORR), progression-free survival (PFS), overall survival (OS), and treatment-related toxicity.

The following results were reported:

• The CR and ORR reached 47% and 88% in the CC arm and 46% and 82% in the FC arm (P=0.25 and P=0.11, respectively).
• The median PFS was 2.34 years with CC and 2.27 years with FC (P=0.51).
• The most common grade 3/4 complications were infections (27% in the CC arm and 28% in the FC arm; P=0.84), cytopenias, and autoimmune haemolytic anaemia (10% in the CC arm and 7% in the FC arm; P=0.30).
• At the time of this report, the median follow-up among the censored patients was 3 years 2 months. For all study participants, the median OS had not been reached

The researchers concluded that first-line treatment with the CC regimen gives similar response rate, response duration, survival, and toxicity to treatment with FC in patients with progressive CLL.