Investigational study data of REVLIMID with rituximab or rituximab-containing regimen in CLL patients presented at ASH

Celgene International Sàrl (NASDAQ: CELG) announced that clinical data from two investigational studies evaluating the use of REVLIMID^® (lenalidomide) either with rituximab or following a rituximab-containing regimen in patients with chronic lymphocytic leukaemia (CLL) were presented at the 52^nd American Society of Hematology annual meeting.

In the first study, 38 of 44 patients with previously untreated CLL received six cycles of pentostatin (2 mg/m²), cyclophosphamide (600 mg/m²) and rituximab (375 mg/m²) (PCR) every 21 days. Following this treatment regimen, 34 patients continued to consolidation therapy with lenalidomide starting at 5 mg per day, escalating to 10 mg per day as tolerated for a median of seven cycles.

At a median follow-up of 21 months, 91% (40/44) of patients were still alive, and 21% (7/34) of patients who received at least one cycle of lenalidomide consolidation showed an improvement in the quality of their response, including three patients who converted from minimal residual disease (MRD)-positive to MRD-negative disease. The median duration of response has not been reached.

Additionally, a comparison of these data against historic PCR data showed the proportion of patients receiving consolidation who were free of retreatment at 12 months was 95% (42/44), compared to 86% (55/64) of patients without lenalidomide consolidation in the historic study.

For patients receiving lenalidomide consolidation treatment in the study, the most common grade 3 or higher adverse events were neutropenia (grade 3, 41% 14/38; grade 4, 21% 7/38), leukopenia (grade 3, 32% 11/38), platelet count decrease (grade 3, 9% 3/38) and rash (grade 3, 6%, 2/38).

In the second study, 59 patients with relapsed/refractory CLL received rituximab 375 mg/m² intravenously weekly for four weeks in cycle one, then once every four weeks during cycles three through 12. Oral lenalidomide 10 mg/day was started on day nine of cycle one on a continuous dosing schedule. Cycles were 28 days, with intention to continue therapy for 12 cycles or longer if the patient achieved a clinical response. Dose reductions were made following grade 3 or 4 lenalidomide-related adverse events, and allopurinol 300 mg daily was prescribed during the first two weeks as tumour lysis syndrome prophylaxis.

All 59 patients were evaluable for response, with evaluations performed after cycles three, six, and every six cycles thereafter. In the study, the overall response rate was 63% (37/59), with 5% (3/59) achieving a complete response. Additionally, 2% of patients (1/59) achieved a complete response with incomplete haematological recovery. 14% of patients (8/59) achieved nodular partial responses and 42% (25/59) achieved partial responses. Most responses (59%, 35/59) occurred within the first six cycles of therapy.

During the study, the highest incidences of grade 3/4 adverse events were neutropenia (68%, 40/59), thrombocytopenia (22%, 13/59) and anaemia (10%, 6/59). Grade 3/4 infections occurred in 18 patients (31%), mostly in the upper respiratory tract. One patient experienced grade 3 tumour lysis syndrome. One treatment-related death occurred during the study due to ischemic stroke with infection.

These data are from an investigational study. Lenalidomide is not approved as a treatment for patients with chronic lymphocytic leukaemia.