Efficacy of Lenalidomide in Different Clinical Settings in Patients with Relapsed or Progressive Multiple Myeloma: Updated Analysis of 111 Cases of the Spanish Compassionate Use Program

Aim: To evaluate the efficacy of Lenalidomide (Len) as compassionate use in relapsed or progressive Multiple Myeloma (MM) up to its approval in Spain.

Patients and Methods: GEM-PETHEMA designed a transverse and retrospective, multicenter analysis of MM cases which Len compassionate use was requested until December, 2007. The decision to treat these patients was previous and independent from the decision to conduct the present analysis and depended only on the clinical criteria of the responsible doctors. At least, one response assessment was a must for efficacy analysis.

Results: 111 MM patients have been included. Eligible patients for efficacy were 103. Mean age was 65.7 (38–85); 53 m, 50 f. Previous median lines of therapy were 3 (1–8): 92 (89.3%) have received bortezomib; 37 (35.9%) autologous PBSCT and 26 (25.2%) thalidomide. Extramedullary plasmocitomas were present in 25 (24.3%). Mean Len dose was 22.8 mg (± 4.9): 82 (79.6%) received the standard dose and schedule (25 mg d for 3 w every 4 w) and 21 (20.4%) received less dose and/or different schedule. 92 (89.3%) received Dexametasone (mean dose 58.33 mg/w) [± 35.8]). Response: 4 (3.9%) sCR, 11 CR (10.7%), 12 VGPR (11.7%), 41 PR (39.8%), 20 SD (19.4%), 13 PD (12.6%), 2 NE (1.9). Among groups, response equal or superior to PR was observed in all settings: 64.1% in prior exposed to bortezomib, 46.1% in prior exposed to thalidomide and 40.0% in patients with extramedullary plasmocitomas. Previous transplant, the number of previous lines received, renal failure, age, or cytogenetic did not affect significantly the overall response rate. Median duration of treatment was 7.7 m (1–21); median TTP was 8.3 m and median global survival since starting Len therapy was 11 m (6–22). Median survival since diagnostic was 49 m (40–60). At the time of analysis, 46 (45.5%) patients were still on Len therapy, and 72 (79.6%) were alive. Toxicity: ≥ grade II: neutropenia, 51 (46.4%); thrombocytopenia, 39 (35.5%); DVT, 5 (4.5%); rash, 3 (2.7%); neutropenic fever, 8 (7.3%); others, 13 (11.8%). DVT/PE prophylaxis was used in 89 (86.4%) patients: LWMH in 43.8 % and low dose aspirin in 48.3 %. No PE was reported.

Conclusions: Lenalidomide is effective in this heavily pre-treated MM population-progressive or refractory to standard therapy-even in different clinical settings. The most frequent association to Len was intermediate dose of Dex. Although response rate was superior in patients exposed previously to bortezomib, no differences on duration and survival were observed. Patients with extramedullary plasmocitomas showed also response. Toxicity, mainly myelosupression was predictable and manageable with dose adjustments and cytokine support.