Has the Prognostic of Primary Plasma Cell Leukemia Improved with New drugs?

The outcome of patients with plasma-cell leukemia (PCL) is poor. Avet-Loiseau reported on behalf the IFM, our first experience in PCL patients and showed that the median overall survival (OS) was 8 months (Avet-Loiseau, Blood, 2001). Since 1999, novel agents such as Thalidomide, Bortezomib (Velcade) or Lenalidomide (Revlimid) have been widely used in the treatment of multiple myeloma, both at the time of relapse or part of upfront therapy.

In this retrospective analysis, we have looked at the outcome of PCL patients treated within the IFM since 1999 in order to study the impact of novel agents on survival.

31 cases, 20 males, 11 females, median age 55 years (34-78) were analyzed. Twenty one patients less than 65 years received high-dose therapy as part of frontline treatment : 19 autologous haematopoietic stem cell transplantation (HSCT) and 5 allogeneic transplantation. Novel agents were used part of induction therapy in 6 cases, at the time of relapse for 9 patients, for both induction and relapse in 16 cases. Thirteen patients received 1 novel agent, 11 received 2 and 7 patients received the 3 novel agents. The median number of lines of therapy was 2 (1 to 4). Bortezomib was used as up front treatment in 15 patients and at relapse for 9 patients. Overall response rate according the IMWG criterias was 70% (17/24) including 11 CR or VGPR (45%). PAD (Bortezomib, Adriamycin and Dexamethasone) and VTD (Bortezomib, Thalidomide, Dexamethasone) regimens provided the best response rates. Lenalidomide was used in 13 patients mostly at relapse. A response was obtained in 53% of patients including 2CR and 2 VGPR (30%). Nineteen patients were treated with Thalidomide-based regimens. Overall response rate was 52% (10/19) including 2 CR and 6 VGPR (31%).

Overall, for the whole group of patients, the median progression-free survival was 8 months (0-26) and the median OS was 15 months (6-108). When comparing this survival with that described in our previous experience reported before 1999, we clearly showed that the use of novel agents improved the survival of patients with PCL.

In this retrospective study, novel agents improved the prognosis of P-PCL. Prospective IFM phase II studies are ongoing to confirm these results.

No relevant conflicts of interest to declare.