Treatment with bortezomib-based regimens improves overall response and predicts for survival in patients with primary or secondary plasma cell leukemia: Analysis of the Greek myeloma study group.

Plasma cell leukemia (PCL) is a rare and aggressive plasma cell disorder, with poor outcome. Bortezomib-based regimens (BBR) are highly effective in myeloma, but there is limited information about their efficacy and safety in PCL. Thus, we retrospectively collected data from 42 consecutive PCL patients (25 with primary PCL-pPCL and 17 with secondary PCL-sPCL) to explore the role of BBR in this entity. BBR were administered in 29 of 42 patients, while 6 of 25 patients with pPCL underwent autologous transplantation. Objective response (≥partial response) was significantly higher in patients treated with BBR versus conventional therapies (69% vs. 30.8%, P = 0.04); 27.5% of patients treated with BBR achieved at least very good partial response (vgPR). The highest ORR was observed in pPCL patients treated with BBR (88.9%; ≥vgPR: 33.3%). In BBR-group, grade 3 of 4 hematological, neurological and renal toxicity and neutropenic infections were observed in 41.4%, 7%, 3.4%, and 31%, respectively. With a median follow-up of 51 months, median overall survival (OS) for patients treated with BBR versus conventional therapies was 13 versus 2 months (P < 0.007). Median OS of patients with pPCL and sPCL treated with BBR was 18 and 7 months, respectively (P < 0.001). In the multivariate analysis normal PLTs, treatment with BBR and high quality response were the only powerful predictors for survival. Our study carrying the longest reported median follow-up, demonstrated that treatment of PCL with BBR induces high response rates and prolongs survival over conventional therapies, regardless of additional autologous transplantation rescue or established high risk features, with manageable toxicity.

Re-evaluation of prognostic markers including staging, serum free light chains or their ratio and serum lactate dehydrogenase in multiple myeloma patients receiving novel agents.

International Staging System (ISS), serum free light chain ratio (sFLCR) and lactate dehydrogenase (LDH) are well known, easily assessed independent prognostic indicators of outcome in multiple myeloma (MM). The purpose of the study was to re-examine the prognostic contribution of these variables in a multicenter setting with special attention to MM patients treated with autologous stem cell transplantation (ASCT) or novel agents (NA). Three hundred and five symptomatic newly diagnosed MM patients were retrospectively studied. Twenty-seven per cent, 32% and 41% were in ISS stages 1, 2, and 3, respectively. Fifty-six per cent of them presented kappa light chain monoclonality; median sFLCR was 27.04 (0.37-1.9 × 10(5) ) and 47.97 (0.26-2.3 × 10(7) ) for kappa patients and lambda patients, respectively; patients with sFLCR above median constituted the high sFLCR group. Thirty-one per cent of patients had increased LDH. As first line treatment, 55.7% received conventional treatment and 44.3% NA. After induction, 24% underwent ASCT, whereas 76% received NA at any line, either bortezomib (82.5%), thalidomide (48%) or lenalidomide (27%). When the 305 patients were analyzed together, staging, high sFLCR and abnormal LDH were predictive of survival. The same was true for patients that never received NA, whereas neither high sFLCR nor abnormal LDH constituted adverse factors in patients that received NA frontline. In the last group of patients, no difference was observed between ISS stages 2 and 3. The median 5-year survival of patients that never received NA versus those who did frontline was 29% vs 47%, 7% vs 52% and 24% vs 40% in patients with abnormal LDH, high sFLCR and ISS stage 3, respectively (p = 0.03, p < 0.00001 and p = 0.035). In conclusion, patients gaining the most from NA are those with an aggressive disease as reflected by advanced stage, abnormal LDH and high sFLCR. In addition, the adverse impact of these three variables is obscured by NA.