María Teresa Cibeira

Outcome of AL amyloidosis after high-dose melphalan and autologous stem cell transplantation: long-term results in a series of 421 patients.

Previous studies have suggested that, in patients with AL amyloidosis treated with high-dose melphalan and autologous stem-cell transplantation (HDM/SCT), the greatest benefit is seen in those patients achieving a hematologic complete response (CR). We analyzed a series of 421 consecutive patients treated with HDM/SCT at a single referral center and compared outcomes for patients with and without CR. Treatment-related mortality was 11.4% overall (5.6% in the last 5 years). By intention-to-treat analysis, the CR rate was 34% and the median event-free survival (EFS) and overall survival (OS) were 2.6 and 6.3 years, respectively. Eighty-one patients died within the first year after HDM/SCT and were not evaluable for hematologic and organ response. Of 340 evaluable patients, 43% achieved CR and 78% of them experienced an organ response. For CR patients, median EFS and OS were 8.3 and 13.2 years, respectively. Among the 195 patients who did not obtain CR, 52% achieved an organ response, and their median EFS and OS were 2 and 5.9 years, respectively. Thus, treatment of selected AL patients with HDM/SCT resulted in a high organ response rate and long OS, even for those patients who did not achieve CR.

Soft-Tissue Plasmacytomas in Multiple Myeloma: Incidence, Mechanisms of Extramedullary Spread, and Treatment Approach

We provide an overview on soft-tissue extramedullary plasmacytomas (EMPs) in multiple myeloma (MM). We reviewed the incidence of EMPs in MM, myeloma bone marrow homing, possible mechanisms of extramedullary spread, and prognosis and response to therapy. The incidence of EMPs is 7% to 18% at MM diagnosis and up to 20% at relapse. The current notion that EMPs are more frequent after treatment with novel agents remains to be proven, especially considering that different patterns of disease recurrence can emerge as patients live longer in the era of novel drugs. Bone marrow genetic abnormalities are not associated with extramedullary spread per se, which also suggests that microenvironmental interactions are key. Possible mechanisms of extramedullary spread include decreased adhesion molecule expression and downregulation of chemokine receptors. EMPs usually show plasmablastic morphology with negative CD56 expression. High-dose therapy with autologous stem-cell transplantation (ASCT) can overcome the negative prognostic impact of extramedullary disease in younger selected patients. EMPs do not typically respond to thalidomide alone, but in contrast, responses to bortezomib have been reported. The incidence of EMPs in patients with MM is high and is associated with poor outcome in patients treated conventionally. A potential first-line treatment option seems to be a bortezomib-containing regimen followed by ASCT, whenever possible. Experimental studies on the mechanisms of myeloma cell adhesion, myeloma growth at extramedullary sites, and drug sensitivity are priorities for this area of continuing therapeutic challenge.

Hematopoietic stem cell transplantation for multiple myeloma beyond 2010

Autologous stem cell transplantation (ASCT) is considered the gold standard in the frontline therapy of younger patients with multiple myeloma because it results in higher complete remission (CR) rates and longer event-free survival than conventional chemotherapy. The greatest benefit from ASCT is obtained in patients achieving CR after transplantation, the likelihood of CR being associated with the M-protein size at the time of transplantation. The incorporation of novel agents results in higher pre- and posttransplantation CR rates. Induction with bortezomib-containing regimens is encouraging in patients with poor-risk cytogenetics. However, longer follow-up is required to assess the impact of this increased CR on long-term survival. The results of posttransplantation consolidation/maintenance with new drugs are encouraging. All this indicates that, in the era of novel agents, high-dose therapy should be optimized rather than replaced. Because of its high transplantation-related mortality, myeloablative allografting has been generally replaced by reduced-intensity conditioning (reduced intensity conditioning allogeneic transplantation). The best results are achieved after a debulky ASCT, with a progression-free survival plateau of 25% to 30% beyond 6 years from reduced intensity conditioning allogeneic transplantation. The development of novel reduced-intensity preparative regimens and peri- and posttransplantation strategies aimed at minimizing graft-versus-host disease, and enhancing the graft-versus-myeloma effect are key issues.

Pathogenesis and progression of monoclonal gammopathy of undetermined significance

In Caucasians, monoclonal gammopathy of undetermined significance (MGUS) is an age-related condition with prevalence as high as 3% in persons older than 50 years. Compared with whites, blacks have around two- and threefold higher prevalence rates of MGUS and multiple myeloma (MM), respectively. Risk of progression from MGUS to MM has been found to be very similar in whites and blacks. On average, the transformation rate to a malignant monoclonal gammopathy is 1% per year, with the mechanisms of progression likely related to bone marrow microenvironment and/or the cytokine network. Overall, the actuarial probability of progression at 25 years of follow-up is about 30%. However, when the competing causes of death are taken into account, the actual rate of progression is only 11%. The predictors of malignant transformation are the plasma cell mass (M-protein size and/or proportion of plasma cell in the bone marrow), IgA isotype, serum free light-chain ratio and ‘evolving’ type and ratio between phenotypically aberrant and normal bone marrow plasma cells. It is recommended to follow these patients, particularly those with high risk of progression, annually to detect MM before complications, such as renal failure or extensive skeletal, involvement occur.

Phase II Clinical and Pharmacokinetic Study of Plitidepsin 3-Hour Infusion Every Two Weeks Alone or with Dexamethasone in Relapsed and Refractory Multiple Myeloma

Purpose: This trial evaluated the antitumor activity and safety of the marine-derived cyclodepsipeptide plitidepsin in patients with relapsed/refractory multiple myeloma. Experimental Design: This was a prospective, multicenter, open-label, single-arm, phase II trial with plitidepsin at 5 mg/m2 as a 3-hour i.v. infusion every two weeks. The protocol was amended to allow patients with suboptimal response to single-agent plitidepsin to add 20 mg/day on days 1 to 4 of oral dexamethasone every two weeks. Results: Fifty-one patients started treatment with plitidepsin and 47 were evaluable for efficacy. The overall response rate (complete response plus partial response plus minimal response) was 13% with plitidepsin alone and 22% in the cohort of patients with the addition of dexamethasone (n = 19, 18 evaluable). Both plitidepsin alone and with dexamethasone were feasible and well tolerated. Anemia (29%) and thrombocytopenia (18%) were the most frequent grade 3/4 hematologic toxicities. Fatigue (16%), muscular toxicity (6%), and transient alanine aminotransferase/aspartate aminotransferase (27%) and creatine phosphokinase (23%) increases were the most relevant nonhematologic side effects. A prolonged plasma half-life was observed in responding patients as compared with nonresponding patients (P = 0.009). Conclusions: Single-agent plitidepsin has limited but reproducible activity in relapsed/refractory multiple myeloma patients. Activity observed after dexamethasone addition merits further study. Both regimens were well tolerated in this heavily pretreated population. Clin Cancer Res; 16(12); 3260–9. ©2010 AACR.

Abnormal serum free light chain ratio in patients with multiple myeloma in complete remission has strong association with the presence of oligoclonal bands: implications for stringent complete remission definition

The prevalence of an abnormal serum free light chain (FLC) ratio in 34 patients with multiple myeloma in complete response (CR) after hematopoietic stem cell transplantation was studied. Fourteen of 34 patients (41.2%) showed an abnormal FLC ratio. The frequency of abnormal FLC ratio in patients with or without oligoclonal bands was 72.7% versus 26%, respectively (P = .023). The median value of FLC ratio was 2.55 (95% confidence interval, 1.89-3.20) in patients with oligoclonal bands versus 0.87 (95% confidence interval, 0.70-1.04) for those with no oligoclonal bands (P = .011). This is the first report showing that the presence of oligoclonal bands in patients with multiple myeloma in CR frequently results in an abnormal FLC ratio. Because an oligoclonal immune response is associated with a good outcome, our results question the current definition of stringent CR and support that the prognostic impact of oligoclonal bands should be also assessed on multivariate analysis.

Impact of MiRSNPs on Survival and Progression in Patients with Multiple Myeloma Undergoing Autologous Stem Cell Transplantation

Purpose: A distinctive new group of polymorphisms is constituted by single-nucleotide polymorphism (SNP) in miRNA processing machinery in miRNA precursor molecules and in miRNA-binding sites, known as miRSNPs. The aim of this study was to ascertain the prognostic impact of six miRSNPs in patients with multiple myeloma and analyze the functional consequences. Experimental Design: One hundred and thirty-seven patients with chemosensitive multiple myeloma (73M/64F) intensified with autologous stem cell transplantation (ASCT) were studied. The median follow-up was 4 years. The genes and SNPs evaluated in genomic DNA by allelic discrimination were KRT81 (rs3660), AFF1 (rs17703261), FAM179b (rs1053667), and MIR196A2 (rs11614913) for miRNA target genes and TRBP (rs784567) and XPO5 (rs11077) for miRNA biogenesis pathway. Results: Overall survival (OS) was significantly longer in patients with KRT81 rs3660 C/C variant (P = 0.037). Functional analysis showed that the presence of C variant in KRT81 3′ untranslated region (UTR) is related with a reduction of the protein levels. Moreover, the reduction of KRT81 protein levels by siRNA in multiple myeloma cell lines is related to a decreased proliferation. On the other hand, OS was significantly longer in patients with C/C or A/C variant in XPO5 rs11077 (P = 0.012). There was also a significantly longer progression-free survival (PFS) for this SNP (P = 0.013). This SNP retained its prognostic impact on PFS and OS in a multivariate regression analysis (P = 0.028 and P = 0.014, respectively). Conclusion: This is the first report that relates miRSNPs with prognosis in multiple myeloma either in a keratin gene (KRT81), target of diverse miRNA multiple myeloma clusters, or in the miRNA biogenesis pathway–related protein exportin-5. Clin Cancer Res; 18(13); 3697–704. ©2012 AACR.

Emergence of oligoclonal bands in patients with multiple myeloma in complete remission after induction chemotherapy: association with the use of novel agents.

The emergence of oligoclonal bands is associated with a favorable outcome after autologous stem cell transplantation in multiple myeloma. The aim of this study was to determine the prevalence of immunoglobulin oligoclonality in 33 patients with multiple myeloma in complete remission achieved with primary therapy with either cytotoxic agents (n=18, 54.5%) or new induction regimens incorporating novel drugs (n=15, 45.4%). Eleven patients (33.3%) developed oligoclonal bands. In the group treated with novel agents, this oligoclonal immune response was observed in 60% (9 of 15) of the patients versus only 11.1% (2 of 18) of those given cytotoxic therapy (P=0.003). This is the first report showing a different frequency of oligoclonal humoral response in patients in complete remission achieved after conventional cytotoxic therapy versus induction incorporating novel agents. This difference could be due to a higher antitumor effect associated with the use of novel drugs, a stronger immune reconstitution, or both.

Natural history and prognostic impact of oligoclonal humoral response in patients with multiple myeloma after autologous stem cell transplantation: long-term results from a single institution

The emergence of an oligoclonal humoral response, resulting in the appearance of a different serum M-protein to that observed at diagnosis is a well-recognized event after autologous stem cell transplantation in multiple myeloma in complete response, and it has been considered to be a benign phenomenon. The aim of the present study was to investigate the incidence, biological characteristics and prognostic value of the oligoclonal bands in patients with myeloma who underwent autologous transplantation at our institution in the last 18 years. We proceed with a retrospective systematic review of all serum and urine immunofixation studies performed in the 211 patients with multiple myeloma who underwent melphalan-based autologous transplantation. Oligoclonal bands were observed in 34% of the patients, with a significantly higher prevalence with the use of novel agents versus conventional chemotherapy in induction (63% vs. 22%; P=0.0001). The incidence of oligoclonal bands was most frequent in non-IgG isotype, particularly in light chain only myeloma. The oligoclonal phenomenon was almost exclusive to patients in complete remission compared to other degrees of response (87% vs. 13%; P=0.0001), and lasted for a median of 1.35 years, persisting during follow up in all patients except in those who relapsed. In prognostic terms, the presence of oligoclonality resulted in a significantly longer progression-free and overall survival. Patients with oligoclonal humoral response lasting for more than one year after transplantation had a significantly longer clinical progression-free and overall survival than those with shorter duration (P=0.008 and P=0.0001, respectively), likely reflecting the importance of a robust humoral immune response.

Efficacy, safety and quality-of-life associated with lenalidomide plus dexamethasone for the treatment of relapsed or refractory multiple myeloma: the Spanish experience

Abstract Here we report the efficacy, safety and health-related quality-of-life (HRQoL) associated with long-term lenalidomide and dexamethasone (Len + Dex) treatment in patients with relapsed or refractory multiple myeloma (RRMM) enrolled in the Spanish cohort of the MM-018 study. In this open-label, multicenter, single-arm expanded access study, 63 patients received Len + Dex until disease progression. The overall response rate was 78%, with 21% of the patients achieving a complete response. The quality of response improved with continuous treatment. The median duration of response was 18.4 months. Median time-to-progression and progression-free survival was 13.3 months for both; median overall survival was not reached. Len + Dex had a manageable safety profile consistent with previously reported phase III studies. HRQoL assessments (n = 42) at baseline and 6 months using the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 and QLQ MY-20 questionnaires revealed that patients with RRMM treated with long-term lenalidomide reported clinically relevant improvements in certain QoL and symptoms scores regardless of treatment response (ClinicalTrials.gov: NCT00420849).