Remission status defined by immunofixation vs. electrophoresis after autologous transplantation has a major impact on the outcome of multiple myeloma patients

Biological relapse in multiple myeloma: Outcome and treatment strategies in a Spanish real-world setting

Recommendations regarding the best time to start treatment in patients with relapsed/refractory multiple myeloma (RRMM) after biological relapse/progression (BR) are unclear. This observational, prospective, multicenter registry aimed to evaluate the impact on time to progression (TTP) of treatment initiation at BR versus at symptomatic clinical relapse (ClinR) based on the Spanish routine practice in adult patients with RRMM. Patients had two or less previous treatment lines and at least one previous partial response. Baseline characteristics and treatment outcomes were recorded, and survival was analyzed. Of 225 patients, 110 were treated at BR (TxBR group) and 115 at ClinR (TxClinR group) according to the investigators' criteria. The proportion of patients with higher ECOG, previous noncomplete remission (CR), and second relapse were significantly higher in the TxBR group compared to the TxClinR group. TheTxClinR group showed improved outcomes, including TTP, compared to the TxBR group. Progression-free survival increased in the TxClinR group (56.2 months) compared to the TxBR group (32.5 months) (p = 0.0137), and median overall survival also increased (p = 0.0897). Median TTP was significantly longer in patients relapsing from a CR (50.4 months) and in their first relapse (38.7 months) compared to those relapsing from a non-CR response (32.9 months) and in their second relapse (25.2 months). Physicians seemed to start treatment earlier in RRMM patients with poor prognosis features. Previous responses to anti-MM treatment and the number of prior treatment lines were identified as prognosis factors, whereby relapse from CR and first relapse were associated with a longer time to progression.

Evaluation of measurable residual disease in multiple myeloma by multiparametric flow cytometry: Current paradigm, guidelines, and future applications

Multiple myeloma (MM) is a heterogeneous group of mature B-cell diseases that are typically characterized by the presence and accumulation of abnormal plasma cells (PCs), which results in the excess production of monoclonal immunoglobulin and/or light chain found in the serum and/or urine. Multiparametric flow cytometry (MFC) is an indispensable tool to supplement the diagnosis, classification and monitoring of the disease due to its high patient applicability, excellent sensitivity and encouraging results from various clinical trials. In this regard, minimal or, more appropriately, measurable residual disease (MRD) negativity by MFC has been recognized as a powerful predictor of favourable long-term outcomes. Before flow cytometry can be effectively implemented in the clinical setting for MM MRD testing, sample preparation, panel configuration, analysis and gating strategies must be optimized to ensure accurate results. This manuscript will discuss the current consensus guidelines for flow cytometric processing of samples and reporting of results for MM MRD testing. We also discuss alternative approaches to detect plasma cells in the presence of daratumumab treatment. Finally, there is a lack of information describing the subclonal distribution of myeloma cells based on their protein expression. The advent of high-dimensional analysis may assist in following the evolution of antigen expression patterns on abnormal plasma cells in patients with relapsed/refractory disease. This in turn can help identify clonal subtypes that are more aggressive for potential informed decision. An analysis using t-SNE to identify the emergence of PCs subclones by MFC, along with the analysis of their immunophenotypic profiles are presented as a future perspective.

Role of urine immunofixation in the complete response assessment of MM patients other than light-chain-only disease

Response criteria for multiple myeloma (MM) require monoclonal protein (M-protein)–negative status on both serum immunofixation electrophoresis (sIFE) and urine (uIFE) immunofixation electrophoresis for classification of complete response (CR). However, uIFE is not always performed for sIFE-negative patients. We analyzed M-protein evaluations from 384 MM patients (excluding those with light-chain-only disease) treated in the GEM2012MENOS65 (NCT01916252) trial to determine the uIFE-positive rate in patients who became sIFE-negative posttreatment and evaluate rates of minimal residual disease (MRD)–negative status and progression-free survival (PFS) among patients achieving CR, CR but without uIFE available (uncertain CR; uCR), or very good partial response (VGPR). Among 107 patients with M-protein exclusively in serum at diagnosis who became sIFE-negative posttreatment and who had uIFE available, the uIFE-positive rate was 0%. Among 161 patients with M-protein in both serum and urine at diagnosis who became sIFE-negative posttreatment, 3 (1.8%) were uIFE positive. Among patients achieving CR vs uCR, there were no significant differences in postconsolidation MRD-negative (<10−6; 76% vs 75%; P = .9) and 2-year PFS (85% vs 88%; P = .4) rates; rates were significantly lower among patients achieving VGPR. Our results suggest that uIFE is not necessary for defining CR in MM patients other than those with light-chain-only disease.

Autologous Transplantation, Consolidation, and Maintenance Therapy in Multiple Myeloma: Results of the BMT CTN 0702 Trial

PURPOSE

Single-cycle melphalan 200 mg/m2 and autologous hematopoietic cell transplantation (AHCT) followed by lenalidomide (len) maintenance have improved progression-free survival (PFS) and overall survival (OS) for transplantation-eligible patients with multiple myeloma (MM). We designed a prospective, randomized, phase III study to test additional interventions to improve PFS by comparing AHCT, tandem AHCT (AHCT/AHCT), and AHCT and four subsequent cycles of len, bortezomib, and dexamethasone (RVD; AHCT + RVD), all followed by len until disease progression.

PATIENTS AND METHODS

Patients with symptomatic MM within 12 months from starting therapy and without progression who were age 70 years or younger were randomly assigned to AHCT/AHCT + len (n = 247), AHCT + RVD + len (n = 254), or AHCT + len (n = 257). The primary end point was 38-month PFS.

RESULTS

The study population had a median age of 56 years (range, 20 to 70 years); 24% of patients had high-risk MM, 73% had a triple-drug regimen as initial therapy, and 18% were in complete response at enrollment. The 38-month PFS rate was 58.5% (95% CI, 51.7% to 64.6%) for AHCT/AHCT + len, 57.8% (95% CI, 51.4% to 63.7%) for AHCT + RVD + len, and 53.9% (95% CI, 47.4% to 60%) for AHCT + len. For AHCT/AHCT + len, AHCT + RVD + len, and AHCT + len, the OS rates were 81.8% (95% CI, 76.2% to 86.2%), 85.4% (95% CI, 80.4% to 89.3%), and 83.7% (95% CI, 78.4% to 87.8%), respectively, and the complete response rates at 1 year were 50.5% (n = 192), 58.4% (n = 209), and 47.1% (n = 208), respectively. Toxicity profiles and development of second primary malignancies were similar across treatment arms.

CONCLUSION

Second AHCT or RVD consolidation as post-AHCT interventions for the up-front treatment of transplantation-eligible patients with MM did not improve PFS or OS. Single AHCT and len should remain as the standard approach for this population.

Diagnosis of Plasma Cell Dyscrasias and Monitoring of Minimal Residual Disease by Multiparametric Flow Cytometry

Plasma cell dyscrasia (PCD) is a heterogeneous disease that has seen a tremendous change in outcomes due to improved therapies. Over the past few decades, multiparametric flow cytometry has played an important role in the detection and monitoring of PCDs. Flow cytometry is a high-sensitivity assay for early detection of minimal residual disease (MRD) that correlates well with progression-free survival and overall survival. Before flow cytometry can be effectively implemented in the clinical setting, sample preparation, panel configuration, analysis, and gating strategies must be optimized to ensure accurate results. Current consensus methods and reporting guidelines for MRD testing are discussed.

Association between complete response and outcomes in transplant-eligible myeloma patients in the era of novel agents

OBJECTIVES

Achieving complete response (CR) has been linked to improved progression-free (PFS) and overall (OS) survival in myeloma. A meta-analysis was conducted to investigate whether this holds true in the era of novel agents (bortezomib, lenalidomide, thalidomide).

METHODS

A total of 24 studies in newly diagnosed patients undergoing autologous stem cell transplantation (ASCT) that reported associations between responses and long-term outcomes (PFS/OS rates post-ASCT by response, or hazard ratios with 95% confidence intervals from Cox models) were identified and analyzed.

RESULTS

Achievement of CR vs. <CR post-ASCT reduced risk of progression/death by 38% [risk ratio (RR): 0.62, P < 0.0001]; risk of death was 41% lower (RR: 0.59, P < 0.0001). Subgroup meta-analyses showed significant PFS risk reduction with CR post-ASCT with novel (RR: 0.32, P < 0.006) and non-novel (RR: 0.72, P < 0.0001) agents, and corresponding OS risk reduction with novel (RR: 0.33, P = 0.0013) and non-novel (RR: 0.64, P < 0.0001) agents. Risk reduction was greater with novel vs. non-novel agents (PFS: P = 0.047; OS: P = 0.058).

CONCLUSIONS

Achieving CR during first-line therapy remains important in the novel-agent era; magnitude of association between achieving CR and outcomes appears higher for CR obtained using novel vs. non-novel agents.

Impact of informative censoring on the Kaplan-Meier estimate of progression-free survival in phase II clinical trials

Informative censoring in a progression-free survival (PFS) analysis arises when patients are censored for initiation of an effective anticancer treatment before the protocol-defined progression, and these patients are at a different risk for treatment failure than those who continue on therapy. This may cause bias in the estimated PFS when using the Kaplan-Meier method for analysis. Although there are several articles that discuss this issue from a theoretical perspective or in randomized phase III studies, there are little data to demonstrate the magnitude of the bias on the estimated quantities from a phase II trial. This article describes the issues by using two oncology phase II trials as examples, evaluates the impact of the bias using simulations, and provides recommendations. The two trials were selected because they demonstrate two different reasons for censoring. Simulations show that the magnitude of the bias depends primarily on the proportion of patients who are informatively censored and secondarily on the hazard ratio between the group of patients who remain on study and the group of patients who are informatively censored. Recommendations include using an alternative end point, which includes inadequate response and initial signs of clinical progression as treatment failure, and a competing risk analysis for studies in which competing events preclude or modify the probability of observing the primary event of interest. If informative censoring cannot be avoided, then all patients should be observed until progression, and sensitivity analyses should be used as appropriate.

Long-term results in multiple myeloma after high-dose melphalan and autologous transplantation according to response categories in the era of old drugs

BACKGROUND

The aim of this study was to investigate the correlation between the long-term prognosis of multiple myeloma (MM) and the quality of response to therapy in a cohort of 173 patients treated with high-dose melphalan (HDM) and autologous transplantation in the era of old drugs.

PATIENTS AND METHODS

A total of 173 patients with de novo MM who received a transplant between 1994 and 2010 were analyzed. VAD (vincristine, doxorubicin [Adriamycin], dexamethasone) was used as front-line regimen before auto-HPCT. The conditioning was HDM 200 mg/m(2). Patients were evaluated for clinical response using the criteria from the European Group for Blood and Marrow Transplantation, modified to include near complete remission (nCR) and very good partial remission (VGPR).

RESULTS

The response distribution after transplantation in our series was complete remission (CR) in 33 cases (19%), nearly complete remission (nCR) in 38 cases (22%), VGPR in 30 cases (17%), partial remission (PR) in 65 cases (38%), and stable disease (SD) in 7 cases (4%). Patients were followed for 48 ± 36 months. Median overall survival (OS) was not reached for the CR group. Progression-free survival (PFS) was 122 months for CR, 55 months for nCR, 56 months for VGPR, 32 months for PR, and 22 months for SD. Significant differences in PFS and OS were found between the CR and nCR groups (P = .003 and P = .001, respectively), between the CR and VGPR groups (P = .002 and P = .001, respectively), and between the CR and PR groups (P = .000 and P = .001, respectively). Responses were clustered in 3 main categories, ie, CR, nCR + VGPR + PR, and SD. The respective 10-year PFS and OS values were 58% and 70% for CR, 15% and 18% for nCR + VGPR + PR, and 0% and 0% for SD.

CONCLUSION

The achievement of depth and prolonged response represents the most important prognostic factor. The relapse rate is low for patients in CR after 10 years of follow-up, possibly signifying a cure.

Impact of high-risk cytogenetics and achievement of molecular remission on long-term freedom from disease after autologous-allogeneic tandem transplantation in patients with multiple myeloma

Within a prospective protocol, the incidence and impact of achievement of molecular remission (mCR) and high-risk cytogenetics was investigated in 73 patients with multiple myeloma (MM) after autologous (auto)-allogeneic (allo) tandem stem cell transplantation (SCT). After induction chemotherapy, patients received melphalan 200 mg/m(2) before undergoing auto-SCT, followed 3 months later by melphalan 140 mg/m(2) and fludarabine 180 mg/m(2) before allo-SCT. Sixteen patients had high-risk cytogenetic features, defined by positive FISH for del(17p13) and/or t(4;14). Overall, 66% of the patients achieved CR or near-CR, and 41% achieved mCR, which was sustained negative (at least 4 consecutive samples negative) in 15 patients (21%), with no significant difference in incidence between the patients with high-risk cytogenetics and others (P = .70). After a median follow-up of 6 years, overall 5-year progression-free survival was 29%, with no significant difference between del 17p13/t(4;14)-harboring patients and others (24% versus 30%; P = .70). The 5-year progression-free survival differed substantially according to the achieved remission: 17% for partial remission, 41% for CR, 57% for mCR, and 85% for sustained mCR. These results suggest that auto-allo tandem SCT may overcome the negative prognostic effect of del(17p13) and/or t(4;14) and that achievement of molecular remission resulted in long-term freedom from disease.

Durable responses after donor lymphocyte infusion for patients with residual multiple myeloma following non-myeloablative allogeneic stem cell transplant

The role of donor lymphocyte infusion (DLI) in mediating the graft-versus-myeloma (GvM) effect after allogeneic hematopoietic stem cell transplant (allo-HCT) is not clearly defined. We evaluated the safety and utility of DLI in patients with either persistent or recurrent multiple myeloma (MM) after allo-HCT. Twenty-three patients with MM received DLI after allo-HCT at the University of Texas M. D. Anderson Cancer Center between July 1996 and June 2008. Eight patients received preemptive DLI for residual disease (RD) while 15 patients received DLI for the treatment of recurrent or progressive disease (PD). We evaluated the response to DLI and the factors that may predict a response. Median DLI dose was 3.3 × 10(7) CD3 + cells (range 0.5-14.8 × 10(7)). Grade II-IV acute graft-versus-host disease (GvHD) was seen in five patients (22%). Median follow-up in surviving patients was 24 months. Five of 23 patients (22%) achieved a complete or a very good partial response (two CR, three VGPR), while eight patients (34%) had stable disease (SD) after the DLI. Patients who received DLI for RD had a higher response rate (≥ VGPR 50% vs. 7%, p = 0.03), a longer overall survival (28.3 vs. 7.6 months, p = 0.03) and a trend toward longer progression-free survival (11.9 vs. 5.2 months, p = 0.1). In this largest single institution study, we conclude that the use of preemptive, non-manipulated DLI for RD after reduced-intensity conditioning allo-HCT is encouraging, and it was associated with a higher response rate and a longer overall survival when given preemptively. The role of DLI needs to be further explored in prospective clinical trials.

Radiotherapy for solitary plasmacytoma of bone and soft tissue: outcomes and prognostic factors

We investigated treatment outcomes of radiotherapy for solitary plasmacytoma (SP) and prognostic factors affecting survival. Between 1996 and 2010, a total of 38 patients were treated with radiotherapy for histologically proven plasmacytoma without evidence of multiple myeloma. Among these, 16 and 22 patients had SP originating from extramedullary soft tissue (EMP) and bone, respectively. Thirteen patients received adjuvant chemotherapy, and three patients underwent surgery prior to radiotherapy. At a median follow-up of 50 months (range, 8-142), radiotherapy demonstrated excellent local control (5- and 10-year local control rates, 81%). However, the 10-year multiple myeloma-free survival (MMFS) was 54% and the 10-year overall survival (OS) rates was 35%. Solitary bone plasmacytoma (SBP) more frequently progressed to multiple myeloma (MM) than EMP (10-year MMFS, 0% vs. 71%, p = 0.02). Radiotherapy with doses ≥40 Gy demonstrated better local control (10-year LC, 100% vs. 60%, p = 0.04) in SBP. In the multivariate analysis, elevated β₂-microglobulin was a significantly unfavorable prognostic factor affecting OS (p = 0.03). In conclusion, radiotherapy effectively treated SP without significant toxicity. However, progression to MM presents a challenging problem. Novel therapeutics are needed for patients with unfavorable prognostic factors.

Response-adjusted ISS (RaISS) is a simple and reliable prognostic scoring system for predicting progression-free survival in transplanted patients with multiple myeloma

Complete response (CR) is associated with better outcome in patients with multiple myeloma (MM) treated with autologous transplant even though the progression-free survival (PFS) can be very variable among patients with good response. No simple and reliable prognostic scoring system, able to predict the duration of response, are so far available. Aim of this study was to identify any correlation between baseline clinical findings, response after transplant and the length of PFS, and thus develop a prognostic model. The new prognostic model was developed in a learning cohort of 549 patients with MM transplanted in five Italian hospitals. The prognostic value of this new score was confirmed in a validation cohort of 276 distinct patients with MM transplanted in two different Italian hospital. Univariate and multivariate analyses were performed using Cox models. The most important independent baseline predictor of transplant outcome, together with response after transplant, was International Staging System (ISS). We thus incorporated response to transplant and baseline ISS in a new scoring system, named response-adjusted international scoring system (RaISS), that was able to classify patients in three risk groups (low, intermediate, high) with different probabilities of progression after transplant (median PFS 35.9-15.4 months). The prognostic value of this new score was confirmed in the validation cohort. In conclusion, RaISS is a new simple and easily available scoring system that, accurately defining the risk of progression, can allow to identify patients who could deserve further treatment after transplant (consolidation, maintenance).

Autologous haemopoietic stem-cell transplantation followed by allogeneic or autologous haemopoietic stem-cell transplantation in patients with multiple myeloma (BMT CTN 0102): a phase 3 biological assignment trial

BACKGROUND

Autologous haemopoietic stem-cell transplantation (HSCT) improves survival in patients with multiple myeloma, but disease progression remains an issue. Allogeneic HSCT might reduce disease progression, but can be associated with high treatment-related mortality. Thus, we aimed to assess effectiveness of allogeneic HSCT with non-myeloablative conditioning after autologous HSCT compared with tandem autologous HSCT.

METHODS

In our phase 3 biological assignment trial, we enrolled patients with multiple myeloma attending 37 transplant centres in the USA. Patients (<70 years old) with adequate organ function who had completed at least three cycles of systemic antimyeloma therapy within the past 10 months were eligible for inclusion. We assigned patients to receive an autologous HSCT followed by an allogeneic HSCT (auto-allo group) or tandem autologous HSCTs (auto-auto group) on the basis of the availability of an HLA-matched sibling donor. Patients in the auto-auto group subsequently underwent a random allocation (1:1) to maintenance therapy (thalidomide plus dexamethasone) or observation. To avoid enrolment bias, we classified patients as standard risk or high risk on the basis of cytogenetics and β2-microglobulin concentrations. We used the Kaplan-Meier method to estimate differences in 3-year progression-free survival (PFS; primary endpoint) between patients with standard-risk disease in the auto-allo group and the best results from the auto-auto group (maintenance, observation, or pooled). This study is registered with ClinicalTrials.gov, number NCT00075829.

FINDINGS

Between Dec 17, 2003, and March 30, 2007, we enrolled 710 patients, of whom 625 had standard-risk disease and received an autologous HSCT. 156 (83%) of 189 patients with standard-risk disease in the auto-allo group and 366 (84%) of 436 in the auto-auto group received a second transplant. 219 patients in the auto-auto group were randomly assigned to observation and 217 to receive maintenance treatment, of whom 168 (77%) completed this treatment. PFS and overall survival did not differ between maintenance and observation groups and pooled data were used. Kaplan-Meier estimates of 3-year PFS were 43% (95% CI 36-51) in the auto-allo group and 46% (42-51) in the auto-auto group (p=0·671); overall survival also did not differ at 3 years (77% [95% CI 72-84] vs 80% [77-84]; p=0·191). Within 3 years, 87 (46%) of 189 patients in the auto-allo group had grade 3-5 adverse events as did 185 (42%) of 436 patients in the auto-auto group. The adverse events that differed most between groups were hyperbilirubinaemia (21 [11%] patients in the auto-allo group vs 14 [3%] in the auto-auto group) and peripheral neuropathy (11 [6%] in the auto-allo group vs 52 [12%] in the auto-auto group).

INTERPRETATION

Non-myeloablative allogeneic HSCT after autologous HSCT is not more effective than tandem autologous HSCT for patients with standard-risk multiple myeloma. Further enhancement of the graft versus myeloma effect and reduction in transplant-related mortality are needed to improve the allogeneic HSCT approach.

FUNDING

US National Heart, Lung, and Blood Institute and the National Cancer Institute.

Long-term prognostic significance of response in multiple myeloma after stem cell transplantation

For establishing the true effect of different response categories in patients with multiple myeloma (MM) treated with autologous stem cell transplantation, we evaluated, after a median follow-up of 153 months, 344 patients with MM who received a transplant between 1989 and 1998. Overall survival (OS) at 12 years was 35% in complete response (CR) patients, 22% in near complete response (nCR), 16% in very good partial response (VGPR), and 16% in partial response (PR) groups. Significant differences in OS and progression-free survival were found between CR and nCR groups (P = .01 and P = .002, respectively), between CR and VGPR groups (P = .0001 and P = .003), or between CR and PR groups (P = .003 and P = < 10(-5)); no differences were observed between the nCR and VGPR groups (P = .2 and P = .9) or between these groups and the PR group (P = .1 and P = .8). A landmark study found a plateau phase in OS after 11 years; 35% patients in the CR group and 11% in the nCR+VGPR+PR group are alive at 17 years; 2 cases had relapsed in the nCR+VGPR+PR group. In conclusion, MM achieving CR after autologous stem cell transplantation is a central prognostic factor. The relapse rate is low in patients with > 11 years of follow-up, possibly signifying a cure for patients in CR.

The importance of complete response in outcomes in myeloma

Outcomes for patients with multiple myeloma have dramatically improved during the past 20 years as a result of improved therapeutic options and a better understanding of malignant plasma cell biology. Until the past 10 years, the major limitations on improving outcomes were related to the minimal efficacy of existing agents and balancing the toxicity of therapy in an older patient population. However, despite these limitations, there have been advances that have resulted in improvements in progression-free survival and overall survival (OS). High-dose therapy and autologous transplant were the first among therapies to demonstrate an improvement in OS; but more recent analyses have demonstrated that there can be improvement in OS, which is also associated with improvement in the complete response (CR) rate, even among nontransplant patients as well. Thus, achieving CR has been associated with improved OS and has become a therapeutic goal. In the current era of new agents, such as thalidomide, bortezomib, and lenalidomide, the fraction of patients who achieve a CR is now greater than before, and the data regarding the importance of achieving this benchmark of response have never been more benefit.

Depth of response assessed by quantitative ASO-PCR predicts the outcome after stem cell transplantation in multiple myeloma

Achievement of complete response (CR) is a new goal of therapy for multiple myeloma (MM). By sensitive methods, the depth of response can be measured even among the patients in CR. We used a sensitive real-time quantitative polymerase chain reaction by allele-specific primers (qASO-PCR) to assess the level of minimal residual disease (MRD) in bone marrow of 37 patients with myeloma who had achieved CR/near-to-CR after autologous or allogeneic stem cell transplantation (SCT). Allele-specific primers could be successfully designed for 86% of patients. Three to six months after autotransplantation, the PCR target was not detectable in 53% of patients (16/30 patients), and the respective figure after allotransplantation was 71% (5/7 patients); the median sensitivity of PCR assay was <0.002%. The proportion of patients without detectable PCR target was 22% of all autotransplanted patients. A threshold level of 0.01% in the qASO-PCR assay 3-6 months after SCT was found to be a useful cut-off limit to divide the patients into two prognostic groups: MRD low/negative vs. MRD high. Low/negative MRD after SCT was a significant predictive factor for the prolongation of progression free (70 vs. 19 months; P = 0.003) and suggestively also for overall survival. We conclude that not only CR but also its depth is important for the long-term outcome in MM.

Total marrow irradiation: a new ablative regimen as part of tandem autologous stem cell transplantation for patients with multiple myeloma

PURPOSE

To establish feasibility, maximum tolerated dose (MTD), and potential efficacy of ablative dose total marrow irradiation (TMI) delivered by helical tomotherapy in patients with multiple myeloma (MM).

EXPERIMENTAL DESIGN

Patients with responding or stable MM received tandem autologous stem cell transplants, first with melphalan 200 mg/m(2), and 60 days or later with TMI. TMI doses were to be escalated from 1,000 cGy by increments of 200 cGy. All patients received thalidomide and dexamethasone maintenance.

RESULTS

Twenty-two of 25 enrolled patients (79%) received tandem autologous stem cell transplantation (TASCT): TMI was administered at a median of 63.5 days (44-119) after melphalan. Dose-limiting toxicities at level 5 (1,800 cGy) included reversible grade 3 pneumonitis, congestive heart failure, and enteritis (1), and grade 3 hypotension (1). The estimated median radiation dose to normal organs was 11% to 81% of the prescribed marrow dose. Late toxicities included reversible enteritis (1), and lower extremity deep venous thrombosis during maintenance therapy (2). The complete and very good partial response rates were 55% and 27% following TASCT and maintenance therapy. At a median of 35 months of follow-up (21-50+ months), progression-free and overall survival for all patients were 49% (95% CI, 0.27-0.71) and 82% (0.67-1.00).

CONCLUSION

Ablative dose TMI as part of TASCT is feasible, and the complete response rate is encouraging. Careful monitoring of late toxicities is needed. Further assessment of this modality is justified at the 1,600 cGy MTD level in MM patients who are candidates for ASCT.

NCI first international workshop on the biology, prevention, and treatment of relapse after allogeneic hematopoietic stem cell transplantation: report from the committee on disease-specific methods and strategies for monitoring relapse following allogeneic stem cell transplantation. part II: chronic leukemias, myeloproliferative neoplasms, and lymphoid malignancies

Relapse has become the major cause of treatment failure after allogeneic hematopoietic stem cell transplantation. Outcome of patients with clinical relapse after transplantation generally remains poor, but intervention prior to florid relapse improves outcome for certain hematologic malignancies. To detect early relapse or minimal residual disease, sensitive methods such as molecular genetics, tumor-specific molecular primers, fluorescence in situ hybridization (FISH), and multiparameter flow cytometry (MFC) are commonly used after allogeneic stem cell transplantation to monitor patients, but not all of them are included in the commonly employed disease-specific response criteria. The highest sensitivity and specificity can be achieved by molecular monitoring of tumor- or patient-specific markers measured by polymerase chain reaction-based techniques, but not all diseases have such targets for monitoring. Similar high sensitivity can be achieved by determination of recipient-donor chimerism, but its specificity regarding detection of relapse is low and differs substantially among diseases. Here, we summarize the current knowledge about the utilization of such sensitive monitoring techniques in chronic leukemias, myeloproliferative neoplasms, and lymphoid malignancies based on tumor-specific markers and cell chimerism and how these methods might augment the standard definitions of posttransplant remission, persistence, progression, relapse, and the prediction of relapse. Critically important is the need for standardization of the different residual disease techniques and to assess the clinical relevance of minimal residual disease and chimerism surveillance in individual diseases, which in turn must be followed by studies to assess the potential impact of specific interventional strategies.

Importance of achieving a complete response in multiple myeloma, and the impact of novel agents

The goal of treatment for multiple myeloma (MM) is to improve patients' long-term outcomes. One important factor that has been associated with prolonged progression-free and overall survival is the quality of response to treatment, particularly achievement of a complete response (CR). There is extensive evidence from clinical studies in the transplant setting in first-line MM demonstrating that CR or maximal response post-transplant is significantly associated with prolonged progression-free and overall survival, with some studies demonstrating a similar association with postinduction response. Supportive evidence is also available from studies in the nontransplant and relapsed settings. With the introduction of bortezomib, thalidomide, and lenalidomide, higher rates of CR are being achieved in both first-line and relapsed MM compared with previous chemotherapeutic approaches, thereby potentially improving long-term outcomes. While standard CR by established response criteria has been shown to have differential prognostic impact compared with lesser responses, increasingly sensitive analytic techniques are now being explored to define more stringent degrees of CR or elimination of minimal residual disease (MRD), including multiparameter flow cytometry and polymerase chain reaction. Demonstrating eradication of MRD by these techniques has already been shown to predict for improved outcomes. Here, we review the prognostic significance of achieving CR in MM and highlight the importance of CR as an increasingly realizable goal at all stages of treatment. We discuss clinical management issues and provide recommendations relevant to practicing oncologists, such as the routine use of sensitive techniques for assessment of disease status to inform evidence-based decisions on optimal patient management.

Achievement of at least very good partial response is a simple and robust prognostic factor in patients with multiple myeloma treated with high-dose therapy: long-term analysis of the IFM 99-02 and 99-04 Trials

PURPOSE

The prognostic impact of complete response (CR) achievement in multiple myeloma (MM) has been shown mostly in the context of autologous stem-cell transplantation. Other levels of response have been defined because, even with high-dose therapy, CR is a relatively rare event. The purpose of this study was to analyze the prognostic impact of very good partial response (VGPR) in patients treated with high-dose therapy.

PATIENTS AND METHODS

All patients were included in the Intergroupe Francophone du Myelome 99-02 and 99-04 trials and treated with vincristine, doxorubicin, and dexamethasone (VAD) induction therapy followed by double autologous stem-cell transplantation (ASCT). Best post-ASCT response assessment was available for 802 patients.

RESULTS

With a median follow-up of 67 months, median event-free survival (EFS) and 5-year EFS were 42 months and 34%, respectively, for 405 patients who achieved at least VGPR after ASCT versus 32 months and 26% in 288 patients who achieved only partial remission (P = .005). Five-year overall survival (OS) was significantly superior in patients achieving at least VGPR (74% v 61% P = .0017). In multivariate analysis, achievement of less than VGPR was an independent factor predicting shorter EFS and OS. Response to VAD had no impact on EFS and OS. The impact of VGPR achievement on EFS and OS was significant in patients with International Staging System stages 2 to 3 and for patients with poor-risk cytogenetics t(4;14) or del(17p).

CONCLUSION

In the context of ASCT, achievement of at least VGPR is a simple prognostic factor that has importance in intermediate and high-risk MM and can be informative in more patients than CR.

The role of complete response in multiple myeloma

In multiple myeloma (MM), the impact of complete response (CR) could be shown only after introduction of high-dose therapy plus autologous stem cell transplantation (ASCT). In the context of ASCT, achieving CR (negative immunofixation and normal bone marrow) or at least very good partial response is associated with longer progression-free survival and in most studies longer survival. With novel agents, high CR rates are achieved and this prognostic impact of CR is being shown as well, both in relapsed and in newly diagnosed MM. However the benefit of CR achievement depends on the type of treatment and is not identical for all patients. In elderly patients, treatments inducing more CR may be more toxic. Although CR achievement is necessary in patients with poor-risk disease, it might not be as critical for long survival in more indolent MM. CR achievement is not the only objective of treatment because it is possible to further improve the depth of response and the outcome by continuing treatment after CR achievement. Finally, there are several levels of CR and in the future it will be necessary to confirm the prognostic impact of immunophenotypic or molecular CR or of CR defined by imaging procedures.

Thrombopoietic cytokine and P-selectin levels in patients with multiple myeloma undergoing autologous stem cell transplantation: decrease in posttransplantation P-selectin levels might predict the degree of maximum response

PURPOSE

This study was designed to determine the pretransplantation levels of thrombopoietic cytokines, which have a fundamental role in both megakaryopoiesis and myeloma pathogenesis and P-selectin in patients with multiple myeloma undergoing autologous hematopoietic stem cell transplantation (AHSCT) and to correlate the cytokine levels with time to platelet recovery. The effect of AHSCT on the levels of the cytokines and its correlation with maximum disease response was also investigated.

PATIENTS AND METHODS

The levels of thrombopoietin, interleukin (IL)-6, IL-11, IL-1beta, and P-selectin was measured before and 30 days after AHSCT in 32 patients with a median age of 55 years. The median time to platelet recovery was day +11 (range, 0-14 days) without any significant correlation with pretransplantation cytokine levels.

RESULTS

No significant change was observed in thrombopoietic cytokines after AHSCT, whereas serum P-selectin levels showed a significant decrease after AHSCT (P = .001). The decrease in P-selectin was found to be significant in patients who achieved complete remission (P1 = .008) and partial remission (P2 = .018) early after AHSCT. Our data suggest that the level of thrombopoietic cytokines does not have a role in time to platelet recovery.

CONCLUSION

The change in P-selectin levels early after transplantation could be a surrogate marker in determining the maximum posttransplantation response.

Post-transplant immunotherapy with donor-lymphocyte infusion and novel agents to upgrade partial into complete and molecular remission in allografted patients with multiple myeloma

OBJECTIVE

To investigate post-transplant immunotherapy with escalating donor-lymphocyte infusions (DLI) and novel agents (thalidomide, bortezomib, and lenalidomide) to target complete remission (CR).

MATERIALS AND METHODS

Thirty-two patients with multiple myeloma who achieved only partial remission after allogeneic stem cell transplantation were treated with DLI. If no CR was achieved, one of the novel agents was added to target CR.

RESULTS

CR defined either by European Group for Blood and Marrow Transplantation criteria, flow cytometry, or molecular methods as assessed by patient-specific immunoglobulin H-polymerase chain reaction or plasma cell chimerism polymerase chain reaction was accomplished in 59%, 63%, and 50% of patients, respectively. Achievement of CR resulted in improved 5-year progressive-free and overall survival, according to European Group for Blood and Marrow Transplantation criteria (53% vs 35%; p=0.03 and 90% vs 62%; p=0.06), flow cytometry (74% vs 15%; p=0.001 and 100% vs 52%; p=0.1), or molecular methods (84% vs 38%; p=0.001 and 100% vs 71%; p=0.03).

CONCLUSIONS

Our finding demonstrates the clinical relevance of posttransplantation therapies to upgrade remission, and of remission's depth for long-term survival in myeloma patients.

Predicting durable remissions following thalidomide therapy for relapsed myeloma

In multiple myeloma (MM), it remains unclear whether the depth of response correlates with progression-free survival (PFS) and overall survival (OS). We updated long-term follow-up data on the two previously published multi-centre phase-II trials in patients with relapsed or refractory MM using thalidomide +/- IFN alpha-2B (n = 75, median follow-up 6.1 years) celecoxib-thalidomide combination (n = 66, median follow-up 4.0 years), and assessed the predictors of durable response and impact of depth of response. Twenty-seven of the 141 (19%) patients remained progression-free beyond 24 months. The most significant baseline predictor for durable PFS and OS was a serum beta(2)-microglobulin <or=3.0 mg/L. The median PFS for patients who achieved complete remission/very good partial remission, partial remission and stable disease were 69.4, 13.6 and 4.1 months, respectively (p < 0.001). The OS for these groups were >69.8, 35.4 and 11.7 months, respectively (p < 0.001). These findings support the therapeutic goal of achieving 'maximum depth of response' in patients with relapsed myeloma.

Outcomes after auto-SCT in African Americans with multiple myeloma

To study the impact of auto-SCT on the outcomes in African Americans (AA) with multiple myeloma (MM), we evaluated 101 consecutive AA patients who underwent auto-SCT. The median PFS and OS were 15.6 and 50.8 months, respectively. The median OS from diagnosis was 60 months. Traditional pre and post transplant prognostic variables earlier examined in Caucasian Americans (CA), including beta-2 microglobulin (B2M), chromosome 13 deletion, CR status after auto-SCT, gender, stage, Ig subtype, time to transplant, number of prior regimens and presence of lytic lesions, were not predictive of improved PFS or OS on univariate analysis. Age, lower CD34 cell dose infused, history of palliative radiation therapy (XRT) prior to auto-SCT and refractory disease at the time of auto-SCT were predictive of inferior PFS. History of palliative XRT was the only predictive factor of inferior PFS and OS after auto-SCT on multivariate analysis. In conclusion, MM in AA tends to relapse early after auto-SCT. It is unclear whether early relapses impact OS. Common prognostic peritransplant variables known in CA with MM may not be applicable to AA with MM.

Influence of pre- and post-transplantation responses on outcome of patients with multiple myeloma: sequential improvement of response and achievement of complete response are associated with longer survival

PURPOSE

Complete response (CR) is considered an important goal in most hematologic malignancies. However, in multiple myeloma (MM), there is no consensus regarding whether immunofixation (IF)-negative CR, IF-positive near-CR (nCR), and partial response (PR) are associated with different survivals. We evaluated the prognostic influence on event-free survival (EFS) and overall survival (OS) of these responses pre- and post-transplantation in newly diagnosed patients with MM.

PATIENTS AND METHODS

We analyzed 632 patients from the prospective Grupo Español de Mieloma 2000 protocol who were uniformly treated with vincristine, carmustine, cyclophosphamide, melphalan, and predisone/vincristine, carmustine, adryamcine, and dexamethasone induction followed by high-dose therapy and autologous stem-cell transplantation.

RESULTS

Post-transplantation response markedly influenced outcomes. Patients achieving CR had significantly longer EFS (median, 61 v 40 months; P < 10(-5)) and OS (medians not reached; P = .01) versus patients achieving nCR, who likewise had somewhat better outcomes compared with patients achieving PR (median EFS, 34 months, P = .07 v nCR; median OS, 61 months, P = .04). EFS and OS and influence of response were similar among older (age 65 to 70 years) and younger (age < 65 years) patients. Similar findings were observed with pretransplantation response, with trends toward EFS (P = .1; P = .05) and OS (P = .1; P = .07) benefit in patients achieving CR versus nCR and PR, respectively. Post-transplantation response was markedly influenced by pretransplantation response; improvements in response were associated with prolonged survival.

CONCLUSION

Quality of response post-transplantation, notably CR, is significantly associated with EFS and OS prolongation in newly diagnosed patients with MM. There were trends toward similar associations with pretransplantation response status.

The outcome of haemopoietic stem cell transplantation in the treatment of lymphoplasmacytic lymphoma in the UK: a British Society Bone Marrow Transplantation study

Lymphoplasmacytic lymphoma (LL) is incurable by standard therapy (median survival: 60 months). UK transplant registry data 1984-2003 identified 18 cases of histologically verified LL (median age: 50 years, range: 38-58 years). Nine patients received high dose chemotherapy [plus total body irradiation (TBI) in 1/9] and autologous peripheral blood stem cells (PBSC). Disease status at transplant was complete remission (2), partial remission (5), primary refractory (1) or relapse (1). Transplant related mortality (TRM) at 12 months was 0%. Median follow-up is 44 months with 4 year disease free survival 43% and overall survival 73%. Karnofsky performance status (KPS) is 80-100%. The nine allografted patients (median age: 49 years, range: 39-56 years) were conditioned with standard TBI (2), BEAM (2) or FLU-MEL (5) and received PBSC from HLA-matched sibling (8) or unrelated (1) donors. Disease status at transplant was partial remission (7) or primary refractory (2). TRM at 12 months was 44%. Complications included graft failure (2), grades I-II acute graft versus host disease (aGVHD) (2), grades III-IV aGVHD (3) and chronic GVHD (4). Median follow-up is 32 months with 4 year disease free survival 44% and overall survival 56%. KPS is 70-100%.

Bortezomib in the front-line treatment of multiple myeloma

Front-line therapy for multiple myeloma is rapidly evolving with the development of new, highly active regimens based on novel agents such as bortezomib. Bortezomib-based regimens are demonstrating substantial efficacy both as induction prior to stem cell transplantation and as treatment for patients ineligible for transplant, offering rapid and durable responses with consistently high rates of complete response, a surrogate end point for improved overall survival. Combinations of bortezomib plus established and novel agents, such as melphalan-prednisone, dexamethasone, doxorubicin, thalidomide-dexamethasone and, most recently, lenalidomide-dexamethasone, are proving superior to or more promising than previous standards of care. Importantly, these regimens are demonstrating enhanced activity across the front-line population, including patients with renal impairment, high-risk cytogenetics and advanced bone disease. Impressive Phase 3 results with bortezomib-melphalan-prednisone, bortezomib-dexamethasone and bortezomib-thalidomide-dexamethasone should facilitate the establishment of these highly effective regimens as key therapies for newly diagnosed myeloma.

High-dose treatment with autologous stem cell transplantation in multiple myeloma: past, present, and future

High-dose chemotherapy (HDT) with autologous stem cell transplantation (ASCT) has been used in the treatment of multiple myeloma since the early 1980s. Its present position as the backbone of first-line treatment in patients up to 60 to 65 years of age is the result of several controlled randomized trials, where its superiority over standard chemotherapy has been demonstrated. However, the method is not considered to have curative potential, with the possible exception of a small proportion of about 5% to 10% of patients with very long-standing complete remissions (CRs) of more than 8 years. Over the years, there have been several attempts to improve the technique, where, for example, tandem transplants and post-transplant maintenance treatment have been successful, at least in certain subgroups of patients, while others, such as graft purging, have been of no value. Treatment results need further improvement, particularly in poor-prognosis disease--based on abnormal karyotype and high beta2-microglobulin--and the future will show if the introduction of novel drugs like bortezomib, thalidomide, and lenalidomide will lead to longer survival and prolongation of disease control in multiple myeloma.

Prognostic factors and staging in multiple myeloma

The field of multiple myeloma prognostication is replete with studies that have shown the value of independent predictors in determining clinical outcome. It is clear that host factors and factors intrinsic to the cells are the ultimate determinants of prognosis. In the immediate period after diagnosis, those factors related to the host are likely to be more relevant, whereas with passing time factors intrinsic to the cells predominate. At a minimum, we recommend that a comprehensive molecular cytogenetic assessment be performed at diagnosis, together with conventional evaluation, including beta2-microglobulin and albumin. In addition, information on proliferative activity of plasma cells may be of value. The introduction of novel methods of prognostication should be strongly considered in all clinical trials.

Stem-Cell Transplantation for Multiple Myeloma in the Era of Novel Drugs

The treatment of multiple myeloma (MM) is changing rapidly. During the last 10 years, higher rates of complete response (CR) and prolonged progression-free and overall survival have been seen with high-dose chemotherapy plus autologous stem-cell transplantation (HDT-ASCT). Achievement of CR and good partial response have been shown to be key prognostic factors for prolonged survival, with eradication of minimal residual disease seeming crucial to long-term disease-free survival. Until recently, high rates of CR and other major responses were primarily seen with HDT-ASCT, but insights into the biology of MM have led to the development and approval of new drugs with significant activity, and new induction regimens based on these novel agents are offering improved responses. Thalidomide, bortezomib, and lenalidomide have been combined with corticosteroids, alkylators, and anthracyclines in front-line MM treatment. Phase II studies have indicated that high rates of response and CR may be achieved. The substantial activity seen with these new drug combinations has prompted a re-examination of the role of SCT in MM treatment. Will achievement of major responses with these new regimens translate into improved survival after consolidation with transplantation? Will these improved induction regimens reduce the need for tandem transplantation, or does achievement of CR obviate the need for front-line transplantation altogether? To help address these questions, randomized trials are needed, as well as tests with improved sensitivity to better define depth of remission.

Clinically relevant end points and new drug approvals for myeloma

This manuscript summarizes the recommendations of the American Society of Hematology/US Food and Drug Administration Workshop on Clinical Endpoints in Multiple Myeloma, which brought together clinical investigators in multiple myeloma, the United States Food and Drug Administration, pharmaceutical companies, patient advocates and other concerned scientists and physicians to provide guidance, consensus and consistency in the definition of clinically relevant end points to expedite new drug approvals for multiple myeloma in the appropriate trial design settings. This manuscript will therefore be a most valuable resource to provide the framework for the design of appropriate clinical trial strategies for more rapid new drug approval in myeloma.

Initial Therapy of Multiple Myeloma in Patients who are Candidates for Stem Cell Transplantation

Multiple myeloma (MM), a B cell hematologic malignancy involving plasma cells, responds to a variety of drugs including alkylators, steroids, anthracyclines, immunomodulators and proteosome inhibitors. The disease, however, remains largely incurable for the majority of patients. For patients who are suitable candidates, high dose chemotherapy with autologous stem cell support (ASCT) after induction therapy has been shown to improve response rates, progression free survival and overall survival compared to conventional chemotherapy. The availability of new drugs including thalidomide, lenalidomide and bortezomib has rapidly changed induction strategies. These drugs have been combined with corticosteroids, alkylators and anthracyclines to treat front-line patients with MM. Preliminary, phase 1-2 studies have indicated very high response rates and complete response rates formerly only seen with ASCT. Emerging data from randomized trials suggest that older regimens such as vincristine, adriamycin and dexamethasone (VAD) are not as effective for induction as newer combinations. Thus new regimens incorporating novel agents should improve overall response rates, increase complete responders which should translate into improved progression free and overall survival.

Risk factors for relapse after complete remission with high-dose therapy for multiple myeloma

Complete remission (CR) is an important surrogate for long-term survival for patients with multiple myeloma. However, most patients achieving CR eventually relapse and die from their disease. To better define the predictors of relapse, we conducted a retrospective review of outcomes for patients who achieved CR after autografting at our institution. From January 1990 to December 2002, among >400 patients transplanted, 81 (54 males and 27 females) achieved CR. With a median follow up of 58 months for all surviving patients, the 5-year progression-free survival (PFS) was 33% [95% confidence interval (CI) = 23 - 44] and 5-year overall survival (OS) was 67% (95% CI = 54 - 77). Median PFS was 37 months and median OS has not yet been reached. On multivariate analysis, high tumor mass at diagnosis emerged as a predictor of poor outcome. We conclude that high tumor mass at diagnosis predicts a significantly shorter remission duration for myeloma patients undergoing autografting.

Bortezomib in Combination with Pegylated Liposomal Doxorubicin for the Treatment of Multiple Myeloma

Many novel agents and new combinations (including bortezomib, thalidomide, and lenalidomide) have been developed in recent years for the treatment of multiple myeloma (MM), creating major shifts in therapeutic management. Achieving complete response (CR)/near CR (nCR) generally serves as a reliable clinical surrogate for overall treatment outcome, ie, prolonged survival. Indeed, some newer induction regimens are yielding similar median time to disease progression effects compared with transplantation. Thus, it can be a dilemma whether a patient with CR/nCR needs to be subjected to the potential morbidity associated with transplantation after induction therapy. Combining new agents with chemotherapy-based regimens appears to offer higher overall response and CR/nCR rates than similar combinations that do not include chemotherapy. We review the preclinical and clinical rationale for combining bortezomib with pegylated liposomal doxorubicin for the treatment of MM. The synergistic interaction in sensitizing each other toward myeloma cells in vitro and their complementary in vivo activities have justified clinical studies. We summarize data for completed and ongoing phase I/II trials of this combination. To date, results have been sufficiently encouraging to initiate an international, multicenter, randomized, phase III trial comparing bortezomib with or without pegylated liposomal doxorubicin in patients with relapsed/refractory MM. The results of this trial will confirm whether the rationale for combining bortezomib with pegylated liposomal doxorubicin is validated by improved clinical outcome, ie, improved time to progression, for patients with MM.

Low tolerance and high toxicity of thalidomide as maintenance therapy after double autologous stem cell transplant in multiple myeloma patients

Although a double autologous peripheral blood stem cell transplant (APBSCT) is an effective therapy for patients (pts) with multiple myeloma and extends progression-free survival and overall survival, pts show a continued pattern of recurrent disease. The feasibility and tolerability of thalidomide (Thal) administered in the post-transplantation period as maintenance therapy was tested in 17 pts at a dose of 100 mg/d starting between 3 and 5 months after the second transplantation and continuing either until toxicity precluded further therapy or until pts had disease progression. After a median administration of 13 months (range: 3-26), 76.5% (13 pts) failed to tolerate Thal because of: transiet ischemic attack (three pts), severe fatigue (two), neutropenia (one), piastrinopenia (one), severe opportunistic infectious (two), erectile impotence (one), gastrointestinal toxicity (anorexia with weight loss one), peripheral neuropathy (two). After a median follow-up of 36 months (range: 10-59) from the second transplant, 13 patients attained a CR + near CR (with a conversion rate from 47.1% to 76.5%). In conclusion, Thal as maintenance therapy after double ASCT is associated with low feasibility and high toxicity and could prevent a lengthy use of this antineoplastic agent.

Treatment Strategies in Elderly Patients with Multiple Myeloma

Multiple myeloma (MM), a plasma cell malignancy, is a disorder of the elderly with an increasing prevalence as the average life expectancy increases. Survival remains unacceptably low in elderly patients with MM, in whom the gold standard of treatment has been, until recently, oral melphalan and prednisolone, which induces a response rate of approximately 50% and overall survival of <3 years. In the last 15 years, traditional treatment paradigms for elderly patients with MM have been challenged not only as a result of the change in what we define as 'elderly' but also as a result of the reduced morbidity and treatment-related mortality associated with high-dose chemoradiotherapy (HDT) and autologous stem cell transplantation (ASCT), and the emergence of novel therapies including thalidomide, its immunomodulator drug derivative lenalidomide and the first-in-class proteasome inhibitor, bortezomib. In this review, we examine currently available data regarding the treatment of MM in the elderly population. Recent years have seen a paradigm shift in the standard of care of elderly patients with MM from oral melphalan and prednisolone to approaches including HDT with ASCT using intermediate-dose melphalan in selected elderly patients, and the evaluation of and incorporation of drugs such as thalidomide, bortezomib and lenalidomide. Importantly, we now have been able to change the traditional goal of palliation in the elderly group of patients to a more ambitious objective of achieving a complete response or a near complete response, in the hope that this will translate into improved progression-free survival, overall survival and quality of life.

Bortezomib plus melphalan and prednisone in elderly untreated patients with multiple myeloma: results of a multicenter phase 1/2 study

Standard first-line treatment for elderly multiple myeloma (MM) patients ineligible for stem cell transplantation is melphalan plus prednisone (MP). However, complete responses (CRs) are rare. Bortezomib is active in patients with relapsed MM, including elderly patients. This phase 1/2 trial in 60 untreated MM patients aged at least 65 years (half older than 75 years) was designed to determine dosing, safety, and efficacy of bortezomib plus MP (VMP). VMP response rate was 89%, including 32% immunofixation-negative CRs, of whom half of the IF– CR patients analyzed achieved immunophenotypic remission (no detectable plasma cells at 10–4 to 10–5 sensitivity). VMP appeared to overcome the poor prognosis conferred by retinoblastoma gene deletion and IgH translocations. Results compare favorably with our historical control data for MP—notably, response rate (89% versus 42%), event-free survival at 16 months (83% versus 51%), and survival at 16 months (90% versus 62%). Side effects were predictable and manageable; principal toxicities were hematologic, gastrointestinal, and peripheral neuropathy and were more evident during early cycles and in patients aged 75 years or more. In conclusion, in elderly patients ineligible for transplantation, the combination of bortezomib plus MP appears significantly superior to MP, producing very high CR rates, including immunophenotypic CRs, even in patients with poor prognostic features.

Application of self-quenched JH consensus primers for real-time quantitative PCR of IGH gene to minimal residual disease evaluation in multiple myeloma

Monitoring multiple myeloma patients for relapse requires sensitive methods to measure minimal residual disease and to establish a more precise prognosis. The present study aimed to standardize a real-time quantitative polymerase chain reaction (PCR) test for the IgH gene with a JH consensus self-quenched fluorescence reverse primer and a VDJH or DJH allele-specific sense primer (self-quenched PCR). This method was compared with allele-specific real-time quantitative PCR test for the IgH gene using a TaqMan probe and a JH consensus primer (TaqMan PCR). We studied nine multiple myeloma patients from the Spanish group treated with the MM2000 therapeutic protocol. Self-quenched PCR demonstrated sensitivity of >or=10(-4) or 16 genomes in most cases, efficiency was 1.71 to 2.14, and intra-assay and interassay reproducibilities were 1.18 and 0.75%, respectively. Sensitivity, efficiency, and residual disease detection were similar with both PCR methods. TaqMan PCR failed in one case because of a mutation in the JH primer binding site, and self-quenched PCR worked well in this case. In conclusion, self-quenched PCR is a sensitive and reproducible method for quantifying residual disease in multiple myeloma patients; it yields similar results to TaqMan PCR and may be more effective than the latter when somatic mutations are present in the JH intronic primer binding site.

International uniform response criteria for multiple myeloma

New uniform response criteria are required to adequately assess clinical outcomes in myeloma. The European Group for Blood and Bone Marrow Transplant/International Bone Marrow Transplant Registry criteria have been expanded, clarified and updated to provide a new comprehensive evaluation system. Categories for stringent complete response and very good partial response are added. The serum free light-chain assay is included to allow evaluation of patients with oligo-secretory disease. Inconsistencies in prior criteria are clarified making confirmation of response and disease progression easier to perform. Emphasis is placed upon time to event and duration of response as critical end points. The requirements necessary to use overall survival duration as the ultimate end point are discussed. It is anticipated that the International Response Criteria for multiple myeloma will be widely used in future clinical trials of myeloma.

Maintenance therapy with thalidomide improves overall survival after autologous hematopoietic progenitor cell transplantation for multiple myeloma

BACKGROUND

High-dose chemotherapy with autologous hematopoietic progenitor cell (HPC) transplantation improves survival for patients with multiple myeloma (MM); however, most patients develop recurrent disease after undergoing transplantation, and new treatment approaches are needed. The objective of this retrospective review of autologous HPC transplantation for patients with MM was to evaluate the impact of conditioning regimens and posttransplantation therapy on survival.

METHODS

The authors reviewed 112 patients with MM who received autologous HPC grafts at their institution. Between June 1992 and August 2001, 54 patients received busulfan, cyclophosphamide, and etoposide (Bu/Cy/VP-16), and 58 patients received high-dose melphalan (MEL-200) followed by autologous HPC transplantation. After transplantation, 36 patients received thalidomide for maintenance or salvage therapy, and 76 patients received no posttransplantation thalidomide.

RESULTS

At a median follow-up of 58 months, the median survival was 54 months. There was no statistically significant difference noted with regard to response to conditioning regimen, progression-free survival, or overall survival between the Bu/Cy/VP-16 and MEL-200 cohorts. Patients who received thalidomide after transplantation had improved median survival (65.5 months) compared with patients who did not receive thalidomide (44.5 months; P = .09). When they were separated according to reasons for thalidomide use, patients who received thalidomide as maintenance had improved overall survival compared with patients who received thalidomide as salvage (65 months vs. 54 months; P = .05).

CONCLUSIONS

Combination chemotherapy provided no advantage over high-dose melphalan in patients with MM who underwent autologous HPC transplantation. The posttransplantation use of thalidomide seemed to improve the survival of patients compared with historical controls from the prethalidomide era. Further prospective trials are underway to confirm the benefit of thalidomide in the posttransplantation setting.

Complete response in multiple myeloma: clinical trial E9486, an Eastern Cooperative Oncology Group study not involving stem cell transplantation

BACKGROUND

The importance of obtaining a complete response (CR) in multiple myeloma (MM) treated with chemotherapy is unclear.

METHODS

The Eastern Cooperative Oncology Group evaluated 653 previously untreated patients with active MM randomized to vincristine, carmustine (BCNU), melphalan, cyclophosphamide, and prednisone (VBMCP), to VBMCP and recombinant interferon alfa-2 (INFalpha-2), or to VBMCP and high-dose cyclophosphamide.

RESULTS

Objective response was achieved in 420 (67%) of the 628 eligible patients, and 85 (14%) achieved a CR. Patients receiving VBMCP and recombinant INFalpha-2 had a significantly higher CR (18%) than those receiving VBMCP alone (10%) (P = .02). The CR rate for VBMCP and high-dose cyclophosphamide was 12%. Median duration of survival was 3.5 years for all eligible patients, and the estimated 5-year survival rate was 31%. The median duration of survival from the date of objective response was 5.1 years for those who achieved a CR and 3.3 years for those with a partial response (P < .0001). The median postresponse survival was 6.6 years in the 21 patients in CR with nonclonal disease and 4.4 years in the 11 patients in CR who had persistent clonal disease. All patients with negative immunofixation results and nonclonal plasma cells in whom polymerase chain reaction was performed had a positive result (presence of tumor DNA).

CONCLUSION

Patients in whom a CR was achieved had a longer survival than those who had a partial response.

Cure of multiple myeloma -- more hype, less reality

Randomized studies have firmly established the role of autologous transplant as initial therapy in multiple myeloma (MM). Indeed, MM has emerged as the commonest indication for autologous SCT in North America. The conceptual basis for high-dose therapy is the goal of complete remission (CR) through steep reduction in tumor burden affected by single and tandem transplants. Careful analysis of the data challenges the notion of CR as a surrogate to success. Intrinsically aggressive MM, defined by known unfavorable biologic risk factors, overrides the benefit of CR. In contrast, subgroups of patients with favorable biological risk factors may achieve prolonged survival, often without ever achieving CR. Unfortunately, even with tandem transplants, there is no plateau in survival curves. To this end, sequential autologous followed by nonmyeloablative allotransplants are a novel attempt at 'curing' myeloma, but the results thus far have failed to show a definite plateau in survival. Given the improvements in supportive care and concomitant reduction in transplant-related mortality, conventional myeloablative allogeneic transplants need to be re-examined as an option in high-risk aggressive myeloma. At the same time, novel antimyeloma therapies, newer risk stratification and staging tools are transforming the treatment algorithm. We examine the changing role of transplantation in myeloma in the context of novel drug therapy, biologic risk stratification and improving supportive care while arguing that the current 'one size fits all' transplant approaches are far from a cure.

Autologous stem cell transplantation followed by consolidation chemotherapy for patients with multiple myeloma

Although high-dose therapy and autologous stem cell transplant (ASCT) is superior to conventional chemotherapy for treatment of myeloma, most patients relapse and the time to relapse depends upon the initial prognostic factors. The administration of non-cross-resistant chemotherapies during the post-transplant period may delay or prevent relapse. We prospectively studied the role of consolidation chemotherapy (CC) after single autologous peripheral blood stem cell transplant (auto-PBSCT) in 103 mostly newly diagnosed myeloma patients (67 patients were < or =6 months from the initial treatment). Patients received conditioning with BCNU, melphalan+/-gemcitabine and auto-PBSCT followed by two cycles of the DCEP+/-G regimen (dexamethasone, cyclophosphamide, etoposide, cisplatin+/-gemcitabine) at 3 and 9 months post-transplant and alternating with two cycles of DPP regimen (dexamethasone, cisplatin, paclitaxel) at 6 and 12 months post-transplant. With a median follow-up of 61.2 months, the median event-free survival (EFS) and overall survival (OS) are 26 and 54.1 months, respectively. The 5-year EFS and OS are 23.1 and 42.5%, respectively. Overall, 51 (49.5%) patients finished all CC, suggesting that a major limitation of this approach is an inability to deliver all planned treatments. In order to improve results following autotransplantation, novel agents or immunologic approaches should be studied in the post-transplant setting.

Pharmacotherapy of multiple myeloma

Multiple myeloma is a malignant process of the plasma cell. There is no cure for this disease and at present the focus is to manage the disease as a chronic process to achieve a good quality of life. Hopefully, with the advancement in the understanding of the pathophysiology of the disease, target therapy should allow for the control of multiple myeloma, its prevention, and/or the reversal of organ damage; therefore prolonging survival. Proteasome inhibitors and immune modulators are the first of new therapies that target the malignant plasma cell microenvironment. In this review, different aspects of these agents are discussed.