Comparison of autologous and allogeneic hematopoietic cell transplantation strategies in patients with primary plasma cell leukemia, with dynamic prediction modeling.

Primary plasma cell leukemia (pPCL) is a rare and challenging malignancy. There are limited data regarding optimum transplant approaches. We therefore undertook a retrospective analysis from 1998-2014 of 751 patients with pPCL undergoing one of four transplant strategies; single autologous transplant (single auto), single allogeneic transplant (allo-first) or a combined tandem approach with an allogeneic transplant following an autologous transplant (auto-allo) or a tandem autologous transplant (auto-auto). To avoid time bias, multiple analytic approaches were employed including Cox models with time-dependent covariates and dynamic prediction by landmarking. Initial comparisons were made between patients undergoing allo-first (n=70) versus auto-first (n=681), regardless of a subsequent second transplant. The allo-first group had a lower relapse rate (45.9%, 95% confidence interval [95% CI]: 33.2-58.6 vs. 68.4%, 64.4-72.4) but higher non-relapse mortality (27%, 95% CI: 15.9-38.1 vs. 7.3%, 5.2-9.4) at 36 months. Patients who underwent allo-first had a remarkably higher risk in the first 100 days for both overall survival and progression-free survival. Patients undergoing auto-allo (n=122) had no increased risk in the short term and a significant benefit in progression-free survival after 100 days compared to those undergoing single auto (hazard ratio [HR]=0.69, 95% CI: 0.52- 0.92; P=0.012). Auto-auto (n=117) was an effective option for patients achieving complete remission prior to their first transplant, whereas in patients who did not achieve complete remission prior to transplantation our modeling predicted that auto-allo was superior. This is the largest retrospective study reporting on transplantation in pPCL to date. We confirm a significant mortality risk within the first 100 days for allo-first and suggest that tandem transplant strategies are superior. Disease status at time of transplant influences outcome. This knowledge may help to guide clinical decisions on transplant strategy.

Are Autologous Stem Cell Transplants Still Required to Treat Myeloma in the Era of Novel Therapies? A Review from the Chronic Malignancies Working Party of the EBMT.

Melphalan at a myeloablative dose followed by autologous stem cell transplantation (ASCT) remains the standard of care for transplant-eligible patients with myeloma. However, therapies such as new immunomodulatory drugs and proteasome inhibitors and, more recently, monoclonal antibodies and chimeric antigen receptor T cells are challenging the traditional role of ASCT. Which patients benefit from ASCT? Can its use be delayed until first relapse? The field is moving rapidly as novel agents lead to new patient care strategies. The place of ASCT in this changing landscape will be reviewed and reassessed.

Evolution or revolution in multiple myeloma therapy and the role of the UK.

The knowledge of disease biology as well as the therapeutic landscape in multiple myeloma (MM) has expanded exponentially in recent years. These advances have seen improvements in survivorship, not only in the clinical trial setting but also in the real setting. Importantly there is also every evidence to indicate that such improvements in our understanding and treatments will continue. This article is not intended to be a comprehensive review; rather it aims to give a temporal context to these developments with exemplars, and highlight the central role that UK clinicians, healthcare workers, scientists and most importantly patients and their relatives have played in this revolution.

Incidence of Second Primary Malignancies after Autologous Transplantation for Multiple Myeloma in the Era of Novel Agents.

The advent of novel agents for multiple myeloma (MM) is cause for a re-examination of the incidence of second primary malignancies (SPMs). We examined the SPM rate in MM patients who were enrolled in the prospective observational CALM (Collaboration to Collect Autologous Transplant outcome in Lymphoma and Myeloma) study. Between 2008 and 2012, 3204 patients with MM underwent a first autologous hematopoietic stem cell transplantation. Plerixafor was used as a mobilizing agent for patients with poor (or potentially poor) stem cell mobilization as defined by the respective centers. A total of 135 patients developed SPMs, with a cumulative incidence of 5.3% (95% confidence interval, 4.4 to 6.3) at 72 months. Ninety-four patients developed solid tumors, 30 developed hematologic malignancies, and 11 developed an SPM of an unknown type. The cumulative incidence of known hematologic and solid malignancies were 1.4% and 3.6%, respectively, at 72 months. In a univariate analysis, use of radiotherapy, type of induction regimen, hematopoietic stem cell dose, poor mobilizer status, plerixafor use, and sex did not influence the cumulative incidence of SPMs. Only age over 65 years was statistically associated with an increased incidence. Overall, the incidence of SPMs was comparable to earlier estimations of SPMs in MM.

Melphalan 140 mg/m2 or 200 mg/m2 for autologous transplantation in myeloma: results from the Collaboration to Collect Autologous Transplant Outcomes in Lymphoma and Myeloma (CALM) study. A report by the EBMT Chronic Malignancies Working Party.

Melphalan at a dose of 200 mg/m2 is standard conditioning prior to autologous hematopoietic stem cell transplantation for multiple myeloma, but a dose of 140 mg/m2 is often used in clinical practice in patients perceived to be at risk of excess toxicity. To determine whether melphalan 200 mg/m2 and melphalan 140 mg/m2 are equally effective and tolerable in clinically relevant patient subgroups we analyzed 1964 first single autologous transplantation episodes using a series of Cox proportional-hazards models. Overall survival, progression-free survival, cumulative incidence of relapse, non-relapse mortality, hematopoietic recovery and second primary malignancy rates were not significantly different between the melphalan 140 mg/m2 (n=245) and melphalan 200 mg/m2 (n=1719) groups. Multivariable subgroup analysis showed that disease status at transplantation interacted with overall survival, progression-free survival, and cumulative incidence of relapse, with a significant advantage associated with melphalan 200 mg/m2 in patients transplanted in less than partial response (adjusted hazard ratios for melphalan 200 mg/m2versus melphalan 140 mg/m2: 0.5, 0.54, and 0.56). In contrast, transplantation in very good partial or complete response significantly favored melphalan 140 mg/m2 for overall survival (adjusted hazard ratio: 2.02). Age, renal function, prior proteasome inhibitor treatment, gender, or Karnofsky score did not interact with overall/progression-free survival or relapse rate in the melphalan dose groups. There were no significant survival or relapse rate differences between melphalan 200 mg/m2 and melphalan 140 mg/m2 patients with high-risk or standard-risk chromosomal abnormalities. In conclusion, remission status at the time of transplantation may favor the use of melphalan 200 mg/m2 or melphalan 140 mg/m2 for key transplant outcomes (NCT01362972).

Response Assessment in Myeloma: Practical Manual on Consistent Reporting in an Era of Dramatic Therapeutic Advances.

The understanding and treatment of multiple myeloma (MM) have dramatically improved in recent years. However, accurate assessment of the response of myeloma to therapy and its subsequent relapse remains a difficult task. Criteria have changed over time and new parameters have recently been incorporated to evaluate minimal residual disease status. We present a practical approach to assess response and relapse/progression in myeloma in the context of its treatment. A robust reporting schema is crucial to correctly evaluate any treatment protocol and compare results across trials. MM is a highly heterogeneous disease with multifarious manifestations. To assess the tumor load decline after treatment and its increase during relapse/progression, numerous parameters need to be taken into account. As our ability and the tools to measure low levels of disease have improved over time, so have the accepted definitions of response, most recently in August 2016. The goal of this article is to define, describe, and clarify the practical methodological aspects of disease evaluation in response to therapy and in progression or relapse. We expect this practical manual will help myeloma professionals and research workers in data collection for registries and databases and clinical trial reporting.

High-dose therapy and autologous stem cell transplantation in patients with POEMS syndrome: a retrospective study of the Plasma Cell Disorder sub-committee of the Chronic Malignancy Working Party of the European Society for Blood & Marrow Transplantation.

POEMS syndrome is a rare para-neoplastic syndrome secondary to a plasma cell dyscrasia. Effective treatment can control the disease-related symptom complex. We describe the clinical outcome of autologous stem cell transplantation for patients with POEMS syndrome, determining the impact of patient- and disease-specific factors on prognosis. One hundred and twenty-seven patients underwent an autologous stem cell transplantation between 1997-2010 with a median age of 50 years (range 26-69 years). Median time from diagnosis to autologous stem cell transplantation was 7.5 months with 32% of patients receiving an autologous stem cell transplantation more than 12 months from diagnosis. Engraftment was seen in 97% patients and engraftment syndrome was documented in 23% of autologous stem cell transplantation recipients. Hematologic response was characterized as complete response in 48.5%, partial response in 20.8%, less than partial repsonse in 30.7%. With a median follow up of 48 months (95%CI: 38.3, 58.6), 90% of patients are alive and 16.5% of patients have progressed. The 1-year non-relapse mortality was 3.3%. The 3-year probabilities of progression-free survival and overall survival are 84% and 94%, respectively, with 5-year probabilities of progression-free survival and overall survival of 74% and 89%. In a cohort of graft recipients, detailed organ-specific symptom response demonstrated clear symptom benefit after autologous stem cell transplantation especially in relation to neurological symptom control. The data analyzed in this study demonstrate the clinical utility of autologous stem cell transplantation for patients with POEMS syndrome.

Stem Cell Harvesting after Bortezomib-Based Reinduction for Myeloma Relapsing after Autologous Transplantation: Results from the British Society of Blood and Marrow Transplantation/United Kingdom Myeloma Forum Myeloma X (Intensive) Trial.

The phase III British Society of Blood and Marrow Transplantation/United Kingdom Myeloma Forum Myeloma X trial (MMX) demonstrated prospectively, for the first time, superiority of salvage autologous stem cell transplantation over chemotherapy maintenance for multiple myeloma (MM) in first relapse after previous ASCT. However, many patients have stored insufficient stem cells (PBSC) for second ASCT and robust evidence for remobilization after first ASCT is lacking. We report the feasibility, safety, and efficacy of remobilization after bortezomib-doxorubicin-dexamethasone reinduction in MMX and outcomes of second ASCT with these cells. One hundred ten patients underwent ≥1 remobilization with 32 and 4, undergoing second and third attempts, respectively. Toxicities of remobilization were similar to those seen in first-line mobilization. After all attempts, 52% of those with insufficient previously stored PBSC had harvested a sufficient quantity to proceed to second ASCT. Median PBSC doses infused, neutrophil engraftment, and time to discharge after second ASCT were similar regardless of stem cell source, as were the toxicities of second ASCT. No significant differences between PBSC sources were noted in depth of response to ASCT or time to progression. Harvesting after bortezomib-doxorubicin-dexamethasone reinduction for MM at first relapse is safe and feasible and yields a reliable cell product for second ASCT. The study is registered with ClinicalTrials.gov (NCT00747877) and EudraCT (2006-005890-24).

Efficacy and outcome of allogeneic transplantation in IgD and nonsecretory myeloma. A report on behalf of the Myeloma Subcommittee of the Chronic Malignancies Working Party of the European Group for Blood and Marrow Transplantation.

We have recently reported on the outcome of autologous transplantation in the rare myelomas (IgD, IgE, IgM, and nonsecretory [NS]) but there is no real information on the outcome of these conditions after allogeneic transplantation. We used the European Group for Blood and Marrow Transplantation myeloma database to compare the outcomes after allogeneic transplantation of 1354 common myelomas (IgG, IgA, and light chain myeloma) with the outcome in 26 IgD myelomas and 52 NS myelomas. There was little difference between common and the IgD and NS myeloma patients with respect to prognostic factors although the IgD group had a higher beta 2 microglobulin at diagnosis, shorter time to transplantation, and more T cell depletion. IgD and NS patients had a significantly greater achievement of complete remission at conditioning but this did not translate into equivalent progression-free survival and overall survival for the IgD patients although the NS outcome was very similar to that of common myeloma. The PFS and OS of IgD, common, and NS myelomas appear similar after allogeneic transplantation, despite a tendency for higher early relapse rate in IgD myeloma. Allogeneic transplantation may, therefore, be an option to investigate in prospective observational studies.

Bendamustine, thalidomide and dexamethasone combination therapy for relapsed/refractory myeloma patients: results of the MUKone randomized dose selection trial.

There is a significant unmet need in effective therapy for relapsed myeloma patients once they become refractory to bortezomib and lenalidomide. While data from the front line setting suggest bendamustine is superior to melphalan, there is no information defining optimal bendamustine dose in multiply-treated patients. We report a multi-centre randomized two-stage phase 2 trial simultaneously assessing deliverability and activity of two doses of bendamustine (60 mg/m2 vs. 100 mg/m2) days 1 and 8, thalidomide (100 mg) days 1-21 and low dose dexamethasone (20 mg) days 1, 8, 15 and 22 of a 28-d cycle. Ninety-four relapsing patients were treated on trial, with a median three prior treatment lines. A pre-planned interim deliverability and activity assessment led to closure of the 100 mg/m2 arm due to excess cytopenias, and led to amendment of entry criteria for cytopenias. Non-haematological toxicities including thromboembolism and neurotoxicity were infrequent. In the 60 mg/m2 arm, treatment was deliverable in 61.1% subjects and the partial response rate was 46.3% in the study eligible population, with 7.5 months progression-free survival. This study demonstrates bendamustine at 60 mg/m2 twice per month with thalidomide and dexamethasone is deliverable for repeated cycles in heavily pre-treated myeloma patients and has substantial clinical activity.

Autologous/reduced-intensity allogeneic stem cell transplantation vs autologous transplantation in multiple myeloma: long-term results of the EBMT-NMAM2000 study.

Long-term follow-up of prospective studies comparing allogeneic transplantation to autologous transplantation in multiple myeloma is few and controversial. This is an update at a median follow-up of 96 months of the European Group for Blood and Marrow Transplantation Non-Myeloablative Allogeneic stem cell transplantation in Multiple Myeloma (NMAM)2000 study that prospectively compares tandem autologous/reduced intensity conditioning allogeneic transplantation (auto/RICallo) to autologous transplantation alone (auto). There are 357 myeloma patients up to age 69 years enrolled. Patients with an HLA-identical sibling were allocated to auto/RICallo (n = 108) and those without to auto alone (n = 249). At 96 months progression-free survival (PFS) and overall survival (OS) were 22% and 49% vs 12% (P = .027) and 36% (P = .030) with auto/RICallo and auto respectively. The corresponding relapse/progression rate (RL) was 60% vs 82% (P = .0002). Non-relapse mortality at 36 months was 13% vs 3% (P = .0004). In patients with the del(13) abnormality corresponding PFS and OS were 21% and 47% vs 5% (P = .026), and 31% (P = .154). Long-term outcome in patients with multiple myeloma was better with auto/RICallo as compared with auto only and the auto/RICallo approach seemed to overcome the poor prognostic impact of del(13) observed after autologous transplantation. Follow up longer than 5 years is necessary for correct interpretation of the value of auto/RICallo in multiple myeloma.

Should the standard dimethyl sulfoxide concentration be reduced? Results of a European Group for Blood and Marrow Transplantation prospective noninterventional study on usage and side effects of dimethyl sulfoxide.

BACKGROUND: Dimethyl sulfoxide (DMSO) is essential for the preservation of liquid nitrogen-frozen stem cells, but is associated with toxicity in the transplant recipient. STUDY DESIGN AND METHODS: In this prospective noninterventional study, we describe the use of DMSO in 64 European Blood and Marrow Transplant Group centers undertaking autologous transplantation on patients with myeloma and lymphoma and analyze side effects after return of DMSO-preserved stem cells. RESULTS: While the majority of centers continue to use 10% DMSO, a significant proportion either use lower concentrations, mostly 5 or 7.5%, or wash cells before infusion (some for selected patients only). In contrast, the median dose of DMSO given (20 mL) was much less than the upper limit set by the same institutions (70 mL). In an accompanying statistical analysis of side effects noted after return of DMSO-preserved stem cells, we show that patients in the highest quartile receiving DMSO (mL and mL/kg body weight) had significantly more side effects attributed to DMSO, although this effect was not observed if DMSO was calculated as mL/min. Dividing the myeloma and lymphoma patients each into two equal groups by age we were able to confirm this result in all but young myeloma patients in whom an inversion of the odds ratio was seen, possibly related to the higher dose of melphalan received by young myeloma patients. CONCLUSION: We suggest better standardization of preservation method with reduced DMSO concentration and attention to the dose of DMSO received by patients could help reduce the toxicity and morbidity of the transplant procedure.

What can we do about patients presenting with myeloma and severe renal failure? Observations from the UK MERIT plasma exchange trial.

Myeloma patients presenting with renal failure continue to have a poor prognosis despite significant advances in anti-myeloma therapy. MERIT was a randomised clinical trial (RCT), set up to evaluate if mechanical reduction of elevated free light chain levels (FLC) would result in clinical benefit. Completion of the planned seven plasma exchanges (PEs) in the first 14 days failed to show, for the exchange group, a greater reduction in FLC or any improvement in dialysis independence at 100 days or subsequently. To improve prognosis for these patients requires earlier diagnosis and prompt anti-myeloma therapy with effectiveness guided by frequent FLC monitoring.

Complications of Autologous Stem Cell Transplantation in Multiple Myeloma: Results from the CALM Study.

Background: The main goal of this post hoc analysis of the Collaboration to Collect Autologous Transplant Outcomes in Lymphoma and Myeloma (CALM) study was to evaluate the rate of short- and long-term infectious and non-infectious complications occurring after ASCT in patients with multiple myeloma (MM). Methods: The analysis included all patients with MM from the CALM study who underwent ≥1 ASCT. The primary endpoint of the analysis was to determine the rate of infectious and non-infectious complications after ASCT and to compare them in three time periods: 0−100 days, 101 days−1 year, and >1 year after the first transplant. Results: The analysis included a total of 3552 patients followed up for a median of 56.7 months (range 0.4−108.1). Complication rates decreased with the time from ASCT with 24.85 cases per 100 patient-years from day 0 to 100 days after the transplant, and <2.31 cases per 100 patient-years from the 101st day. At 100 days after ASC T, 45.7% of patients had complications, with infectious events being twice as frequent as non-infectious complications. Bacterial infections (6.5 cases per 100 patient-years, 95% CI: 6.1−7.0) and gastrointestinal complications (4.7 cases per 100 patient-years, 95% CI: 4.3−5.1) were the most common early events. The pattern of complications changed with time from ASCT. The presence of complications after ASCT was not associated with overall survival. Conclusions: Our data provide a solid basis for comparing ASCT-related complications to those caused by emerging treatments in multiple myeloma, such as CAR T-cell therapy and other immunotherapies.

IgD Subtype But Not IgM or Non-Secretory Is a Prognostic Marker for Poor Survival Following Autologous Hematopoietic Cell Transplantation in Multiple Myeloma. Results From the EBMT CALM (Collaboration to Collect Autologous Transplant Outcomes in Lymphomas and Myeloma) Study.

BACKGROUND: The Collaboration to Collect Autologous Transplant Outcomes in Lymphoma and Myeloma (CALM) study has provided an opportunity to evaluate the real-world outcomes of patients with myeloma. The aim of this study was to compare the outcome according to the different subtypes of myeloma using CALM data. PATIENTS: This study compared overall survival (OS), progression-free survival (PFS), and complete remission (CR) and the impact of novel versus non-novel drug containing induction regimens prior to autologous hematopoietic cell transplantation (HCT) of 2802 patients with "usual" and "rare" myelomas. RESULTS: Our data suggest that IgM and non-secretory myeloma have superior PFS and OS compared with IgD myeloma and outcomes comparable to those for usual myeloma. Patients who received novel agent induction had higher rates of CR prior to transplant. Non-novel induction regimens were associated with inferior PFS but no difference in OS. Although not the primary focus of this study, we show that poor mobilization status is associated with reduced PFS and OS, but these differences disappear in multivariate analysis suggesting that poor mobilization status is a surrogate for other indicators of poor prognosis. CONCLUSION: We confirm that IgD myeloma is associated with the worst prognosis and inferior outcomes compared with the other isotypes.

Unrelated stem cell transplantation after reduced intensity conditioning for patients with multiple myeloma relapsing after autologous transplantation.

From 2002 to 2007, 49 myeloma patients who relapsed following autologous SCT were included in a prospective multicenter trial to determine the efficacy of a reduced melphalan/fludarabine regimen followed by allogeneic SCT from unrelated donors. All patients showed leucocyte and platelet engraftment after a median of 15 and 19 d, respectively. Grade II-IV acute graft-versus-host disease (GvHD) occurred in 25% of patients and 35% had chronic GvHD. Overall response rate at day 100 was 95% including 46% complete remission (CR). Cumulative incidence of non-relapse mortality at 1 year was 25% [95% confidence interval (CI): 13-37%] and was significantly lower for human leucocyte antigen (HLA)-matched compared to -mismatched SCT (10% vs. 53%, P = 0.001). The cumulative incidence of relapse at 3 years was 55% (95% CI: 40-70%). After a median follow up of 43 months, the estimated 5-year progression-free and overall survival rates were 20% and 26% respectively and were significantly better for matched in CR at day 100 (41% vs. 7%, P = 0.04 and 56% vs. 16%, P = 0.02). We conclude that optimal donor selection is mandatory for a low non-relapse mortality and high relapse incidence, which remains a major concern, should be improved by including post-transplant strategies to upgrade remission status.

Primary plasma cell leukemia and autologous stem cell transplantation.

BACKGROUND: Primary plasma cell leukemia is a rare disorder accounting for less than 5% of malignant plasma cell diseases. It has a poor prognosis compared to multiple myeloma, with a median survival of 8-12 months. The results of conventional therapy are disappointing though autologous stem cell transplantation may improve survival. DESIGN AND METHODS: A retrospective analysis was undertaken of the European Group for Blood and Marrow Transplantation experience of 272 patients with plasma cell leukemia and 20844 with multiple myeloma undergoing first autologous transplantation between 1980 and 2006. All patients were reported to the European Group for Blood and Marrow Transplantation registry using MED-A (limited data) or MED-B (extensive data) forms. All patients were included regardless of availability of complete data. RESULTS: There was no difference in type of graft or use of total body irradiation between patients with plasma cell leukemia and multiple myeloma, but the group with plasma cell leukemia was transplanted earlier after diagnosis (6.0 versus 7.7 months, P=0.000). Patients with plasma cell leukemia were more likely to enter complete remission after transplantation but their overall survival (25.7 months, 95% confidence interval 19.5-31.9 months) was inferior to that of patients with multiple myeloma (62.3 months, 95% confidence interval 60.4-64.3 months) (P=0.000), due to the short duration of their post-transplant response and increased non-relapse-related mortality. CONCLUSIONS: This largest study ever reported on plasma cell leukemia suggests that autologous transplantation can improve outcome, although results are markedly inferior to those achieved in patients with multiple myeloma, highlighting the need for novel approaches to this aggressive disorder.

Efficacy and outcome of autologous transplantation in rare myelomas.

BACKGROUND: As rare myelomas, i.e. the IgD, IgE, IgM and non-secretory forms, constitute only a small proportion of any study, relatively little is known about their prognosis in the era of peripheral stem cell transplantation. DESIGN AND METHODS: We used the European Group for Blood and Marrow Transplantation Myeloma Database to compare the outcome following autologous transplantation of over 20,000 patients with common myelomas (IgG, IgA and light chain myeloma) with the outcome of patients with rare myelomas: 379 IgD, 13 IgE, 72 IgM and 976 non-secretory cases. RESULTS: The study confirms the multiple adverse prognostic factors seen in IgD myeloma. Somewhat surprisingly, patients with IgD and non-secretory myeloma both had higher complete remission rates before and after transplantation than patients with common myelomas. However, while the overall survival of patients with non-secretory myeloma was similar to that of the patients with common myelomas, the survival of patients with IgD myeloma was significantly worse (although better than survival rates reported for non-transplanted patients); this was due to higher transplant-related mortality and relapse/progression rates. The post-transplantation survival of patients with IgE or IgM myeloma appears to be very poor. CONCLUSIONS: This study provides data on the biological features of rare myelomas. The overall survival of patients with IgD, IgE or IgM myeloma is poor following autologous transplantation but substantially better than that reported for patients who were not transplanted.

Results from a multicenter, noninterventional registry study for multiple myeloma patients who received stem cell mobilization regimens with and without plerixafor.

Plerixafor plus granulocyte-colony stimulating factor (G-CSF) enhances the mobilization of hematopoietic stem cells (HSCs) for collection and subsequent autologous hematopoietic stem cell transplantation (HSCT) in patients with multiple myeloma (MM). This international, multicenter, noninterventional registry study (NCT01362972), evaluated long-term outcomes for MM patients who received plerixafor versus other mobilization regimens. The comparisons were: G-CSF + plerixafor (G-CSF + P) versus G-CSF-; G-CSF + P versus G-CSF + chemotherapy (G-CSF + C); and G-CSF + P + C versus G-CSF + C. Propensity score matching was used to balance groups. Primary outcome measures were progression free survival (PFS), overall survival (OS), and cumulative incidence of relapse (CIR) after transplantation. After propensity matching, 77 versus 41 patients in the G-CSF + P versus G-CSF cohorts, 129 versus 129 in the G-CSF + P versus G-CSF + C cohorts, and 117 versus 117 in the G-CSF + P + C versus G-CSF + C cohorts were matched, respectively. Propensity score matching resulted in a smaller sample size and imbalances were not completely overcome. For both PFS and OS, the upper limits of the hazard ratio 95% confidence intervals exceeded prespecified boundaries; noninferiority was not demonstrated. CIR rates were higher in the plerixafor cohorts. G-CSF + P remains an option for the mobilization of HSCs in poor mobilizers with MM with no substantial differences in PFS, OS, and CIR in comparison with other regimens.

Assessment of the role of timing of second transplantation in multiple myeloma by multistate modeling.

OBJECTIVE: Stem cell transplantation has a place in the management of many patients with hematological disorders, but is no longer the final and definitive treatment for most of these individuals. The relapsing patient may be offered further therapy, and evaluating the contribution of the treatments available has become statistically challenging. This study was designed to evaluate further the benefit and timing of double autologous transplantation in the management of patients with myeloma. MATERIALS AND METHODS: We investigated the potential benefit of a second autologous transplantation for myeloma before relapse or progression ("elective" transplantation) and the importance of the timing of the procedure using a multistate approach. We used data from 7452 patients with myeloma who received autologous transplantation and who were reported to the registry of the European Group for Blood and Marrow Transplantation. RESULTS: With use of statistical and visual models, the multistate approach shows the benefit of being able to undergo a second transplantation within 12 months of the first transplantation. CONCLUSION: Our study focuses on the importance of appropriate statistical analysis and illustrates how use of the Cox model within a multistate framework may be applied to the assessment of the role of an intermediate event in the disease process. The study illustrates both mathematically and visually the improved survival resulting from undertaking an elective second transplantation in patients with myeloma as soon as medically prudent-usually within 3 to 6 months of the first transplantation.