Bortezomib and high-dose melphalan conditioning regimen in frontline multiple myeloma: an IFM randomized phase 3 study.

High-dose melphalan (HDM) and transplantation are recommended for eligible patients with multiple myeloma. No other conditioning regimen has proven to be more effective and/or safer. We previously reported in a phase 2 study that bortezomib can safely and effectively be combined with HDM (Bor-HDM), with a 32% complete response (CR) rate after transplantation. These data supported a randomized phase 3 trial. Randomization was stratified according to risk and response to induction: 300 patients were enrolled, and 154 were allocated to the experimental arm (ie, arm A) with bortezomib (1 mg/m2 intravenously [IV]) on days -6, -3, +1, and +4 and melphalan (200 mg/m2 IV) on day -2. The control arm (ie, arm B) consisted of HDM alone (200 mg/m2 IV). There were no differences in stringent CR + CR rates at day 60 posttransplant (primary end point): 22.1% in arm A vs 20.5% in arm B (P = .844). There were also no differences in undetectable minimum residual disease rates: 41.3% vs 39.4% (P = .864). Median progression-free survival was 34.0 months for arm A vs 29.6 months for arm B (adjusted HR, 0.82; 95% CI, 0.61-1.13; P = .244). The estimated 3-year overall survival was 89.5% in both arms (hazard ratio, 1.28; 95% CI, 0.62-2.64; P = .374). Sixty-nine serious adverse events occurred in 18.7% of Bor-HDM-treated patients (vs 13.1% in HDM-treated patients). The proportion of grade 3/4 AEs was similar within the 2 groups (72.0% vs 73.1%), mainly (as expected) blood and gastrointestinal disorders; 4% of patients reported grade 3/4 or painful peripheral neuropathy in arm A (vs 1.5% in arm B). In this randomized phase 3 study, a conditioning regimen with Bor-HDM did not improve efficacy end points or outcomes compared with HDM alone. The original trial was registered at www.clinicaltrials.gov as #NCT02197221.

Up-front carfilzomib, lenalidomide, and dexamethasone with transplant for patients with multiple myeloma: the IFM KRd final results.

Bortezomib, lenalidomide, and dexamethasone plus transplant is a standard of care for eligible patients with multiple myeloma. Because responses can deepen with time, regimens with longer and more potent induction/consolidation phases are needed. In this phase 2 study, patients received eight 28-day cycles of carfilzomib (K) 20/36 mg/m2 (days 1-2, 8-9, 15-16), lenalidomide (R) 25 mg (days 1-21), and dexamethasone (d) 20 mg (days 1-2, 8-9, 15-16, 22-23). All patients proceeded to transplant after 4 cycles and received 1 year of lenalidomide maintenance (10 mg, days 1-21). The primary objective was stringent complete response at the completion of consolidation. Overall, 48 patients were screened and 46 enrolled; 21% had adverse cytogenetics. Among 42 evaluable patients after consolidation, 26 were in stringent complete response (CR; 61.9%), 27 were at least in CR (64.3%): 92.6% had undetectable minimal residual disease according to flow cytometry (≥2.5 × 10-5) and 63.0% according to next-generation sequencing (10-6). Median time to CR was 10.6 months. According to multiparametric flow cytometry and next-generation sequencing, 69.0% and 66.7% of patients, respectively, had undetectable minimal residual disease at some point. With a median follow-up of 60.5 months, 21 patients progressed, and 10 died (7 of multiple myeloma). Median progression-free survival was 56.4 months. There were no KRd-related deaths. Four patients discontinued the program due to toxicities; 56 serious adverse events were reported in 31 patients, including 8 cardiovascular events (2 heart failures, 5 pulmonary embolisms or deep vein thrombosis). Common grade 3/4 adverse events were hematologic (74%) and infectious (22%). In summary, 8 cycles of KRd produce fast and deep responses in transplant-eligible patients with newly diagnosed multiple myeloma. The safety profile is acceptable, but cardiovascular adverse events should be closely monitored. This clinical trial is registered at www.clinicaltrials.gov as #NCT02405364.

Integrated transcriptomic, phenotypic, and functional study reveals tissue-specific immune properties of mesenchymal stromal cells.

Clinical-grade mesenchymal stromal cells (MSCs) can be expanded from bone marrow and adipose tissue to treat inflammatory diseases and degenerative disorders. However, the influence of their tissue of origin on their functional properties, including their immunosuppressive activity, remains unsolved. In this study, we produced paired bone marrow-derived mesenchymal stromal cell (BM-MSC) and adipose-derived stromal cell (ASC) batches from 14 healthy donors. We then compared them using transcriptomic, phenotypic, and functional analyses and validated our results on purified native MSCs to infer which differences were really endowed by tissue of origin. Cultured MSCs segregated together owing to their tissue of origin based on their gene expression profile analyzed using differential expression and weighted gene coexpression network analysis. This translated into distinct immune-related gene signatures, phenotypes, and functional cell interactions. Importantly, sorted native BM-MSCs and ASCs essentially displayed the same distinctive patterns than their in vitro-expanded counterparts. As a whole, ASCs exhibited an immune profile consistent with a stronger inhibition of immune response and a lower immunogenicity, supporting the use of adipose tissue as a valuable source for clinical applications.

Role of additional chromosomal changes in the prognostic value of t(4;14) and del(17p) in multiple myeloma: the IFM experience.

In multiple myeloma, cytogenetic changes are important predictors of patient outcome. In this setting, the most important changes are deletion 17p, del(17p), and translocation of chromosomes 4 and 14, t(4;14), conferring a poor outcome. However, a certain degree of heterogeneity is observed in the survival of these high-risk patients. We hypothesized that other chromosomal changes may impact the outcome. We retrospectively analyzed a large series of 242 patients displaying either t(4;14) (157 patients) or del(17p) (110 patients), 25 patients presenting both abnormalities, using single nucleotide polymorphism array. In patients with t(4;14), del(1p32), del22q, and >30 chromosomal structural changes negatively impacted progression-free survival (PFS). For overall survival (OS), del(13q14), del(1p32), and the number of chromosomal structural changes worsened the prognosis of patients. For patients with del(17p), del6q worsened the prognosis of patients, whereas trisomy 15 and monosomy 14 were found to have a protective effect on PFS. For OS, del(1p32) worsened the prognosis of patients, whereas having >8 numerical changes was found to have a protective effect on survival. This study, which is the largest series of high-risk patients analyzed with the most modern genomic technique, identified 1 main factor negatively impacting survival: del(1p32).

Understanding the role of hyperdiploidy in myeloma prognosis: which trisomies really matter?

The prognosis of multiple myeloma is mainly dependent upon chromosomal changes. The 2 major abnormalities driving poor outcome are del(17p) and t(4;14). However, the outcome of these high-risk patients is not absolutely uniform, with some patients presenting long survival. We hypothesized that these better outcomes might be related to concomitant "good-risk" chromosomal changes exploring hyperdiploidy. We analyzed a large series of 965 myeloma patients, including 168 patients with t(4;14) and 126 patients with del(17p), using high-throughput single-nucleotide polymorphism arrays after plasma cell sorting. As expected, trisomic chromosomes were highly associated. Using the LASSO model, we found that only chromosome 3, when trisomic, was associated with a longer progression-free survival and that 3 trisomies modulated overall survival (OS) in myeloma patients: trisomies 3 and 5 significantly improved OS, whereas trisomy 21 worsened OS. In patients with t(4;14), trisomies 3 and/or 5 seemed to overcome the poor prognosis. For the first time, using a specific modeling approach, we show that not all trisomies display the same prognostic impact. This finding could be important for routine assessment of prognosis in myeloma, and some high-risk patients with a traditional evaluation could in fact be standard-risk patients.

Clinical activity of a new regimen combining gemcitabine and alemtuzumab in high-risk relapsed/refractory chronic lymphocytic leukemia patients.

Optimal treatment strategies are lacking in relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL). Gemcitabine has shown activity and acceptable safety profile in B-cell lymphomas. We present a retrospective case review of gemcitabine and alemtuzumab, every 21 d (for up to six courses) in 27 community-based patients with high-risk R/R CLL. Median age was 70 yr (44-83 yr), 55% patients had Binet stage C, deletion 17p (del(17p)) and/or deletion 11q (del(11q)) were found in 65% and 27%, bulky disease in 55.5%, and fludarabine-refractoriness in 48% of cases, respectively. Overall response rate was 63% (29.6% clinical CR and 33.4% PR). At a median follow-up of 31 months, median PFS and OS were 15.4 and 24 months. In multivariate analysis, median OS is influenced by prior lines of treatment = 3 and bulky disease. Combination of alemtuzumab and gemcitabine appears to be an active, easy to administrate treatment in routine practice, high-risk R/R CLL patients.

Age is a prognostic factor even among patients with multiple myeloma younger than 66 years treated with high-dose melphalan: the IFM experience on 2316 patients.

Age is a strong prognostic factor in multiple myeloma. The overall survival is shorter in patients older than 66 years, and even shorter in those older than 75 years. Whether age is also a prognostic parameter in patients younger than 66 years treated homogeneously with intensive approaches is unknown. To address this issue, we retrospectively analyzed a series of 2316 patients treated homogeneously with 3-4 cycles of induction chemotherapy followed by a high-dose melphalan course, without any consolidation or maintenance. We show that patients older than 60 years have a statistically significant shorter overall survival. The analysis of prognostic parameters did not show a higher incidence of high-risk cytogenetics, but a higher incidence of International Staging System (ISS) stages 2 and 3, mainly due to higher ß2-microglobulin levels. This study is the first to demonstrate the impact of age in the outcome of 'young' patients with multiple myeloma, and suggests that this parameter should be included in the stratification factors for future prospective clinical trials.

Non-interventional Study Evaluating the Mobilization of Stem Cells by Plerixafor Before Salvage Autologous Stem Cell Transplant in Relapsed Multiple Myeloma (IFM-2015-03).

INTRODUCTION: Despite the implementation of new therapeutic agents, management of relapsed multiple myeloma (MM) remains a challenge. Salvage autologous hematopoietic cell transplant (AHCT) remains a valid therapeutic option for eligible patients who achieve prolonged response after a first AHCT. However, a second graft is not always available, and these patients may need a second mobilization. PATIENTS AND METHODS: This prospective, non-interventional, multicenter study aimed to collect data on the feasibility of salvage AHCT using a plerixafor-based hematopoietic cell mobilization in relapsed MM, according to the plerixafor label in France. Adult patients with relapsed MM eligible for a second AHCT and mobilized using granulocyte- colony stimulating factor (G-CSF) and plerixafor were included. RESULTS: Of the 23 patients, 17 achieved a successful hematopoietic cell mobilization and 13 were able to proceed to a second AHCT. Median age was 62.9 years (min-max 51-71). Ten patients (77%) were male. Eleven (85%) received AHCT as a third-line treatment or more. Median time between first and second AHCT was 5.4 years (range, 2.6-16.3). Among 18 evaluable patients, mobilization was successful for 17 (94%) of them [95% CI 84-100], with no reported side effects. Among the 13 patients who underwent salvage AHCT, the median time to engraftment was 14 days (min-max 11-29). One-year progression-free and overall survival were 88.9% [95% CI 43.3-98.4] and 100%, respectively. CONCLUSION: This study demonstrated that plerixafor allows safe and efficient mobilization in relapsed MM patients who are candidates for a salvage AHCT. TRIAL REGISTRATION: NCT02439476 Registered 8 May 2015, https://clinicaltrials.gov/ct2/show/NCT02439476 .

Integrated analysis of randomized controlled trials evaluating bortezomib + lenalidomide + dexamethasone or bortezomib + thalidomide + dexamethasone induction in transplant-eligible newly diagnosed multiple myeloma.

Objective: Providing the most efficacious frontline treatment for newly diagnosed multiple myeloma (NDMM) is critical for patient outcomes. No direct comparisons have been made between bortezomib + lenalidomide + dexamethasone (VRD) and bortezomib + thalidomide + dexamethasone (VTD) induction regimens in transplant-eligible NDMM. Methods: An integrated analysis was performed using patient data from four trials meeting prespecified eligibility criteria: two using VRD (PETHEMA GEM2012 and IFM 2009) and two using VTD (PETHEMA GEM2005 and IFM 2013-04). Results: The primary endpoint was met, with VRD demonstrating a noninferior rate of at least very good partial response (≥ VGPR) after induction vs VTD. GEM comparison demonstrated improvement in the ≥ VGPR rate after induction for VRD vs VTD (66.3% vs 51.2%; P = .00281) that increased after transplant (74.4% vs 53.5%). Undetectable minimal residual disease rates post induction (46.7% vs 34.9%) and post transplant (62.4% vs 47.3%) support the benefit of VRD vs VTD. Treatment-emergent adverse events leading to study and/or treatment discontinuation were less frequent with VRD (3%, GEM2012; 6%, IFM 2009) vs VTD (11%, IFM 2013-04). Conclusion: These results supported the benefit of VRD over VTD for induction in transplant-eligible patients with NDMM. The trials included are registered with ClinicalTrials.gov (NCT01916252, NCT01191060, NCT00461747, and NCT01971658).

Daratumumab plus lenalidomide and dexamethasone in transplant-ineligible newly diagnosed multiple myeloma: frailty subgroup analysis of MAIA.

In the phase 3 MAIA study of patients with transplant-ineligible newly diagnosed multiple myeloma (NDMM), daratumumab plus lenalidomide/dexamethasone (D-Rd) improved progression-free survival (PFS) versus lenalidomide/dexamethasone (Rd). We present a subgroup analysis of MAIA by frailty status. Frailty assessment was performed retrospectively using age, Charlson comorbidity index, and baseline Eastern Cooperative Oncology Group performance status score. Patients were classified as fit, intermediate, non-frail (fit + intermediate), or frail. Of the randomized patients (D-Rd, n = 368; Rd, n = 369), 396 patients were non-frail (D-Rd, 196 [53.3%]; Rd, 200 [54.2%]) and 341 patients were frail (172 [46.7%]; 169 [45.8%]). After a 36.4-month median follow-up, non-frail patients had longer PFS than frail patients, but the PFS benefit of D-Rd versus Rd was maintained across subgroups: non-frail (median, not reached [NR] vs 41.7 months; hazard ratio [HR], 0.48; P < 0.0001) and frail (NR vs 30.4 months; HR, 0.62; P = 0.003). Improved rates of complete response or better and minimal residual disease (10-5) negativity were observed for D-Rd across subgroups. The most common grade 3/4 treatment-emergent adverse event in non-frail and frail patients was neutropenia (non-frail, 45.4% [D-Rd] and 37.2% [Rd]; frail, 57.7% and 33.1%). These findings support the clinical benefit of D-Rd in transplant-ineligible NDMM patients enrolled in MAIA, regardless of frailty status.

Front-line daratumumab-VTd versus standard-of-care in ASCT-eligible multiple myeloma: matching-adjusted indirect comparison.

Aim: To compare daratumumab plus standard-of-care (SoC; bortezomib/thalidomide/dexamethasone [VTd]) and VTd alone with other SoC for transplant-eligible newly diagnosed multiple myeloma. Patients & methods: We conducted an unanchored matching-adjusted indirect comparison of progression-free and overall survival (PFS/OS) with D-VTd/VTd versus bortezomib/lenalidomide/dexamethasone (VRd), bortezomib/cyclophosphamide/dexamethasone (VCd) and bortezomib/dexamethasone (Vd). Results: After matching adjustment, significant improvements in PFS were estimated for D-VTd versus VRd (hazard ratio [HR]: 0.47 [95% CI: 0.33-0.69]), VCd (HR: 0.35 [95% CI: 0.21-0.58]) and Vd (HR: 0.42 [95% CI: 0.28-0.63]). OS was significantly longer with D-VTd versus VRd (HR: 0.31 [95% CI: 0.16-0.57]), VCd (HR: 0.35 [95% CI: 0.14-0.86]) and Vd (HR: 0.38 [95% CI: 0.18-0.77]). No significant PFS/OS differences were seen for VTd versus other SoC. Conclusion: This analysis supports front-line daratumumab for transplant-eligible newly diagnosed multiple myeloma.

Functional Comparison between Healthy and Multiple Myeloma Adipose Stromal Cells.

Multiple myeloma (MM) is an incurable B cell neoplasia characterized by the accumulation of tumor plasma cells within the bone marrow (BM). As a consequence, bone osteolytic lesions develop in 80% of patients and remain even after complete disease remission. We and others had demonstrated that BM-derived mesenchymal stromal cells (MSCs) are abnormal in MM and thus cannot be used for autologous treatment to repair bone damage. Adipose stromal cells (ASCs) represent an interesting alternative to MSCs for cellular therapy. Thus, in this study, we wondered whether they could be a good candidate in repairing MM bone lesions. For the first time, we present a transcriptomic, phenotypic, and functional comparison of ASCs from MM patients and healthy donors (HDs) relying on their autologous MSC counterparts. In contrast to MM MSCs, MM ASCs did not exhibit major abnormalities. However, the changes observed in MM ASCs and the supportive property of ASCs on MM cells question their putative and safety uses at an autologous or allogenic level.

Health-related quality of life results from the IFM 2009 trial: treatment with lenalidomide, bortezomib, and dexamethasone in transplant-eligible patients with newly diagnosed multiple myeloma.

The Intergroupe Francophone du Myelome 2009 trial (NCT01191060) assessed health-related quality of life (HRQoL) in patients with newly diagnosed multiple myeloma (NDMM) receiving lenalidomide/bortezomib/dexamethasone (RVd) induction therapy followed by consolidation therapy with either autologous stem cell transplantation (ASCT) plus RVd (RVd-ASCT) or RVd-alone; both groups then received lenalidomide maintenance therapy for 1 year. Global HRQoL, physical functioning, and role functioning scores significantly improved for both cohorts from baseline to the end of consolidation and were sustained during maintenance and follow-up, with clinically meaningful changes (RVd-alone: p = .0002; RVd-ASCT: p < .001). Similarly, both groups showed clinically meaningful improvements from baseline in fatigue, pain, and disease symptom scores. Side effects of treatment scores remained stable. In the RVd-ASCT group, there was transient worsening in HRQoL immediately after ASCT. These findings suggest that the clinical improvements observed with RVd-based treatment are accompanied by overall improvements in HRQoL for patients with NDMM.

Bortezomib, thalidomide, and dexamethasone with or without daratumumab for transplantation-eligible patients with newly diagnosed multiple myeloma (CASSIOPEIA): health-related quality of life outcomes of a randomised, open-label, phase 3 trial.

BACKGROUND: In part 1 of the two-part CASSIOPEIA study, treatment before and after autologous haematopoietic stem-cell transplantation (HSCT) with daratumumab plus bortezomib, thalidomide, and dexamethasone (D-VTd) significantly improved rates of stringent complete response and progression-free survival versus bortezomib, thalidomide, and dexamethasone (VTd) in patients with newly diagnosed multiple myeloma. METHODS: CASSIOPEIA is an ongoing randomised, open-label, active-controlled, parallel-group, phase 3 trial done at 111 academic and community practice centres in Europe. Transplantation-eligible adults with newly diagnosed multiple myeloma were randomly assigned (1:1) to D-VTd or VTd. Treatment consisted of four 28-day cycles of induction therapy before autologous HSCT and two 28-day cycles of consolidation therapy after. In this prespecified secondary analysis, patient-reported outcomes were assessed using the European Organization for Research and Treatment of Cancer quality of life questionnaire-core 30-item (EORTC QLQ-C30) and EuroQol 5-dimensional descriptive system (EQ-5D-5L) questionnaire at baseline, after induction (cycle 4, day 28), and after consolidation (day 100 after autologous HSCT). The analysis was done in all patients in the intention-to-treat population with a baseline and at least one post-baseline patient-reported outcome assessment. The trial is registered at ClinicalTrials.gov (NCT02541383). FINDINGS: Between Sept 22, 2015, and Aug 1, 2017, 1085 patients were enrolled and randomly assigned D-VTd (n=543) or VTd (n=542). Questionnaire completion rates were high at baseline (511 [94%] of 543 in the D-VTd group vs 510 [94%] of 542 in the VTd group). Compliance rates (calculated from the number of completed surveys as a proportion of the predicted number of participants still on study treatment) were high at post-induction (431 [84%] of 513 vs 405 [80%] of 509) and post-consolidation (414 [90%] of 460 vs 386 [88%] of 438) assessments and were similar between treatment groups. Mean changes in global health status scores from baseline to post-induction were not different between the D-VTd group (3·8 [95% CI 1·6 to 6·0]) and VTd group (2·9 [0·7 to 5·1]; p=0·43), or from baseline to post-consolidation between the two groups (D-VTd group, 9·7 (95% CI 7·4 to 11·9) vs VTd group, 8·7 (6·5 to 11·0; p=0·45). Improvements from baseline in EORTC QLQ-C30 global health status and EQ-5D-5L visual analogue scale scores were observed in post-consolidation scores in both groups. Post-consolidation scores showed significantly greater mean decreases in pain (-23·3 [95% CI -26·6 to -20·0] in the D-VTd group vs -19·7 [-23·0 to -16·3] in the VTd group; p=0·042), significantly smaller reductions in cognitive functioning (-5·0 [-7·6 to -2·4] vs -7·9 [-10·6 to -5·3]; p=0·036), and significantly greater improvements in emotional functioning (13·0 [10·4 to 15·5] vs 9·5 [6·9 to 12·1]; p=0·013) and in constipation (-3·2 [-7·3 to 0·9] vs 1·8 [-2·4 to 6·0]; p=0·025) with D-VTd versus VTd. Between-group differences in change from baseline for all other scales were not significant. INTERPRETATION: D-VTd and VTd were associated with on-treatment health-related quality of life improvements from baseline in transplantation-eligible patients with newly diagnosed multiple myeloma. The significantly greater reductions in pain, less deterioration of cognitive functioning, and greater emotional functioning improvements complement the clinical benefits observed with D-VTd versus VTd, and support the addition of daratumumab to standard regimens in patients with newly diagnosed multiple myeloma. FUNDING: Intergroupe Francophone du Myélome, The Dutch-Belgian Cooperative Trial Group for Hematology Oncology, and Janssen Research and Development.

DKK1 and sclerostin are early markers of relapse in multiple myeloma.

Recent studies have shown that Dickkopf-related protein (DKK1) and sclerostin decrease when a complete response (CR) is obtained after chemotherapy in myeloma multiple (MM). To study variations in DKK1, sclerostin and P1NP in patients treated for MM, between complete response (CR) and relapse, we carried out a prospective study ancillary to the IFM 2009 protocol (IFM). The aim of IFM was to compare progression-free survival between patients treated with chemotherapy with or without transplantation. We selected 69 patients who reached CR and relapsed. We assayed by ELISA: DKK1, sclerostin and P1NP at 3 end points T1: CR, T2: 4 months before relapse and T3: relapse. There was a significant increase in DKK1 and sclerostin between T1, T2 and T3. (DKK1 medians (IQR): T1 = 30 pmol/l (20.4-41.1), T2 = 37.4 pmol/l (29.8-49.4), p < 0.0001, T3 = 42 pmol/l (33.8-55.5), p < 0.0001 sclerostin medians (IQR): T1 = 0.57 (0.47-0.69), T2 = 0.62 ng/ml (0.53-0.79), p < 0.0001, T3 = n0.64 ng/ml (0.56-0.79), p = 0.005). No significant variation was detected in the levels of P1NP. No association was observed between the characteristics of the MM, or the treatment received and the variation between T1-T3 for DKK1, sclerostin or P1NP. A significant increase in DKK1 and sclerostin was observed four months before relapse.

Heavy + light chain analysis to assign myeloma response is analogous to the IMWG response criteria.

Automated serum heavy + light chain (HLC) immunoassays can measure the intact immunoglobulins of each light chain type separately. We though to compare HLC assays with electrophoretic techniques in determining International Myeloma Working Group (IMWG) response criteria. 114 myeloma patients from 2 trials were included. HLC measurements were made utilizing archived sera and response assessments compared with those based on electrophoretic analysis at the time of the trials. Assessments at ∼90 days and maximal response were compared as was the power of the 2 techniques for predicting later responses, overall survival, and progression. The kappa statistic indicated good agreement between the 2 methods for determining IMWG response criteria, although HLC measurements might give better predictions of subsequent responses and frequently gave an earlier indication of change. HLC measurements could represent an alternative to electrophoretic techniques in determining IMWG response. Validation with a greater range of patient responses is needed for confirmation.

Analysis of a Compartmental Model of Endogenous Immunoglobulin G Metabolism with Application to Multiple Myeloma.

Immunoglobulin G (IgG) metabolism has received much attention in the literature for two reasons: (i) IgG homeostasis is regulated by the neonatal Fc receptor (FcRn), by a pH-dependent and saturable recycling process, which presents an interesting biological system; (ii) the IgG-FcRn interaction may be exploitable as a means for extending the plasma half-life of therapeutic monoclonal antibodies, which are primarily IgG-based. A less-studied problem is the importance of endogenous IgG metabolism in IgG multiple myeloma. In multiple myeloma, quantification of serum monoclonal immunoglobulin plays an important role in diagnosis, monitoring and response assessment. In order to investigate the dynamics of IgG in this setting, a mathematical model characterizing the metabolism of endogenous IgG in humans is required. A number of authors have proposed a two-compartment nonlinear model of IgG metabolism in which saturable recycling is described using Michaelis-Menten kinetics; however it may be difficult to estimate the model parameters from the limited experimental data that are available. The purpose of this study is to analyse the model alongside the available data from experiments in humans and estimate the model parameters. In order to achieve this aim we linearize the model and use several methods of model and parameter validation: stability analysis, structural identifiability analysis, and sensitivity analysis based on traditional sensitivity functions and generalized sensitivity functions. We find that all model parameters are identifiable, structurally and taking into account parameter correlations, when several types of model output are used for parameter estimation. Based on these analyses we estimate parameter values from the limited available data and compare them with previously published parameter values. Finally we show how the model can be applied in future studies of treatment effectiveness in IgG multiple myeloma with simulations of serum monoclonal IgG responses during treatment.

Front-line transplantation program with lenalidomide, bortezomib, and dexamethasone combination as induction and consolidation followed by lenalidomide maintenance in patients with multiple myeloma: a phase II study by the Intergroupe Francophone du Myélome.

PURPOSE: The three-drug combination of lenalidomide, bortezomib, and dexamethasone (RVD) has shown significant efficacy in multiple myeloma (MM). The Intergroupe Francophone du Myélome (IFM) decided to evaluate RVD induction and consolidation therapies in a sequential intensive strategy for previously untreated transplantation-eligible patients with MM. PATIENTS AND METHODS: In this phase II study, 31 symptomatic patients age < 65 years were enrolled to receive three RVD induction cycles followed by cyclophosphamide harvest and transplantation. Patients subsequently received two RVD consolidation cycles and 1-year lenalidomide maintenance. RESULTS: Very good partial response rate or better at the completion of induction, transplantation, and consolidation therapy was 58%, 70%, and 87%, respectively. Maintenance upgraded responses in 27% of patients. Overall, 58% of patients achieved complete response, and 68% were minimal residual disease (MRD) negative by flow cytometry. The most common toxicities with RVD were neurologic and hematologic, including grade 1 to 2 sensory neuropathy (55%), grade 3 to 4 neutropenia (35%), and thrombocytopenia (13%). Two basal cell carcinomas in the same patient and one case of breast cancer were observed. There was no treatment-related mortality. With a median follow-up of 39 months, estimated 3-year progression-free and overall survival were 77% and 100%, respectively. None of the patients who achieved MRD negativity relapsed. CONCLUSION: The transplantation program with RVD induction and consolidation followed by lenalidomide maintenance produced high-quality responses and showed favorable tolerability in patients with newly diagnosed MM. Overall, 68% of patients achieved MRD negativity; none of these patients relapsed. This program is being evaluated in the ongoing IFM/Dana-Farber Cancer Institute 2009 phase III study.