In a recent phase 3 trial, bortezomibmelphalan-prednisone-thalidomide followed by maintenance treatment with bortezomib-thalidomide demonstrated superior efficacy compared with bortezomib-melphalan-prednisone. To decrease neurologic toxicities, the protocol was amended and patients in both arms received once-weekly instead of the initial twice-weekly bortezomib infusions: 372 patients received once-weekly and 139 twice-weekly bortezomib. In this posthoc analysis we assessed the impact of the schedule change on clinical outcomes and safety. Long-term outcomes appeared similar: 3-year progression-free survival rate was 50% in the once-weekly and 47% in the twice-weekly group (P > .999), and 3-year overall survival rate was 88% and 89%, respectively (P ‫؍‬ .54). The complete response rate was 30% in the onceweekly and 35% in the twice-weekly group (P ‫؍‬ .27). Nonhematologic grade 3/4 adverse events were reported in 35% of once-weekly patients and 51% of twice-weekly patients (P ‫؍‬ .003). The incidence of grade 3/4 peripheral neuropathy was 8% in the once-weekly and 28% in the twice-weekly group (P < .001); 5% of patients in the once-weekly and 15% in the twice-weekly group discontinued therapy because of peripheral neuropathy (P < .001). This improvement in safety did not appear to affect efficacy. This study is registered at http://www.clinicaltrials.gov as NCT01063179. (Blood. 2010;116(23): 4745-4753)

PURPOSE We investigated the effect on minimal residual disease, by qualitative and real-time quantitative polymerase chain reaction (RQ-PCR), of a consolidation regimen that included bortezomib, thalidomide, and dexamethasone (VTD) in patients with multiple myeloma (MM) responding to autologous stem-cell transplantation (auto-SCT). PATIENTS AND METHODS Patients achieving at least very good partial response who had an available molecular marker based on the immunoglobulin heavy-chain rearrangement received four courses of treatment every month: four infusions per month of bortezomib at 1.6 mg/m(2), thalidomide at 200 mg/d, and dexamethasone at 20 mg/d on days 1 to 4, 8 to 11, and 15 to 18. Patients were studied with tumor-clone-specific primers by qualitative nested PCR and RQ-PCR. Results Of 39 patients enrolled, 31 received the four VTD courses. Immunofixation complete responses increased from 15% after auto-SCT to 49% after VTD. Molecular remissions (MRs) were 3% after auto-SCT and 18% after VTD. Median time to maximum response was 3.5 months. So far, no patient in MR has relapsed (median follow-up, 42 months). VTD consolidation induced an additional depletion of 4.14 natural logarithms of tumor burden by RQ-PCR. Patients with a tumor load less than the median value after VTD had outcomes better than those who had tumor loads above the median value after VTD (at median follow-up: progression-free survival, 100% v 57%; P < .001). CONCLUSION To the best of our knowledge, this study is the first to document the occurrence of persistent MRs in a proportion of MM patients treated without allogeneic transplantation. Moreover, the major reduction in tumor load recorded by RQ-PCR after VTD suggests that unprecedented levels of tumor cell reduction can be achieved in MM thanks to the new nonchemotherapeutic drugs.

Background Maintenance therapy following autologous stem cell transplantation can delay disease progression and prolong survival in multiple myeloma (MM). Ixazomib is ideally suited for maintenance therapy given its efficacy, convenient once-weekly oral dosing, and low toxicity profile. Methods The phase 3, double-blind, placebo-controlled, TOURMALINE-MM3 study randomised 656 patients with newly diagnosed MM from 227 clinical/hospital sites in 30 countries in Europe, the Middle East, Africa,

Polymerase chain reaction (PCR)-based minimal residual disease (MRD) analysis is a useful prognostic tool in multiple myeloma (MM), although its long-term impact still needs to be addressed. This report presents the updated results of the GIMEMA-VEL-03-096 trial. Thirty-nine MM patients receiving bortezomib-thalidomide-dexamethasone after autologous transplantation were monitored for MRD by both nested and real-time quantitative-PCR until relapse. Our data confirm the strong impact of MRD on survival: overall survival was 72% at 8 years median follow-up for patients in major MRD response versus 48% for those experiencing MRD persistence (P=0.041). In addition, MRD kinetics resulted predictive for relapse: indeed median remission duration was not reached for patients in major MRD response, 38 months for those experiencing MRD reappearance and 9 months for patients with MRD persistence (P<0.001). Moreover: (1) 26 patients achieving major MRD response (67%) benefit of excellent disease control (median TNT: 42 months); (2) MRD reappearance heralds relapse, with a TNT comparable to that of MRD persistence (9 versus 10 months, P=0.706); (3) the median lag between MRD reappearance and need for salvage treatment is 9 months. These results suggest the usefulness of a long-term MRD monitoring in MM patients and the need for maintenance or pre-emptive treatments ensuring durable responses.

BackgroundMultiple myeloma (MM) is a plasma cell malignancy with a multifaceted immune dysfunction. Indoleamine 2,3-dioxygenase 1 (IDO1) degrades tryptophan into kynurenine (KYN), which inhibits effector T cells and promote regulatory T-cell (Treg) differentiation. It is presently unknown whether MM cells express IDO1 and whether IDO1 activity correlates with immune system impairment.MethodsWe investigated IDO1 expression in 25 consecutive patients with symptomatic MM and in 7 patients with either monoclonal gammopathy of unknown significance (MGUS; n=3) or smoldering MM (SMM; n=4). IDO1-driven tryptophan breakdown was correlated with the release of hepatocyte growth factor (HGF) and with the frequency of Treg cells and NY-ESO-1-specific CD8+ T cells.ResultsKYN was increased in 75% of patients with symptomatic MM and correlated with the expansion of CD4+CD25+FoxP3+ Treg cells and the contraction of NY-ESO-1-specific CD8+ T cells. In vitro, primary MM cells promoted the differentiation of allogeneic CD4+ T cells into bona fide CD4+CD25hiFoxP3hi Treg cells and suppressed IFN-γ/IL-2 secretion, while preserving IL-4 and IL-10 production. Both Treg expansion and inhibition of Th1 differentiation by MM cells were reverted, at least in part, by d,l-1-methyl-tryptophan, a chemical inhibitor of IDO. Notably, HGF levels were higher within the BM microenvironment of patients with IDO+ myeloma disease compared with patients having IDO- MM. Mechanistically, the antagonism of MET receptor for HGF with SU11274, a MET inhibitor, prevented HGF-induced AKT phosphorylation in MM cells and translated into reduced IDO protein levels and functional activity.ConclusionsThese data suggest that IDO1 expression may contribute to immune suppression in patients with MM and possibly other HGF-producing cancers.