The genomic profiling of high-risk smoldering myeloma patients treated with an intensive strategy unveils potential markers of resistance and progression.

Smoldering multiple myeloma (SMM) precedes multiple myeloma (MM). The risk of progression of SMM patients is not uniform, thus different progression-risk models have been developed, although they are mainly based on clinical parameters. Recently, genomic predictors of progression have been defined for untreated SMM. However, the usefulness of such markers in the context of clinical trials evaluating upfront treatment in high-risk SMM (HR SMM) has not been explored yet, precluding the identification of baseline genomic alterations leading to drug resistance. For this reason, we carried out next-generation sequencing and fluorescent in-situ hybridization studies on 57 HR and ultra-high risk (UHR) SMM patients treated in the phase II GEM-CESAR clinical trial (NCT02415413). DIS3, FAM46C, and FGFR3 mutations, as well as t(4;14) and 1q alterations, were enriched in HR SMM. TRAF3 mutations were specifically associated with UHR SMM but identified cases with improved outcomes. Importantly, novel potential predictors of treatment resistance were identified: NRAS mutations and the co-occurrence of t(4;14) plus FGFR3 mutations were associated with an increased risk of biological progression. In conclusion, we have carried out for the first time a molecular characterization of HR SMM patients treated with an intensive regimen, identifying genomic predictors of poor outcomes in this setting.

Diagnosis, treatment, and response assessment in solitary plasmacytoma: updated recommendations from a European Expert Panel.

Solitary plasmacytoma is an infrequent form of plasma cell dyscrasia that presents as a single mass of monoclonal plasma cells, located either extramedullary or intraosseous. In some patients, a bone marrow aspiration can detect a low monoclonal plasma cell infiltration which indicates a high risk of early progression to an overt myeloma disease. Before treatment initiation, whole body positron emission tomography-computed tomography or magnetic resonance imaging should be performed to exclude the presence of additional malignant lesions. For decades, treatment has been based on high-dose radiation, but studies exploring the potential benefit of systemic therapies for high-risk patients are urgently needed. In this review, a panel of expert European hematologists updates the recommendations on the diagnosis and management of patients with solitary plasmacytoma.

Prognostic value of antigen expression in multiple myeloma: a PETHEMA/GEM study on 1265 patients enrolled in four consecutive clinical trials.

Persistence of minimal residual disease (MRD) after treatment for myeloma predicts inferior outcomes, but within MRD-positive patients there is great heterogeneity with both early and very late relapses. Among different MRD techniques, flow cytometry provides additional information about antigen expression on tumor cells, which could potentially contribute to stratify MRD-positive patients. We investigated the prognostic value of those antigens required to monitor MRD in 1265 newly diagnosed patients enrolled in the GEM2000, GEM2005MENOS65, GEM2005MAS65 and GEM2010MAS65 protocols. Overall, CD19pos, CD27neg, CD38lo, CD45pos, CD81pos, CD117neg and CD138lo expression predicted inferior outcomes. Through principal component analysis, we found that simultaneous CD38lowCD81posCD117neg expression emerged as the most powerful combination with independent prognostic value for progression-free survival (HR:1.69; P=0.002). This unique phenotypic profile retained prognostic value among MRD-positive patients. We then used next-generation flow to determine antigen stability throughout the course of the disease, and found that the expression of antigens required to monitor MRD is mostly stable from diagnosis to MRD stages, except for CD81 whose expression progressively increased from baseline to chemoresistant tumor cells (14 vs 28%). Altogether, we showed that the phenotypic profile of tumor cells provides additional prognostic information, and could be used to further predict risk of relapse among MRD-positive patients.

Natural history of relapsed myeloma, refractory to immunomodulatory drugs and proteasome inhibitors: a multicenter IMWG study.

Introduction of new myeloma therapies offers new options for patients refractory to immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs). In this multicenter study, patients with relapsed multiple myeloma, who have received at least three prior lines of therapy, are refractory to both an IMiD (lenalidomide or pomalidomide) and a PI (bortezomib or carfilzomib), and have been exposed to an alkylating agent were identified. The time patients met the above criteria was defined as time zero (T0). Five hundred and forty-three patients diagnosed between 2006 and 2014 were enrolled in this study. Median age at T0 was 62 years (range 31-87); 61% were males. The median duration between diagnosis and T0 was 3.1 years. The median number of lines of therapy before T0 was 4 (range 3-13). The median overall survival (OS) from T0 for the entire cohort was 13 (95% confidence interval (CI) 11, 15) months. At least one regimen recorded after T0 in 462 (85%) patients, with a median (95% CI) progression-free survival and OS from T0 of 5 (4, 6), and 15.2 (13, 17) months, respectively. The study provides the expected outcome of relapsed multiple myeloma that is refractory to a PI and an IMiD, a benchmark for comparison of new therapies being evaluated.

Carfilzomib-lenalidomide-dexamethasone vs lenalidomide-dexamethasone in relapsed multiple myeloma by previous treatment.

Carfilzomib, a proteasome inhibitor, is approved as monotherapy and in combination with dexamethasone or lenalidomide-dexamethasone (Rd) for relapsed or refractory multiple myeloma. The approval of carfilzomib-lenalidomide-dexamethasone (KRd) was based on results from the randomized, phase 3 study ASPIRE (NCT01080391), which showed KRd significantly improved progression-free survival (PFS) vs Rd (median 26.3 vs 17.6 months; hazard ratio (HR)=0.690; P=0.0001). This subgroup analysis of ASPIRE evaluated KRd vs Rd by number of previous lines of therapy and previous exposure to bortezomib, thalidomide or lenalidomide. Treatment with KRd led to a 12-month improvement in median PFS vs Rd after first relapse (HR 0.713) and a 9-month improvement after ⩾2 previous lines of therapy (HR 0.720). Treatment with KRd led to an approximate 8-month improvement vs Rd in median PFS in bortezomib-exposed patients (HR 0.699), a 15-month improvement in thalidomide-exposed patients (HR 0.587) and a 5-month improvement in lenalidomide-exposed patients (HR 0.796). Objective response and complete response or better rates were higher with KRd vs Rd, irrespective of previous treatment. KRd had a favorable benefit-risk profile and should be considered an appropriate treatment option for patients with 1 or ⩾2 previous lines of therapy and those previously exposed to bortezomib, thalidomide or lenalidomide.

Bortezomib and thalidomide maintenance after stem cell transplantation for multiple myeloma: a PETHEMA/GEM trial.

The phase III trial GEM05MENOS65 randomized 390 patients 65 years old or younger with newly diagnosed symptomatic multiple myeloma (MM) to receive induction with thalidomide/dexamethasone, bortezomib/thalidomide/dexamethasone and Vincristine, BCNU, melphalan, cyclophosphamide, prednisone/vincristine, BCNU, doxorubicin, dexamethasone bortezomib (VBMCP/VBAD/B) followed by autologous stem cell transplantation (ASCT) with MEL-200. After ASCT, a second randomization was performed to compare thalidomide/bortezomib (TV), thalidomide (T) and alfa-2b interferon (alfa2-IFN). Maintenance treatment consisted of TV (thalidomide 100 mg daily plus one cycle of intravenous bortezomib at 1.3 mg/m2 on days 1, 4, 8 and 11 every 3 months) versus T (100 mg daily) versus alfa2-IFN (3 MU three times per week) for up to 3 years. A total of 271 patients were randomized (TV: 91; T: 88; alfa2-IFN: 92). The complete response (CR) rate with maintenance was improved by 21% with TV, 11% with T and 17% with alfa2-IFN (P, not significant). After a median follow-up of 58.6 months, the progression-free survival (PFS) was significantly longer with TV compared with T and alfa2-IFN (50.6 vs 40.3 vs 32.5 months, P=0.03). Overall survival was not significantly different among the three arms. Grade 2-3 peripheral neuropathy was observed in 48.8%, 34.4% and 1% of patients treated with TV, T and alfa2-IFN, respectively. In conclusion, bortezomib and thalidomide maintenance resulted in a significantly longer PFS when compared with thalidomide or alfa2-IFN. (no. EUDRA 2005-001110-41).

A randomized phase III study of carfilzomib vs low-dose corticosteroids with optional cyclophosphamide in relapsed and refractory multiple myeloma (FOCUS).

This randomized, phase III, open-label, multicenter study compared carfilzomib monotherapy against low-dose corticosteroids and optional cyclophosphamide in relapsed and refractory multiple myeloma (RRMM). Relapsed and refractory multiple myeloma patients were randomized (1:1) to receive carfilzomib (10-min intravenous infusion; 20 mg/m2 on days 1 and 2 of cycle 1; 27 mg/m2 thereafter) or a control regimen of low-dose corticosteroids (84 mg of dexamethasone or equivalent corticosteroid) with optional cyclophosphamide (1400 mg) for 28-day cycles. The primary endpoint was overall survival (OS). Three-hundred and fifteen patients were randomized to carfilzomib (n=157) or control (n=158). Both groups had a median of five prior regimens. In the control group, 95% of patients received cyclophosphamide. Median OS was 10.2 (95% confidence interval (CI) 8.4-14.4) vs 10.0 months (95% CI 7.7-12.0) with carfilzomib vs control (hazard ratio=0.975; 95% CI 0.760-1.249; P=0.4172). Progression-free survival was similar between groups; overall response rate was higher with carfilzomib (19.1 vs 11.4%). The most common grade ⩾3 adverse events were anemia (25.5 vs 30.7%), thrombocytopenia (24.2 vs 22.2%) and neutropenia (7.6 vs 12.4%) with carfilzomib vs control. Median OS for single-agent carfilzomib was similar to that for an active doublet control regimen in heavily pretreated RRMM patients.

Impact of prior treatment on patients with relapsed multiple myeloma treated with carfilzomib and dexamethasone vs bortezomib and dexamethasone in the phase 3 ENDEAVOR study.

The randomized phase 3 ENDEAVOR study (N=929) compared carfilzomib and dexamethasone (Kd) with bortezomib and dexamethasone (Vd) in relapsed multiple myeloma (RMM). We performed a subgroup analysis from ENDEAVOR in patients categorized by number of prior lines of therapy or by prior treatment. Median progression-free survival (PFS) for patients with one prior line was 22.2 months for Kd vs 10.1 months for Vd, and median PFS for patients with ⩾2 prior lines was 14.9 months for Kd vs 8.4 months for Vd. For patients with prior bortezomib exposure, the median PFS was 15.6 months for Kd vs 8.1 months for Vd, and for patients with prior lenalidomide exposure the median PFS was 12.9 months for Kd vs 7.3 months for Vd. Overall response rates (Kd vs Vd) were 81.9 vs 65.5% (one prior line), 72.0 vs 59.7% (⩾2 prior lines), 71.2 vs 60.3% (prior bortezomib) and 70.1 vs 59.3% (prior lenalidomide). The safety profile in the prior lines subgroups was qualitatively similar to that in the broader ENDEAVOR population. In RMM, outcomes are improved when receiving treatment with carfilzomib compared with bortezomib, regardless of the number of prior therapy lines or prior exposure to bortezomib or lenalidomide.

Absence of spontaneous response improvement beyond day +100 after autologous stem cell transplantation in multiple myeloma.

The response evaluation after autologous stem-cell transplantation (ASCT) is usually performed at day +100 in patients with multiple myeloma (MM). A recent report suggests that improvement in the response can be observed beyond day +100. The aim of the present study has been to evaluate the rate of improved response and outcome beyond day +100 after ASCT, with and without maintenance therapy. One hundred and forty-four patients who underwent single ASCT with chemosensitive disease and achieved less than CR at day 100 post ASCT were evaluated. Seventy-four patients (51.4%) did not receive any maintenance with only one of them showing an upgrade in the response. The remaining 70 patients (48.6%) received maintenance therapy; eleven of them (15.7%) improved their response beyond day +100. The outcome of these patients was better than those who did not upgrade their response in both progression-free survival and overall survival (P=0.019 and P=0.031, respectively). In conclusion, the improvement in response beyond day +100 after ASCT in patients not receiving any therapy is exceedingly rare. A minority of patients receiving maintenance therapy after ASCT upgrades their response and this finding is associated with better outcome.

Carfilzomib-dexamethasone vs bortezomib-dexamethasone in relapsed or refractory multiple myeloma by cytogenetic risk in the phase 3 study ENDEAVOR.

The randomized phase 3 study ENDEAVOR demonstrated a statistically significant and clinically meaningful improvement in progression-free survival (PFS) for carfilzomib and dexamethasone (Kd) vs bortezomib and dexamethasone (Vd) in relapsed or refractory multiple myeloma (MM). We conducted a preplanned subgroup analysis of ENDEAVOR to evaluate Kd vs Vd by cytogenetic risk. Of 785 patients with known cytogenetics, 210 (27%) had high-risk cytogenetics (Kd, n=97 (25%); Vd, n=113 (28%)) and 575 (73%) had standard-risk cytogenetics (Kd, n=284 (75%); Vd, n=291 (72%)). Median PFS in the high-risk group was 8.8 months for Kd vs 6.0 months for Vd (hazard ratio (HR), 0.65; 95% confidence interval (CI), 0.45-0.92; P=0.0075). Median PFS in the standard-risk group was not estimable for Kd vs 10.2 months for Vd (HR, 0.44; 95% CI, 0.33-0.58; P<0.0001). Overall response rates were 72.2% (Kd) vs 58.4% (Vd) in the high-risk group and 79.2% (Kd) vs 66.0% (Vd) in the standard-risk group. In the high-risk group, 15.5% (Kd) vs 4.4% (Vd) achieved a complete response (CR) or better. In the standard-risk group, 13.0% (Kd) vs 7.9% (Vd) achieved ⩾CR. This preplanned subgroup analysis found that Kd was superior to Vd in relapsed or refractory MM, regardless of cytogenetic risk.

Allogeneic hematopoietic SCT in multiple myeloma: long-term results from a single institution.

The role of allogeneic hematopoietic SCT (allo-HCT) in multiple myeloma (MM) remains controversial. A total of 58 patients received an allo-HCT (25 of them with myeloablative conditioning-allo-MAC-and 33 with reduced-intensity conditioning-allo-RIC) at our institution over a 28-year period. The CR rate for allo-MAC was 36%. The incidence of grade III-IV acute GVHD (aGVHD) and chronic GVHD (cGVHD) was 28% and 39%, respectively The TRM at any time was 60% and the main causes of death were aGVHD or infectious complications not directly related to GVHD. The estimated PFS and OS at 15 years were 8% and 15%, respectively. The CR rate with allo-RIC was 45%. The incidence of grade III-IV aGVHD and cGVHD were 24% and 41%, respectively. The TRM at any time was 33% and was mainly related to aGVHD. The estimated PFS and OS at 5 years were 22% and 38%, respectively. Despite its high TRM, a proportion of patients with high-risk myeloma (early relapse and newly diagnosed ultrahigh risk) may obtain long-term disease control with allo-HCT. New approaches aimed at decreasing the incidence of aGVHD, and consequently to decrease the TRM, are needed.

Pattern of relapse and progression after autologous SCT as upfront treatment for multiple myeloma.

The achievement of CR is the crucial step for a prolonged PFS and OS after an autologous SCT in multiple myeloma (MM). Unfortunately, even with the use of new regimens and the current high CR rates, most, if not all, patients will ultimately relapse or progress. We analyzed the type of relapse or progression (asymptomatic vs symptomatic), clinical features including the presence of extramedullary involvement and time to next treatment in 211 patients who underwent melphalan-based autologous SCT over an 18-year period at our institution. After autologous SCT, serological or asymptomatic relapse/progression was observed in about one half of the patients. The treatment-free interval was significantly longer in patients relapsing from CR than in those progressing from PR (P=0.017). Patients with serological relapse/progression had a significantly longer OS than those relapsing from symptomatic disease (P=0.002). The relapse pattern was similar to the initial clinical presentation. Survival after relapse/progression was shorter in those patients with a 24-h urine M-protein excretion of at least 200 mg (P=0.048). Extramedullary involvement was frequent (24%), being the highest risk in patients with extramedullary involvement at diagnosis (P=0.001).

A multiparameter flow cytometry immunophenotypic algorithm for the identification of newly diagnosed symptomatic myeloma with an MGUS-like signature and long-term disease control.

Achieving complete remission (CR) in multiple myeloma (MM) translates into extended survival, but two subgroups of patients fall outside this paradigm: cases with unsustained CR, and patients that do not achieve CR but return into a monoclonal gammopathy of undetermined significance (MGUS)-like status with long-term survival. Here, we describe a novel automated flow cytometric classification focused on the analysis of the plasma-cell compartment to identify among newly diagnosed symptomatic MM patients (N=698) cases with a baseline MGUS-like profile, by comparing them to MGUS (N=497) patients and validating the classification model in 114 smoldering MM patients. Overall, 59 symptomatic MM patients (8%) showed an MGUS-like profile. Despite achieving similar CR rates after high-dose therapy/autologous stem cell transplantation vs other MM patients, MGUS-like cases had unprecedented longer time-to-progression (TTP) and overall survival (OS; ~60% at 10 years; P<0.001). Importantly, MGUS-like MM patients failing to achieve CR showed similar TTP (P=0.81) and OS (P=0.24) vs cases attaining CR. This automated classification also identified MGUS patients with shorter TTP (P=0.001, hazard ratio: 5.53) and ultra-high-risk smoldering MM (median TTP, 15 months). In summary, we have developed a biomarker that identifies a subset of symptomatic MM patients with an occult MGUS-like signature and an excellent outcome, independently of the depth of response.

Clinical significance of CD81 expression by clonal plasma cells in high-risk smoldering and symptomatic multiple myeloma patients.

The presence of CD19 in myelomatous plasma cells (MM-PCs) correlates with adverse prognosis in multiple myeloma (MM). Although CD19 expression is upregulated by CD81, this marker has been poorly investigated and its prognostic value in MM remains unknown. We have analyzed CD81 expression by multiparameter flow cytometry in MM-PCs from 230 MM patients at diagnosis included in the Grupo Español de Mieloma (GEM)05>65 years trial as well as 56 high-risk smoldering MM (SMM). CD81 expression was detected in 45% (103/230) MM patients, and the detection of CD81(+) MM-PC was an independent prognostic factor for progression-free (hazard ratio=1.9; P=0.003) and overall survival (hazard ratio=2.0; P=0.02); this adverse impact was validated in an additional series of 325 transplant-candidate MM patients included in the GEM05 <65 years trial. Moreover, CD81(+) SMM (n=34/56, 57%) patients had a shorter time to progression to MM (P=0.02). Overall, our results show that CD81 may have a relevant role in MM pathogenesis and represent a novel adverse prognostic marker in myeloma.

Serial intestinal endoscopic examinations of patients with persistent diarrhea after allo-SCT.

Gastrointestinal (GI) GVHD after allo-SCT is diagnosed on the basis of symptoms and findings in endoscopic mucosal biopsy specimens. However, GI symptoms often persist despite treatment and whether a second endoscopy may be helpful in determining the most suitable therapy is not established. We identified 31 patients with persistent diarrhea who underwent more than one endoscopic study. All cases underwent serial microbiological stool analysis and CMV-detecting assays on serum and biopsies. Of the 31 initial GI biopsies, 20 (64.5%) were classified as GVHD, two (6.5%) as GVHD with CMV, four (13%) as non-CMV infection, and five (16%) as normal or unspecific. The second GI biopsies were diagnostic of GVHD in nine cases (29%), GVHD simultaneously with CMV infection in four (13%), regenerative changes post-GVHD in five (16%), CMV infection in four (13%), and normal or unspecific in nine (29%). In 22 of the 31 patients (71%), the histological findings of the second/third endoscopic biopsies differed from the findings of the first endoscopy and led to a therapy change in 77%. In conclusion, serial GI endoscopies are of reliable diagnostic value and can impact on therapeutic decision-making for patients with persistent diarrhea after allo-SCT.

Multiple myeloma.

Multiple myeloma (MM) constitutes 1% of malignant diseases and 15% of haematological malignancies. In virtually all patients MM is preceded by monoclonal gammopathy of undetermined significance (MGUS). The cause of monoclonal gammopathies and the mechanisms of progression are unknown. The diagnosis of MM requires the presence of an M-protein in serum and/or urine, increased bone marrow plasma cells and related organ or tissue impairment. Cytogenetic status, serum ß2-microglobulin and response to therapy are the key prognostic factors. The treatment of younger patients with MM should include a triple-agent induction regimen (i.e. bortezomib/thalidomide/dexamethasone), autologous stem cell transplantation (ASCT) and consolidation and maintenance incorporating novel agents along with sequential minimal residual disease studies to determine for how long treatment is still of benefit. Allogeneic transplantation with reduced-intensity conditioning is promising but remains experimental. For patients not eligible for ASCT the best initial regimens are melphalan/prednisone/thalidomide (MPT), melphalan/prednisone/bortezomib (MPV) and lenalidomide/dexamethasone. In relapsing patients, the choice of salvage therapy should depend on: (i) the components of initial therapy, (ii) the degree and duration of response, (iii) type of relapse: aggressive versus indolent, (iv) previous toxicities and (v) age and performance status. A sequential approach is preferred over combination of multiple agents. Supportive measures include the use of bisphosphonates and erythropoietin according to the updated guidelines.

Engraftment syndrome after auto-SCT: analysis of diagnostic criteria and risk factors in a large series from a single center.

Engraftment syndrome (ES) is increasingly observed in patients who receive auto-SCT. To investigate this fact, validate the clinical criteria for ES diagnosis and analyze the risk factors for this complication, we reviewed 328 consecutive peripheral blood auto-SCT performed during the past 7 years. A total of 43 patients presented with clinical or biological data suggestive of ES. Of the total, 41 (95%) and 22 (51%) could be diagnosed with ES using the Maiolino criteria (MC) and the Spitzer criteria (SC), respectively. The SC were less sensitive as they do not consider some relevant clinical data and limit the observation time after engraftment. All ES cases had high C-reactive protein (CRP) values not observed in the remaining patients at engraftment (median +/- s.d.: 17.5 +/- 7.3 vs 2.4 +/- 3.4 mg per 100 ml; P=0.0001). Multivariate analysis showed a higher risk of ES in SCT performed in recent years (relative risk (RR) 2.3, 95% confidence interval (CI 1.0-4.7), female patients (RR 2.5, 95% CI 1.2-5.2), and absence of intensive chemotherapy before SCT (RR 8.8, 95% CI 3.3-20.5). All patients except one improved after treatment with corticosteroids. The MC seem to be the best tool to establish a diagnosis of ES. In doubtful cases, the diagnosis could be confirmed by evaluating CRP. Auto-SCT in patients not receiving previous chemotherapy could explain the increasing incidence of ES in the past years.