Pembrolizumab as consolidation strategy in patients with multiple myeloma: Results of the GEM-Pembresid clinical trial

PD1 expression in CD4+ and CD8+ T cells is increased after treatment in multiple myeloma patients with persistent disease. The GEM-Pembresid trial analyzed the efficacy and safety of pembrolizumab as consolidation in patients achieving at least very good partial response but with persistent measurable disease after first- or second-line treatment. Moreover, the characteristics of the immune system were investigated to identify potential biomarkers of response to pembrolizumab. One out of the 17 evaluable patients showed a decrease in the amount of M-protein, although a potential late effect of high-dose melphalan could not be ruled out. Fourteen adverse events were considered related to pembrolizumab, two of which (G3 diarrhea and G2 pneumonitis) prompted treatment discontinuation and all resolving without sequelae. Interestingly, pembrolizumab induced a decrease in the percentage of NK cells at cycle 3, due to the reduction of the circulating and adaptive subsets (0.615 vs. 0.43, p = 0.007; 1.12 vs. 0.86, p = 0.02). In the early progressors, a significantly lower expression of PD1 in CD8+ effector memory T cells (MFI 1327 vs. 926, p = 0.03) was observed. In conclusion, pembrolizumab used as consolidation monotherapy shows an acceptable toxicity profile but did not improve responses in this MM patient population. The trial was registered at clinicaltrials.gov with identifier NCT02636010 and with EUDRACT number 2015-003359-23

Flow cytometry for fast screening and automated risk assessment in systemic light-chain amyloidosis

Early diagnosis and risk stratification are key to improve outcomes in light-chain (AL) amyloidosis. Here we used multidimensional-flow-cytometry (MFC) to characterize bone marrow (BM) plasma cells (PCs) from a series of 166 patients including newly-diagnosed AL amyloidosis (N = 94), MGUS (N = 20) and multiple myeloma (MM, N = 52) vs. healthy adults (N = 30). MFC detected clonality in virtually all AL amyloidosis (99%) patients. Furthermore, we developed an automated risk-stratification system based on BMPCs features, with independent prognostic impact on progression-free and overall survival of AL amyloidosis patients (hazard ratio: ≥ 2.9;P ≤ .03). Simultaneous assessment of the clonal PCs immunophenotypic protein expression profile and the BM cellular composition, mapped AL amyloidosis in the crossroad between MGUS and MM; however, lack of homogenously-positive CD56 expression, reduction of B-cell precursors and a predominantly-clonal PC compartment in the absence of an MM-like tumor PC expansion, emerged as hallmarks of AL amyloidosis (ROC-AUC = 0.74;P < .001), and might potentially be used as biomarkers for the identification of MGUS and MM patients, who are candidates for monitoring pre-symptomatic organ damage related to AL amyloidosis. Altogether, this study addressed the need for consensus on how to use flow cytometry in AL amyloidosis, and proposes a standardized MFC-based automated risk classification ready for implementation in clinical practice

Predicting long-term disease control in transplant-ineligible patients with multiple myeloma: impact of an MGUS-like signature

Disease control at 5 years would be a desirable endpoint for elderly multiple myeloma (MM) patients, but biomarkers predicting this are not defined. Therefore, to gain further insights in this endpoint, a population of 498 newly diagnosed transplant-ineligible patients enrolled in two Spanish trials (GEM2005MAS65 and GEM2010MAS65), has been analyzed. Among the 435 patients included in this post-hoc study, 18.6% remained alive and progression free after 5 years of treatment initiation. In these patients, overall survival (OS) rate at 10 years was 60.8% as compared with 11.8% for those progressing within the first 5 years. Hemoglobin (Hb) >= 12 g/dl (OR 2.74, p = 0.001) and MGUS-like profile (OR 4.18, p = 0.005) were the two baseline variables associated with long-term disease-free survival. Upon including depth of response (and MRD), Hb >= 12 g/dl (OR 2.27) and MGUS-like signature (OR 7.48) retained their predictive value along with MRD negativity (OR 5.18). This study shows that despite the use of novel agents, the probability of disease control at 5 years is still restricted to a small fraction (18.6%) of elderly MM patients. Since this endpoint is associated with higher rates of OS, this study provides important information about diagnostic and post-treatment biomarkers helpful in predicting the likelihood of disease control at 5 years

Phenotypic and genomic analysis of multiple myeloma minimal residual disease tumor cells: a new model to understand chemoresistance

Persistence of chemoresistant minimal residual disease (MRD) plasma cells (PCs) is associated with inferior survival in multiple myeloma (MM). Thus, characterization of the minor MRD subclone may represent a unique model to understand chemoresistance, but to our knowledge, the phenotypic and genetic features of the MRD subclone have never been investigated. Here, we compared the antigenic profile of MRD vs diagnostic clonal PCs in 40 elderly MM patients enrolled in the GEM2010MAS65 study and showed that the MRD subclone is enriched in cells overexpressing integrins (CD11a/CD11c/CD29/CD49d/CD49e), chemokine receptors (CXCR4), and adhesion molecules (CD44/CD54). Genetic profiling of MRD vs diagnostic PCs was performed in 12 patients; 3 of them showed identical copy number alterations (CNAs), in another 3 cases, MRD clonal PCs displayed all genetic alterations detected at diagnosis plus additional CNAs that emerged at the MRD stage, whereas in the remaining 6 patients, there were CNAs present at diagnosis that were undetectable in MRD clonal PCs, but also a selected number of genetic alterations that became apparent only at the MRD stage. The MRD subclone showed significant downregulation of genes related to protein processing in endoplasmic reticulum, as well as novel deregulated genes such as ALCAM that is prognostically relevant in MM and may identify chemoresistant PCs in vitro. Altogether, our results suggest that therapy-induced clonal selection could be already present at the MRD stage, where chemoresistant PCs show a singular phenotypic signature that may result from the persistence of clones with different genetic and gene expression profiles. This trial was registered at www.clinicaltrials.gov as #NCT01237249

Minimal residual disease monitoring and immune profiling using second generation flow cytometry in elderly multiple myeloma

The value of minimal residual disease (MRD) in multiple myeloma (MM) has been more frequently investigated in transplant-eligible than elderly patients. Since an optimal balance between treatment efficacy and toxicity is of utmost importance in elderly MM, sensitive MRD monitoring might be particularly valuable in this patient population. Here, we used 2nd generation 8-color multiparameter-flow-cytometry (MFC) to monitor MRD in 162 transplant-ineligible MM patients enrolled in the PETHEMA/GEM2010MAS65 study, The transition from 1st to 2nd generation MFC resulted in increased sensitivity, and allowed to identify three patient groups according to MRD levels: MRD-negative (75-years (HR:4.8; P<.001), and those with high-risk cytogenetics (HR:12.6; P=.01). Using 2nd generation MFC, immune profiling concomitant to MRD monitoring also contributed to identify patients with poor, intermediate and favorable outcome (25%, 61% and 100% OS at 3-years; P=.01); the later patients being characterized by an increased compartment of mature B-cells. Our results show that similarly to transplant-candidates, MRD monitoring is one of the most relevant prognostic factors in elderly MM, irrespectively of patients’ age and cytogenetic risk

Lenalidomide in combination with R-ESHAP in patients with relapsed or refractory diffuse large B-cell lymphoma: a phase 1b study from GELTAMO group

Diffuse large B-cell lymphoma (DLBCL) patients failing rituximab-containing therapy have a poor outcome with the current salvage regimens. We conducted a phase 1b trial to determine the maximum tolerated dose (MTD) of lenalidomide in combination with R-ESHAP (rituximab, etoposide, cisplatin, cytarabine, methylprednisolone) (LR-ESHAP) in patients with relapsed or refractory DLBCL. Efficacy data were collected as a secondary objective. Subjects received 3 cycles of lenalidomide at escalating doses (5, 10 or 15 mg) given on days 1–14 of every 21-day cycle, in combination with R-ESHAP. Responding patients received BEAM (carmustine, etoposide, cytarabine, melphalan) followed by autologous stem-cell transplantation. Lenalidomide 10 mg/d was identified as the MTD because, in the 15 mg cohort, one patient experienced dose-limiting toxicity (grade 3 angioedema) and two patients had mobilization failure. A total of 19 patients (3, 12 and 4 in the 5, 10 and 15 mg cohorts, respectively) were evaluable. All toxicities occurring during LR-ESHAP cycles resolved appropriately and no grade 4–5 non-haematological toxicities were observed. The complete remission and overall response rates were 47·4% and 78·9%, respectively. With a median follow-up of 24·6 (17·4–38·2) months, the 2-year progression-free survival and overall survival were 44% and 63%, respectively. In conclusion, the LR-ESHAP regimen is feasible and yields encouraging outcomes

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

A dose-finding Phase 2 study of single agent isatuximab (anti-CD38 mAb) in relapsed/refractory multiple myeloma

A Phase 2 dose-finding study evaluated isatuximab, an anti-CD38 monoclonal antibody, in relapsed/refractory multiple myeloma (RRMM; NCT01084252). Patients with ≥3 prior lines or refractory to both immunomodulatory drugs and proteasome inhibitors (dual refractory) were randomized to isatuximab 3 mg/kg every 2 weeks (Q2W), 10 mg/kg Q2W(2 cycles)/Q4W, or 10 mg/kg Q2W. A fourth arm evaluated 20 mg/kg QW(1 cycle)/Q2W. Patients (N = 97) had a median (range) age of 62 years (38–85), 5 (2–14) prior therapy lines, and 85% were double refractory. The overall response rate (ORR) was 4.3, 20.0, 29.2, and 24.0% with isatuximab 3 mg/kg Q2W, 10 mg/kg Q2W/Q4W, 10 mg/kg Q2W, and 20 mg/kg QW/Q2W, respectively. At doses ≥10 mg/kg, median progression-free survival and overall survival were 4.6 and 18.7 months, respectively, and the ORR was 40.9% (9/22) in patients with high-risk cytogenetics. CD38 receptor density was similar in responders and non-responders. The most common nonhematologic adverse events (typically grade ≤2) were nausea (34.0%), fatigue (32.0%), and upper respiratory tract infections (28.9%). Infusion reactions (typically with first infusion and grade ≤2) occurred in 51.5% of patients. In conclusion, isatuximab is active and generally well tolerated in heavily pretreated RRMM, with greatest efficacy at doses ≥10 mg/kg

A dose-finding Phase 2 study of single agent isatuximab (anti-CD38 mAb) in relapsed/refractory multiple myeloma

A Phase 2 dose-finding study evaluated isatuximab, an anti-CD38 monoclonal antibody, in relapsed/refractory multiple myeloma (RRMM; NCT01084252). Patients with ≥3 prior lines or refractory to both immunomodulatory drugs and proteasome inhibitors (dual refractory) were randomized to isatuximab 3 mg/kg every 2 weeks (Q2W), 10 mg/kg Q2W(2 cycles)/Q4W, or 10 mg/kg Q2W. A fourth arm evaluated 20 mg/kg QW(1 cycle)/Q2W. Patients (N = 97) had a median (range) age of 62 years (38–85), 5 (2–14) prior therapy lines, and 85% were double refractory. The overall response rate (ORR) was 4.3, 20.0, 29.2, and 24.0% with isatuximab 3 mg/kg Q2W, 10 mg/kg Q2W/Q4W, 10 mg/kg Q2W, and 20 mg/kg QW/Q2W, respectively. At doses ≥10 mg/kg, median progression-free survival and overall survival were 4.6 and 18.7 months, respectively, and the ORR was 40.9% (9/22) in patients with high-risk cytogenetics. CD38 receptor density was similar in responders and non-responders. The most common nonhematologic adverse events (typically grade ≤2) were nausea (34.0%), fatigue (32.0%), and upper respiratory tract infections (28.9%). Infusion reactions (typically with first infusion and grade ≤2) occurred in 51.5% of patients. In conclusion, isatuximab is active and generally well tolerated in heavily pretreated RRMM, with greatest efficacy at doses ≥10 mg/kg