Efficacy of ixazomib, lenalidomide, dexamethasone regimen in daratumumab-exposed relapsed/refractory multiple myeloma patients: A retrospective analysis.

We performed retrospective analysis of relapsed/refractory multiple myeloma (RRMM) patients previously exposed to daratumumab treated with ixazomib, lenalidomide, dexamethasone (IRd) regimen in real clinical practice. Our aim was to evaluate efficacy of IRd in these patients and select a subset of patients that would benefit from this treatment the most. In total, we analyzed 43 daratumumab-exposed RRMM patients treated in our center. Minimal response or better was achieved by 53.5% of patients from the cohort. Median progression free survival (PFS) was 4.56 months (95% CI: 2.56, 8.03) and median overall survival (OS) was 28.92 months (95% CI: 5.4, NR). Duration of response (DOR) was evaluable in 28 patients and reached a median of 21.3 months (95% CI: 6.85, NR). Next, we evaluated hazard ratios (HR) for OS and PFS. There was improved OS in patients that were not-triple refractory or worse (HR = 0.39, 95%Cl (0.14; 1.10), p = .07) and in patients, that had less than three previous lines of treatment (LOT) (HR = 0.13, 95%Cl (0.03; 0.6) p = .003). Similar to OS, there was improved PFS in patients, that were not triple-refractory or worse (HR = 0.52, 95%Cl (0.25; 1.10), p = .08). We concluded, that the best survival benefit for RRMM patients pretreated with daratumumab to IRd regimen was observed in patients that were not triple-refractory and had less than three previous lines of treatment (LOT). The DOR in these patients was 21.3 months (95% CI: 6.85, NR).

Daratumumab with lenalidomide and dexamethasone in relapsed or refractory multiple myeloma patients - real world evidence analysis.

We performed real world evidence (RWE) analysis of daratumumab, lenalidomide and dexamethasone (Dara-Rd) versus lenalidomide and dexamethasone (Rd) treatment in relapsed/refractory multiple myeloma patients (RRMM). In total, 240 RRMM patients were treated with Dara-Rd from 2016 to 2022 outside of clinical trials in all major Czech hematology centers. As a reference, 531 RRMM patients treated with Rd were evaluated. Patients' data were recorded in the Czech Registry of Monoclonal Gammopathies (RMG). Partial response (PR) or better response (ORR) was achieved in significantly more patients in Dara-Rd than in Rd group (91.2% vs. 69.9%; p < 0.001). The median progression free survival (PFS) was 26.9 months in the Dara-Rd and 12.8 months in the Rd group (p < 0.001). Median overall survival (OS) was not reached in the Dara-Rd compared to 27.2 months in the Rd group (p = 0.023). In patients with 1-3 previous treatment lines, there was significant PFS benefit of Dara-Rd compared to Rd (median PFS not reached vs. 13.2 months; p < 0.001). In patients with > 3 previous treatment lines, there was no significant PFS benefit of Dara-Rd treatment (7.8 months vs. 9.9 months; p = 0.874), similarly in patients refractory to PI + IMIDs (11.5 months vs. 9.2 months; p = 0.376). In RWE conditions, the median PFS in RRMM patients treated with Dara-Rd is shorter when compared to clinical trials. In heavily pretreated RRMM patients, efficacy of Dara-Rd treatment is limited; best possible outcomes of Dara-Rd are achieved in minimally pretreated patients.

More Than 2% of Circulating Tumor Plasma Cells Defines Plasma Cell Leukemia-Like Multiple Myeloma.

PURPOSE: Primary plasma cell leukemia (PCL) is the most aggressive monoclonal gammopathy. It was formerly characterized by ≥ 20% circulating plasma cells (CTCs) until 2021, when this threshold was decreased to ≥ 5%. We hypothesized that primary PCL is not a separate clinical entity, but rather that it represents ultra-high-risk multiple myeloma (MM) characterized by elevated CTC levels. METHODS: We assessed the levels of CTCs by multiparameter flow cytometry in 395 patients with newly diagnosed transplant-ineligible MM to establish a cutoff for CTCs that identifies the patients with ultra-high-risk PCL-like MM. We tested the cutoff on 185 transplant-eligible patients with MM and further validated on an independent cohort of 280 transplant-ineligible patients treated in the GEM-CLARIDEX trial. The largest published real-world cohort of patients with primary PCL was used for comparison of survival. Finally, we challenged the current 5% threshold for primary PCL diagnosis. RESULTS: Newly diagnosed transplant-ineligible patients with MM with 2%-20% CTCs had significantly shorter progression-free survival (3.1 v 15.6 months; P < .001) and overall survival (14.6 v 33.6 months; P = .023) than patients with < 2%. The 2% cutoff proved to be applicable also in transplant-eligible patients with MM and was successfully validated on an independent cohort of patients from the GEM-CLARIDEX trial. Most importantly, patients with 2%-20% CTCs had comparable dismal outcomes with primary PCL. Moreover, after revealing a low mean difference between flow cytometric and morphologic evaluation of CTCs, we showed that patients with 2%-5% CTCs have similar outcomes as those with 5%-20% CTCs. CONCLUSION: Our study uncovers that ≥ 2% CTCs is a biomarker of hidden primary PCL and supports the assessment of CTCs by flow cytometry during the diagnostic workup of MM.

Involvement of Small Non-Coding RNA and Cell Antigens in Pathogenesis of Extramedullary Multiple Myeloma.

Extramedullary multiple myeloma (EMD) is an aggressive disease; malignant plasma cells lose their dependence in the bone marrow microenvironment and migrate into tissues. EMD is a negative prognostic factor of survival. Using flow cytometry and next-generation sequencing, we aimed to identify antigens and microRNAs (miRNAs) involved in EMD pathogenesis. Flow cytometry analysis revealed significant differences in the level of clonal plasma cells between MM and EMD patients, while the expression of CD markers was comparable between these two groups. Further, miR-26a-5p and miR-30e-5p were found to be significantly down-regulated in EMD compared to MM. Based on the expression of miR-26a-5p, we were able to distinguish these two groups of patients with high sensitivity and specificity. In addition, the involvement of deregulated miRNAs in cell cycle regulation, ubiquitin-mediated proteolysis and signaling pathways associated with infections or neurological disorders was observed using GO and KEGG pathways enrichment analysis. Subsequently, a correlation between the expression of analyzed miRNAs and the levels of CD molecules was observed. Finally, clinicopathological characteristics as well as CD antigens associated with the prognosis of MM and EMD patients were identified. Altogether, we identified several molecules possibly involved in the transformation of MM into EMD.

Unexpected Heterogeneity of Newly Diagnosed Multiple Myeloma Patients with Plasmacytomas.

In multiple myeloma (MM), malignant plasma cells infiltrate the bone marrow. In some cases, plasma cells migrate out of the bone marrow creating either para-skeletal plasmacytomas (PS) or infiltrating soft tissues as extramedullary plasmacytomas (EMD). The aim of this study was to define risk groups in newly diagnosed MM (NDMM) patients with PS and EMD plasmacytomas. In total, 523 NDMM patients with PS plasmacytomas and 196 NDMM patients with EMD plasmacytomas were diagnosed in the Czech Republic between 2004 and 2021 using modern imaging methods. Patients' data were analyzed from the Registry of Monoclonal Gammopathies of the Czech Myeloma Group. In NDMM patients with PS plasmacytomas, we found a subgroup with <5% of bone-marrow plasma cells to have the best prognosis (mPFS: 58.3 months (95% CI: 33.0−NA); mOS: not reached). The subgroup with >5% of bone-marrow plasma cells and ≥3 plasmacytomas had the worst prognosis (mPFS: 19.3 months (95% CI: 13.4−28.8), p < 0.001; mOS: 27.9 months (95% CI: 19.3−67.8), p < 0.001). Our results show association between tumor burden and prognosis of NDMM patients with plasmacytomas. In the case of PS plasmacytomas, NDMM patients with low BM PC infiltration have an excellent prognosis.

Proteomic analysis of the bone marrow microenvironment in extramedullary multiple myeloma patients.

Multiple myeloma (MM) is a heterogeneous hematological malignancy characterized by the uncontrolled clonal proliferation of bone marrow (BM) plasma cells. The poor prognosis of patients is associated with the presence of extramedullary disease (EMD). Previously, different mechanisms involved in the colonization of BM niches by MM cells and their escape during EMD have been described. Thus, we aimed to investigate the expression of selected cytokines in the BM plasma of MM patients as well as EMD patients to reveal novel molecules involved in EMD pathogenesis. Expression of 120 different cytokines was measured in BM plasma of 13 MM and 11 EMD patients using Proteome Profiler Antibody Arrays. The correlation between statistically significant cytokines and clinicopathological parameters of patients was determined using the Spearman correlation analysis. Finally, protein-protein interactions were analyzed, and GO and KEGG pathways enrichment analysis was performed. In total, 27 cytokines were found to be differently expressed between MM and EMD patients. After the Benjamini-Hochberg correction for multiple testing, the statistical significance of two cytokines downregulated in EMD (EGF, BDNF) and six cytokines upregulated in EMD (NAP-2, ADIPOQ, CRP, MIG, BAFF, and THBS1) was maintained. Correlation analysis proved a significant association between the expression of these molecules and selected clinical-pathological features of MM/EMD patients. Protein association network analysis revealed important protein-protein interactions between THBS1/EGF, MIG/NAP-2, THBS1/NAP-2, EGF/NAP-2, and ADIPOQ/CRP. Finally, identified cytokines were proved to be significantly involved in focal adhesion, PI3K/AKT, and MAPK signaling pathways, and regulation of cell development, localization, proliferation, migration, differentiation, immune system processes, and stress response. Obtained results confirm the key function of the BM microenvironment in the pathogenesis of MM and indicate the essential role of numerous cytokines in disease progression and EMD development. However, the exact mechanisms need to be further clarified.

LncRNAs LY86-AS1 and VIM-AS1 Distinguish Plasma Cell Leukemia Patients from Multiple Myeloma Patients.

Long non-coding RNAs (lncRNAs) are functional RNAs longer than 200 nucleotides. Due to modern genomic techniques, the involvement of lncRNAs in tumorigenesis has been revealed; however, information concerning lncRNA interplay in multiple myeloma (MM) and plasma cell leukemia (PCL) is virtually absent. Herein, we aimed to identify the lncRNAs involved in MM to PCL progression. We investigated representative datasets of MM and PCL patients using next-generation sequencing. In total, 13 deregulated lncRNAs (p < 0.00025) were identified; four of them were chosen for further validation in an independent set of MM and PCL patients by RT-qPCR. The obtained results proved the significant downregulation of lymphocyte antigen antisense RNA 1 (LY86-AS1) and VIM antisense RNA 1 (VIM-AS1) in PCL compared to MM. Importantly, these two lncRNAs could be involved in the progression of MM into PCL; thus, they could serve as promising novel biomarkers of MM progression.

Necessity of flow cytometry assessment of circulating plasma cells and its connection with clinical characteristics of primary and secondary plasma cell leukaemia.

Plasma cell leukaemia (PCL) is a rare and very aggressive plasma cell disorder. Preventing a dismal outcome of PCL requires early diagnosis with appropriate analytical tools. Therefore, the investigation of 33 patients with primary and secondary PCL was done when the quantity of circulating plasma cells (PCs) using flow cytometry (FC) and morphology assessment was evaluated. The phenotypic profile of the PCs was also analysed to determine if there is an association with clinical outcomes and to evaluate the prognostic value of analysed markers. Our results revealed that FC is an excellent method for identifying circulating PCs as a significantly higher number was identified by FC than by morphology (26·7% vs. 13·5%, P = 0·02). None of secondary PCL cases expressed CD19 or CD20. A low level of expression with similar positivity of CD27, CD28, CD81 and CD117 was found in both PCL groups. A decrease of CD44 expression was detected only in secondary PCL. Expression of CD56 was present in more than half of PCL cases as well as cytoplasmic nestin. A decreased level of platelets, Eastern Cooperative Oncology Group score of 2-3 and lack of CD20+ PC were associated with a higher risk of death. FC could be incorporated in PCL diagnostics not only to determine the number of circulating PCs, but also to assess their phenotype profile and this information should be useful in patients' diagnosis and possible prognosis.

Outcome of COVID-19 infection in 50 multiple myeloma patients treated with novel drugs: single-center experience.

Infections are the primary cause of morbidity and mortality in multiple myeloma (MM) patients (pts). The aim of our retrospective analysis was to evaluate incidence and course of COVID-19 infection in a cohort of 351 MM outpatients treated with novel drugs. COVID-19 disease was detected in 50/351 pts (14%); median age was 68 years. Gender, ISS stage, and last treatment lines were as follows: male 32, female 18; ISS-I 19, ISS-II 20, ISS-III 11; daratumumab-based 15, lenalidomide-based 12, bortezomib-based 17, other 6. Positive PCR test at COVID-19 diagnosis was present in all pts; anti-myeloma treatment was interrupted. Hospitalizations for COVID-19 pneumonia were necessary for 28/50 pts (56%), 18/50 pts (36%) in standard unit (SU) 10/50 pts (20%) in intensive care unit (ICU), and 9/50 pts (18%) died. The statistically significant parameters for COVID-19 hospitalization were as follows: responsive versus non-responsive disease (p = 0.027), ECOG performance status 0-2 versus ≥ 3 (p = 0.014), presence of comorbidities (0-1 versus ≥ 2, p = 0.043). The statistically significant factors for COVID-19 death were as follows: ECOG 0-2 versus ≥ 3 (p = 0.001), presence of comorbidities (0-1 versus ≥ 2, p = 0.007), serious course of COVID-19 disease with ICU hospitalization (SU versus ICU, p = 0.001). None of the other studied risk factors was associated with poor outcome (age, gender, ISS stage, immunoparesis, type of anti-myeloma treatment). Full recovery from COVID-19 infection was observed in 41/50 pts (82%) in median of 32 days. The course of COVID-19 disease in MM pts was mostly moderate or serious with 56% of hospitalizations and 18% of deaths.

Prognostic significance of lymphocyte patterns in multiple myeloma patients after autologous transplant.

Despite the high efficacy of current induction regimens, most multiple myeloma (MM) patients relapse over time. The link between changes in the immune system and the prognosis of the disease is still not entirely clear. Therefore, we analyzed whether the pattern of bone marrow (BM) lymphocytes during routine BM examination after autologous stem cell transplant (ASCT) is related to disease prognosis or MRD negative complete remission. From 2009 to 2018, 98 MM patients underwent routine BM testing after the first ASCT. Using multi-parametric flow cytometry, twelve BM lymphocyte subtypes were analyzed. In 60% of patients who achieved a complete response (CR), MRD by flow cytometric analysis (sensitivity threshold 10-6) was evaluated. We found an association of relative proportion of BM lymphocyte subtypes with treatment response, progression-free survival (PFS), overall survival (OS), and minimal residual disease (MRD) negativity. Higher relative proportion of memory B cells was associated with inferior median PFS [HR 1.089 (95% CI: 1.023-1.160), p=0.008] and median OS [HR 1.170 (95% CI: 1.074-1.274), p<0.001]. In non-responding patients (minimal response and worse), higher proportion of memory B cells was found when compared to patients achieving CR [3.8% (range 0.5-35.0) vs. 1.0% (range 0.1-12.5); p=0.001]. No significant association of BM lymphocyte subtypes proportion with MRD negative CR was found. Our results show that changes in BM lymphocyte subsets including memory B cells may have prognostic value in MM patients after ASCT.