[Efficacy and safety of first-line treatment with anti-CD38 monoclonal antibody-based regimen for primary plasma cell leukemia].

Objective: To analyze the efficacy and safety of first-line treatment with an anti-CD38 monoclonal antibody regimen for primary plasma cell leukemia (pPCL). Methods: Patients diagnosed with pPCL from December 1st, 2018 to July 26th, 2023, receiving first-line treatment of anti-CD38 monoclonal antibody-based regimens across multiple centers including Peking University People's Hospital, Fuxing Hospital of Capital Medical University, Qingdao Municipal Hospital, Shengjing Hospital of China Medical University, Handan Central Hospital, the First Affiliated Hospital of Harbin Medical University, the Fourth Hospital of Hebei Medical University and General Hospital of Ningxia Medical University were consecutively included. A total of 24 pPCL patients were included with thirteen being male and eleven being female. The median age [M(Q1, Q3)] was 60 (57, 70) years. Patients were grouped according to peripheral blood plasma cell (PBPC) percentage [5%-19% (n=14) vs ≥20% (n=10)]. Last follow-up date was September 26th, 2023. The median follow-up period was 9.1 (4.2, 15.5) months. Patients' data related with clinical baseline characteristics, efficacy, survival and safety were retrospectively collected. Cox proportional hazards regression model was used to analyze risk factors associated with survival. Results: Among 24 pPCL patients, 16 (66.7%) patients had anemia at diagnosis, 13(54.2%) patients had thrombocytopenia, 8 (33.3%) patients had a baseline estimated glomerular filtration rate (eGFR)<40 ml·min-1·(1.73m2)-1, 13 (54.2%) patients had elevated lactate dehydrogenase (LDH) levels. The median PBPC percentage was 16% (8%, 26%) . Fluorescence in situ hybridization testing indicated that patients harboring 17p deletion, t(4;14) or t(14;16) were 6 (25.0%), 4 (16.7%) and 4 (16.7%), respectively. The overall response rate was 83.3% (20/24). The median progression-free survival (PFS) was 20.5 (95%CI: 15.8-25.2) months, and the median overall survival (OS) was not reached. Estimated 1-year and 2-year PFS and OS rates were 75.0% and 89.1%, 37.5% and 53.4%, respectively. The median PFS and OS for patients with PBPC percentages 5%-19% and≥20% were not reached and 20.5 (95%CI:15.7-25.3) months, 17.8 months and not reached, respectively. There was no significant statistical difference of PFS and OS between two groups (all P>0.05). Multivariate Cox regression analysis showed that 1p32 deletion was the risk factor associated with PFS (HR=7.7, 95%CI: 1.1-54.9, P=0.043). Seventeen patients (70.8%) developed grade 3-4 hematologic toxicities. Twelve patients (50.0%) developed grade 3-4 thrombocytopenia. Sixteen patients (66.7%) developed infection. All hematologic toxicities and infections were improved after supportive treatment. Conclusion: First-line treatment with anti-CD38 monoclonal antibody-based therapy for pPCL is effective and safe.

Identification of signature genes and drug candidates for primary plasma cell leukemia: An integrated system biology approach.

BACKGROUND: Plasma cell leukemia (PCL) is one of the rare cancer which is characterized by the uncontrolled proliferation of plasma cells in peripheral blood and bone marrow. The aggressive behavior of the disease and high mortality rate among PCL patients makes it a thirst area to be explored. METHODS: The dataset for PCL was obtained from the GEO database and was analyzed using GEO2R for differentially expressed genes. Further, the functional enrichment analysis was carried out for DEGs using DAVID. The protein-protein interactions (PPI) for DEGs were obtained using STRING 11.5 and were analyzed in Cytoscape 3.7.2. to obtain the key hub genes. These key hub genes were investigated for their interaction with suitable drug candidates using DGIdb, DrugMAP, and Schrodinger's version 2022-1. RESULTS: Out of the total of 104 DEGs, 39 genes were up-regulated whereas 65 genes were down-regulated. A total of 11 biological processes, 2 cellular components, and 5 molecular functions were enriched along with the 7 KEGG pathways for the DEGs. Further, a total of 11 hub genes were obtained from the PPI of DEGs of which TP53, MAPK1, SOCS1, MBD3, and YES1 were the key hub genes. Oxaliplatin, mitoxantrone, and ponatinib were found to have the highest binding affinity towards the p53, MAPK1, and YES1 proteins respectively. CONCLUSION: TP53, MAPK1, SOCS1, MBD3, and YES1 are the signature hub genes that might be responsible for the aggressive prognosis of PCL leading to poor survival rate. However, p53, MAPK1, and YES1 can be targeted with oxaliplatin, mitoxantrone, and ponatinib.

The Current State of Knowledge About Evolution of Multiple Myeloma to Plasma Cell Leukemia.

Plasma cell leukemia is a rare form of multiple myeloma (MM). In contrast to de novo primary plasma cell leukemia (pPCL), which is very uncommon presentation of MM, there is increasing frequency of transformation to secondary plasma cell leukemia (sPCL) with increasing survival of patients (MM). The molecular basis of sPCL remains poorly understood sPCL is particularly aggressive and is associated with an extremely poor prognosis, constituting a major unmet medical need. High-quality data in sPCL regarding presentation, treatment and outcomes is limited. Herein we review the current state of knowledge on sPCL diagnostics, molecular biology, clinical characteristics, prognosis and reported treatment outcomes and the emergence of the new therapeutic strategies.

Reversal of life-threatening bleeding with protamine sulfate in a patient with plasma cell leukemia.

Plasma cell disorders, such as multiple myeloma, can cause numerous derangements of hemostasis. In this case report, we present a life-threatening coagulopathy in a patient with progressing multiple myeloma in which the antibody-producing heparin-like activity is a free light chain. The patient's bleeding was successfully treated using protamine sulfate, which then allowed treatment of her plasma cell leukemia. In the literature, other authors have reported similar patients who have responded to protamine sulphate either in vitro or in vivo , providing further evidence for the role of protamine sulfate in the reversal of coagulopathy and resolution of bleeding diathesis. Standard treatments of transfusion with fresh frozen plasma and cryoprecipitate are likely to be ineffective in life-threatening bleeding related to this mechanism (heparin-like effect), and it is essential that treating physicians are aware of this potential mechanism of bleeding in their patients.

[Rapid response of secondary plasma cell leukemia after carfilzomib and dexamethasone therapy].

An 83-year-old man was admitted to our hospital due to a recurrence of multiple myeloma, accompanied by the appearance of plasma cells in the peripheral blood (PB). Subsequently, he was diagnosed with secondary plasma cell leukemia (sPCL). A chemotherapy regimen of carfilzomib and dexamethasone (Cd) combination therapy was selected, and 15 days later, plasma cells completely disappeared from the PB. Cd therapy was continued, and the free kappa chain levels normalized. Three months later, M-protein could not be detected using serum electrophoresis. This is a valuable report wherein Cd combination therapy was successful in treating sPCL.

Plasma cell leukemia: Retrospective review of cases at Monter Cancer Center/Northwell Health Cancer Institute, 2014-2019.

Plasma cell leukemia (PCL) is an aggressive malignancy and an area of unmet need. The diagnostic criteria for PCL are in flux and the molecular basis of disease is complex. Due to its fulminant course and lack of prospective clinical trials in PCL, the optimal therapeutic approach remains controversial. "Novel therapy" in this manuscript refers to immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs). "Newer agents" refers to currently approved and investigational targeted therapies such as monoclonal antibodies (mAbs), example daratumumab (Dara), bi- or tri-specific antibodies, and antibody-drug conjugate therapies (ADCs). Novel therapy and use of newer agents borrowed from treatment advances in multiple myeloma (MM), is impacting PCL outcomes. Therefore, it is crucial to analyze effects of newer agents on PCL survival with respect to disease characteristics and specific treatment regimens used. In this retrospective study, we report outcomes of eight cases of PCL, primary and secondary, the prognostic factors in each case and the impact of different treatment regimens on overall survival (OS).

Complete response following treatment of plasma cell leukemia with venetoclax and dexamethasone: A case report.

INTRODUCTION: Plasma cell leukemia (PCL) is a rare but aggressive variant of multiple myeloma (MM) with a poor prognosis. Due to the limited number of prospective clinical trials studying PCL, treatment options are often extrapolated from data available for the treatment of MM. Venetoclax has recently demonstrated antimyeloma activity in patients with relapsed/refractory MM carrying the t(11;14) translocation. However, few cases have reported the analogous efficacy of venetoclax in PCL. CASE REPORT: A 64-year-old Caucasian male developed relapsed PCL despite treatment with hyperCD (hyperfractionated cyclophosphamide and dexamethasone) and Dara-KRd (daratumumab, carfilzomib, lenalidomide, dexamethasone). Due to the refractory nature of his disease and the presence of a t(11:14) translocation, the patient was subsequently initiated on venetoclax 400 mg daily and dexamethasone 4 mg once weekly. MANAGEMENT AND OUTCOME: The patient achieved a complete response by International Myeloma Working Group criteria three months after initiating venetoclax-dexamethasone, including a repeat bone marrow biopsy that showed no abnormal plasma cells. He successfully underwent consolidation with melphalan-based autologous stem cell transplantation. He remains disease-free 9 months after venetoclax initiation. DISCUSSION: Combination all-oral therapy with venetoclax and dexamethasone can induce deep hematologic responses in patients with relapsed/refractory PCL carrying the t(11;14) translocation.

[Multiple extramedullary plasmacytomas responding to a reduced dose of carfilzomib following drug-induced thrombotic microangiopathy].

Herein, we report the findings of a 79-year-old male patient who presented with multiple extramedullary plasmacytomas following a relapse of primary plasma cell leukemia. He developed thrombotic microangiopathy (TMA) while receiving carfilzomib, lenalidomide, and dexamethasone (KLd) therapy. He was diagnosed with plasma cell leukemia 3 years ago; he demonstrated a very good partial response (VGPR) after undergoing two regimens, including either bortezomib or lenalidomide, and he had been followed up without any other treatment due to complications of infection. Following relapse, KLd was initiated. On day 7 of KLd, TMA developed; therefore, the treatment was discontinued. The TMA improved only with the discontinuation of KLd. A reduced dose of KLd was readministered; the TMA did not relapse. He demonstrated VGPR after three courses of reduced-KLd; he has since remained in remission through ten courses. Therefore, carfilzomib therapy may be useful in relapsing and refractory cases. Drug-induced TMA has been reported to be caused by either immune-mediated or dose-dependent toxicity mechanisms. In patients who develop dose-dependent TMA with carfilzomib, dose reduction could be considered in cases showing an effective response to the treatment.

KD-PACE Salvage Therapy for Aggressive Relapsed Refractory Multiple Myeloma, Plasma Cell Leukemia and Extramedullary Myeloma.

BACKGROUND: Patients with advanced/aggressive multiple myeloma have limited treatment options to achieve rapid disease control. In eligible patients, bortezomib, dexamethasone, thalidomide, cisplatin, doxorubicin, cyclophosphamide, and etoposide is often used. However, many patients are refractory to or have toxicities from bortezomib and there is a need for bridging therapy. We have used a modified regimen incorporating the second-generation proteasome inhibitor carfilzomib (carfilzomib, dexamethasone, thalidomide, cisplatin, doxorubicin, cyclophosphamide and etoposide [KD-PACE]) instead of bortezomib for relapsed/refractory multiple myeloma. PATIENTS AND METHODS: This 2-center retrospective study included consecutive patients receiving KD-PACE for relapsed or refractory multiple myeloma, plasma cell leukemia, or extramedullary myeloma. The primary outcome was the feasibility of KD-PACE as a bridging therapy to a more definitive treatment option. RESULTS: Fifty-two patients were included. The median age was 57 years, and 67% were male. Thirty-one patients were bridged with KD-PACE to autologous hematopoietic stem cell transplant (29%), allogenic hematopoietic stem cell transplant (27%), or a clinical trial (12%). Patients bridged to autologous hematopoietic stem cell transplant, allogenic hematopoietic stem cell transplant, or a clinical trial had a superior progression-free survival (8.3 months vs 2.3 months in the nonbridged group; P < .001) and overall survival (median, 16.7 months vs 4.3 months in the nonbridged group; P < .001). No unexpected toxicities occurred from the treatment regimen. CONCLUSION: KD-PACE is a promising treatment option for select patients with advanced/aggressive forms of myeloma requiring rapid disease control before a more definitive salvage therapy such as auto/allotransplantation or a clinical trial.

MUKnine OPTIMUM protocol: a screening study to identify high-risk patients with multiple myeloma suitable for novel treatment approaches combined with a phase II study evaluating optimised combination of biological therapy in newly diagnosed high-risk multiple myeloma and plasma cell leukaemia.

INTRODUCTION: Multiple myeloma (MM) is a plasma cell tumour with over 5800 new cases each year in the UK. The introduction of biological therapies has improved outcomes for the majority of patients with MM, but in approximately 20% of patients the tumour is characterised by genetic changes which confer a significantly poorer prognosis, generally termed high-risk (HR) MM. It is important to diagnose these genetic changes early and identify more effective first-line treatment options for these patients. METHODS AND ANALYSIS: The Myeloma UK nine OPTIMUM trial (MUKnine) evaluates novel treatment strategies for patients with HRMM. Patients with suspected or newly diagnosed MM, fit for intensive therapy, are offered participation in a tumour genetic screening protocol (MUKnine a), with primary endpoint proportion of patients with molecular screening performed within 8 weeks. Patients identified as molecularly HR are invited into the phase II, single-arm, multicentre trial (MUKnine b) investigating an intensive treatment schedule comprising bortezomib, lenalidomide, daratumumab, low-dose cyclophosphamide and dexamethasone, with single high-dose melphalan and autologous stem cell transplantation (ASCT) followed by combination consolidation and maintenance therapy. MUKnine b primary endpoints are minimal residual disease (MRD) at day 100 post-ASCT and progression-free survival. Secondary endpoints include response, safety and quality of life. The trial uses a Bayesian decision rule to determine if this treatment strategy is sufficiently active for further study. Patients identified as not having HR disease receive standard treatment and are followed up in a cohort study. Exploratory studies include longitudinal whole-body diffusion-weighted MRI for imaging MRD testing. ETHICS AND DISSEMINATION: Ethics approval London South East Research Ethics Committee (Ref: 17/LO/0022, 17/LO/0023). Results of studies will be submitted for publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ISRCTN16847817, May 2017; Pre-results.

A phase I study of anti-BCMA CAR T cell therapy in relapsed/refractory multiple myeloma and plasma cell leukemia.

BACKGROUND: Relapsed/refractory (R/R) multiple myeloma (MM) patients and primary plasma cell leukemia (PCL) have an unfavorable prognosis and no effective treatment. This study was designed to assess the safety and preliminary efficacy of a novel anti-B-cell maturation antigen (BCMA) chimeric antigen receptor (CAR) T cell in R/R MM and PCL. METHODS: Between February 22, 2017, and June 25, 2018, 28 R/R and two R/R primary PCL patients received a median dose of 11.2 × 106 CAR+ cells/kg. The subjects were refractory to a proteasome inhibitor and/or an immunomodulatory agent. Fludarabine and cyclophosphamide were given as lymphodepletion chemotherapy. RESULTS: Results for these 30 consecutive patients who received an anti-BCMA CAR T cell infusion are reported. The patients had received a median of four prior lines of therapy. A total of 44 different types of adverse events were recorded, and hematologic toxic effects were the most common events of any grade during treatment. Hematologic toxic effects were also the most common events of grade 3 or higher. A total of 29 patients (96.7%) had cytokine release syndrome, which was of grade 1 or 2 in 24 patients (80%) and grade 3 in five patients (16.7%). Neurologic toxic effects only occurred in one patient (3.3%) and were of grade 1. The objective response rate was 90%, and the complete response rate was 43.3%. With a median follow-up of 12.6 months, the median progression-free survival (PFS) and overall survival were 5.2 months and 14.0 months. One of the two primary PCL achieved a complete response with a PFS of 307 days. The other patients achieved a very good partial response with a PFS of 117 days. CONCLUSIONS: Anti-BCMA CAR T cell treatment is safe and highly active in R/R multiple myeloma.

Clinical Characteristics and Outcomes of Patients With Primary Plasma Cell Leukemia in the Era of Novel Agent Therapy.

OBJECTIVE: To evaluate the clinical outcomes of patients with primary plasma cell leukemia (pPCL) defined by 5% or greater clonal circulating plasma cells on peripheral blood smear and treated with novel agent induction therapies. PATIENTS AND METHODS: A cohort of 68 patients with pPCL diagnosed at the Mayo Clinic in Rochester, Minnesota, from January 1, 2000, to December 31, 2019, and treated with novel agent induction therapies was evaluated. RESULTS: The median follow-up was 46 (95% CI, 41 to 90) months. The median bone marrow plasma cell content was 85% (range, 10% to 100%) and median clonal circulaitng plasma cell percentage on the peripheral blood smear was 26% (range, 5% to 93%). There was a preponderance of t(11;14) primary cytogenetic abnormality in this cohort. The median time to next therapy (TTNT) and overall survival (OS) for all patients with pPCL patients in this cohort was 13 (95% CI, 9 to 17) and 23 (95% CI, 19 to 38) months, respectively. However, when stratified by cytogenetic risk, the median TTNT and OS were 16 and 51 months for standard risk vs 9 and 19 months for high risk (P=.01 for OS). CONCLUSION: Primary plasma cell leukemia remains an aggressive disease with poor prognosis despite novel agent-based therapies. Some patients have better than expected survival and this phenomenon may be influenced by the absence of high-risk cytogenetics. Newer treatment regimens are needed to improve the prognosis of this devastating disease.

Plasma cell leukaemia with t(11;14) not responsive to venetoclax.

A 70-year-old man with medical history of IgG kappa multiple myeloma, initially diagnosed in 2017, underwent induction therapy with carfilzomib, lenalidomide and dexamethasone followed by autologous haematopoietic stem cell transplantation. Nine months following transplant, disease relapsed in the form of plasma cell leukaemia. Fluorescent in situ hybridisation of malignant plasma cells revealed t(11;14). A combination therapy including venetoclax was used based on efficacy data for Bcl-2 inhibitor venetoclax from available early-phase clinical trials in patients with relapsed multiple myeloma with t(11;14) and other published case studies. Unfortunately, the disease was primary refractory, and after further ineffective therapies, the patient did not have a successful outcome.

[Successful disease control of plasma cell leukemia by the treatment comprising proteasome inhibitors, followed by daratumumab, lenalidomide, and dexamethasone therapy].

A 59-year-old woman was referred by her family doctor to our hospital owing to anemia, nausea, and malaise. She was diagnosed with primary plasma cell leukemia based on her laboratory and morphologic findings. She was treated with high dose of dexamethasone; cyclophosphamide, bortezomib, and dexamethasone; and carfilzomib, lenalidomide, and dexamethasone. She achieved partial treatment response. We switched her treatment to daratumumab, lenalidomide, and dexamethasone (DRd) owing to progression of peripheral neuropathy. Bone marrow examination performed after 15 courses of DRd revealed minimal residual disease-negative status. Sequential multidrug combination chemotherapies may be related to long-term successful disease control.