Real-world data on prognosis and outcome of primary plasma cell leukemia in the era of novel agents: a multicenter national study by the Greek Myeloma Study Group. Blood Cancer J. 2018;8:31. [PMID: 29523783 PMCID: PMC5849880 DOI: 10.1038/s41408-018-0059-6]

Clinical and cytogenetic characteristics of primary and secondary plasma cell leukemia under the new IMWG definition criteria: a retrospective study

BACKGROUND

Plasma cell leukemia (PCL) is a rare and aggressive plasma cell disorder, exhibiting a more unfavorable prognosis than multiple myeloma. PCL is classified into pPCL and sPCL. Recently, the IMWG has recommended new PCL definition criteria, which require the presence of ≥5% circulating plasma cells in peripheral blood smears. Due to its low incidence, research on pPCL and sPCL is limited.

METHODS

We conducted a retrospective study and analyzed clinical and cytogenetic data of pPCL and sPCL patients. Overall survival (OS) and progression-free survival (PFS) were assessed by the Kaplan-Meier method, and survival distributions were compared using the log-rank test.

RESULTS

This is a small cohort comprising 23 pPCL and 9 sPCL patients. Notably, sPCL patients showed a higher incidence of extramedullary infiltration and a higher percentage of bone marrow plasma cells (p = 0.015 and 0.025, respectively). Although no significant difference was found between the two groups in OS and PFS, a trend emerged suggesting a superior survival outcome for pPCL patients, with a higher cumulative 1-year PFS rate (38.3% vs. 13.3%) and a lower early mortality rate (mortality rate at 3 months: 15% vs. 33%). We also suggested that pPCL patients carrying t(11;14) may have a longer median survival time than individuals with other cytogenetic abnormalities, but this was not confirmed due to the small sample size.

CONCLUSION

Our study revealed clinical and cytogenetic features of pPCL and sPCL patients according to the new diagnostic criteria. The findings suggested a generally better prognosis for pPCL than sPCL and the likelihood of t(11;14) translocation acting as a favorable prognostic factor in pPCL. It is important to note that our study had a limited sample size, which may lead to bias. We hope well-designed studies can be conducted to provide more results.

Sequential autologous and allogeneic stem cell transplantation for treatment of primary plasma cell leukemia: A case report

Primary plasma cell leukemia (pPCL) is a rare and aggressive form of plasma cell disorder, which accounts for ~70% of all PCL. Survival of pPCL remains poor, and is related with early mortality. There is no standard therapy for patients with pPCL. In the present study, a 26-year-old man who was diagnosed with pPCL was reported. The patient achieved stringent complete remission to the successful treatment of intensive chemotherapy combined with sequential autologous and allogeneic stem cell transplantation (SCT) followed by maintenance therapy with oral administration of ixazomib, thalidomide and dexamethasone (IRD regimen). Development of complex treatment algorithms that combine novel agents, SCT and post-transplantation remission strategies may translate into survival in patients with pPCL.

Daratumumab, Cyclophosphamide, Bortezomib, Lenalidomide, and Dexamethasone as Induction and Extended Consolidation Improves Outcome in Ultra-High-Risk Multiple Myeloma

PURPOSE

The multicenter OPTIMUM (MUKnine) phase II trial investigated daratumumab, low-dose cyclophosphamide, lenalidomide, bortezomib, and dexamethasone (Dara-CVRd) before and after autologous stem-cell transplant (ASCT) in newly diagnosed patients with molecularly defined ultra-high-risk (UHiR) multiple myeloma (NDMM) or plasma cell leukemia (PCL). To provide clinical context, progression-free survival (PFS) and overall survival (OS) were referenced to contemporaneous outcomes seen in patients with UHiR NDMM treated in the recent Myeloma XI (MyeXI) trial.

METHODS

Transplant-eligible all-comers NDMM patients were profiled for UHiR disease, defined by presence of ≥2 genetic risk markers t(4;14)/t(14;16)/t(14;20), del(1p), gain(1q), and del(17p), and/or SKY92 gene expression risk signature. Patients with UHiR MM/PCL were offered treatment with Dara-CVRd induction, V-augmented ASCT, extended Dara-VR(d) consolidation, and Dara-R maintenance. UHiR patients treated in MyeXI with carfilzomib, lenalidomide, dexamethasone, and cyclophosphamide, or lenalidomide, dexamethasone, and cyclophosphamide, ASCT, and R maintenance or observation were identified by mirrored molecular screening. OPTIMUM PFS at 18 months (PFS18m) was compared against MyeXI using a Bayesian framework, and patients were followed up to the end of consolidation for PFS and OS.

RESULTS

Of 412 screened NDMM OPTIMUM patients, 103 were identified as UHiR or PCL and subsequently treated on trial with Dara-CVRd; 117 MyeXI patients identified as UHiR formed the external comparator arm, with comparable clinical and molecular characteristics to OPTIMUM. Comparison of PFS18m per Bayesian framework resulted in a 99.5% chance of OPTIMUM being superior to MyeXI. At 30 months' follow-up, PFS was 77% for OPTIMUM versus 39.8% for MyeXI, and OS 83.5% versus 73.5%, respectively. Extended post-ASCT Dara-VRd consolidation therapy was highly deliverable, with limited toxicity.

CONCLUSION

Our results suggest that Dara-CVRd induction and extended post-ASCT Dara-VRd consolidation markedly improve PFS for UHiR NDMM patients over conventional management, supporting further evaluation of this strategy.

Improved survival of patients with primary plasma cell leukemia with VRd or daratumumab-based quadruplets: A multicenter study by the Greek myeloma study group

We evaluated the efficacy and prognostic impact of bortezomib-lenalidomide triplet (VRd) or daratumumab-based quadruplets (DBQ) versus previous anti-myeloma therapies, that is, bortezomib standard combinations (BSC) or conventional chemotherapy (CT), in a large cohort of patients with primary plasma cell leukemia (pPCL), including those fulfilling the revised diagnostic criteria, that is, circulating plasma cells (cPCS): ≥5%; 110 pPCL patients (M/F: 51/59; median age 65 years, range: 44-86) out of 3324 myeloma patients (3%), registered in our database between 2001 and 2021, were studied; 37% had cPCS 5%-19%; 89% received novel combinations including DBQ (21%), VRd (16%) and BSC (52%); 35% underwent autologous stem cell transplantation. 83% achieved objective responses. Treatment with VRd/DBQ strongly correlated with a higher complete response rate (41% vs. 17%; p = .008). After a median follow-up of 51 months (95% CI: 45-56), 67 patients died. Early mortality was 3.5%. Progression-free survival was 16 months (95% CI: 12-19.8), significantly longer in patients treated with VRd/DBQ versus BSC/CT (25 months, 95% CI: 13.5-36.5 vs. 13 months 95% CI: 9-16.8; p = .03). Median overall survival (OS) was 29 months (95% CI: 19.6-38.3), significantly longer in patients treated with VRd/DBQ versus BSC/CT (not reached vs. 20 months, 95% CI: 14-26; 3-year OS: 70% vs. 32%, respectively; p < .001; HzR: 3.88). In the multivariate analysis VRd/DBQ therapy, del17p(+) and PLT <100.000/μL, independently predicted OS (p < .05). Our study has demonstrated that in the real-world setting, treatment with VRd/DBQ induces deep and durable responses and is a strong prognostic factor for OS representing currently the best therapeutic option for pPCL.

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.

Primary plasma cell leukemia in Latin America: demographic, clinical, and prognostic characteristics. A study of GELAMM group

Primary plasma cell leukemia (pPCL) is an infrequent and aggressive plasma cell disorder. The prognosis is still very poor, and the optimal treatment remains to be established. A retrospective, multicentric, international observational study was performed. Patients from 9 countries of Latin America (LATAM) with a diagnosis of pPCL between 2012 and 2020 were included. 72 patients were included. Treatment was based on thalidomide in 15%, proteasome inhibitors (PI)-based triplets in 38% and chemotherapy plus IMIDs and/or PI in 29%. The mortality rate at 3 months was 30%. The median overall survival (OS) was 18 months. In the multivariate analysis, frontline PI-based triplets, chemotherapy plus IMIDs and/or PI therapy, and maintenance were independent factors of better OS. In conclusion, the OS of pPCL is still poor in LATAM, with high early mortality. PI triplets, chemotherapy plus IMIDs, and/or PI and maintenance therapy were associated with improved survival.

Bortezomib advanced mechanisms of action in multiple myeloma, solid and liquid tumors along with its novel therapeutic applications

Bortezomib (BTZ) is a first-in-class reversible and selective proteasome inhibitor. It inhibits the ubiquitin proteasome pathway that leads to the degradation of many intracellular proteins. Initially, BTZ was FDA approved for the treatment of refractory or relapsed multiple myeloma (MM) in 2003. Later, its usage was approved for patients with previously untreated MM. In 2006, BTZ was approved for the treatment of relapsed or refractory Mantle Cell Lymphoma (MCL) and, in 2014, for previously untreated MCL. BTZ has been extensively studied either alone or in combination with other drugs for the treatment of different liquid tumors especially in MM. However, limited data evaluated the efficacy and safety of using BTZ in patients with solid tumors. In this review, we will discuss the advanced and novel mechanisms of action of BTZ documented in MM, solid tumors and liquid tumors. Moreover, we will shed the light on the newly discovered pharmacological effects of BTZ in other prevalent diseases.

The clinical characteristics and prognosis of patients with primary plasma cell leukemia (pPCL) according to the new IMWG definition criteria

Recently, the definition of primary plasma cell leukemia (pPCL) has been revised as the presence of circulating plasma cells (CPCs) ≥5% in peripheral blood smear. Consequently, the clinical features and prognosis of this aggressive disease can be truly identified by the larger patient cohort. Herein, we identified 158 new-defined pPCL patients among 2,266 MM patients (7.0%), and such prevalence doubled the previous estimate. Our study firstly provided solid support for the application of the new definition. We also found that cytopenias and adverse prognostic biomarkers were more common in new-defined pPCL compared with MM (p < 0.05). Besides, the patients receiving proteasome inhibitors based regimen in combination with stem cell transplantation could experience a considerable survival benefit. Strikingly, we showed that the presence of conventional high-risk cytogenetic abnormalities in pPCL didn't exert a great prognostic effect like MM, while elevated LDH reflecting tumor cells proliferation rate was the only independent predictor.

Case report: Plasma cell leukemia secondary to multiple myeloma successfully treated with anti-BCMA CAR-T cell therapy

Chimeric antigen receptor (CAR)-T cell therapy provides an effective salvage treatment for relapsed/refractory multiple myeloma (RRMM) patients. End-stage RRMM with plasma cell leukemia (PCL) transformation is highly aggressive and resistant to conventional therapy. There is an urgent need for new therapeutics and CAR-T therapy may play an important role. We report a case of PCL secondary to RRMM successfully treated with CAR-T cell therapy targeting B-cell maturation antigen (BCMA). A woman was diagnosed as having MM 4 years ago and progressed to secondary PCL (sPCL) of five prior lines of treatment including proteasome inhibitors, an immunomodulatory agent, cytotoxic drugs, and an anti-CD38 monoclonal antibody. After receiving a BCMA CAR-T therapy, she achieved a stringent complete response that lasted 9 months. Then, the patient irregularly took venetoclax 10 mg per day due to a slightly higher λ FLC concentration, which did not meet the criteria for progression. She maintained a complete response for the following 7 months. In conclusion, BCMA CAR-T therapy may be a promising therapeutic approach in PCL patients. More studies are needed to evaluate the benefit of anti-BCMA CAR-T therapy in PCL patients.

Clinical Trial Registration:www.chictr.org.cn, ChiCTR1900024388, Registered 9 July 2019.

Identification of High-Risk Multiple Myeloma With a Plasma Cell Leukemia-Like Transcriptomic Profile

Primary plasma cell leukemia (pPCL) is an aggressive subtype of multiple myeloma, which is distinguished from newly diagnosed multiple myeloma (NDMM) on the basis of the presence of ≥ 20% circulating tumor cells (CTCs). A molecular marker for pPCL is currently lacking, which could help identify NDMM patients with high-risk PCL-like disease, despite not having been recognized as such clinically.

Leucocytoclastic Vasculitis, Cryoglobulinemia, or Plasma Cell Leukemia: A Diagnostic Conundrum

Plasma cell leukemia is rare and could be life-threatening. Even rarer and equally life-threatening is cryoglobulinemia. Both of them occurring together paints a grim clinical picture. We present the case of a 63-year-old male with plasma cell leukemia complicated by cryoglobulinemia with skin lesions. The report briefly reviews the clinical and diagnostic characteristics of plasma cell leukemia and well as available treatment options. It also highlights the need to consider non-chemotherapy-based regimens and clinical trials in the care of plasma cell leukemia patients.

Plasma cell leukemia: A review of the molecular classification, diagnosis, and evidenced-based treatment

Plasma cell leukemia is a rare and aggressive plasma cell dyscrasia associated with dismal outcomes. It may arise de novo, primary plasma cell leukemia, or evolve from an antecedent diagnosis of multiple myeloma, secondary plasma cell leukemia. Despite highly effective therapeutics, survival for plasma cell leukemia patients remains poor. Molecular knowledge of plasma cell leukemia has recently expanded with use of gene expression profiling and whole exome sequencing, lending new insights into prognosis and therapeutic development. In this review, we describe the molecular knowledge, clinical characteristics, evidenced-based therapeutic approaches and treatment outcomes of plasma cell leukemia.

Allogeneic Stem Cell Transplantation in Patients with High-Risk Multiple Myeloma: Utopia or Continuous Challenge in Aiming for Cure?

OPINION STATEMENT

Nowadays, several novel agents have been introduced in the treatment of multiple myeloma, not only resulting in high response rates and prolonged survival but also offering good quality of life. However, the potential of cure, especially for patients with advanced or unfavorable disease features, remains elusive. Allogeneic hematopoietic stem cell transplantation, based mainly on the graft vs. myeloma effect, can offer prolonged disease control and probability of cure but unfortunately at the cost of considerable transplant-related toxicity rates. Therefore, the role of allogeneic hematopoietic stem cell transplantation in the treatment of multiple myeloma has been called into question. Recently, several studies, particularly those with long-term follow-up, demonstrated a trend of survival superiority for allografted patients with high-risk disease. These data fuel again the interest in allogeneic stem cell transplantation for selected patients with high-risk multiple myeloma, especially if the high remission rates which can be achieved with the currently used treatment protocols could be long-life sustained through the additional exploitation of the long-lasting anti-multiple myeloma effect, originating from the allograft.

Venetoclax in combination with chidamide and dexamethasone in relapsed/refractory primary plasma cell leukemia without t(11;14): A case report

BACKGROUND

Conventional therapies for primary plasma cell leukemia (pPCL) are usually ineffective, with a short remission time with the use of multiple myeloma medications, showing aggressiveness of pPCL. B-cell lymphoma-2 inhibitor venetoclax is usually used for relapsed/refractory multiple myeloma (RRMM) with t(11;14). There are very few studies published on the use of venetoclax in pPCL without t(11;14). Similarly, histone deacetylase inhibitors are considered effective for the treatment of RRMM, but there are no reports on their use in pPCL.

CASE SUMMARY

A 57-year-old woman with severe anemia, thrombocytopenia, multiple bone destruction, impaired renal function, and 42.7% of peripheral plasma cells is reported. After multiple chemotherapy regimens and chimeric antigen receptor T-cell treatment, the disease progressed again. The patient had very good partial response and was maintained for a long time on venetoclax in combination with chidamide and dexamethasone therapy.

CONCLUSION

The success of venetoclax-chidamide-dexamethasone combination therapy in achieving a very good partial response suggested that it can be used for refractory/relapsed pPCL patients who have been exhausted with the use of various drug combinations and had poor survival outcomes.

[Prevalence investigation of plasma cell leukemia in China: a calculation based on national urban medical insurance in 2016]

目的

分析我国城市人口中浆细胞白血病（PCL）的流行病学特征，并测算2016年PCL患病率。

方法

利用我国23个省2016年1月1日至2016年12月31日的城镇基本医疗保险数据进行测算。利用医疗保险数据中的疾病诊断名称和疾病诊断编码识别PCL患者。按性别、地区和年龄进行亚组分析，并通过敏感性分析考察结果的稳健性。基于我国2010年全国人口普查数据计算按年龄调整的标准化患病率。

结果

2016年我国城市人口中PCL患病率为0.11/10万（95％CI 0.05～0.19），其中男性和女性患病率分别为0.12/10万（95％CI 0.06～0.21），0.10/10万（95％CI 0.04～0.19）。PCL的患病率在70～79岁时达高峰。敏感性分析显示本研究结果具有稳健性。根据我国2010年全国人口普查数据所得的标化患病率为0.12/10万（95％CI 0.11～0.13）。

结论

本研究首次利用全国城镇医疗保险数据测算我国PCL的患病率，为PCL相关研究和政策制定提供依据。

A clinical perspective on plasma cell leukemia; current status and future directions

Primary plasma cell leukemia (pPCL) is an aggressive plasma cell disorder with a guarded prognosis. The diagnosis is confirmed when peripheral blood plasma cells (PCs) exceed 20% of white blood cells or 2000/μL. Emerging data demonstrates that patients with lower levels of circulating (PCs) have the same adverse prognosis, challenging the clinical disease definition, but supporting the adverse impact of circulating PCs. The cornerstone of treatment consists of combination therapy incorporating a proteasome inhibitor, an immunomodulatory agent, steroids, and/or anthracyclines and alkylators as part of more-intensive chemotherapy, followed by consolidative autologous hematopoietic cell transplantation in eligible patients and then maintenance therapy. Monoclonal antibodies are also currently being evaluated in this setting with a strong rationale for their use based on their activity in multiple myeloma (MM). Due to limited therapeutic studies specifically evaluating pPCL, patients with pPCL should be considered for clinical trials. In contrast to MM, the outcomes of patients with pPCL have only modestly improved with novel therapies, and secondary PCL arising from MM in particular is associated with a dismal outlook. Newer drug combinations, immunotherapy, and cellular therapy are under investigation, and these approaches hopefully will demonstrate efficacy to improve the prognosis of pPCL.

Single-Cell Transcriptomic Analysis Reveals BCMA CAR-T Cell Dynamics in a Patient with Refractory Primary Plasma Cell Leukemia

Chimeric antigen receptor T cell (CAR-T) therapy has revolutionized the clinical treatment of hematological malignancies due to the prominent anti-tumor effects. B cell maturation antigen (BCMA) CAR-T cells have demonstrated promising effects in patients with relapsed/refractory multiple myeloma. However, the dynamics of CAR-T cell proliferation and cytotoxicity in clinical patients remains unexplored. Here, we longitudinally profiled the transcriptomes of 55,488 T cells including CAR-T products, CAR-T cells, and endogenous T cells at the peak and remission phases in a plasma cell leukemia (PCL) patient treated with BCMA CAR-T cells by single-cell transcriptomic analysis. Our results showed distinct CAR-T and endogenous T cell subsets indicating stage-specific expression in proliferation, cytotoxicity, and intercellular signaling pathways. Furthermore, we found that CAR-T cells at peak phase gradually convert to a highly cytotoxic state from a highly proliferative state along a development trajectory. Moreover, re-analysis of a single cell study from CD8+ CD19 CAR-T confirmed our findings. These commonalities suggest conserved mechanisms for CAR-T treatment across hematological malignancies. Taken together, our current study provides insight into CAR-T cell dynamics during CAR-T therapy and proves that both BCMA CAR-T and CD19 CAR-T have similar transcriptional characteristics, especially at the CAR-T peak phase.

Bortezomib-induced diffuse alveolar hemorrhage in a patient with plasma cell leukemia

Bortezomib, a chemotherapeutic agent used in the treatment of hematologic malignancies, has been associated with multiple forms of lung injury including diffuse alveolar hemorrhage (DAH). We present the first reported case of bortezomib-induced DAH in a patient with plasma cell leukemia. This 59-year-old female developed hemoptysis, severe cough, and diffuse bilateral ground glass opacities on CT scan of the chest after receiving one dose of bortezomib, with DAH subsequently confirmed on bronchoalveolar lavage. Unlike most previously reported cases, she did not develop respiratory failure requiring high dose corticosteroids, and in fact did not require any supplemental oxygen. We also provide a comparative summary of all reports of bortezomib-induced DAH in the literature to date. This case provides additional insight into the spectrum of disease severity observed in DAH secondary to bortezomib therapy.

Plasma Cell Leukemia - Facts and Controversies: More Questions than Answers?

Plasma cell leukemia (PCL) is an aggressive hematological malignancy characterized by an uncontrolled clonal proliferation of plasma cells (PCs) in the bone marrow and peripheral blood. PCL has been defined by an absolute number of circulating PCs exceeding 2.0 × 10⁹/L and/or >20% PCs in the total leucocyte count. It is classified as primary PCL, which develops de novo, and secondary PCL, occurring at the late and advanced stages of multiple myeloma (MM). Primary and secondary PCL are clinically and biologically two distinct entities. After the diagnosis, treatment should be immediate and should include a proteasome inhibitor and immunomodulator-based combination regimens as induction, followed by stem cell transplantation (SCT) in transplant-eligible individuals who have cleared the peripheral blood of circulating PCs. Due to the rarity of the condition, there have been very few clinical trials. Furthermore, virtually all of the myeloma trials exclude patients with active PCL. The evaluation of response has been defined by the International Myeloma Working Group and consists of both acute leukemia and MM criteria. With conventional chemotherapy, the prognosis of primary PCL has been ominous, with reported overall survival (OS) ranging from 6.8 to 12.6 months. The use of novel agents and autologous SCT appears to be associated with deeper response and an improved survival, although it still remains low. The PCL prognostic index provides a simple score to risk-stratify PCL. The prognosis of secondary PCL is extremely poor, with OS of only 1 month.

Primary Plasma Cell Leukemia: Real-World Retrospective Study of 46 Patients From a Single-Center Study in China

BACKGROUND

Primary plasma cell leukemia (PPCL) is a rare and aggressive plasma cell disorder. The use of novel agents, together with autologous stem cell transplantation, has improved survival outcome in PPCL. However, the prognosis is still very poor, and the optimal treatment remains an unmet clinical need.

PATIENTS AND METHODS

We studied the efficacy and prognostic impact of novel agents in 46 patients with PPCL patients at the Blood Diseases Hospital in China. We examined the impact of clinical and laboratory features, as well as therapies (bortezomib- and/or immunomodulatory drug-based therapies, chemotherapy) on survival and extent of clinical response, including progression-free survival and overall survival (OS). Progression-free survival and OS were assessed by the Kaplan-Meier method, and survival distributions were compared by log-rank test.

RESULTS

In our cohort of 46 PPCL patients, the median age at the time of diagnosis was 54 years. Overall response rate was 54% (25/46). The median (95% confidence interval) progression-free survival time was 6 (0-12.5) months, and OS time was 14 (4.6-23.4) months. The OS time was significantly longer in patients treated with bortezomib-based versus non-bortezomib-based therapies (median [95% confidence interval], 19 [9-28.9] vs. 5 [4-24] months; P = .019).

CONCLUSION

This large single-center study of PPCL supports the use of bortezomib-based therapies as frontline treatment in PPCL patients.

Successful treatment with bortezomib-containing regimen of primary plasma cell leukemia: a case report

Plasma cell leukemia represents the most aggressive form of plasma cell dyscrasia. We report a 67-year old male with no previous medical illnesses presented with anemic symptoms. Blood film revealed 35% circulating plasma cells, bone marrow biopsy showed plasma cells constituting 85%. Diagnosis of primary plasma cell leukemia was completed. Induction chemotherapy with bortezomib, doxorubicin, and dexamethasone was started. After the first cycle, plasma cells in peripheral blood disappeared. The patient had complete remission at evaluation after the third cycle. Re-evaluation after the sixth cycle showed that he maintained remission. As he was non-transplant eligible, he was we kept on maintenance bortezomib. Twenty-four months after the diagnosis, the patient remains in remission.

Bortezomib-based Regimens Improve the Outcome of Patients with Primary or Secondary Plasma Cell Leukemia: A Retrospective Cohort Study

Objective:

The management experience for plasma cell leukemia (PCL) is still limited by PCL’s rare incidence and aggressive course. The goal of this study was to further identify the efficacy of bortezomib-containing regimens for PCL in Chinese patients.

Materials and Methods:

In this study, 56 consecutive PCL patients [14 primary PCL (pPCL) and 42 secondary PCL (sPCL) cases] were retrospectively enrolled and 42/56 patients received bortezomib-based regimens (BBRs), including 10/14 pPCL and 32/42 sPCL patients. The patients’ survival data, clinical information, and safety data were collected and analyzed.

Results:

In pPCL and sPCL patients, the overall response rate in the bortezomib group was 90.0% and 25.0%, respectively. The median progression-free survival from PCL diagnosis for pPCL and sPCL was 8.3 months vs. 2.9 months (p=0.043) and median overall survival (OS) from PCL diagnosis was 23.3 months vs. 4.0 months. The OS for patients receiving BBRs was significantly longer for both pPCL (8.3 vs. 1.2 months, p=0.002) and sPCL (4.3 vs. 1.1 months, p<0.001). In multivariate COX analysis, BBR treatment [p=0.008, hazard ratio (HR)=0.38, 95% confidence interval (CI)=0.19-0.77] and very good partial response or better (≥VGPR) (p=0.035, HR=0.19, 95% CI=0.04-0.74) were independent predictors of OS for sPCL patients. For pPCL patients, BBR predicted OS (p=0.029, HR=0.056, 95% CI=0.004-0.745) instead of ≥VGPR (p=0.272, HR=3.365, 95% CI=0.38-29.303).

Conclusion:

It was found that BBRs could significantly improve OS for both pPCL and sPCL patients.

An update on biology, diagnosis and treatment of primary plasma cell leukemia

INTRODUCTION

Primary plasma cell leukemia (PPCL) is one of the most aggressive hematological malignancies. The prognosis of PPCL patients remains poor, although some improvements have been made in recent years. Areas covered: In this review recent clinical and biological advances in PPCL are reported. Some recommendations for the practical management of these patients are provided, with a particular focus on the role of novel agents and transplant procedures. A brief description of the currently ongoing clinical trials with new drugs is also enclosed. Expert opinion: PPCL still represents a difficult challenge for all hematologists. Here the authors provide a personal view on how the current, generally unsatisfactory results in this neoplastic disorder could be improved. In particular, dedicated studies exploring alternative therapies are necessary and eagerly awaited. Such studies should possibly be based on new biological information that could be of help in identifying novel genetic biomarkers for risk stratification and new actionable molecular targets.

Plasma Cell Leukemia: Definition, Presentation, and Treatment

Purpose of Review

We discuss current topics on the definition of plasma cell leukemia and the distinction between plasma cell leukemia and multiple myeloma. Moreover, we review the latest literature on how to treat plasma cell leukemia.

Recent Findings

Plasma cell leukemia is clinically and genetically distinct from multiple myeloma. Plasma cell leukemia is defined by the observation in blood of more than 20% clonal plasma cells by differential count of the leucocytes or by counting more than 2 × 10⁹ per liter circulating clonal plasma cells. However, patients with lower levels of circulating plasma cells have the same adverse prognosis, which challenges the disease definition. Survival has improved after implementation of high-dose chemotherapy with stem-cell support, bortezomib, and lenalidomide in the treatment; yet, the prognosis remains poor. The results of allo-transplants have been disappointing.

Summary

The diagnostic criteria of PCL are currently discussed in the international myeloma community. Despite some improvement in survival, the prognosis remains adverse. New, more targeted treatment modalities, including immunotherapies, will hopefully improve the outcome in the near future.

Systemic joint laxity and mandibular range of movement

Primary plasma cell leukemia (pPCL) is a rare and aggressive form of multiple myeloma (MM) that is characterized by the presence of ≥20% circulating plasma cells. Overall survival remains poor despite advances of anti-MM therapy. The disease biology as well as molecular mechanisms that distinguish pPCL from non-pPCL MM remain poorly understood and, given the rarity of the disease, are challenging to study. In an attempt to identify key biological mechanisms that result in the aggressive pPCL phenotype, we performed whole-exome sequencing and gene expression analysis in 23 and 41 patients with newly diagnosed pPCL, respectively. The results reveal an enrichment of complex structural changes and high-risk mutational patterns in pPCL that explain, at least in part, the aggressive nature of the disease. In particular, pPCL patients with traditional low-risk features such as translocation t(11;14) or hyperdiploidy accumulated adverse risk genetic events that could account for the poor outcome in this group. Furthermore, gene expression profiling showed upregulation of adverse risk modifiers in pPCL compared to non-pPCL MM, while adhesion molecules and extracellular matrix proteins became increasingly downregulated. In conclusion, this is one of the largest studies to dissect pPCL on a genomic and molecular level.