Absolute Lymphocyte Count after BCMA CAR-T Therapy is a Predictor of Response and Outcomes in Relapsed Multiple Myeloma.

BCMA-targeting CAR-T cells used in multiple myeloma (MM) are rapidly becoming a mainstay in the treatment of relapsed/refractory (RR) disease, and CAR-T cell expansion post-infusion has been shown to inform depth and duration of response, but measuring this process remains investigational. This multicenter study describes the kinetics and prognostic impact of absolute lymphocyte count (ALC) in the first 15 days after CAR-T infusion in 156 relapsed MM patients treated with the BCMA-targeting agents cilta-cel and ide-cel. Patients with higher maximum ALC (ALCmax) had better depth of response, progression-free survival (PFS), and duration of response (DoR). Patients with ALCmax >1.0 x103/uL had a superior PFS (30.5 versus 6 months, p <0.001) compared to those ≤1.0x103/uL, while patients with ALCmax ≤0.5 x103/uL represent a high-risk group with early disease progression and short PFS (HR 3.4, 95 CI: 2 -5.8, P <0.001). In multivariate analysis, ALCmax >1.0 x103/uL and non-paraskeletal extramedullary disease were the only independent predictors of PFS and DoR after accounting for ISS staging, age, CAR-T product, high-risk cytogenetics and number of previous lines. Moreover, our flow cytometry data suggests that ALC is a surrogate for BCMA CAR-T expansion and can be used as an accessible prognostic marker. We report for the first time the association of ALC after BCMA CAR-T infusion with clinical outcomes and its utility in predicting response in RRMM patients.

CD38 antibody re-treatment in daratumumab-refractory multiple myeloma after time on other therapies.

Monoclonal antibodies targeting CD38 are important for treatment of both newly diagnosed and relapsed multiple myeloma (MM). Daratumumab and isatuximab are anti-CD38 antibodies with the US Food and Drugs Administration approval in multiple different combinations. Despite good initial efficacy, patients inevitably develop drug resistance. Whether patients can be effectively re-treated with these antibodies in subsequent lines of therapy is unclear. Thus far, studies have mostly been limited to clinical retrospectives with short washout periods. To answer whether patients regain sensitivity after longer washouts, we used ex vivo sensitivity testing to isolate the anti-CD38 antibody-specific cytotoxicity in samples obtained from patients who had been exposed to and then off daratumumab for up to 53 months. MM cells from patients who had been off daratumumab for >1 year showed greater sensitivity than those with <1 year, although they still were less sensitive than those who were daratumumab naïve. CD38 expression on MM cells gradually recovered, although, again, not to the level of anti-CD38 antibody-naïve patients. Interestingly, low MM CD38 explained only 45% of cases identified to have daratumumab resistance. With clinical follow-up, we found ex vivo sensitivity predicted subsequent clinical response but CD38 overexpression did not. Patients clinically re-treated with anti-CD38 antibodies had <6 months of clinical benefit, but 1 patient who was daratumumab exposed but not refractory achieved complete response lasting 13 months. We conclude that transient efficacy can be achieved by waiting 1 year before CD38 antibody rechallenge, but this approach may be best used as a bridge to, or after, chimeric antigen receptor T-cell therapy.

A pipeline for malignancy and therapy agnostic assessment of cancer drug response using cell mass measurements.

Functional precision medicine offers a promising complement to genomics-based cancer therapy guidance by testing drug efficacy directly on a patient's tumor cells. Here, we describe a workflow that utilizes single-cell mass measurements with inline brightfield imaging and machine-learning based image classification to broaden the clinical utility of such functional testing for cancer. Using these image-curated mass measurements, we characterize mass response signals for 60 different drugs with various mechanisms of action across twelve different cell types, demonstrating an improved ability to detect response for several slow acting drugs as compared with standard cell viability assays. Furthermore, we use this workflow to assess drug responses for various primary tumor specimen formats including blood, bone marrow, fine needle aspirates (FNA), and malignant fluids, all with reports generated within two days and with results consistent with patient clinical responses. The combination of high-resolution measurement, broad drug and malignancy applicability, and rapid return of results offered by this workflow suggests that it is well-suited to performing clinically relevant functional assessment of cancer drug response.

Advances in the molecular characterization of multiple myeloma and mechanism of therapeutic resistance.

Recent insight in the genomic landscape of newly diagnosed multiple myeloma (NDMM) and its precursor conditions, monoclonal gammopathy of uncertain significance (MGUS), and smoldering myeloma have allowed the identification of patients with precursor conditions with a high risk of progression. These cases with "progressor" MGUS/SMM have a higher average mutation burden, have higher rates of mutations in specific genes such as MAPK, DNA repair, MYC, DIS3, and are enriched for specific mutational signatures when compared to non-progressors and are comparable to those found in NDMM. The highly preserved clonal heterogeneity seen upon progression of SMM, combined with the importance of these early variables, suggests that the identification of progressors based on these findings could complement and enhance the currently available clinical models based on tumor burden. Mechanisms leading to relapse/refractory multiple myeloma (RRMM) are of clinical interest given worse overall survival in this population. An Increased mutational burden is seen in patients with RRMM when compared to NDMM, however, there is evidence of branching evolution with many of these mutations being present at the subclonal level. Likewise, alterations in proteins associated with proteosome inhibitor and immunomodulatory drugs activity could partially explain clinical resistance to these agents. Evidence of chromosomal events leading to copy number changes is seen, with the presence of TP53 deletion, mutation, or a combination of both being present in many cases. Additional chromosomal events such as 1q gain and amplification may also interact and lead to resistance.

Patient characteristics, treatment patterns, and outcomes among black and white patients with multiple myeloma initiating daratumumab: A real-world chart review study.

BACKGROUND: Daratumumab was approved for multiple myeloma (MM) in 2015. While its safety and efficacy are well documented, there is limited real-world information on its use and outcomes in patients of different races. METHODS: We conducted a retrospective chart review of adult patients with MM initiating daratumumab in any line of therapy (LOT) between November 2015 and May 2020. De-identified data were retrieved from 2 US clinical sites; patient characteristics, treatment patterns, and response rate were described for black and white patients, stratified by LOT. Overall response rate (ORR), progression-free survival (PFS), and time to next LOT (TTNT) were compared between black and white patients initiating daratumumab in second line (2L) or later, adjusting for age and number of prior lines. RESULTS: Two hundred and fifty-two patient charts (89 black, 163 white) were extracted. Black patients were younger at diagnosis (61.7 vs. 67.0 years) and had a similar proportion of females (black: 44.9%, white: 46.6%). Black patients had longer time between MM diagnosis and daratumumab initiation (43.2 vs. 34.1 months) and received more prior LOTs (median 3.0 vs. 2.0). ORR for black and white patients initiating daratumumab in 1L was 100.0%, with very good partial response or better in 75.0% and 66.7%, respectively. Similar trends were observed in 2L and 3L+. There were no significant differences in ORR, PFS, or TTNT between groups. CONCLUSION: Daratumumab had similar clinical outcomes (ORR, PFS, and TTNT) in black and white patients. Black patients initiated daratumumab later in their treatment, suggesting potential discrepancies in access to new MM treatments.

Carfilzomib and dexamethasone induction with lenalidomide, clarithromycin and dexamethasone consolidation and lenalidomide maintenance for newly diagnosed multiple myeloma.

Combination treatment regimens including a proteasome inhibitor (PI), an immunomodulatory agent (IMiD) and a corticosteroid are standards of care for initial treatment of multiple myeloma (MM). We aimed to evaluate if a sequential treatment program using PI induction followed by IMiD based consolidation and maintenance could achieve similar outcomes with reduced toxicities. This phase 2 study was designed to assess the safety and efficacy of the Car-BiRd regimen: carfilzomib and dexamethasone (Kd) induction until maximum response, followed by lenalidomide, clarithromycin and dexamethasone (BiRd) consolidation until next maximum response, then lenalidomide maintenance in patients with newly diagnosed MM. Seventy-two patients, including both transplant eligible and ineligible patients, were enrolled and evaluated for response. The overall response rate to the Car-BiRd regimen was 94% with 83% of patients achieving a ≥ VGPR and 35% achieving a CR/sCR. The rate of CR/sCR increased from 7% with Kd induction to 21% with BiRd consolidation and 35% with lenalidomide maintenance. These results did not meet the study's target endpoint of a CR rate of 55%. The median PFS using this deferred transplant approach was 37.3 months (95% CI 27.9, 52.7) and median OS was not reached with a median follow-up of 60 months. Toxicities were primarily low grade and manageable. Hematologic toxicities were lower than those expected with a combination PI/IMiD protocol. The sequential Car-BiRd regimen is an effective and safe approach for the upfront treatment of MM including patients unfit for transplant.

Plasma Cell Myeloma Presenting With Amyloid-Laden Crystal-Negative Histiocytosis.

OBJECTIVES: Crystal-storing histiocytosis (CSH) is rare in plasma cell dyscrasias, with only 3 cases reported in the setting of amyloid. No cases of crystal-negative histiocytosis coincident with multiple myeloma and amyloidosis have been reported previously. METHODS: A 58-year-old woman presented with pain due to destructive bone lesions and was found to have plasma cell myeloma (PCM) and marrow amyloid deposition associated with crystal-negative histiocytosis. Differential diagnoses included Langerhans cell histiocytosis, Erdheim-Chester disease, and Rosai Dorfman disease. BRAF mutations were negative, and there was no evidence of paraprotein crystals, arguing against typical CSH. RESULTS: The patient was treated with bortezomib, cyclophosphamide, and dexamethasone, and she subsequently underwent autologous stem cell transplant and ixazomib maintenance. She achieved complete remission with improvement of her symptoms and preserved remission after following up at 60 months. CONCLUSIONS: We describe a case of crystal-negative histiocytosis associated with PCM. CSH is a rare disorder associated with paraprotein-producing conditions in which immunoglobulins aggregate as intracellular crystals in the lysosomes of organ-specific phagocytic macrophages. Light chain tropism in PCM can also lead to the development of amyloid deposition in organs and, in rare cases, is associated with light chain aggregation as intracellular crystals in macrophages.

Different MAF translocations confer similar prognosis in newly diagnosed multiple myeloma patients.

The MAF translocations, t(14;16) and t(14;20), are considered as adverse prognostic factors based on few studies with small sample sizes. We report on their prognostic impact in a large group of 254 patients - 223 (87.8%) with t(14;16) and 31 (12.2%) with t(14;20). There were no intergroup differences in survival estimates. Median progression-free survival was 16.6 months for t(14;16) and 24.9 months for t(14;20) (p = 0.28). Median overall survival (OS) was 54.0 months and 49.0 months, respectively (p = 0.62). Median OS in patients who underwent double autologous stem cell transplantation (ASCT) was 107.0 months versus 60.0 months in patients who received single ASCT (p < 0.001). ISS 3 was associated with shorter OS (HR = 1.89; 95% CI 1.24-3.19; p = 0.005) in Cox analysis. Our study suggests that t(14;20) should be considered as an adverse factor of equal prognostic implication to t(14;16).

A multicenter retrospective study of 223 patients with t(14;16) in multiple myeloma.

The t(14;16) translocation, found in 3%-5% of newly diagnosed (ND) multiple myeloma (MM), has been associated with adverse outcomes. However, the studies establishing the characteristics of t(14;16) included solely small cohorts. The goal of the current international, multicenter (n = 25 centers), retrospective study was to describe the characteristics and outcomes of t(14;16) patients in a large, real-world cohort (n = 223). A substantial fraction of patients had renal impairment (24%) and hemoglobin <10 g/dL (56%) on initial presentation. Combined therapy of both immunomodulatory drug and proteasome inhibitor (PI) in the first line was used in 35% of patients. Autologous stem cell transplantation was performed in 42% of patients. With a median follow up of 4.1 years (95% CI 3.7-18.7), the median progression-free survival (PFS) and overall survival (OS) from first line therapy were 2.1 years (95% CI 1.5-2.4) and 4.1 years (95% CI 3.3-5.5), respectively. Worse OS was predicted by age > 60 years (HR = 1.65, 95% CI [1.05-2.58]), as well as revised International Scoring System (R-ISS) 3 (vs R-ISS 2; HR = 2.59, 95% CI [1.59-4.24]). In conclusion, based on the largest reported cohort of t(14;16) patients, quarter of this subset of MM patients initially presents with renal failure, while older age and the R-ISS 3 predict poor survival.

Caspase-8 Inhibition Prevents the Cleavage and Degradation of E3 Ligase Substrate Receptor Cereblon and Potentiates Its Biological Function.

Cereblon (CRBN), a substrate receptor of cullin 4-RING E3 ligase (CRL4), mediates the ubiquitination and degradation of constitutive substrates and immunomodulatory drug-induced neo-substrates including MEIS2, c-Jun, CLC1, IKZF1/3, CK1α, and SALL4. It has been reported that CRBN itself could be degraded through the ubiquitin-proteasome system by its associated or other cullin-RING E3 ligases, thus influencing its biological functions. However, it is unknown whether the CRBN stability and its biological function could be modulated by caspases. In this study, using model cell lines, we found that activation of the death receptor using tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) leads to the decreased CRBN protein level. Through pharmacological inhibition and activation of caspase-8 (CASP-8), we disclosed that CASP-8 regulates CRBN cleavage in cell lines. Site mapping experiments revealed that CRBN is cleaved after Asp9 upon CASP-8 activation, resulting in the reduced stability. Using myeloma as a model system, we further revealed that either inhibition or genetic depletion of CASP-8 enhances the anti-myeloma activity of lenalidomide (Len) by impairing CRBN cleavage, leading to the attenuated IKZF1 and IKZF3 protein levels and the reduced viability of myeloma cell lines and primary myeloma cells from patients. The present study discovered that the stability of the substrate receptor of an E3 ligase can be modulated by CASP-8 and suggested that administration of CASP-8 inhibitors enhances the overall effectiveness of Len-based combination therapy in myeloma.

Hematogenous extramedullary relapse in multiple myeloma - a multicenter retrospective study in 127 patients.

The current study assesses the characteristics and outcomes of multiple myeloma (MM) patients, treated with novel agents for hematogenous extramedullary (HEMM) relapse. Consecutive patients diagnosed with HEMM between 2010-2018 were included. Patients' characteristics at diagnosis and at HEMM presentation, response to treatment, survival and factors predicting survival were recorded and analyzed. A group of 127 patients, all diagnosed with HEMM by imaging (87.3%) and/or biopsy (79%), were included. Of those, 44% were initially diagnosed with ISS3, 57% presented with plasmacytomas, and 30% had high-risk cytogenetics. Median time to HEMM was 32 months. In multivariate analysis, ISS3 and bone plasmacytoma predicted shorter time to HEMM (P = .005 and P = .008, respectively). Upfront autograft was associated with longer time to HEMM (P = .002). At HEMM, 32% of patients had no BM plasmacytosis, 20% had non-secretory disease and 43% had light-chain disease. Multiple HEMM sites were reported in 52% of patients, mostly involving soft tissue, skin (29%), and pleura/lung (25%). First treatment for HEMM included proteasome inhibitors (50%), immunomodulatory drugs (IMiDs) (39%), monoclonal antibodies (10%), and chemotherapy (53%). Overall response rate (ORR) was 57%. IMiDs were associated with higher ORR (HR 2.2, 95% CI 1.02-4.7, P = .04). Median survival from HEMM was 6 months (CI 95% 4.8-7.2). Failure to achieve ≥VGPR was the only significant factor for worse OS in multivariate analyses (HR = 9.87, CI 95% 2.35 - 39, P = .001). In conclusion, HEMM occurs within 3 years of initial myeloma diagnosis and is associated with dismal outcome. The IMiDs might provide a higher response rate, and achievement of ≥VGPR predicts longer survival.

Phase II study of carfilzomib and dexamethasone therapy for newly diagnosed multiple myeloma.

Carfilzomib and dexamethasone (Kd) has significant activity in relapsed and refractory multiple myeloma. Kd has not previously been evaluated in newly diagnosed multiple myeloma (NDMM). We report a single-arm phase 2 study of 72 patients with NDMM to evaluate the efficacy and tolerability of Kd induction. Carfilzomib was administered in two dosing cohorts with dosing of 20/45 mg/m2 in the first 25 patients and 20/56 mg/m2 in the subsequent 47 patients. Carfilzomib was administered on days 1, 2, 8, 9, 15 and 16 of a 28-day cycle, dexamethasone 20 mg was administered orally on days 1, 2, 8, 9, 15, 16, 22 and 23. Treatment was continued to maximum response, progression of disease, or regimen intolerability. Endpoints included overall response rate (ORR), regimen toxicity and impact of carfilzomib on CD34+ stem cell collection yield. Sixty-five pts achieved at least a partial response (PR) for an ORR of 90%. The maximum response achieved was complete response or better in 5 (7%), very good partial response (VGPR) in 42 (58%), PR in 18 (25%) and stable disease in 7 pts (10%). Toxicities were predominantly low grade with 547 grade 1/2 adverse events and 44 grade ≥3 events. The rate of grade ≥3 cardiovascular adverse events was 11.1% with eight observed events. The activity of Kd described represents the highest rate of overall response and ≥VGPR for any 2-agent combination in NDMM reported to date. Kd demonstrated a safety profile consistent with previously reported carfilzomib studies.

Phase 2 study of clarithromycin, pomalidomide, and dexamethasone in relapsed or refractory multiple myeloma.

The addition of clarithromycin enhances the efficacy of lenalidomide plus dexamethasone in treatment-naive multiple myeloma (MM). We conducted a phase 2 trial to evaluate the safety and efficacy of clarithromycin, pomalidomide, and dexamethasone (ClaPd) in relapsed or refractory multiple myeloma (RRMM) with prior lenalidomide exposure. One hundred twenty patients with a median of 5 prior lines of therapy received clarithromycin 500 mg orally twice daily, pomalidomide 4 mg orally on days 1 to 21, and dexamethasone 40 mg orally on days 1, 8, 15, and 22 of a 28-day cycle. The overall response rate (ORR) was 60% with 23% achieving at least a very good partial response. There was no statistical difference in response rates for patients who were refractory to lenalidomide (ORR, 58%), bortezomib (ORR, 55%), or both lenalidomide and bortezomib (ORR, 54%). Median progression-free survival (PFS) for the cohort was 7.7 months and median overall survival (OS) was 19.2 months. A history of dual-refractoriness to lenalidomide and bortezomib did not significantly impact either PFS or OS. The most common toxicities were neutropenia (83%), lymphopenia (74%), and thrombocytopenia (71%). The most common grade ≥3 toxicities included neutropenia (58%), thrombocytopenia (31%), and anemia (28%). ClaPd is an effective combination in RRMM with response and survival outcomes that are independent of lenalidomide- or bortezomib-refractory status. Toxicities are manageable with low rates of nonhematologic or high-grade events. ClaPd is a convenient, all-oral option in RRMM with comparable efficacy to other highly active, 3-drug, pomalidomide-based combinations. This trial was registered at www.clinicaltrials.gov as #NCT01159574.

Secondary plasma cell leukemia: a multicenter retrospective study of 101 patients.

This multicenter retrospective study included 101 patients (median age 62 years) with secondary plasma cell leukemia (sPCL). The median time from initial multiple myeloma diagnosis to sPCL was 31 months. Fifty-five out of 72 patients (75%) who received any therapy were treated with immunomodulators (IMiDs) and/or proteasome inhibitors (PIs), and 14/72 (19%) underwent salvage autologous stem cell transplantation (ASCT). The overall response rate in patients who received ASCT or PI (either alone or in combination) was higher than in those who did not (93% vs. 36% and 60% vs. 30%, respectively). The median overall survival (OS) in patients who received therapy was 4.2 months (95% CI: 1.3; 8.0) with a 1-year OS of 19%. Platelet count ≤100 × 109/L at sPCL diagnosis was the only independent predictor of a poorer OS in treated patients (HR = 3.98, p = .0001). These findings suggest that patients with sPCL may benefit from salvage ASCT- and PI-based regimens.

Multiple myeloma in patients up to 30 years of age: a multicenter retrospective study of 52 cases.

A small proportion of patients with multiple myeloma (MM) are diagnosed at a very young age. The clinicopathological characteristics and prognosis of these patients are not well known. This analysis included 52 patients diagnosed with MM at the age of ≤30 years (range: 8-30 years). 68% of patients had International Scoring System (ISS) 1 MM; 22% presented with the light chain-only disease, and 48% with elevated serum lactate dehydrogenase (LDH). 85% of patients were treated with novel agents, and 62% received front-line autologous stem cell transplantation (ASCT). Overall response rate (ORR) to front-line treatment and ASCT were 71% and 90%, respectively. The group was followed-up for the median period of 86 months. The median overall survival (OS) was 166 months (95% CI: 53-222), with 5-year OS rate of 77% (95% CI: 61.0-87.9). This findings suggest that the prognosis in young MM patients may be as good if not better than in the general population of MM patients.

Germline Lysine-Specific Demethylase 1 (LSD1/KDM1A) Mutations Confer Susceptibility to Multiple Myeloma.

Given the frequent and largely incurable occurrence of multiple myeloma, identification of germline genetic mutations that predispose cells to multiple myeloma may provide insight into disease etiology and the developmental mechanisms of its cell of origin, the plasma cell (PC). Here, we identified familial and early-onset multiple myeloma kindreds with truncating mutations in lysine-specific demethylase 1 (LSD1/KDM1A), an epigenetic transcriptional repressor that primarily demethylates histone H3 on lysine 4 and regulates hematopoietic stem cell self-renewal. In addition, we found higher rates of germline truncating and predicted deleterious missense KDM1A mutations in patients with multiple myeloma unselected for family history compared with controls. Both monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma cells have significantly lower KDM1A transcript levels compared with normal PCs. Transcriptome analysis of multiple myeloma cells from KDM1A mutation carriers shows enrichment of pathways and MYC target genes previously associated with myeloma pathogenesis. In mice, antigen challenge followed by pharmacologic inhibition of KDM1A promoted PC expansion, enhanced secondary immune response, elicited appearance of serum paraprotein, and mediated upregulation of MYC transcriptional targets. These changes are consistent with the development of MGUS. Collectively, our findings show that KDM1A is the first autosomal-dominant multiple myeloma germline predisposition gene providing new insights into its mechanistic roles as a tumor suppressor during post-germinal center B-cell differentiation.Significance: KDM1A is the first germline autosomal dominant predisposition gene identified in multiple myeloma and provides new insights into multiple myeloma etiology and the mechanistic role of KDM1A as a tumor suppressor during post-germinal center B-cell differentiation. Cancer Res; 78(10); 2747-59. ©2018 AACR.

Novel pedigree analysis implicates DNA repair and chromatin remodeling in multiple myeloma risk.

The high-risk pedigree (HRP) design is an established strategy to discover rare, highly-penetrant, Mendelian-like causal variants. Its success, however, in complex traits has been modest, largely due to challenges of genetic heterogeneity and complex inheritance models. We describe a HRP strategy that addresses intra-familial heterogeneity, and identifies inherited segments important for mapping regulatory risk. We apply this new Shared Genomic Segment (SGS) method in 11 extended, Utah, multiple myeloma (MM) HRPs, and subsequent exome sequencing in SGS regions of interest in 1063 MM / MGUS (monoclonal gammopathy of undetermined significance-a precursor to MM) cases and 964 controls from a jointly-called collaborative resource, including cases from the initial 11 HRPs. One genome-wide significant 1.8 Mb shared segment was found at 6q16. Exome sequencing in this region revealed predicted deleterious variants in USP45 (p.Gln691* and p.Gln621Glu), a gene known to influence DNA repair through endonuclease regulation. Additionally, a 1.2 Mb segment at 1p36.11 is inherited in two Utah HRPs, with coding variants identified in ARID1A (p.Ser90Gly and p.Met890Val), a key gene in the SWI/SNF chromatin remodeling complex. Our results provide compelling statistical and genetic evidence for segregating risk variants for MM. In addition, we demonstrate a novel strategy to use large HRPs for risk-variant discovery more generally in complex traits.

Prognostic indicators in primary plasma cell leukaemia: a multicentre retrospective study of 117 patients.

We report a multicentre retrospective study that analysed clinical characteristics and outcomes in 117 patients with primary plasma cell leukaemia (pPCL) treated at the participating institutions between January 2006 and December 2016. The median age at the time of pPCL diagnosis was 61 years. Ninety-eight patients were treated with novel agents, with an overall response rate of 78%. Fifty-five patients (64%) patients underwent upfront autologous stem cell transplantation (ASCT). The median follow-up time was 50 months (95% confidence interval [CI] 33; 76), with a median overall survival (OS) for the entire group of 23 months (95% CI 15; 34). The median OS time in patients who underwent upfront ASCT was 35 months (95% CI 24·3; 46) as compared to 13 months (95% CI 6·3; 35·8) in patients who did not receive ASCT (P = 0·001). Multivariate analyses identified age ≥60 years, platelet count ≤100 × 109 /l and peripheral blood plasma cell count ≥20 × 109 /l as independent predictors of worse survival. The median OS in patients with 0, 1 or 2-3 of these risk factors was 46, 27 and 12 months, respectively (P < 0·001). Our findings support the use of novel agents and ASCT as frontline treatment in patients with pPCL. The constructed prognostic score should be independently validated.