Oral Selinexor-Dexamethasone for Triple-Class Refractory Multiple Myeloma.

BACKGROUND: Selinexor, a selective inhibitor of nuclear export compound that blocks exportin 1 (XPO1) and forces nuclear accumulation and activation of tumor suppressor proteins, inhibits nuclear factor κB, and reduces oncoprotein messenger RNA translation, is a potential novel treatment for myeloma that is refractory to current therapeutic options. METHODS: We administered oral selinexor (80 mg) plus dexamethasone (20 mg) twice weekly to patients with myeloma who had previous exposure to bortezomib, carfilzomib, lenalidomide, pomalidomide, daratumumab, and an alkylating agent and had disease refractory to at least one proteasome inhibitor, one immunomodulatory agent, and daratumumab (triple-class refractory). The primary end point was overall response, defined as a partial response or better, with response assessed by an independent review committee. Clinical benefit, defined as a minimal response or better, was a secondary end point. RESULTS: A total of 122 patients in the United States and Europe were included in the modified intention-to-treat population (primary analysis), and 123 were included in the safety population. The median age was 65 years, and the median number of previous regimens was 7; a total of 53% of the patients had high-risk cytogenetic abnormalities. A partial response or better was observed in 26% of patients (95% confidence interval, 19 to 35), including two stringent complete responses; 39% of patients had a minimal response or better. The median duration of response was 4.4 months, median progression-free survival was 3.7 months, and median overall survival was 8.6 months. Fatigue, nausea, and decreased appetite were common and were typically grade 1 or 2 (grade 3 events were noted in up to 25% of patients, and no grade 4 events were reported). Thrombocytopenia occurred in 73% of the patients (grade 3 in 25% and grade 4 in 33%). Thrombocytopenia led to bleeding events of grade 3 or higher in 6 patients. CONCLUSIONS: Selinexor-dexamethasone resulted in objective treatment responses in patients with myeloma refractory to currently available therapies. (Funded by Karyopharm Therapeutics; STORM ClinicalTrials.gov number, NCT02336815.).

Quality of life analyses in patients with multiple myeloma: results from the Selinexor (KPT-330) Treatment of Refractory Myeloma (STORM) phase 2b study.

BACKGROUND: Selinexor is an oral, selective nuclear export inhibitor. STORM was a phase 2b, single-arm, open-label, multicenter trial of selinexor with low dose dexamethasone in patients with penta-exposed relapsed/refractory multiple myeloma (RRMM) that met its primary endpoint, with overall response of 26% (95% confidence interval [CI], 19 to 35%). Health-related quality of life (HRQoL) was a secondary endpoint measured using the Functional Assessment of Cancer Therapy - Multiple Myeloma (FACT-MM). This study examines impact of selinexor treatment on HRQoL of patients treated in STORM and reports two approaches to calculate minimal clinically important differences for the FACT-MM. METHODS: FACT-MM data were collected at baseline, on day 1 of each 4-week treatment cycle, and at end of treatment (EOT). Changes from baseline were analyzed for the FACT-MM total score, FACT-trial outcome index (TOI), FACT-General (FACT-G), and the MM-specific domain using mixed-effects regression models. Two approaches for evaluating minimal clinically important differences were explored: the first defined as 10% of the instrument range, and the second based on estimated mean baseline differences between Eastern Cooperative Oncology Group performance status (ECOG PS) scores. Post-hoc difference analysis compared change in scores from baseline to EOT for treatment responders and non-responders. RESULTS: Eighty patients were included in the analysis; the mean number of prior therapies was 7.9 (standard deviation [SD] 3.1), and mean duration of myeloma was 7.6 years (SD 3.4). Each exploratory minimal clinically important difference threshold yielded consistent results whereby most patients did not experience HRQoL decline during the first six cycles of treatment (range: 53.9 to 75.7% for the first approach; range: 52.6 to 72.9% for the second). Treatment responders experienced less decline in HRQoL from baseline to EOT than non-responders, which was significant for the FACT-G, but not for other scores. CONCLUSION: The majority of patients did not experience decline in HRQoL based on minimal clinically important differences during early cycles of treatment with selinexor and dexamethasone in the STORM trial. An anchor-based approach utilizing patient-level data (ECOG PS score) to define minimal clinically important differences for the FACT-MM gave consistent results with a distribution-based approach. TRIAL REGISTRATION: This trial was registered on ClinicalTrials.gov under the trial-ID NCT02336815 on January 8, 2015.

Carfilzomib or bortezomib in combination with lenalidomide and dexamethasone for patients with newly diagnosed multiple myeloma without intention for immediate autologous stem-cell transplantation (ENDURANCE): a multicentre, open-label, phase 3, randomised, controlled trial.

BACKGROUND: Bortezomib, lenalidomide, and dexamethasone (VRd) is a standard therapy for newly diagnosed multiple myeloma. Carfilzomib, a next-generation proteasome inhibitor, in combination with lenalidomide and dexamethasone (KRd), has shown promising efficacy in phase 2 trials and might improve outcomes compared with VRd. We aimed to assess whether the KRd regimen is superior to the VRd regimen in the treatment of newly diagnosed multiple myeloma in patients who were not being considered for immediate autologous stem-cell transplantation (ASCT). METHODS: In this multicentre, open-label, phase 3, randomised controlled trial (the ENDURANCE trial; E1A11), we recruited patients aged 18 years or older with newly diagnosed multiple myeloma who were ineligible for, or did not intend to have, immediate ASCT. Participants were recruited from 272 community oncology practices or academic medical centres in the USA. Key inclusion criteria were the absence of high-risk multiple myeloma and an Eastern Cooperative Oncology Group performance status of 0-2. Enrolled patients were randomly assigned (1:1) centrally by use of permuted blocks to receive induction therapy with either the VRd regimen or the KRd regimen for 36 weeks. Patients who completed induction therapy were then randomly assigned (1:1) a second time to either indefinite maintenance or 2 years of maintenance with lenalidomide. Randomisation was stratified by intent for ASCT at disease progression for the first randomisation and by the induction therapy received for the second randomisation. Allocation was not masked to investigators or patients. For 12 cycles of 3 weeks, patients in the VRd group received 1·3 mg/m2 of bortezomib subcutaneously or intravenously on days 1, 4, 8, and 11 of cycles 1-8, and day 1 and day 8 of cycles nine to twelve, 25 mg of oral lenalidomide on days 1-14, and 20 mg of oral dexamethasone on days 1, 2, 4, 5, 8, 9, 11, and 12. For nine cycles of 4 weeks, patients in the KRd group received 36 mg/m2 of intravenous carfilzomib on days 1, 2, 8, 9, 15, and 16, 25 mg of oral lenalidomide on days 1-21, and 40 mg of oral dexamethasone on days 1, 8, 15, and 22. The coprimary endpoints were progression-free survival in the induction phase, and overall survival in the maintenance phase. The primary analysis was done in the intention-to-treat population and safety was assessed in patients who received at least one dose of their assigned treatment. The trial is registered with ClinicalTrials.gov, NCT01863550. Study recruitment is complete, and follow-up of the maintenance phase is ongoing. FINDINGS: Between Dec 6, 2013, and Feb 6, 2019, 1087 patients were enrolled and randomly assigned to either the VRd regimen (n=542) or the KRd regimen (n=545). At a median follow-up of 9 months (IQR 5-23), at a second planned interim analysis, the median progression-free survival was 34·6 months (95% CI 28·8-37·8) in the KRd group and 34·4 months (30·1-not estimable) in the VRd group (hazard ratio [HR] 1·04, 95% CI 0·83-1·31; p=0·74). Median overall survival has not been reached in either group. The most common grade 3-4 treatment-related non-haematological adverse events included fatigue (34 [6%] of 527 patients in the VRd group vs 29 [6%] of 526 in the KRd group), hyperglycaemia (23 [4%] vs 34 [6%]), diarrhoea (23 [5%] vs 16 [3%]), peripheral neuropathy (44 [8%] vs four [<1%]), dyspnoea (nine [2%] vs 38 [7%]), and thromboembolic events (11 [2%] vs 26 [5%]). Treatment-related deaths occurred in two patients (<1%) in the VRd group (one cardiotoxicity and one secondary cancer) and 11 (2%) in the KRd group (four cardiotoxicity, two acute kidney failure, one liver toxicity, two respiratory failure, one thromboembolic event, and one sudden death). INTERPRETATION: The KRd regimen did not improve progression-free survival compared with the VRd regimen in patients with newly diagnosed multiple myeloma, and had more toxicity. The VRd triplet regimen remains the standard of care for induction therapy for patients with standard-risk and intermediate-risk newly diagnosed multiple myeloma, and is a suitable treatment backbone for the development of combinations of four drugs. FUNDING: US National Institutes of Health, National Cancer Institute, and Amgen.

A Phase I Dose-Escalation Study of Clofarabine in Patients with Relapsed or Refractory Low-Grade or Intermediate-Grade B-Cell or T-Cell Lymphoma.

LESSONS LEARNED: Clofarabine can be active in relapsed and refractory lymphoid malignancies on a weekly dosing schedule.Responses were seen in patients with T-cell lymphomas, including cutaneous T-cell lymphoma, but not in patients with aggressive B-cell lymphomas. BACKGROUND: Clofarabine is a second-generation purine nucleoside analog currently approved for the treatment of pediatric relapsed or refractory acute lymphoblastic leukemia. In adults, clofarabine has been investigated in several phase I and II trials as a single agent and in combination for relapsed or refractory acute leukemia. These studies have shown that clofarabine has activity and an acceptable safety profile in patients with hematological malignancies. In this phase I dose escalation trial, clofarabine was evaluated in patients with relapsed or refractory, low-grade or intermediate-grade, B-cell or T-cell lymphoma. METHODS: The starting dose of 10 mg/m2 per week was administered intravenously (IV) for 3 consecutive weeks every 28 days, and doses were escalated in cohorts of three. The study objectives were to determine the maximum tolerated dose (MTD), characterize and quantify the toxicity profile, and determine the overall response rate of clofarabine administered once a week for 3 weeks and repeated every 4 weeks. Eligible patients were over the age of 18, had a histologically confirmed low-grade or intermediate-grade B-cell or T-cell lymphoma, and must have previously been treated with one standard chemotherapy regimen, excluding single-agent rituximab. The primary objectives included in statistical analyses were MTD, toxicity, and overall response rate (ORR). Four patients were enrolled in cohort 1 (clofarabine 10 mg/m2), four in cohort 2 (clofarabine 15 mg/m2), three in cohort 3 (clofarabine 20 mg/m2), two in cohort 4 (clofarabine 30 mg/m2), and one in cohort 5 (clofarabine 40 mg/m2) (Table 2). RESULTS: MTD was not reached in the study. The most common toxicity observed was myelosuppression. A total of four (29%) patients experienced grade 3 leukopenia, with three (21%) patients experiencing grade 4 neutropenia. The myelosuppression was not considered to be a dose-limiting toxicity, as it resolved within 7 days.Fourteen patients were enrolled: 10 patients with T-cell non-Hodgkin lymphoma (NHL) and 4 patients with B-cell NHL (see Table 1). All 14 patients received at least one dose of clofarabine and were evaluable for response. One patient with cutaneous T-cell lymphoma (CTCL) had a partial response; five (36%) had stable disease, and eight patients (57%) had no response. The one patient with a response had stage III erythroderma and was treated in the 10 mg/m2 cohort; a nodal complete response by positron emission tomography scan was observed with a partial response of the skin. CONCLUSION: In this study, weekly administration of clofarabine was demonstrated to be safe and associated with minimal hematologic toxicity at doses ranging from 10-40 mg/m2. In prior studies when dosed daily for 5 consecutive days, the MTD was shown to be 4 mg/m2. Weekly dosing within this dose range did not result in dose modifications, and the MTD was not reached. Clinical efficacy was observed in one patient with CTCL who was treated in the lowest-dose cohort.

Peripheral Blasts in a Patient Receiving Chemotherapy.

An older patient with stage II bladder carcinoma presented with 1 week of fatigue and 2 days of dyspnea on exertion. He was receiving carboplatin/gemcitabine with 6 mg of pegylated G-CSF chemotherapy; his white blood cell count was elevated, hemoglobin low, and ferritin notably increased. What is the diagnosis and what would you do next?

Management of isolated calf vein thrombosis in cancer patients.

The treatment of isolated calf vein thrombosis remains widely debated. This study highlights the characteristics of isolated calf vein thrombosis in cancer patients and compares to isolated calf vein thrombosis in patients without history of cancer. Between July 2013 and April 2014, a retrospective chart review of consecutive patients with isolated calf vein thrombosis was performed recording patient risk factors, ultrasound characteristics of the thrombus, treatment modalities, long-term recurrence of venous-thromboembolism, incidence of bleeding, and mortality. Of 131 patients with isolated calf vein thrombosis, 53 (40.1%) had history of cancer. Isolated calf vein thrombosis occurred at an older age in cancer patients (66.7 vs 58.5 years, p = 0.004). The anatomical characteristics of isolated calf vein thrombosis on ultrasound were comparable in both groups. Isolated calf vein thrombosis in cancer patients was less likely to be treated with anticoagulation (60.4% vs 80.8%, p = 0.018). However, a trend towards higher incidence of bleeding after initiation of anticoagulation for isolated calf vein thrombosis in cancer patients (11.3% vs 6.4%, p = 0.351) was noted. Mortality in cancer patients was higher (37.7% vs 9.00%, p < 0.001) but was unrelated to isolated calf vein thrombosis or its treatment. In conclusion, the risks of bleeding seem to exceed the benefits of anticoagulation in approximately 50% of cancer patients with isolated calf vein thrombosis. The management of isolated calf vein thrombosis does not seem to impact the survival of cancer patients.

Prognostic Understanding, Goals of Care, and Quality of Life in Hospitalized Patients with Leukemia or Multiple Myeloma.

Background: Prior studies reveal a lack of illness understanding and prognostic awareness among patients with hematological malignancies. We evaluated prognostic awareness and illness understanding among patients with acute leukemia and multiple myeloma (MM) and measured patient-hematologist discordance. Methods: We prospectively enrolled patients with acute leukemia and MM at Mount Sinai Hospital or Yale New Haven Hospital between August 2015 and February 2020. Patients were administered a survey assessing prognostic awareness, goals of care (GOC), and quality of life. Hematologists completed a similar survey for each patient. We assessed discordance across the cohort of patients and hematologists using the likelihood-ratio chi-square test and within patient-hematologist pairs using the kappa (κ) statistic. Results: We enrolled 185 patients (137 with leukemia and 48 with MM) and 29 hematologists. Among patients, 137 (74%) self-identified as White, 27 (15%) as Black, and 21 (11%) as Hispanic. Across the entire cohort, patients were significantly more optimistic about treatment goals compared with hematologists (p = 0.027). Within patient-hematologist pairs, hematologists were significantly more optimistic than patients with respect to line of treatment (κ = 0.03). For both leukemia and MM cohorts, patients were significantly more likely to respond "don't know" or deferring to a faith-based response with 88 (64%) and 34 (71%), respectively, compared with only 28 (20%) and 11 (23%) of hematologists, respectively. Conclusions: We observed significant discordance regarding prognosis and GOC among patients with hematological malignancies and their hematologists. These data support future interventions to improve prognostic understanding among this patient population to facilitate informed treatment choices.

Pralatrexate: treatment of T-cell non-Hodgkin's lymphoma.

Pralatrexate is a folate analogue metabolic inhibitor manufactured by Allos Therapeutics, Inc., a wholly-owned subsidiary of Spectrum Pharmaceuticals, Inc. In both preclinical and clinical studies, pralatrexate demonstrated activity in lymphoma. Pralatrexate was US FDA approved for the treatment of relapsed/refractory peripheral T-cell lymphoma in 2009. Approval was based on data from the PROPEL trial that demonstrated an overall response rate of 29% in a heavily pretreated patient population. The dose and schedule of pralatrexate is 30-mg/m(2) weekly for 6 weeks, given in 7-week cycles. Folate and vitamin B12 supplementation are required to minimize toxicity. The most common toxicities are mucositis, thrombocytopenia, nausea and fatigue.

Cost-effectiveness of once-weekly selinexor, bortezomib, and dexamethasone in relapsed or refractory multiple myeloma.

The BOSTON trial showed that use of once-weekly selinexor, bortezomib, and dexamethasone (SVd) prolonged progression-free survival compared to twice-weekly bortezomib and dexamethasone (Vd) in patients with relapsed or refractory (R/R) multiple myeloma (MM). In this study, we constructed a Markov model to assess the cost-effectiveness of SVd versus Vd in R/R MM. We calculated the incremental cost-effectiveness ratio (ICER) of each treatment strategy from a US payer perspective, using a lifetime horizon and a willingness-to-pay threshold of $150,000 per quality-adjusted life-year (QALY). Use of SVd was associated with an incremental cost of $170,002 compared to Vd alone ($1,015,120 vs. $845,118, respectively), an incremental effectiveness of 0.35 QALYs (3.43 vs. 3.08 QALYs, respectively), and an ICER of $487,361/QALY. These data suggest that use of once-weekly SVd for R/R M/M is unlikely to be cost-effective compared to twice-weekly Vd.

Cost-Effectiveness of First-Line Versus Second-Line Use of Daratumumab in Older, Transplant-Ineligible Patients With Multiple Myeloma.

PURPOSE: The MAIA trial found that addition of daratumumab to lenalidomide and dexamethasone (DRd) significantly prolonged progression-free survival in transplant-ineligible patients with newly diagnosed multiple myeloma, compared with lenalidomide and dexamethasone alone (Rd). However, daratumumab is a costly treatment and is administered indefinitely until disease progression. Therefore, it is unclear whether it is cost-effective to use daratumumab in the first-line setting compared with reserving its use until later lines of therapy. METHODS: We created a Markov model to compare healthcare costs and clinical outcomes of transplant-ineligible patients treated with daratumumab in the first-line setting compared with a strategy of reserving daratumumab until the second-line. We estimated transition probabilities from randomized trials using parametric survival modeling. Lifetime direct healthcare costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) were calculated for first-line daratumumab versus second-line daratumumab from a US payer perspective. RESULTS: First-line daratumumab was associated with an improvement of 0.52 QALYs and 0.66 discounted life-years compared with second-line daratumumab. While both treatment strategies were associated with considerable lifetime expenditures ($1,434,937 v $1,112,101 in US dollars), an incremental cost of $322,836 for first-line daratumumab led to an ICER of $618,018 per QALY. The cost of daratumumab would need to be decreased by 67% for first-line daratumumab to be cost-effective at a willingness-to-pay threshold of $150,000 per QALY. CONCLUSION: Using daratumumab in the first-line setting for transplant-ineligible patients may not be cost-effective under current pricing. Delaying daratumumab until subsequent lines of therapy may be a reasonable strategy to limit healthcare costs without significantly compromising clinical outcomes. Mature overall survival data are necessary to more fully evaluate cost-effectiveness in this setting.

Tandem high-dose influenza vaccination is associated with more durable serologic immunity in patients with plasma cell dyscrasias.

Patients with plasma cell dyscrasias (PCDs) experience an increased burden of influenza, and current practice of single-dose annual influenza vaccination yields suboptimal protective immunity in these patients. Strategies to improve immunity to influenza in these patients are clearly needed. We performed a randomized, double-blind, placebo-controlled clinical trial comparing tandem Fluzone High-Dose influenza vaccination with standard-of-care influenza vaccination. Standard-of-care vaccination was single-dose age-based vaccination (standard dose, <65 years; high dose, ≥65 years), and patients in this arm received a saline placebo injection at 30 days. A total of 122 PCD patients were enrolled; 47 received single-dose standard-of-care vaccination, and 75 received 2 doses of Fluzone High-Dose vaccine. Rates of hemagglutinin inhibition (HAI) titer seroprotection against all 3 strains (H1N1, H3N2, and influenza B) were significantly higher for patients after tandem high-dose vaccination vs control (87.3% vs 63.2%; P = .003) and led to higher seroprotection at the end of flu season (60.0% vs 31.6%; P = .04). These data demonstrate that tandem high-dose influenza vaccination separated by 30 days leads to higher serologic HAI titer responses and more durable influenza-specific immunity in PCD patients. Similar vaccine strategies may also be essential to achieve protective immunity against other emerging pathogens such as novel coronavirus in these patients. This trial was registered at www.clinicaltrials.gov as #NCT02566265.

Differential effects of PD-L1 versus PD-1 blockade on myeloid inflammation in human cancer.

BACKGROUNDPD-1 and PD-L1 have been studied interchangeably in the clinic as checkpoints to reinvigorate T cells in diverse tumor types. Data for biologic effects of checkpoint blockade in human premalignancy are limited.METHODSWe analyzed the immunologic effects of PD-L1 blockade in a clinical trial of atezolizumab in patients with asymptomatic multiple myeloma (AMM), a precursor to clinical malignancy. Genomic signatures of PD-L1 blockade in purified monocytes and T cells in vivo were also compared with those following PD-1 blockade in lung cancer patients. Effects of PD-L1 blockade on monocyte-derived DCs were analyzed to better understand its effects on myeloid antigen-presenting cells.RESULTSIn contrast to anti-PD-1 therapy, anti-PD-L1 therapy led to a distinct inflammatory signature in CD14+ monocytes and increase in myeloid-derived cytokines (e.g., IL-18) in vivo. Treatment of AMM patients with atezolizumab led to rapid activation and expansion of circulating myeloid cells, which persisted in the BM. Blockade of PD-L1 on purified monocyte-derived DCs led to rapid inflammasome activation and synergized with CD40L-driven DC maturation, leading to greater antigen-specific T cell expansion.CONCLUSIONThese data show that PD-L1 blockade leads to distinct systemic immunologic effects compared with PD-1 blockade in vivo in humans, particularly manifest as rapid myeloid activation. These findings also suggest an additional role for PD-L1 as a checkpoint for regulating inflammatory phenotype of myeloid cells and antigen presentation in DCs, which may be harnessed to improve PD-L1-based combination therapies.TRIAL REGISTRATIONNCT02784483.FUNDINGThis work is supported, in part, by funds from NIH/NCI (NCI CA197603, CA238471, and CA208328).

Integrated safety profile of selinexor in multiple myeloma: experience from 437 patients enrolled in clinical trials.

Selinexor is an oral, small molecule inhibitor of the nuclear export protein exportin 1 with demonstrated activity in hematologic and solid malignancies. Side effects associated with selinexor include nausea, vomiting, fatigue, diarrhea, decreased appetite, weight loss, thrombocytopenia, neutropenia, and hyponatremia. We reviewed 437 patients with multiple myeloma treated with selinexor and assessed the kinetics of adverse events and impact of supportive care measures. Selinexor reduced both platelets and neutrophils over the first cycle of treatment and reached a nadir between 28 and 42 days. Platelet transfusions and thrombopoietin receptor agonists were effective at treating thrombocytopenia, and granulocyte colony stimulating factors were effective at resolving neutropenia. The onset of gastrointestinal side effects (nausea, vomiting, and diarrhea) was most common during the first 1-2 weeks of treatment. Nausea could be mitigated with 5-HT3 antagonists and either neurokinin 1 receptor antagonists, olanzapine, or cannbainoids. Loperamide and bismuth subsalicylate ameliorated diarrhea. The primary constitutional side effects of fatigue and decreased appetite could be managed with methylphenidate, megestrol, cannabinoids or olanzapine, respectively. Hyponatremia was highly responsive to sodium replacement. Selinexor has well-established adverse effects that mainly occur within the first 8 weeks of treatment, are reversible, and respond to supportive care.

Effect of leucovorin administration on mucositis and skin reactions in patients with peripheral T-cell lymphoma or cutaneous T-cell lymphoma treated with pralatrexate.

Peripheral T-cell lymphoma (PTCL) and cutaneous T-cell lymphoma (CTCL) are rare, heterogeneous non-Hodgkin lymphomas with poor prognoses. Pralatrexate has demonstrated efficacy in T-cell lymphomas; however, mucositis has been reported as the most common dose-modifying adverse event. Leucovorin has been shown to minimize mucositis incidence, without sacrificing pralatrexate efficacy. We retrospectively studied 34 patients (7-PTCL/27-CTCL) treated with pralatrexate alone or pralatrexate and leucovorin. Leucovorin was administered preemptively prior to any mucositis occurrence. Pralatrexate dosing ranged from 10-30 mg/m2 and clinical response or disease stabilization was observed in 85.2%. The incidence of mucositis was reduced in CTCL patients to 17% and was ameliorated in all but one patient with PTCL. There was no change the incidence of skin reactions with the addition of leucovorin. The response rates were similar to those previously reported in CTCL and PTCL. The addition of leucovorin reduced the incidence of mucositis in patients with CTCL and PTCL.

Early alterations in stem-like/resident T cells, innate and myeloid cells in the bone marrow in preneoplastic gammopathy.

Preneoplastic lesions carry many of the antigenic targets found in cancer cells but often exhibit prolonged dormancy. Understanding how the host response to premalignancy is maintained and altered during malignant transformation is needed to prevent cancer. In order to understand the immune microenvironment in precursor monoclonal gammopathy of undetermined significance (MGUS) and myeloma, we analyzed bone marrow immune cells from 12 healthy donors and 26 MGUS/myeloma patients by mass cytometry and concurrently profiled transcriptomes of 42,606 single immune cells from these bone marrows. Compared to age-matched healthy donors, memory T cells from both MGUS and myeloma patients exhibit greater terminal-effector differentiation. However, memory T cells in MGUS show greater enrichment of stem-like TCF1/7hi cells. Clusters of T cells with stem-like and tissue-residence genes were also found to be enriched in MGUS by single-cell transcriptome analysis. Early changes in both NK and myeloid cells were also observed in MGUS. Enrichment of stem-like T cells correlated with a distinct genomic profile of myeloid cells and levels of Dickkopf-1 in bone-marrow plasma. These data describe the landscape of changes in both innate and adaptive immunity in premalignancy and suggest that attrition of the bone-marrow-resident T cell compartment due to loss of stem-like cells may underlie loss of immune surveillance in myeloma.

Antigen-mediated regulation in monoclonal gammopathies and myeloma.

A role for antigen-driven stimulation has been proposed in the pathogenesis of monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) based largely on the binding properties of monoclonal Ig. However, insights into antigen binding to clonal B cell receptors and in vivo responsiveness of the malignant clone to antigen-mediated stimulation are needed to understand the role of antigenic stimulation in tumor growth. Lysolipid-reactive clonal Ig were detected in Gaucher disease (GD) and some sporadic gammopathies. Here, we show that recombinant Ig (rIg) cloned from sort-purified single tumor cells from lipid-reactive sporadic and GD-associated gammopathy specifically bound lysolipids. Liposome sedimentation and binding assays confirmed specific interaction of lipid-reactive monoclonal Ig with lysolipids. The clonal nature of lysolipid-binding Ig was validated by protein sequencing. Gene expression profiling and cytogenetic analyses from 2 patient cohorts showed enrichment of nonhyperdiploid tumors in lipid-reactive patients. In vivo antigen-mediated stimulation led to an increase in clonal Ig and plasma cells (PCs) in GD gammopathy and also reactivated previously suppressed antigenically related nonclonal PCs. These data support a model wherein antigenic stimulation mediates an initial polyclonal phase, followed by evolution of monoclonal tumors enriched in nonhyperdiploid genomes, responsive to underlying antigen. Targeting underlying antigens may therefore prevent clinical MM.

Selective Inhibition of Nuclear Export With Oral Selinexor for Treatment of Relapsed or Refractory Multiple Myeloma.

Purpose Selinexor, a first-in-class, oral, selective exportin 1 (XPO1) inhibitor, induces apoptosis in cancer cells through nuclear retention of tumor suppressor proteins and the glucocorticoid receptor, along with inhibition of translation of oncoprotein mRNAs. We studied selinexor in combination with low-dose dexamethasone in patients with multiple myeloma refractory to the most active available agents. Patients and Methods This phase II trial evaluated selinexor 80 mg and dexamethasone 20 mg, both orally and twice weekly, in patients with myeloma refractory to bortezomib, carfilzomib, lenalidomide, and pomalidomide (quad-refractory disease), with a subset also refractory to an anti-CD38 antibody (penta-refractory disease). The primary end point was overall response rate (ORR). Results Of 79 patients, 48 had quad-refractory and 31 had penta-refractory myeloma. Patients had received a median of seven prior regimens. The ORR was 21% and was similar for patients with quad-refractory (21%) and penta-refractory (20%) disease. Among patients with high-risk cytogenetics, including t(4;14), t(14;16), and del(17p), the ORR was 35% (six of 17 patients). The median duration of response was 5 months, and 65% of responding patients were alive at 12 months. The most common grade ≥ 3 adverse events were thrombocytopenia (59%), anemia (28%), neutropenia (23%), hyponatremia (22%), leukopenia (15%), and fatigue (15%). Dose interruptions for adverse events occurred in 41 patients (52%), dose reductions occurred in 29 patients (37%), and treatment discontinuation occurred in 14 patients (18%). Conclusion The combination of selinexor and dexamethasone has an ORR of 21% in patients with heavily pretreated, refractory myeloma with limited therapeutic options.

Changes in bone marrow innate lymphoid cell subsets in monoclonal gammopathy: target for IMiD therapy.

Altered number, subset composition, and function of bone marrow innate lymphoid cells are early events in monoclonal gammopathies.Pomalidomide therapy leads to reduction in Ikzf1 and Ikzf3 and enhanced human innate lymphoid cell function in vivo.