Elranatamab in relapsed or refractory multiple myeloma: the MagnetisMM-1 phase 1 trial

Multiple myeloma (MM) is a plasma cell malignancy expressing B cell maturation antigen (BCMA). Elranatamab, a bispecific antibody, engages BCMA on MM and CD3 on T cells. The MagnetisMM-1 trial evaluated its safety, pharmacokinetics and efficacy. Primary endpoints, including the incidence of dose-limiting toxicities as well as objective response rate (ORR) and duration of response (DOR), were met. Secondary efficacy endpoints included progression-free survival (PFS) and overall survival (OS). Eighty-eight patients with relapsed or refractory MM received elranatamab monotherapy, and 55 patients received elranatamab at efficacious doses. Patients had received a median of five prior regimens; 90.9% were triple-class refractory, 29.1% had high cytogenetic risk and 23.6% received prior BCMA-directed therapy. No dose-limiting toxicities were observed during dose escalation. Adverse events included cytopenias and cytokine release syndrome. Exposure was dose proportional. With a median follow-up of 12.0 months, the ORR was 63.6% and 38.2% of patients achieving complete response or better. For responders, the median DOR was 17.1 months. All 13 patients evaluable for minimal residual disease achieved negativity. Even after prior BCMA-directed therapy, 53.8% achieved response. For all 55 patients, median PFS was 11.8 months, and median OS was 21.2 months. Elranatamab achieved durable responses, manageable safety and promising survival for patients with MM. ClinicalTrials.gov Identifier: NCT03269136 .

Elranatamab in relapsed or refractory multiple myeloma: phase 2 MagnetisMM-3 trial results

Elranatamab is a humanized B-cell maturation antigen (BCMA)-CD3 bispecific antibody. In the ongoing phase 2 MagnetisMM-3 trial, patients with relapsed or refractory multiple myeloma received subcutaneous elranatamab once weekly after two step-up priming doses. After six cycles, persistent responders switched to biweekly dosing. Results from cohort A, which enrolled patients without prior BCMA-directed therapy (n = 123) are reported. The primary endpoint of confirmed objective response rate (ORR) by blinded independent central review was met with an ORR of 61.0% (75/123); 35.0% ≥complete response. Fifty responders switched to biweekly dosing, and 40 (80.0%) improved or maintained their response for ≥6 months. With a median follow-up of 14.7 months, median duration of response, progression-free survival and overall survival (secondary endpoints) have not been reached. Fifteen-month rates were 71.5%, 50.9% and 56.7%, respectively. Common adverse events (any grade; grade 3-4) included infections (69.9%, 39.8%), cytokine release syndrome (57.7%, 0%), anemia (48.8%, 37.4%), and neutropenia (48.8%, 48.8%). With biweekly dosing, grade 3-4 adverse events decreased from 58.6% to 46.6%. Elranatamab induced deep and durable responses with a manageable safety profile. Switching to biweekly dosing may improve long-term safety without compromising efficacy. ClinicalTrials.gov identifier: NCT04649359 .

CORP: Sources and degrees of variability in whole animal intermittent hypoxia experiments

Chamber exposures are commonly used to evaluate the physiological and pathophysiological consequences of intermittent hypoxia in animal models. Researchers in this field use both commercial and custom-built chambers in their experiments. The purpose of this Cores of Reproducibility in Physiology paper is to demonstrate potential sources of variability in these systems that researchers should consider. Evaluating the relationship between arterial oxygen saturation and inspired oxygen concentration, we found that there are important sex-dependent differences in the commonly used C57BL6/J mouse model. The time delay of the oxygen sensor that provides feedback to the system during the ramp-down and ramp-up phases was different, limiting the number of cycles per hour that can be conducted and the overall stability of the oxygen concentration. The time to reach the hypoxic and normoxic hold stages, and the overall oxygen concentration, were impacted by the cycle number. These variables were further impacted by whether there are animals present in the chamber, highlighting the importance of verifying the cycling frequency with animals in the chamber. At ≤14 cycles/h, instability in the chamber oxygen concentration did not impact arterial oxygen saturation but may be important at higher cycle numbers. Taken together, these data demonstrate the important sources of variability that justify reporting and verifying the target oxygen concentration, cycling frequency, and arterial oxygen concentration, particularly when comparing different animal models and chamber configurations.NEW & NOTEWORTHY Intermittent hypoxia exposures are commonly used in physiology and many investigators use chamber systems to perform these studies. Because of the variety of chamber systems and protocols used, it is important to understand the sources of variability in intermittent hypoxia experiments that can impact reproducibility. We demonstrate sources of variability that come from the animal model, the intermittent hypoxia protocol, and the chamber system that can impact reproducibility.

Sex differences in cardiovascular disease and dysregulation in Down syndrome

This meta-analysis, which consisted of a scoping review and retrospective medical record review, is focused on potential sex differences in cardiovascular diseases in patients with Down syndrome. We limited our review to peer-reviewed, primary articles in the English language, in the PubMed and Web of Science databases from 1965 to 2021. Guidelines for scoping reviews were followed throughout the process. Four categorical domains were identified and searched using additional keywords: 1) congenital heart disease, 2) baseline physiology and risk factors, 3) heart disease and hypertension, and 4) stroke and cerebrovascular disease. Articles were included if they reported male and female distinct data, participants with Down syndrome, and one of our keywords. The retrospective medical record review was completed using 75 participating health care organizations to identify the incidence of congenital and cardiovascular diseases and to quantify cardiovascular risk factors in male and female patients. Female patients with Down syndrome are at higher risk of hypertension, ischemic heart disease, and cerebrovascular disease. The risk of congenital heart disease is higher in males with Down syndrome at all ages included in our analyses. Some of the male-to-female sex differences in cardiovascular disease risk in the general patient population are not present, or reversed in the Down syndrome population. This information should be considered for future investigations and ongoing patient care.NEW & NOTEWORTHY In patients with Down syndrome (DS), CHD is the leading cause of death <20 yr old and cardiovascular disease is a leading cause of death in individuals >20 yr old. Men with DS live longer than women. It is unknown if sex differences are present in cardiovascular disease and dysregulation in DS across the lifespan. We observed higher risk of hypertension, ischemic heart disease, and cerebrovascular disease in females and a higher risk of CHD in males with DS.

Acute myeloid leukemia resistant to venetoclax-based therapy: What does the future hold?

Venetoclax is a highly selective B-cell lymphoma-2 (BCL-2) inhibitor, which, combined with a DNA hypomethylating agent or low dose cytarabine, results in high rates of initial responses in patients with acute myeloid leukemia (AML). However, the disease relapses in most patients. Mechanisms of resistance to venetoclax-based therapy include TP53 gene mutations or inactivation of p53 protein, activating kinase mutations such as FLT3 and RAS, and upregulation of other BCL-2 family apoptotic proteins. Current clinical trials are exploring strategies such as doublet or triplet regimens incorporating a p53 activator, an anti-CD47 antibody, or other novel agents that target genes and proteins responsible for resistance to venetoclax. Further studies should focus on identifying predictive biomarkers of response to venetoclax-based therapy and incorporating immunotherapeutic approaches such as checkpoint inhibitors, bispecific antibodies, antibody-drug conjugates, and CAR T-cell therapy to improve outcomes for patients with AML.

Acute myeloid leukemia resistant to venetoclax-based therapy: What does the future hold?

Venetoclax is a highly selective B-cell lymphoma-2 (BCL-2) inhibitor, which, combined with a DNA hypomethylating agent or low dose cytarabine, results in high rates of initial responses in patients with acute myeloid leukemia (AML). However, the disease relapses in most patients. Mechanisms of resistance to venetoclax-based therapy include TP53 gene mutations or inactivation of p53 protein, activating kinase mutations such as FLT3 and RAS, and upregulation of other BCL-2 family apoptotic proteins. Current clinical trials are exploring strategies such as doublet or triplet regimens incorporating a p53 activator, an anti-CD47 antibody, or other novel agents that target genes and proteins responsible for resistance to venetoclax. Further studies should focus on identifying predictive biomarkers of response to venetoclax-based therapy and incorporating immunotherapeutic approaches such as checkpoint inhibitors, bispecific antibodies, antibody-drug conjugates, and CAR T-cell therapy to improve outcomes for patients with AML.

Initial safety results for MagnetisMM-3: A phase 2 trial of elranatamab, a B-cell maturation antigen (BCMA)-CD3 bispecific antibody, in patients (pts) with relapsed/refractory (R/R) multiple myeloma (MM)

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Background: Elranatamab (PF-06863135) is a humanized bispecific antibody that targets both BCMA-expressing MM cells and CD3-expressing T cells. MagnetisMM-3 (NCT04649359) is an open-label, multicenter, non-randomized, phase 2 study to evaluate the safety and efficacy of elranatamab monotherapy in pts with R/R MM. Initial safety results are presented. Methods: MagnetisMM-3 enrolled pts who are refractory to at least 1 proteasome inhibitor, 1 immunomodulatory drug, and 1 anti-CD38 antibody. Pts were assigned to 1 of 2 independent, parallel cohorts: those naïve to BCMA-directed therapies (Cohort A) and those with previous exposure to BCMA-directed antibody-drug conjugates or CAR-T cells (Cohort B). Pts received subcutaneous elranatamab 76 mg QW on a 28-d cycle with a 2-step-up priming dose regimen administered during the first week. Dose modifications were permitted for toxicity. Treatment-emergent adverse events (TEAEs) were graded by CTCAE (v5.0), and cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) by ASTCT criteria. Results: As of the data cutoff on Dec 31, 2021, 60 pts in Cohort A had received ≥1 dose of elranatamab; the last pt’s first dose was ̃2 months prior to the cutoff. Median age was 69.0 y (range, 44−89), 48.3% were male, 63.3% were white, 18.3% were Asian and 11.7% were Black/African American. At baseline, 60.0% of pts had an ECOG performance status 1−2 and pts had received a median of 5 (range, 2−12) prior therapies. Median duration of elranatamab treatment was 9.57 wks (range, 0.1−46.1); median relative dose intensity was 87.4% (range, 23.1−101.4). TEAEs were reported in 100% (Grade [G] 3/4, 75.0%) of pts. Most common (≥30%) hematologic TEAEs were neutropenia (36.7% [G3/4, 35.0%]), anemia (36.7% [G3/4, 30.0%]) and thrombocytopenia (30.0% [G3/4, 21.7%]). Among pts who received the 2-step-up priming regimen (n = 56), CRS and ICANS, respectively, were reported in 58.9% (G3/4, 0%) and 3.6% (G3/4: 0%); of those pts, 57.6% (n = 19/33) and 100% (n = 2/2) received tocilizumab and/or steroids. Most common (≥30%) non-hematologic TEAE, other than CRS/ICANS, was fatigue (31.7% [G3/4, 3.3%]). Infections were reported in 46.7% (G3/4: 18.3%) of pts; most frequently reported were upper respiratory tract infections (11.7% [G3/4: 0%]). Discontinuations due to adverse events were reported in 5.0% of pts. No pts permanently discontinued treatment due to CRS or ICANS. There were 10 deaths; causes were MM progression (n = 8), septic shock (n = 1) and unknown (n = 1). Data will be updated at the time of presentation to include ̃90 pts. Conclusions: Preliminary results of MagnetisMM-3 in pts with R/R MM and no prior BCMA-targeted treatment suggest that 76 mg QW elranatamab with a 2-step-up priming regimen is well tolerated, with no G ≥3 CRS or ICANS observed. Clinical trial information: NCT04649359.

Elranatamab, a BCMA-targeted T-cell redirecting immunotherapy, for patients with relapsed or refractory multiple myeloma: Updated results from MagnetisMM-1

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Background: Elranatamab (PF-06863135) is a bispecific molecule that activates and redirects the T-cell mediated immune response against multiple myeloma (MM), a plasma cell dyscrasia characterized by expression of B-cell maturation antigen (BCMA). MagnetisMM-1 (NCT03269136), the ongoing Phase 1 first-in-human study for elranatamab, was designed to characterize safety, pharmacokinetics (PK), pharmacodynamics, and efficacy for patients (pts) with relapsed or refractory MM. Methods: Elranatamab was given subcutaneously (SC) at doses from 80 to 1000µg/kg either weekly or every 2 weeks (Q2W). Treatment-emergent adverse events (TEAEs) were graded by Common Terminology Criteria for Adverse Events (v4.03) and cytokine release syndrome (CRS) by American Society for Transplantation and Cellular Therapy criteria. PK, cytokine and soluble BCMA profiling, and lymphocyte subset analyses were performed. Response was assessed by International Myeloma Working Group (IMWG) criteria. Minimal residual disease (MRD) was assessed by next generation sequencing at a sensitivity of 1×10-5 in accordance with IMWG criteria. Results: A total of 55 pts received single-agent elranatamab SC at a dose ≥215μg/kg as of 1-Nov-2021. Median age was 64 (range 42-80) years, and 27% of pts were Black/African American or Asian. Median number of prior regimens was 6 (range 2-15), 91% were triple-class refractory, 56% had prior stem cell transplantation, 27% had high cytogenetic risk, and 22% received prior BCMA-targeted therapy. The most common TEAEs regardless of causality included CRS, neutropenia, anemia, injection site reaction, and lymphopenia. With pre-medication and a single priming dose (600µg/kg or 44mg), the overall incidence of CRS at the recommended dose (1000µg/kg or 76mg) was 67% and limited to Grade 1 (33%) or Grade 2 (33%), with no events Grade 3 or higher. Exposure was dose dependent and Q2W dosing achieved exposure associated with anti-myeloma efficacy. Cytokine increases occurred with the first dose and were reduced by pre-medication. Soluble BCMA decreased with disease response, elranatamab therapy was associated with increased peripheral T cell proliferation, and median time to response was 36 days (range 7-73). With a median follow-up of 8.1 months (range 0.3-21) and including only IMWG confirmed responses, 31% of pts achieved complete response or better and the overall response rate was 64% (95% CI 50-75%). For responders (n = 35), median duration of response was not yet reached, but the probability of being event-free at 6 months was 91% (95% CI 73-97%). Single-agent elranatamab induces durable clinical and molecular responses, and updated data including MRD assessment will be presented. Conclusions: Elranatamab shows a manageable safety profile and achieves durable clinical and molecular responses for pts with relapsed or refractory MM. Clinical trial information: NCT03269136.

Wearable Monitors Facilitate Exercise in Adult and Pediatric Stem Cell Transplant

Hematopoietic stem cell transplant (HSCT) is a potentially curative treatment for hematopoietic malignancies, complicated by decreased performance status and quality of life. Exercise therapy improves outcomes in HSCT, but several barriers have prevented exercise from becoming routine clinical practice. Based on existing data that wearable technologies facilitate exercise participation in other sedentary and chronic illness populations, we propose the novel hypothesis that wearable technologies are a valuable tool in transcending barriers and developing exercise therapy programs for HSCT patients.

Efficacy and safety of elranatamab (PF-06863135), a B-cell maturation antigen (BCMA)-CD3 bispecific antibody, in patients with relapsed or refractory multiple myeloma (MM)

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Background: Elranatamab (PF-06863135) is a humanized bispecific monoclonal antibody (IgG2a) that targets BCMA, a member of the tumor necrosis factor receptor superfamily expressed in MM, and CD3 on T cells. We reported results for intravenous (IV) dosing (Raje et al. Blood. 2019;134(S1):1869) and now update for subcutaneous (SC) dosing from the ongoing Phase 1 study (MagnetisMM-1). Methods: Patients (pts) received elranatamab at 80, 130, 215, 360, 600, and 1000μg/kg SC weekly. A modified toxicity probability interval method was used for escalation, with monitoring for dose-limiting toxicity (DLT) to end of the first cycle. Treatment-emergent adverse events (TEAEs) were graded by Common Terminology Criteria for Adverse Events (v4.03), and cytokine release syndrome (CRS) by American Society for Transplantation and Cellular Therapy criteria (Lee et al. Biol Blood Marrow Transplant. 2019;25:625). Response was assessed by International Myeloma Working Group criteria. Pharmacokinetics, cytokine profiling, and T cell immunophenotyping were performed. Results: 30 pts had received elranatamab as of 4-Aug-2020 at 80 (n = 6), 130 (n = 4), 215 (n = 4), 360 (n = 4), 600 (n = 6), or 1000 (n = 6) μg/kg SC weekly. Pts had a median of 8 prior treatments; 87% had triple refractory disease, 97% had prior anti-CD38 therapy, and 23% had prior BCMA-directed antibody drug conjugate or chimeric antigen receptor T cell therapy. The most common all causality TEAEs included lymphopenia (n = 24, 80%; 20% G3, 60% G4), CRS (n = 22, 73%; none > G2), anemia (n = 17, 57%; 43% G3, 3% G4), injection site reaction (n = 16, 53%; none > G2), thrombocytopenia (n = 16, 53%; 23% G3, 17% G4), and neutropenia (n = 12, 40%; 17% G3, 17% G4). Both CRS and immune effector cell-associated neurotoxicity syndrome (n = 6, 20%) were limited to ≤G2 with median durations of 2 and 1.5 days, respectively. No DLT was observed. Exposure increased with dose, and Tmax ranged from 3–7 days. Cytokine increases occurred with the first dose, and increased T-cell proliferation was observed in peripheral blood. The overall response rate (ORR) for doses ≥215μg/kg was 75% (n = 15/20) including partial response (PR; n = 6), very good PR (VGPR; n = 3), complete response (CR; n = 1), and stringent CR (sCR; n = 5). Median time to response was 22 days, and 3 of 4 pts (75%) with prior BCMA-directed therapy achieved response (VGPR, n = 2 and sCR, n = 1). Updated data, including duration of response, will be presented. Conclusions: Elranatamab demonstrated a manageable safety profile, and SC doses ≥215μg/kg achieved ORR of 75% with CR/sCR rate of 30%. These results demonstrate the safety and efficacy of SC elranatamab in this relapsed/refractory population and support ongoing development of elranatamab for pts with MM, both as monotherapy and in combination with standard or novel therapies. Clinical trial information: NCT03269136.

Case Studies in Physiology: Untangling the cause of hypoxemia in a patient with obesity with acute leukemia

Diagnosing the cause of hypoxemia and dyspnea can be complicated in complex patients with multiple comorbidities. This "Case Study in Physiology" describes an man with obesity admitted to the hospital for relapse of acute lymphoblastic leukemia, who experienced progressive hypoxemia, shortness of breath, and dyspnea on exertion during his hospitalization. After initial empirical treatment with diuresis and antibiotics failed to improve his symptoms and because an arterial blood gas measurement was not readily available, we applied a novel, recently described physiological method to estimate the arterial partial pressure of oxygen from the peripheral saturation measurement and calculate the alveolar-arterial oxygen difference to discern the source of his hypoxemia and dyspnea. Using basic physiological principles, we describe how hypoventilation, anemia, and the use of a β blocker and furosemide, collaborated to create a "perfect storm" in this patient that impaired oxygen delivery and limited utilization. This case illustrates the application of innovative physiology methodology in medicine and provides a strong rationale for continuing to integrate physiology education in medical education.NEW & NOTEWORTHY Discerning the cause of dyspnea and hypoxemia in complex patients can be difficult. We describe the "real world" application of an innovative methodology to untangle the underlying physiology in a patient with multiple comorbidities. This case further demonstrates the importance of applying physiology to interrogate the underlying cause of a patient's symptoms when treatment based on probability fails.

Computational Model of Progression to Multiple Myeloma Identifies Optimum Screening Strategies

Purpose

Recent advances have uncovered therapeutic interventions that might reduce the risk of progression of premalignant diagnoses, such as monoclonal gammopathy of undetermined significance (MGUS) to multiple myeloma (MM). It remains unclear how to best screen populations at risk and how to evaluate the ability of these interventions to reduce disease prevalence and mortality at the population level. To address these questions, we developed a computational modeling framework.

Materials and Methods

We used individual-based computational modeling of MGUS incidence and progression across a population of diverse individuals to determine best screening strategies in terms of screening start, intervals, and risk-group specificity. Inputs were life tables, MGUS incidence, and baseline MM survival. We measured MM-specific mortality and MM prevalence after MGUS detection from simulations and mathematic modeling predictions.

Results

Our framework is applicable to a wide spectrum of screening and intervention scenarios, including variation of the baseline MGUS to MM progression rate and evolving MGUS, in which progression increases over time. Given the currently available point estimate of progression risk reduction to 61% risk, starting screening at age 55 years and performing follow-up screening every 6 years reduced total MM prevalence by 19%. The same reduction could be achieved with starting screening at age 65 years and performing follow-up screening every 2 years. A 40% progression risk reduction per patient with MGUS per year would reduce MM-specific mortality by 40%. Specifically, screening onset age and screening frequency can change disease prevalence, and progression risk reduction changes both prevalence and disease-specific mortality. Screening would generally be favorable in high-risk individuals.

Conclusion

Screening efforts should focus on specifically identified groups with high lifetime risk of MGUS, for which screening benefits can be significant. Screening low-risk individuals with MGUS would require improved preventions.

The snoRNA target of t(4;14) in multiple myeloma regulates ribosome biogenesis

The orphan small nucleolar RNA (snoRNA) ACA11 is overexpressed as a result of the t(4;14) chromosomal translocation in multiple myeloma (MM), increases reactive oxygen species, and drives cell proliferation. Like other snoRNAs, ACA11 is predominantly localized to a sub-nuclear organelle, the nucleolus. We hypothesized that increased ACA11 expression would increase ribosome biogenesis and protein synthesis. We found that ACA11 overexpression in MM cells increased nucleolar area and number as well as silver-binding nucleolar organizing regions (AgNORs). Supporting these data, samples from t(4;14)-positive patients had higher AgNORs scores than t(4;14)-negative samples. ACA11 also upregulated ribosome production, pre-47S rRNA synthesis, and protein synthesis in a ROS-dependent manner. Lastly, ACA11 overexpression enhanced the response to proteasome inhibitor in MM cells, while no effect was found in response to high doses of melphalan. Together, these data demonstrate that ACA11 stimulates ribosome biogenesis and influences responses to chemotherapy. ACA11 may be a useful target to individualize the treatment for t(4;14)-positive myeloma patients.

Chronic intermittent hypoxia enhances disease progression in myeloma-resistant mice

Obesity is the only known modifiable risk factor for multiple myeloma (MM), an incurable cancer of bone marrow plasma cells. The mechanism linking the two is unknown. Obesity is associated with an increased risk of sleep apnea, which results in chronic intermittent hypoxia (CIH), and drives solid tumor aggressiveness. Given the link between CIH and solid tumor progression, we tested the hypothesis that CIH drives the proliferation of MM cells in culture and their engraftment and progression in vivo. Malignant mouse 5TGM1 cells were cultured in CIH, static hypoxia, or normoxia as a control in custom, gas-permeable plates. Typically MM-resistant C57BL/6J mice were exposed to 10 h/day CIH (AHI = 12/h), static hypoxia, or normoxia for 7 days, followed by injection with 5TGM1 cells and an additional 28 days of exposure. CIH and static hypoxia slowed the growth of 5TGM1 cells in culture. CIH-exposed mice developed significantly more MM than controls (67 vs. 12%, P = 0.005), evidenced by hindlimb paralysis, gammopathy, bone lesions, and bone tumor formation. Static hypoxia was not a significant driver of MM progression and did not reduce survival (P = 0.117). Interestingly, 5TGM1 cells preferentially engrafted in the bone marrow and promoted terminal disease in CIH mice, despite a lower tumor burden, compared with the positive controls. These first experiments in the context of hematological cancer demonstrate that CIH promotes MM through mechanisms distinct from solid tumors and that sleep apnea may be a targetable risk factor in patients with or at risk for blood cancer.

Elevated IgM and abnormal free light chain ratio are increased in relatives from high-risk chronic lymphocytic leukemia pedigrees

Abnormal serum immunoglobulin (Ig) free light chains (FLC) are established biomarkers of early disease in multiple B-cell lymphoid malignancies, including chronic lymphocytic leukemia (CLL). Heavy chains have also been shown to be biomarkers in plasma cell disorders. An unanswered question is whether these Ig biomarkers are heritable, i.e., influenced by germline factors. CLL is heritable but highly heterogeneous. Heritable biomarkers could elucidate steps of disease pathogenesis that are affected by germline factors, and may help partition heterogeneity and identify genetic pleiotropies across malignancies. Relatives in CLL pedigrees present an opportunity to identify heritable biomarkers. We compared FLCs and heavy chains between relatives in 23 high-risk CLL pedigrees and population controls. Elevated IgM (eIgM) and abnormal FLC (aFLC) ratio was significantly increased in relatives, suggesting that these Ig biomarkers are heritable and could offer risk stratification in pedigree relatives. Within high-risk CLL pedigrees, B-cell lymphoid malignancies were five times more prevalent in close relatives of individuals with eIgM, prostate cancer was three times more prevalent in relatives of individuals with aFLC, and monoclonal B-cell lymphocytosis increased surrounding individuals with normal Ig levels. These different clustering patterns suggest Ig biomarkers have the potential to partition genetic heterogeneity in CLL and provide insight into distinct heritable pleiotropies associated with CLL.

Prevention Is the Best Treatment: The Case for Understanding the Transition from Monoclonal Gammopathy of Undetermined Significance to Myeloma

Multiple myeloma is an invariably fatal cancer of plasma cells. Despite tremendous advances in treatment, this malignancy remains incurable in most individuals. We postulate that strategies aimed at prevention have the potential to be more effective in preventing myeloma-related death than additional pharmaceutical strategies aimed at treating advanced disease. Here, we present a rationale for the development of prevention therapy and highlight potential target areas of study.

A multiple myeloma-specific capture sequencing platform discovers novel translocations and frequent, risk-associated point mutations in IGLL5

Multiple myeloma (MM) is a disease of copy number variants (CNVs), chromosomal translocations, and single-nucleotide variants (SNVs). To enable integrative studies across these diverse mutation types, we developed a capture-based sequencing platform to detect their occurrence in 465 genes altered in MM and used it to sequence 95 primary tumor-normal pairs to a mean depth of 104×. We detected cases of hyperdiploidy (23%), deletions of 1p (8%), 6q (21%), 8p (17%), 14q (16%), 16q (22%), and 17p (4%), and amplification of 1q (19%). We also detected IGH and MYC translocations near expected frequencies and non-silent SNVs in NRAS (24%), KRAS (21%), FAM46C (17%), TP53 (9%), DIS3 (9%), and BRAF (3%). We discovered frequent mutations in IGLL5 (18%) that were mutually exclusive of RAS mutations and associated with increased risk of disease progression (p = 0.03), suggesting that IGLL5 may be a stratifying biomarker. We identified novel IGLL5/IGH translocations in two samples. We subjected 15 of the pairs to ultra-deep sequencing (1259×) and found that although depth correlated with number of mutations detected (p = 0.001), depth past ~300× added little. The platform provides cost-effective genomic analysis for research and may be useful in individualizing treatment decisions in clinical settings.

A Meta-analysis of Multiple Myeloma Risk Regions in African and European Ancestry Populations Identifies Putatively Functional Loci

BACKGROUND

Genome-wide association studies (GWAS) in European populations have identified genetic risk variants associated with multiple myeloma.

METHODS

We performed association testing of common variation in eight regions in 1,318 patients with multiple myeloma and 1,480 controls of European ancestry and 1,305 patients with multiple myeloma and 7,078 controls of African ancestry and conducted a meta-analysis to localize the signals, with epigenetic annotation used to predict functionality.

RESULTS

We found that variants in 7p15.3, 17p11.2, 22q13.1 were statistically significantly (P < 0.05) associated with multiple myeloma risk in persons of African ancestry and persons of European ancestry, and the variant in 3p22.1 was associated in European ancestry only. In a combined African ancestry-European ancestry meta-analysis, variation in five regions (2p23.3, 3p22.1, 7p15.3, 17p11.2, 22q13.1) was statistically significantly associated with multiple myeloma risk. In 3p22.1, the correlated variants clustered within the gene body of ULK4 Correlated variants in 7p15.3 clustered around an enhancer at the 3' end of the CDCA7L transcription termination site. A missense variant at 17p11.2 (rs34562254, Pro251Leu, OR, 1.32; P = 2.93 × 10-7) in TNFRSF13B encodes a lymphocyte-specific protein in the TNF receptor family that interacts with the NF-κB pathway. SNPs correlated with the index signal in 22q13.1 cluster around the promoter and enhancer regions of CBX7 CONCLUSIONS: We found that reported multiple myeloma susceptibility regions contain risk variants important across populations, supporting the use of multiple racial/ethnic groups with different underlying genetic architecture to enhance the localization and identification of putatively functional alleles.

IMPACT

A subset of reported risk loci for multiple myeloma has consistent effects across populations and is likely to be functional. Cancer Epidemiol Biomarkers Prev; 25(12); 1609-18. ©2016 AACR.

TP53 and Decitabine in Acute Myeloid Leukemia and Myelodysplastic Syndromes

BACKGROUND

The molecular determinants of clinical responses to decitabine therapy in patients with acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS) are unclear.

METHODS

We enrolled 84 adult patients with AML or MDS in a single-institution trial of decitabine to identify somatic mutations and their relationships to clinical responses. Decitabine was administered at a dose of 20 mg per square meter of body-surface area per day for 10 consecutive days in monthly cycles. We performed enhanced exome or gene-panel sequencing in 67 of these patients and serial sequencing at multiple time points to evaluate patterns of mutation clearance in 54 patients. An extension cohort included 32 additional patients who received decitabine in different protocols.

RESULTS

Of the 116 patients, 53 (46%) had bone marrow blast clearance (<5% blasts). Response rates were higher among patients with an unfavorable-risk cytogenetic profile than among patients with an intermediate-risk or favorable-risk cytogenetic profile (29 of 43 patients [67%] vs. 24 of 71 patients [34%], P<0.001) and among patients with TP53 mutations than among patients with wild-type TP53 (21 of 21 [100%] vs. 32 of 78 [41%], P<0.001). Previous studies have consistently shown that patients with an unfavorable-risk cytogenetic profile and TP53 mutations who receive conventional chemotherapy have poor outcomes. However, in this study of 10-day courses of decitabine, neither of these risk factors was associated with a lower rate of overall survival than the rate of survival among study patients with intermediate-risk cytogenetic profiles.

CONCLUSIONS

Patients with AML and MDS who had cytogenetic abnormalities associated with unfavorable risk, TP53 mutations, or both had favorable clinical responses and robust (but incomplete) mutation clearance after receiving serial 10-day courses of decitabine. Although these responses were not durable, they resulted in rates of overall survival that were similar to those among patients with AML who had an intermediate-risk cytogenetic profile and who also received serial 10-day courses of decitabine. (Funded by the National Cancer Institute and others; ClinicalTrials.gov number, NCT01687400 .).