Multiple myeloma is an incurable malignancy of plasma cells, and its pathogenesis is poorly understood. Here we report the massively parallel sequencing of 38 tumor genomes and their comparison to matched normal DNAs. Several new and unexpected oncogenic mechanisms were suggested by the pattern of somatic mutation across the dataset. These include the mutation of genes involved in protein translation (seen in nearly half of the patients), genes involved in histone methylation, and genes involved in blood coagulation. In addition, a broader than anticipated role of NF-κB signaling was suggested by mutations in 11 members of the NF-κB pathway. Of potential immediate clinical relevance, activating mutations of the kinase BRAF were observed in 4% of patients, suggesting the evaluation of BRAF inhibitors in multiple myeloma clinical trials. These results indicate that cancer genome sequencing of large collections of samples will yield new insights into cancer not anticipated by existing knowledge.
SUMMARY
We performed massively parallel sequencing of paired tumor/normal samples from 203 multiple myeloma (MM) patients and identified significantly mutated genes and copy number alterations, and discovered putative tumor suppressor genes by determining homozygous deletions and loss-of-heterozygosity. We observed frequent mutations in KRAS (particularly in previously treated patients), NRAS, BRAF, FAM46C, TP53 and DIS3 (particularly in non-hyperdiploid MM). Mutations were often present in subclonal populations, and multiple mutations within the same pathway (e.g. KRAS, NRAS and BRAF) were observed in the same patient. In vitro modeling predicts only partial treatment efficacy of targeting subclonal mutations, and even growth promotion of non-mutated subclones in some cases. These results emphasize the importance of heterogeneity analysis for treatment decisions.
The occurrence of hepatic veno-occlusive disease (VOD) has been reported in up to 60% of patients following stem cell transplantation (SCT), with incidence varying widely between studies depending on the type of transplant, conditioning regimen, and criteria used to make the diagnosis. Severe VOD is characterized by high mortality and progression to multiorgan failure (MOF); however, there is no consensus on how to evaluate severity. This review and analysis of published reports attempts to clarify these issues by calculating the overall mean incidence of VOD and mortality from severe VOD, examining the effect of changes in SCT practice on the incidence of VOD over time, and discussing the methods used to evaluate severity. Across 135 studies performed between 1979 and October 2007, the overall mean incidence of VOD was 13.7% (95% confidence interval [CI] = 13.3%–14.1%). The mean incidence of VOD was significantly lower between 1979–1994 than between 1994–2007 (11.5% [95% CI, 10.9%–12.1%] vs 14.6% [95% CI, 14.0%–15.2%]; P < .05). The mortality rate from severe VOD was 84.3% (95% CI, 79.6%–88.9%); most of these patients had MOF, which also was the most frequent cause of death. Thus, VOD is less common than early reports suggested, but the current incidence appears to be relatively stable despite recent advances in SCT, including the advent of reduced-intensity conditioning. The evolution of MOF in the setting of VOD after SCT can be considered a reliable indication of severity and a predictor of poor outcome.
These results confirm the activity of bortezomib in relapsed or refractory MCL, with predictable and manageable toxicities. Bortezomib provides significant clinical activity in terms of durable and complete responses, and may therefore represent a new treatment option for this population with usually very poor outcome. Studies of bortezomib-based combinations in MCL are ongoing.
AIDS patients undergoing autologous transplantation for lymphoma were treated with gene-modified peripheral blood derived (CD34+) hematopoietic progenitor cells (HPC) expressing 3 RNA-based anti-HIV moieties (Tat/Rev shRNA, TAR decoy and CCR5 ribozyme). In vitro analysis of gene-modified HPC showed no differences in the hematopoietic potential compared with non-transduced cells. In vitro estimates of gene marking were as high as 22% but declined to ~1% over 4 weeks of culture. Ethical study design required that patients were transplanted with both gene modified and unmanipulated hematopoietic progenitor cell apheresis products (HPC-A). All 4 infused patients engrafted (ANC>500) by day 11 post-infusion and showed no unexpected infusion related toxicities. Persistent vector marking in multiple cell lineages has been observed at low levels for up to 24 months as has expression of siRNA and ribozyme. This is the first demonstration of siRNA expression in human blood cells following transplantation of autologous gene-modified CD34+ HPC. These results support the development of an RNA-based cell therapy platform for HIV.
Summary
Stem cell gene therapy for HIV results in sustained RNA expression in the blood of patients for up to 2 years following transplant.
• No new safety signals were observed with daratumumab plus pomalidomide and dexamethasone, except for increased neutropenia.• Daratumumab plus pomalidomide and dexamethasone induced rapid, deep, and durable responses in heavily treated patients with multiple myeloma.Daratumumab plus pomalidomide and dexamethasone (pom-dex) was evaluated in patients with relapsed/refractory multiple myeloma with ‡2 prior lines of therapy who were refractory to their last treatment. Patients received daratumumab 16 mg/kg at the recommended dosing schedule, pomalidomide 4 mg daily for 21 days of each 28-day cycle, and dexamethasone 40 mg weekly. Safety was the primary end point. Overall response rate (ORR) and minimal residual disease (MRD) by next-generation sequencing were secondary end points. Patients (N 5 103) received a median (range) of 4 (1-13) prior therapies; 76% received ‡3 prior therapies. The safety profile of daratumumab plus pomdex was similar to that of pom-dex alone, with the exception of daratumumab-specific infusion-related reactions (50%) and a higher incidence of neutropenia, although without an increase in infection rate. Common grade ‡3 adverse events were neutropenia (78%), anemia (28%), and leukopenia (24%). ORR was 60% and was generally consistent across subgroups (58% in double-refractory patients). Among patients with a complete response or better, 29% were MRD negative at a threshold of 10 25 . Among the 62 responders, median duration of response was not estimable (NE; 95% confidence interval [CI], 13.6-NE). At a median follow-up of 13.1 months, the median progression-free survival was 8.8 (95% CI, 4.6-15.4) months and median overall survival was 17.5 (95% CI, 13.3-NE) months. The estimated 12-month survival rate was 66% (95% CI, 55.6-74.8). Aside from increased neutropenia, the safety profile of daratumumab plus pom-dex was consistent with that of the individual therapies. Deep, durable responses were observed in heavily treated patients. The study was registered at www.clinicaltrials.gov as #NCT01998971. (Blood. 2017;130(8):974-981)
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