Mantle plume capture, anchoring, and outflow during Galápagos plume-ridge interaction

Compositions of basalts erupted between the main zone of Galápagos plume upwelling and adjacent Galápagos Spreading Center (GSC) provide important constraints on dynamic processes involved in transfer of deep-mantle-sourced material to mid-ocean ridges. We examine recent basalts from central and northeast Galápagos including some that have less radiogenic Sr, Nd, and Pb isotopic compositions than plume-influenced basalts (E-MORB) from the nearby ridge. We show that the location of E-MORB, greatest crustal thickness, and elevated topography on the GSC correlates with a confined zone of low-velocity, high-temperature mantle connecting the plume stem and ridge at depths of ∼100 km. At this site on the ridge, plume-driven upwelling involving deep melting of partially dehydrated, recycled ancient oceanic crust, plus plate-limited shallow melting of anhydrous peridotite, generate E-MORB and larger amounts of melt than elsewhere on the GSC. The first-order control on plume stem to ridge flow is rheological rather than gravitational, and strongly influenced by flow regimes initiated when the plume was on axis (>5 Ma). During subsequent northeast ridge migration material upwelling in the plume stem appears to have remained “anchored” to a contact point on the GSC. This deep, confined NE plume stem-to-ridge flow occurs via a network of melt channels, embedded within the normal spreading and advection of plume material beneath the Nazca plate, and coincides with locations of historic volcanism. Our observations require a more dynamically complex model than proposed by most studies, which rely on radial solid-state outflow of heterogeneous plume material to the ridge.We thank Galápagos National Park authorities and CDRS for permitting fieldwork in Galápagos. D. Villagomez and D. Toomey generously shared their extensive seismic data set for Galápagos, and D. McKenzie kindly provided help with temperature calculations. End-member compositions of Galápagos mantle reservoirs in Figure 4 were estimated from principal component analysis; data related to these calculations are available in the supporting information. We are grateful to Kaj Hoernle and two anonymous reviewers for their constructive comments on an earlier version of this manuscript. The research was funded by the University of Cambridge, Geological Society of London, NERC (RG57434), and NSF (EAR 0838461, EAR 0944229, and EAR-11452711).This is the final published version of the article. It first appeared at http://dx.doi.org/10.1002/2015GC00572

MR imaging field strength: prospective evaluation of the diagnostic accuracy of MR for diagnosis of multiple sclerosis at 0.5 and 1.5 T.

PURPOSE: To compare the diagnostic efficacy of middle-field-strength and high-field-strength magnetic resonance (MR) imaging in diagnosis of multiple sclerosis. MATERIALS AND METHODS: One hundred thirty-two patients with suspected multiple sclerosis underwent MR imaging at 0.5 and 1.5 T. Imaging parameters were identical except for band width optimization at middle field strength. Images were interpreted by radiologists expert in MR imaging who were blinded to diagnosis and field strength. The diagnosis of multiple sclerosis was made by experienced neurologists, and indeterminate cases and patients without clinical evidence of multiple sclerosis were followed up for 6 months to 1 year. RESULTS: There was no difference in accuracy, sensitivity, or specificity between scanners in the diagnosis of multiple sclerosis or white matter disease. Equal numbers of lesions were detected at both field strengths in all parts of the brain. Image quality was always good or adequate at middle field strength. CONCLUSION: Higher field strength does not confer higher accuracy in the diagnosis of multiple sclerosis with current-generation MR imagers

MR imaging field strength: prospective evaluation of the diagnostic accuracy of MR for diagnosis of multiple sclerosis at 0.5 and 1.5 T.

PURPOSE: To compare the diagnostic efficacy of middle-field-strength and high-field-strength magnetic resonance (MR) imaging in diagnosis of multiple sclerosis. MATERIALS AND METHODS: One hundred thirty-two patients with suspected multiple sclerosis underwent MR imaging at 0.5 and 1.5 T. Imaging parameters were identical except for band width optimization at middle field strength. Images were interpreted by radiologists expert in MR imaging who were blinded to diagnosis and field strength. The diagnosis of multiple sclerosis was made by experienced neurologists, and indeterminate cases and patients without clinical evidence of multiple sclerosis were followed up for 6 months to 1 year. RESULTS: There was no difference in accuracy, sensitivity, or specificity between scanners in the diagnosis of multiple sclerosis or white matter disease. Equal numbers of lesions were detected at both field strengths in all parts of the brain. Image quality was always good or adequate at middle field strength. CONCLUSION: Higher field strength does not confer higher accuracy in the diagnosis of multiple sclerosis with current-generation MR imagers

Pomalidomide, bortezomib, and dexamethasone for patients with relapsed or refractory multiple myeloma previously treated with lenalidomide (OPTIMISMM): a randomised, open-label, phase 3 trial

Background As lenalidomide becomes increasingly established for upfront treatment of multiple myeloma, patients refractory to this drug represent a population with an unmet need. The combination of pomalidomide, bortezomib, and dexamethasone has shown promising results in phase 1/2 trials of patients with relapsed or refractory multiple myeloma. We aimed to assess the efficacy and safety of this triplet regimen in patients with relapsed or refractory multiple myeloma who previously received lenalidomide.Methods We did a randomised, open-label, phase 3 trial at 133 hospitals and research centres in 21 countries. We enrolled patients (aged >= 18 years) with a diagnosis of multiple myeloma and measurable disease, an Eastern Cooperative Oncology Group performance status of 0-2, who received one to three previous regimens, including a lenalidomide-containing regimen for at least two consecutive cycles. We randomly assigned patients (1:1) to bortezomib and dexamethasone with or without pomalidomide using a permutated blocked design in blocks of four, stratified according to age, number of previous regimens, and concentration of beta(2) microglobulin at screening. Bortezomib (1.3 mg/m(2)) was administered intravenously until protocol amendment 1 then either intravenously or subcutaneously on days 1,4, 8, and 11 for the first eight cycles and subsequently on days 1 and 8. Dexamethasone (20 mg [10 mg if age >75 years]) was administered orally on the same days as bortezomib and the day after. Patients allocated pomalidomide received 4 mg orally on days 1-14. Treatment cycles were every 21 days. The primary endpoint was progression-free survival in the intention-to-treat population, as assessed by an independent review committee. Safety was assessed in all patients who received at least one dose of study medication. This trial is registered at ClinicalTrials.gov, number NCT01734928; patients are no longer being enrolled.Findings Between Jan 7, 2013, and May 15,2017,559 patients were enrolled. 281 patients were assigned pomalidomide, bortezomib, and dexamethasone and 278 were allocated bortezomib and dexamethasone. Median follow-up was 15.9 months (IQR 9.9-21.7). Pomalidomide, bortezomib, and dexamethasone significantly improved progression-free survival compared with bortezomib and dexamethasone (median 11.20 months [95% CI 9.66-13-73] vs 7.10 months [5.88-8-48]; hazard ratio 0.61, 95% CI 0.49-0-77; p<0-0001). 278 patients received at least one dose of pomalidomide, bortezomib, and dexamethasone and 270 patients received at least one dose of bortezomib and dexamethasone, and these patients were included in safety assessments. The most common grade 3 or 4 treatment-emergent adverse events were neutropenia (116 [42%] of 278 patients vs 23 [9%1 of 270 patients; nine p.m vs no patients had febrile neutropenia), infections (86 [31%] vs 48 118%1), and thrombocytopenia (76 [27%1 vs 79 [29%]). Serious adverse events were reported in 159 (57%) of 278 patients versus 114 (42%) of 270 patients. Eight deaths were related to treatment; six (2%) were recorded in patients who received pomalidomide, bortezomib, and dexamethasone (pneumonia [n=2], unknown cause [n=2], cardiac arrest [n=1], cardiorespiratory arrest [n=11) and two (1%) were reported in patients who received bortezomib and dexamethasone (pneumonia In=11, hepatic encephalopathy [n=1.]).Interpretation Patients with relapsed or refractory multiple myeloma who previously received lenalidomide had significantly improved progression-free survival when treated with pomalidomide, bortezomib, and dexamethasone compared with bortezomib and dexamethasone. Adverse events accorded with the individual profiles of pomalidomide, bortezomib, and dexamethasone. This study supports use of pomalidomide, bortezomib, and dexamethasone as a treatment option in patients with relapsed or refractory multiple myeloma who previously received lenalidomide. Copyright (C) 2019 Elsevier Ltd. All rights reserved

Pomalidomide, bortezomib, and dexamethasone for patients with relapsed or refractory multiple myeloma previously treated with lenalidomide (OPTIMISMM): a randomised, open-label, phase 3 trial

BACKGROUND: As lenalidomide becomes increasingly established for upfront treatment of multiple myeloma, patients refractory to this drug represent a population with an unmet need. The combination of pomalidomide, bortezomib, and dexamethasone has shown promising results in phase 1/2 trials of patients with relapsed or refractory multiple myeloma. We aimed to assess the efficacy and safety of this triplet regimen in patients with relapsed or refractory multiple myeloma who previously received lenalidomide. METHODS: We did a randomised, open-label, phase 3 trial at 133 hospitals and research centres in 21 countries. We enrolled patients (aged 6518 years) with a diagnosis of multiple myeloma and measurable disease, an Eastern Cooperative Oncology Group performance status of 0-2, who received one to three previous regimens, including a lenalidomide-containing regimen for at least two consecutive cycles. We randomly assigned patients (1:1) to bortezomib and dexamethasone with or without pomalidomide using a permutated blocked design in blocks of four, stratified according to age, number of previous regimens, and concentration of \u3b2(2) microglobulin at screening. Bortezomib (1\ub73 mg/m(2)) was administered intravenously until protocol amendment 1 then either intravenously or subcutaneously on days 1, 4, 8, and 11 for the first eight cycles and subsequently on days 1 and 8. Dexamethasone (20 mg [10 mg if age >75 years]) was administered orally on the same days as bortezomib and the day after. Patients allocated pomalidomide received 4 mg orally on days 1-14. Treatment cycles were every 21 days. The primary endpoint was progression-free survival in the intention-to-treat population, as assessed by an independent review committee. Safety was assessed in all patients who received at least one dose of study medication. This trial is registered at ClinicalTrials.gov, number NCT01734928; patients are no longer being enrolled. FINDINGS: Between Jan 7, 2013, and May 15, 2017, 559 patients were enrolled. 281 patients were assigned pomalidomide, bortezomib, and dexamethasone and 278 were allocated bortezomib and dexamethasone. Median follow-up was 15\ub79 months (IQR 9\ub79-21\ub77). Pomalidomide, bortezomib, and dexamethasone significantly improved progression-free survival compared with bortezomib and dexamethasone (median 11\ub720 months [95% CI 9\ub766-13\ub773] vs 7\ub710 months [5\ub788-8\ub748]; hazard ratio 0\ub761, 95% CI 0\ub749-0\ub777; p<0\ub70001). 278 patients received at least one dose of pomalidomide, bortezomib, and dexamethasone and 270 patients received at least one dose of bortezomib and dexamethasone, and these patients were included in safety assessments. The most common grade 3 or 4 treatment-emergent adverse events were neutropenia (116 [42%] of 278 patients vs 23 [9%] of 270 patients; nine [3%] vs no patients had febrile neutropenia), infections (86 [31%] vs 48 [18%]), and thrombocytopenia (76 [27%] vs 79 [29%]). Serious adverse events were reported in 159 (57%) of 278 patients versus 114 (42%) of 270 patients. Eight deaths were related to treatment; six (2%) were recorded in patients who received pomalidomide, bortezomib, and dexamethasone (pneumonia [n=2], unknown cause [n=2], cardiac arrest [n=1], cardiorespiratory arrest [n=1]) and two (1%) were reported in patients who received bortezomib and dexamethasone (pneumonia [n=1], hepatic encephalopathy [n=1]). INTERPRETATION: Patients with relapsed or refractory multiple myeloma who previously received lenalidomide had significantly improved progression-free survival when treated with pomalidomide, bortezomib, and dexamethasone compared with bortezomib and dexamethasone. Adverse events accorded with the individual profiles of pomalidomide, bortezomib, and dexamethasone. This study supports use of pomalidomide, bortezomib, and dexamethasone as a treatment option in patients with relapsed or refractory multiple myeloma who previously received lenalidomide. FUNDING: Celgene