The effect of a southward interplanetary magnetic field on St\"ormer's allowed regions

The motion of a charged particle in a magnetic dipole has first been studied by Stormer. The different applications of Stormer's theory to aurorae, cosmic rays and Van Allen radiation belt particles are recalled in an historical perspective. In this paper, we expand the Stormer theory in order to take into account the effects produced by an additional uniform and stationary interplanetary magnetic field (IMF) whose orientation is parallel or antiparallel to the magnetic moment of the dipole. A new expression is derived for the Stormer potential taking into account the additional IMF component. It is shown how Stormer's allowed and forbidden zones are influenced by the implementation of a northward or a southward IMF, and how a southward turning of the IMF orientation makes it easier for Solar Energetic Particle and Galactic Cosmic Rays to enter into the inner part of the geomagnetic field along interconnected magnetic field lines.Comment: 24 Pages; 15 Figures; Tutorial Lecture Presented At The Cospar Colloquium "Plasma Processes In Th Near-Earth Space: Interball And Beyond, Sofia, Bulgaria, 5-10 200

Safety and efficacy of abexinostat, a pan-histone deacetylase inhibitor, in non-Hodgkin lymphoma and chronic lymphocytic leukemia: results of a phase II study

International audienceHistone deacetylase inhibitors are members of a class of epigenetic drugs that have proven activity in T-cell malignancies, but little is known about their efficacy in B-cell lymphomas. Abexinostat is an orally available hydroxamate-containing histone deacetylase inhibitor that differs from approved inhibitors; its unique pharmacokinetic profile and oral dosing schedule, twice daily four hours apart, allows for continuous exposure at concentrations required to efficiently kill tumor cells. In this phase II study, patients with relapsed/refractory non-Hodgkin lymphoma or chronic lymphocytic leukemia received oral abexinostat at 80 mg BID for 14 days of a 21-day cycle and continued until progressive disease or unacceptable toxicity. A total of 100 patients with B-cell malignancies and T-cell lymphomas were enrolled between October 2011 and July 2014. All patients received at least one dose of study drug. Primary reasons for discontinuation included progressive disease (56%) and adverse events (25%). Grade 3 or over adverse events and any serious adverse events were reported in 88% and 73% of patients, respectively. The most frequently reported grade 3 or over treatment-emergent related adverse events were thrombocytopenia (80%), neutropenia (27%), and anemia (12%). Among the 87 patients evaluable for efficacy, overall response rate was 28% (complete response 5%), with highest responses observed in patients with follicular lymphoma (overall response rate 56%), T-cell lymphoma (overall response rate 40%), and diffuse large B-cell lymphoma (overall response rate 31%). Further investigation of the safety and efficacy of abexinostat in follicular lymphoma, T-cell lymphoma, and diffuse large B-cell lymphoma implementing a less dose-intense week-on-week-off schedule is warranted. (Trial registered at: EudraCT-2009-013691-47)

Vantage 095: Vorinostat in Combination with Bortezomib in Salvage Multiple Myeloma Patients: Final Study Results of a Global Phase 2b Trial

Abstract Abstract 480 Introduction: Vorinostat (VOR), an oral inhibitor of histone deacetylase (HDAC) class I and class II proteins, affects pathways regulating cell proliferation and apoptosis in a diverse array of tumor types. Phase 1/2 trials in multiple myeloma (MM) have indicated clinical activity of vorinostat, as both a single agent and in combination with bortezomib (BTZ) and immunomodulatory drugs (IMiDs). Materials and methods: The present study (MK-0683 PN095) was an open-label, single-arm phase 2b trial of VOR plus BTZ in BTZ-refractory patients (defined as &lt; 25% response on therapy, or progression during or &lt; 60 days after completion of therapy) and patients considered to be refractory, intolerant, or ineligible for IMiD-based therapy regimens. Eligible patients were aged ≥ 18 years, had measurable secretory MM, had received ≥ 2 prior anti-myeloma regimens, and relapsed or progressed following prior systemic therapy. Patients received 21-day cycles of BTZ (1.3 mg/m2 intravenously [IV]; days 1, 4, 8, and 11) plus oral VOR 400 mg/d on days 1 to 14. If patient had no change as the best response after 4 cycles of treatment or progressive disease after 2 cycles of treatment, oral dexamethasone 20 mg on the day of and day after each dose of BTZ could be added to the treatment regimen. Patients were treated until disease progression, unacceptable toxicities, or withdrawal from the study. The primary endpoint was overall response rate (ORR; ≥ partial response). Secondary and exploratory endpoints included clinical benefit response (ORR + minimal response), overall survival (OS), time to progression (TTP), progression-free survival (PFS), and safety. Responses and progression were determined according to the International Myeloma Working Group criteria and the European Bone and Marrow Transplantation Group criteria. All efficacy data will be confirmed by an Independent Adjudication Committee. Results: Between January 2009 and October 2010, 143 patients were enrolled from 41 centers in 12 countries across Asia-Pacific, Europe, and North America. Median duration of MM for the entire study population was 4.6 years, including 31% whose disease had progressed on or within 60 days of last therapy and 66% whose disease had achieved &lt; 25% response to the regimen immediately preceding study entry. The study population was heavily pretreated, having received a median of 4 prior lines of therapy (range 2–17, ≥ 4 prior regimens: 69%). Prior anti-myeloma agents included 100% BTZ (median 2 prior regimens containing BTZ), 100% IMiDs (thalidomide [85%], lenalidomide [71%], or pomalidomide [4%]), and 74% stem cell transplant. As of July 2011, 142 of the enrolled patients received study medication, with a median exposure of 4 cycles (mean 6.2 cycles; range 1–26 cycles). The most common treatment-emergent adverse events regardless of relationship to study drug were predominantly hematologic and gastrointestinal disorders. Of interest, peripheral neuropathy was infrequent and grade ≥ 3 PN occurred in 2 patients (1.6%). The final efficacy evaluation of the IAC will occur in September 2011. Conclusions: Final data for all primary and secondary endpoints, including response assessment and time-to-event data for PFS/TTP, OS, and duration of response will be available at the annual ASH meeting. Disclosures: Siegel: Millenium: Honoraria, Research Funding, Speakers Bureau; Merck: Honoraria. Off Label Use: Vorinostat, an inhibitor of histone deacetylase, is approved in the US for the treatment of cutaneous manifestations in patients with cutaneous T cell lymphoma (CTCL) who have progressive, persistent or recurrent disease on or following two systemic therapies. Vorinostat is currently under investigation for the treatment of relapsed malignant pleural mesothelioma, relapsed/refractory B cell lymphoma (in combination with other chemotherapy agents), and relapsed/refractory multiple myeloma (in combination with bortezomib and other chemotherapy agents). Dimopoulos:Celgene, Ortho-Biotech: Consultancy, Honoraria. Yoon:NK Bio: Consultancy; Celgene: Consultancy. Kaufman:Merck; Celgene: Research Funding; Millenium; Onxy; Novartis; Keryx: Consultancy. Goldschmidt:Amgen, Novartis, Chugai: Research Funding; Janssen-Cilag, Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding. Reece:Merck: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Otsuka: Honoraria, Research Funding. Leleu:Janssen Cilag, Celgene, Novartis-Amgen, Leo Pharma, Chugai, Roche: Honoraria, Research Funding. Cavo:Millennium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Jagannath:Merck: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Millennium: Membership on an entity's Board of Directors or advisory committees. Graef:Merck: Employment. Houp:Merck: Employment. Sun:Merck &amp; Co., Inc.: Employment. Howe:Merck: Employment. Anderson:Celgene: Consultancy; Millennium: Consultancy; Novartis: Consultancy; BMS: Consultancy; Onyx: Consultancy; Merck: Consultancy; Acetylon: . </jats:sec