Phase 1 results from a Phase 1/2 study comprise 18 patients with myelodysplastic syndromes (MDS; n = 9), acute myeloid leukemia (AML; n = 8), and chronic myelomonocytic leukemia (CMML; n = 1) who were either hypomethylating agent naïve (n = 10) or relapsed/refractory following prior hypomethylating agent therapy (n = 8) (NCT01926587). Patients received oral rigosertib, an inhibitor of Ras-effector pathways, in 3 successive cohorts (140 mg twice daily, 280 mg twice daily, or 840 mg/day [560 mg morning/280 mg evening]) for 3 weeks of a 4-week cycle. Patients received parenteral azacitidine (75 mg/m/day × 7 days) during the second week; the cycle repeated every 4 weeks.
View Article and Find Full Text PDFThis report summarizes and highlights the fifth International RASopathies Symposium: When Development and Cancer Intersect, held in Orlando, Florida in July 2017. The RASopathies comprise a recognizable pattern of malformation syndromes that are caused by germ line mutations in genes that encode components of the RAS/mitogen-activated protein kinase (MAPK) pathway. Because of their common underlying pathogenetic etiology, there is significant overlap in their phenotypic features, which includes craniofacial dysmorphology, cardiac, cutaneous, musculoskeletal, gastrointestinal and ocular abnormalities, neurological and neurocognitive issues, and a predisposition to cancer.
View Article and Find Full Text PDFThis Phase 1/2, dose-escalating study of rigosertib enrolled 22 patients with higher-risk myelodysplastic syndromes (MDS) (n=9) and acute myeloid leukemia (AML; n=13) who had relapsed or were refractory to standard therapy and for whom no second-line therapies were approved. Patients received 3- to 7-day continuous intravenous infusions of rigosertib, an inhibitor of Ras-effector pathways that interacts with the Ras-binding domains, common to several signaling proteins including Raf and PI3 kinase. Rigosertib was administered at doses of 650-1700mg/m/day in 14-day cycles.
View Article and Find Full Text PDFAppropriate treatment for nonreactive thrombocytosis resulting from a myeloproliferative disorder (MPD) is surrounded by controversy. Although few doubt the association of thrombocytosis with increased risk for life-threatening events such as thrombosis or hemorrhage, or the association between clonal myeloproliferation and the progression to acute leukemia or myelofibrosis, controversy exists regarding the timing and nature of appropriate therapeutic intervention. Studies have shown that treatment with myelosuppressive agents such as chlorambucil, busulfan, radiophosphorus (32P), and hydroxyurea reduces the platelet count.
View Article and Find Full Text PDFIdiopathic myelofibrosis (IM) is characterized by increased numbers of CD34(+) cells in the peripheral blood (PB). We explored the possible mechanisms underlying this abnormal trafficking of CD34(+) cells. Plasma levels of neutrophil elastase (NE), total and active matrix metalloproteinase 9 (MMP-9), and soluble vascular cell adhesion molecule-1 (sVCAM-1) were dramatically increased in IM.
View Article and Find Full Text PDFBiol Blood Marrow Transplant
November 2004
Cord blood transplantation has been used extensively in the allogeneic setting for acquired and genetic disorders of hematopoiesis. There is less experience in the utility of autologous cord blood transplantation, and there is great controversy about the role of autologous cord blood collection and storage. We report on the successful use of autologous cord blood transplantation for the treatment of severe aplastic anemia following fulminant hepatic failure and living related liver transplantation.
View Article and Find Full Text PDFIdiopathic myelofibrosis (IM) is characterized by the constitutive mobilization of CD34(+) cells. IM peripheral blood (PB) CD34(+) cells had a reduced cloning efficiency and a lower frequency of cobblestone areas compared with normal granulocyte colony-stimulating factor (G-CSF)-mobilized PB CD34(+) cells. IM CD34(+) cells engrafted nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice, demonstrating that they contain bone marrow (BM)-repopulating cells.
View Article and Find Full Text PDFMyeloproliferative disorders (MPDs) are chronic conditions that require long-term treatment. MPDs have been considered neoplastic disorders that have a propensity to transform to acute leukemia or myelodysplastic syndrome. One of the MPDs, chronic myeloid leukemia (CML), has the distinct cytogenetic abnormality of the Philadelphia chromosome.
View Article and Find Full Text PDFSemin Hematol
January 2003
Myelofibrosis with myeloid metaplasia, also known as idiopathic myelofibrosis (IF) or agnogenic myeloid metaplasia, is one of the characteristic manifestations of polycythemia vera (PV) in the spent phase, and has a particularly adverse prognosis. IF may also present de novo. To date, treatment strategies for both spent-phase PV and IF have frustrated both clinicians and patients, with little clear progress made over the past 50 years.
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