Due to the unavailability of horse antithymocyte globulin (ATG) in many markets worldwide, patients with severe aplastic anemia (SAA) are limited to the use of rabbit ATG. We aimed to analyze hematologic response and overall survival (OS) of Asian patients treated with rabbit ATG as first-line therapy of SAA. We retrospectively reviewed the medical records of 97 consecutive patients who received rabbit ATG as first-line treatment of SAA from 2006 to 2012 at centers in four Asian countries. The primary endpoint was 6- and 12-month overall response rates (ORR) for patients receiving rabbit ATG within the recommended dose range (2.5-3.75 mg/kg/day). Secondary endpoints included ORR in patients receiving any dose of rabbit ATG and 2-year OS. For patients who received rabbit ATG within the recommended dose range, 6- and 12-month ORRs were 17.4 and 63.6 %, respectively. For patients who received any dose of rabbit ATG, 6- and 12-month ORRs were 24.3 and 68.6 %, respectively. The 2-year OS rate was 86.3 %. Rabbit ATG is effective for treatment of SAA in Asian patients. The 12-month ORR and 2-year OS with rabbit ATG were comparable to historical results obtained with horse ATG.
Myeloproliferative neoplasms (MPN) are a heterogeneous group of clonal hematopoietic stem cell disorders characterized clinically by the proliferation of one or more hematopoietic lineage(s). The classical Philadelphia-chromosome (Ph)-negative MPNs include polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). The Asian Myeloid Working Group (AMWG) comprises representatives from fifteen Asian centers experienced in the management of MPN. This consensus from the AMWG aims to review the current evidence in the risk stratification and treatment of Ph-negative MPN, to identify management gaps for future improvement, and to offer pragmatic approaches for treatment commensurate with different levels of resources, drug availabilities and reimbursement policies in its constituent regions. The management of MPN should be patient-specific and based on accurate diagnostic and prognostic tools. In patients with PV, ET and early/prefibrotic PMF, symptoms and risk stratification will guide the need for early cytoreduction. In younger patients requiring cytoreduction and in those experiencing resistance or intolerance to hydroxyurea, recombinant interferon-α preparations (pegylated interferon-α 2A or ropeginterferon-α 2b) should be considered. In myelofibrosis, continuous risk assessment and symptom burden assessment are essential in guiding treatment selection. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) in MF should always be based on accurate risk stratification for disease-risk and post-HSCT outcome. Management of classical Ph-negative MPN entails accurate diagnosis, cytogenetic and molecular evaluation, risk stratification, and treatment strategies that are outcome-oriented (curative, disease modification, improvement of quality-of-life).