How to diagnose and manage antiphospholipid syndrome.

Antiphospholipid antibodies (aPL) are autoimmune antibodies directed toward phospholipids or phospholipid-protein complexes, particularly those containing ß2-glycoprotein I (ß2GPI). Persistently positive aPL accompanied by arterial or venous thrombosis, or recurrent pregnancy loss, constitutes the antiphospholipid syndrome (APS). Several types of aPL with different specificities have been defined and may be detected in the clinical lab, including lupus anticoagulants (detected using clotting assays) and anticardiolipin, anti-ß2GPI and anti-prothrombin/phosphatidylserine antibodies (detected by ELISA); each of the last 3 aPL may be either IgG, IgM, or IgA, though IgA antibodies are not included in criteria for APS. Due to the relative rarity of APS and the heterogeneity of aPL, thrombosis risk stratification is challenging, and randomized clinical trials for thrombosis treatment and prevention have been limited. This lack of high-quality data has made the clinical management of APS difficult, and existing guidelines are few and could not possibly cover many of the scenarios encountered in managing patients with APS. In this review, we present 3 patients with aPL and/or APS who highlight treatment dilemmas, and we discuss background information that may help guide clinical judgment in developing individualized treatment plans for patients with these enigmatic antibodies.

Emerging Therapies in Antiphospholipid Syndrome.

The antiphospholipid syndrome (APS) is the most common cause of acquired immune-mediated thrombophilia. This syndrome is broadly defined by the presence of arterial or venous thrombosis, or pregnancy morbidity, in the presence of high levels of antiphospholipid antibodies. Despite recognition of this disorder more than 50 years ago, a fundamental unifying pathogenesis has not been determined. Due to this, mechanism-based therapies for APS are not available, and current management following thrombotic events suggests anticoagulation of indeterminate duration, or for obstetric complications, heparin/low molecular weight heparin and aspirin. However, APS is an autoimmune disorder, and several approaches focused on modulating the immune response or its effectors have been employed. Those which have been most extensively studied include hydroxychloroquine, rituximab and eculizumab, an inhibitor of complement C5. In this report, we review in depth, and critique, key clinical studies of these agents. Since all of these studies are small, our conclusions are qualified. However, it appears that hydroxychloroquine may enhance the anticoagulant efficacy of vitamin K antagonists in APS patients, and that rituximab may ameliorate some of the "non-criteria" manifestations of APS. The catastrophic antiphospholipid syndrome (CAPS) is associated with diffuse thrombosis, multi-organ dysfunction, and ∼30% mortality. A high incidence of complement regulatory gene mutations, and compelling data concerning the efficacy of eculizumab in CAPS, suggests an important role for complement in this disorder. However, additional work is needed to clarify the role of complement in non-catastrophic APS, though emerging data suggests that complement inhibition may be effective in preventing thrombosis in these patients as well.

Relapse Prevention with Tyrosine Kinase Inhibitors after Allogeneic Transplantation for Philadelphia Chromosome-Positive Acute Lymphoblast Leukemia: A Systematic Review.

Relapse after stem cell transplantation for Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) remains a significant challenge. In this systematic review, we compare survival outcomes of second-generation tyrosine kinase inhibitors (TKIs) nilotinib and dasatinib with first-generation TKI imatinib when these agents are used after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in Ph+ ALL. In addition, we review the literature on TKI use to prevent relapse in patients who proceed to allo-HSCT beyond first complete response (>CR1). We performed database searches (inception to January 2018) using PubMed, Cochrane Library, and Embase. After exclusions, 17 articles were included in this analysis. Imatinib was used post-transplant either prophylactically or preemptively in 12 studies, 7 prospective studies and 5 retrospective studies. Overall survival (OS) for most prospective studies at 1.5 to 3 and 5 years ranged between 62% to 92% and 74.5% to 86.7%. Disease-free survival at 1.5 to 5 years was 60.4% to 92%. Additionally, imatinib failed to show survival benefit in patients who were >CR1 at the time of allo-HSCT. The cumulative OS for most retrospective studies using imatinib at 1 to 2 and 3 to 5 years was 42% to 100% and 33% to 40% respectively. Event-free survival at 1 to 2 and 3 to 5 years was 33.3% to 67% and 20% to 31% respectively. Dasatinib was used as maintenance treatment in 3 retrospective studies (n = 34). The OS for patients with Ph+ ALL using dasatinib as maintenance regimen after allo-HSCT at 1.4 to 3 years was 87% to 100% and disease-free survival at 1.4 to 3 years was 89% to 100%. Ninety-three percent of patients with minimal residual disease (MRD) positive status after allo-HSCT became MRD negative. Three prospective studies used nilotinib. In 2 studies where investigators studied patients with advanced chronic myeloid leukemia and Ph+ ALL, the cumulative OS and event-free survival at 7.5 months to 2 years were 69% to 84% and 56% to 84%, respectively. In the third study (n = 5) in patients with Ph+ ALL, nilotinib use resulted in OS at 5 years of 60%. Our review showed that use of TKIs (all generations) after allo-HSCT for patients in CR1 improved OS when given as a prophylactic or preemptive regimen. Limited data suggest that second-generation TKIs (ie, dasatinib) have a better OS, especially in patients with MRD-positive status. Imatinib did not improve OS in patients who were >CR1 at the time of allo-HSCT; for this population, no data were available with newer generation TKIs. The evaluation of survival benefit with newer generation TKIs and their efficacy in patients in >CR1 needs further study in large randomized clinical trials.

The Role of Checkpoint Inhibitors in Glioblastoma.

Given its poor prognosis, glioblastoma represents an area of high unmet clinical need. Standard of care for the treatment of glioblastoma in the frontline setting is limited to surgical resection, radiation, and temozolomide, with the more recent addition of Tumor Treating Fields. Several agents, including bevacizumab, lomustine, and carmustine have been approved in the recurrent setting. To date, no therapies have demonstrated substantial survival benefit beyond standard of care. An expanding understanding of the role of the immune system in fighting cancer has led to the development and approval of various immunotherapeutic approaches across solid tumors. In glioblastoma, the notion of a highly immune-restricted central nervous system has also evolved, further providing the rationale for testing therapies that promote immune trafficking to the CNS and infiltration into the tumor to counteract the immunosuppressive mechanisms that support tumor progression. There are five broad categories of immunotherapies currently being tested in GBM: vaccines, cytokine therapy, oncolytic viral therapy, chimeric antigen receptor T cell therapy, and checkpoint inhibitors. This review focuses on checkpoint inhibitors in GBM, the rationale for its use, preclinical data, and early clinical experience. Efficacy data are limited, and while a number of late-stage trials are ongoing, early trials showed no benefit in survival. There is a dizzying array of combinations being tested in clinical studies with an urgent need for a rational approach to determine the role of checkpoint inhibitors in glioblastoma, including the optimal combinations, and identification of biomarkers or predictive models to determine which patients may benefit from immunotherapy.