Effect of Triple Therapy on Cardiovascular and Severe Cardiopulmonary Events in COPD: A Post-hoc Analysis of a Randomized, Double-Blind, Phase 3 Clinical Trial (ETHOS).

Rationale: Chronic obstructive pulmonary disease (COPD) is associated with increased risk of cardiovascular and cardiopulmonary events. In the Phase III, 52-week ETHOS trial (NCT02465567), triple therapy with budesonide/glycopyrrolate/formoterol fumarate (BGF) reduced rates of moderate/severe exacerbations and all-cause mortality versus dual therapy with glycopyrrolate/formoterol fumarate (GFF) or budesonide/formoterol fumarate (BFF). However, the effect of BGF on cardiovascular events versus GFF remains unevaluated. Further, the effect of BGF on time to first severe exacerbation has not been reported. Objective: Assess the effects of BGF 320/18/9.6 µg (BGF 320) and other ICS-containing arms on cardiovascular and severe cardiopulmonary endpoints versus GFF in patients with COPD from ETHOS. Methods: Patients with moderate-to-very severe COPD and a history of exacerbations were randomized to twice-daily BGF 320, BGF 160/18/9.6 µg, BFF 320/9.6 µg, or GFF 18/9.6 µg (GFF). Time to first severe COPD exacerbation was a pre-specified endpoint; post-hoc cardiovascular and severe cardiopulmonary endpoints included time to first major adverse cardiac event (MACE), time to first cardiovascular adverse event (AE) of special interest (CVAESI), time to first cardiac AE, and time to the composite endpoint of first severe cardiopulmonary event. Measurements and Main Results: BGF 320 reduced the rate of first occurrence (hazard ratio [95% confidence interval]) of cardiovascular and severe cardiopulmonary events versus GFF, including for CVAESI (0.63 [0.48, 0.82]), cardiac AE (0.60 [0.48, 0.76]), and severe cardiopulmonary event (0.80 [0.67, 0.95]). Conclusions: BGF had a benefit on cardiovascular endpoints and severe cardiopulmonary events versus GFF in patients with moderate-to-very severe COPD.

Serpins show structural basis for oligomer toxicity and amyloid ubiquity.

Many disorders, including Alzheimer's, the prion encephalopathies and other neurodegenerative diseases, result from aberrant protein aggregation. Surprisingly, cellular toxicity is often due not to the highly-ordered aggregates but to the oligomers that precede their formation. Using serpins as a paradigm, we show how the active and infective interface of oligomers is inherently toxic and can promiscuously bind to unrelated peptides, including neurotransmitters. Extension of the oligomer and its eventual sequestration as amyloid can thus be seen as a protective response to block the toxic interface. We illustrate how the preferential self-association that gives this protection has been selectively favoured.

Heparin-induced substrate behavior of antithrombin Cambridge II.

Cambridge II (A384S) is a highly prevalent antithrombin variant in the British population (1.14 per 1000) and predisposes carriers to a mild but significant increased risk of thrombosis. To determine if the association of Cambridge II with thrombophilia is due to a perturbation of the antithrombin inhibitory mechanism, we expressed and characterized the variant. Antithrombin Cambridge II was found to be normal in its affinity for heparin, its ability to form sodium dodecyl sulfate-stable complexes with factor Xa and thrombin, and its uncatalyzed stoichiometries and rates of inhibition. However, in the presence of full-length heparin there was a 3- and 7-fold increase in stoichiometry of inhibition of factor Xa and thrombin. The stoichiometries were not affected by pentasaccharides, indicating that the inhibitory mechanism of antithrombin Cambridge II is perturbed only in the presence of a bridging glycosaminoglycan. Thus, the vascular localization of antithrombin Cambridge II would render the carrier slightly thrombophilic. The high occurrence of this mutation and its possible propagation from a few founders suggests an evolutionary advantage, perhaps in decreasing postpartum bleeding.

Antithrombin 'DREUX' (Lys 114Glu): a variant with complete loss of heparin affinity.

Here we report the finding of a new natural antithrombin mutation that confirms the critical contribution of lysine 114 to the binding of the core heparin pentasaccharide, with the replacement of lysine 114 by glutamate causing a complete loss in affinity. The variant was identified in a father and son, the father having been investigated for an episode of cerebral ischaemia associated with hypercholesterolaemia. The variant forms SDS-stable complexes with activated factor X (fXa) and its thermal stability and rate of factor Xa inhibition in the absence of heparin are identical to those of normal antithrombin. Normal antithrombin binds to the high affinity heparin pentasaccharide with a Kd of 1nM, as detected by a 45% change in intrinsic fluorescence, resulting in a 230-fold increase in rate of factor Xa inhibition. However, no change in fluorescence was detected for the variant when titrated with heparin or the heparin pentasaccharide, nor was there detectable activation towards factor Xa, indicating a complete loss of heparin binding.