A Multicenter Analysis of Factors Associated With Apixaban-Related Bleeding in Hospitalized Patients With End-Stage Renal Disease on Hemodialysis.

BACKGROUND: In 2014, the United States Food and Drug Administration approved a labeling change for apixaban to include recommendations for patients with severe renal impairment and patients with end-stage renal disease (ESRD) on hemodialysis (HD), though these recommendations are largely based on pharmacokinetic and pharmacodynamic data. OBJECTIVE: Identify variables associated with bleeding events in hospitalized patients with ESRD on HD receiving apixaban. METHODS: This retrospective, multicenter cohort study evaluated hospitalized patients with ESRD on HD receiving apixaban from January 1, 2013, through March 31, 2016. Correlational analysis and logistic regression were completed to identify factors associated with bleeding. RESULTS: A total of 114 adults were included in the analysis. The median length of stay (LOS) was 6.2 (interquartile range = 3.8-11.9) days and bleeding events occurred in a total of 17 patients (15%). A weak correlation was identified for higher cumulative apixaban exposure, increased number of HD sessions while receiving apixaban, and increased hospital LOS ( P < 0.05; correlation coefficient < 0.40). When controlling for confounders, logistic regression revealed that composite bleeding events were independently increased by continuation of outpatient apixaban (odds ratio = 13.07; 95% CI = 1.54-110.54; P = 0.018), increased total daily dose of apixaban (odds ratio = 1.72; 95% CI = 1.20 to 2.48; P = 0.003), and total HD sessions while receiving apixaban (odds ratio = 2.04; 95% CI = 1.06-3.92; P = 0.033). CONCLUSION: The association between these factors and increased bleeding should prompt concern for long-term anticoagulation with apixaban in patients with ESRD receiving chronic HD.

Performance of the pegfilgrastim on-body injector as studied with placebo buffer in healthy volunteers.

OBJECTIVE: The pegfilgrastim on-body injector (OBI) is a single-use, disposable, battery-powered injector that is designed to automatically deliver a single subcutaneous dose of pegfilgrastim beginning approximately 27 hours after activation and continuing over approximately 45 minutes. In this open-label study, we assessed performance of the OBI delivering placebo buffer in healthy volunteers. RESEARCH DESIGN AND METHODS: Healthy men and women aged 18-55 years, with a body mass index of 18-35 kg/m2, were enrolled. OBIs were activated by filling them with placebo buffer, and two injectors were applied concurrently to each subject: one to the abdomen and one to the back of the upper arm. Subjects were monitored for substantial leakage during and after administration. MAIN OUTCOME MEASURES: The primary endpoint of the study was successful delivery of placebo buffer based on a composite of the following: no substantial leakage during or after administration, green status light indicator on the injector during and after administration, and fill indicator bar at the empty position after administration. The secondary endpoint was the incidence of treatment-emergent adverse events (AEs). RESULTS: Of the 150 subjects enrolled, 149 (99.3%) completed the study. Study subjects were 48.0% men, and 52.0% women; 47.3% were white, 35.3% black or African American, 12.7% Asian, and 4.7% other. Mean (SD) age was 35.9 (10.8) years. Of the 297 total deliveries, 292 (98.3%) were considered successful: 147/149 (98.7%; 95% confidence interval [CI]: 95.2%-99.6%) to the abdomen and 145/148 (98.0%; 95% CI: 94.2%-99.3%) to the back of the upper arm. Five deliveries were considered unsuccessful: two due to hazard alarms, and three due to substantial leakage. The most common treatment-emergent AEs (in >2% of subjects overall) by preferred term were medical device site reaction (20.7%), catheter-site hemorrhage (8.7%), and headache (3.3%). No serious AEs were reported. CONCLUSIONS: The pegfilgrastim OBI was well tolerated, and deliveries of placebo buffer were successful 98.3% of the time. The generalizability of these results may be limited by the conduct of this study in healthy subjects in a controlled environment.

Direct visualization of protein adsorption to primary containers by gold nanoparticles.

Adsorption of proteins to primary containers can result in protein loss, protein denaturation, or aggregation. We report a simple and effective method to directly detect and visualize adsorption of proteins to container surfaces by staining adsorbed proteins with gold nanoparticles, which bind proteins nonspecifically. The gold nanoparticle staining method was applied to study adsorption to siliconized glass prefilled syringes (PFSs) of a therapeutic protein in a liquid formulation. The protein was found to preferentially adsorb to glass surfaces over siliconized surfaces in PFSs. The presence of adsorbed proteins on glass surfaces was confirmed by in situ Raman spectroscopy. Gold nanoparticle staining patterns revealed that adsorption of proteins to hydrophobic cyclic olefin polymer plastic vials was minimized compared with hydrophilic type I glass vials. Bovine serum albumin (BSA) also preferentially adsorbed to glass surfaces compared with siliconized surfaces as revealed by the gold staining patterns in PFS incubated with BSA, supporting the use of albumin to minimize loss of proteins in glass containers. The method is particularly valuable for high-concentration protein formulations in which adsorption of proteins to containers cannot be easily detected by other methods.