Measurement Equivalence of Patient-Reported Outcome Measure Response Scale Types Collected Using Bring Your Own Device Compared to Paper and a Provisioned Device: Results of a Randomized Equivalence Trial.

OBJECTIVES: The aim of this study was to assess the measurement equivalence of individual response scale types by using a patient reported outcome measure (PROM) collected on paper and migrated into electronic format for use on the subject's own mobile device (BYOD) and on a provisioned device (site device). METHODS: Subjects suffering from chronic health conditions causing daily pain or discomfort were invited to participate in this single-site, single visit, three-way crossover study. Association between individual item and instrument subscale scores was assessed by using the intraclass correlation coefficient (ICC) and its CI. Participant attitudes toward the use of BYOD in a clinical trial were assessed through use of a questionnaire. RESULTS: In this study, 155 subjects (females 83 [54%]; males 72 [46%]) ages 19 to 69 years (mean ± SD: 48.6 ± 13.1) were recruited. High association between the modes of administration (paper, BYOD, site device) was shown with analysis of ICCs (0.79-0.98) for each response scale type, including visual analogue scale, numeric rating scale, verbal response scale, and Likert scale. Of the subjects, 94% (146 of 155) stated that they would definitely or probably be willing to download an app onto their own mobile device for a forthcoming clinical trial. Forty-five percent of subjects felt BYOD would be more convenient compared with 15% preferring a provisioned device (40% had no preference). CONCLUSIONS: This study provides strong evidence supporting the use of BYOD for PROM collection in terms of the conservation of instrument measurement equivalence across the most widely used response scale types, and high patient acceptance of the approach.

Characterization of N-Acetyl-Tryptophan Degradation in Protein Therapeutic Formulations.

N-Acetyl-tryptophan (NAT) is used as a stabilizer for preparations of human serum albumin and has more recently been demonstrated to provide oxidative protection for labile Trp residues in monoclonal antibodies. As a component in the formulations of protein therapeutics, NAT is sacrificially degraded; therefore, understanding the identity and quantity of NAT degradants potentially formed in these drug products is essential to understanding the potential patient impact of this additive. Here, we report a simple reversed-phase chromatography approach that allows systematic investigation of NAT degradation in relevant formulations under stressed conditions. Screening a panel of NAT-containing samples following a variety of forced stress conditions led to a range of NAT degradation from minimal (3%) to significant (83%). NAT degradants were observed to be largely conserved between oxidative and thermal stress conditions. Online mass spectrometry and standard compound synthesis allowed for identification of the major degradants in the stressed sample panel. NAT degradation was minimal under recommended storage conditions and in relevant thermal stress conditions for a representative protein therapeutic drug product, suggesting that NAT is stable under normal manufacturing, storage, and handling conditions. This work supports the use of NAT as an antioxidant in liquid drug product formulations.