Overlooking Subvisible Particles in Therapeutic Protein Products: Gaps that may Compromise Product Quality

Therapeutic protein products provide unique and effective treatments for numerous human diseases and medical conditions. In many cases, these treatments are used chronically to slow disease progression, reduce morbidity and/or to replace essential proteins that are not produced endogenously in patients. Therefore, any factor that reduces or eliminates the effectiveness of the treatment can lead to patient suffering and even death. One means by which efficacy of therapeutic proteins can be compromised is by an immune response, resulting in antibody-mediated neutralization of the protein’s activity or alterations in bioavailability.1,2 For example, in the case of treatment of hemophilia A, neutralizing antibodies to Factor VIII can cause life-threatening bleeding episodes, resulting in significant morbidity and necessitating treatment with a prolonged course of a tolerance-inducing therapy to reverse immunity.3,4 In other cases, drug-induced antibodies to a therapeutic version of an endogenous protein can cross-react with and neutralize the patient’s endogenous protein. If the endogenous protein serves a non-redundant biological function, such an immune response can have devastating results. For example, pure red cell aplasia can result from neutralizing antibodies to epoetin alpha. 1,2 It is well established that protein aggregates in therapeutic protein products can enhance immunogenicity2, and such an effect is therefore an important risk factor to consider when assessing product quality. The purpose of this commentary is to accomplish the following: i. provide brief summaries on the factors affecting protein aggregation and the key aspects of protein aggregates that are associated with immunogenicity; ii. emphasize the current scientific gaps in understanding and analytical limitations for quantitation of species of large protein aggregates that are referred to as subvisible particles, with specific consideration of those particles 0.1–10 μm in size; iii. offer a rationale for why these gaps may compromise the safety and/or efficacy of a product; iv. provide scientifically sound, risked based recommendations/conclusions for assessment and control of such aggregate species

The Relationship between Impulsive Choice and Impulsive Action: A Cross-Species Translational Study

Maladaptive impulsivity is a core symptom in various psychiatric disorders. However, there is only limited evidence available on whether different measures of impulsivity represent largely unrelated aspects or a unitary construct. In a cross-species translational study, thirty rats were trained in impulsive choice (delayed reward task) and impulsive action (five-choice serial reaction time task) paradigms. The correlation between those measures was assessed during baseline performance and after pharmacological manipulations with the psychostimulant amphetamine and the norepinephrine reuptake inhibitor atomoxetine. In parallel, to validate the animal data, 101 human subjects performed analogous measures of impulsive choice (delay discounting task, DDT) and impulsive action (immediate and delayed memory task, IMT/DMT). Moreover, all subjects completed the Stop Signal Task (SST, as an additional measure of impulsive action) and filled out the Barratt impulsiveness scale (BIS-11). Correlations between DDT and IMT/DMT were determined and a principal component analysis was performed on all human measures of impulsivity. In both rats and humans measures of impulsive choice and impulsive action did not correlate. In rats the within-subject pharmacological effects of amphetamine and atomoxetine did not correlate between tasks, suggesting distinct underlying neural correlates. Furthermore, in humans, principal component analysis identified three independent factors: (1) self-reported impulsivity (BIS-11); (2) impulsive action (IMT/DMT and SST); (3) impulsive choice (DDT). This is the first study directly comparing aspects of impulsivity using a cross-species translational approach. The present data reveal the non-unitary nature of impulsivity on a behavioral and pharmacological level. Collectively, this warrants a stronger focus on the relative contribution of distinct forms of impulsivity in psychopathology

Are Actual and Perceived Intellectual Self–enhancers Evaluated Differently by Social Perceivers?

Do actual and perceived self-enhancement entail differing social impressions (i.e. interpersonal evaluations)? Actual self-enhancement represents unduly positive self-views, as gauged by an objective criterion (in this case, IQ scores), whereas perceived self-enhancement involves the extent to which an individual is seen by informants (i.e. peers or observers) as self-enhancing. In an online survey (N = 337), a laboratory experiment (N = 75), and a round-robin study (N = 183), we tested the effects of actual and perceived intellectual self-enhancement on (informant-rated) emotional stability, social attractiveness, and social influence. Actual self-enhancers were rated as emotionally stable, socially attractive, and socially influential. High perceived self-enhancers were judged as socially influential, whereas low-to-moderate perceived self-enhancers were deemed emotionally stable and socially attractive. Privately entertained, illusory positive (even extreme) self-beliefs confer social benefits, whereas being perceived as self-enhancing buys social influence at the cost of being despised