Incidence and time course of extrapyramidal symptoms with oral and long-acting injectable paliperidone: a posthoc pooled analysis of seven randomized controlled studies

Srihari Gopal,¹ Yanning Liu,¹ Larry Alphs,² Adam Savitz,¹ Isaac Nuamah,¹ David Hough<sup>1

1</sup>Janssen Research and Development, LLC, Raritan, ²Janssen Scientific Affairs, LLC, Titusville, NJ, USA

Background: The purpose of this study was to compare incidence rates and time course of extrapyramidal symptom (EPS)-related treatment-emergent adverse events (TEAEs) between oral and long-acting injectable (LAI) paliperidone.
Methods: The analysis included pooled data (safety analysis set, 2,256 antipsychotic-treated and 865 placebo-treated patients with schizophrenia) from seven randomized, double-blind, placebo-controlled paliperidone studies (three oral [6 weeks each] and four LAI [9–13 weeks]) and assessed comparable doses (oral, 3–15 mg; LAI, 25–150 mg eq. [US doses 39–234 mg]). We summarized incidence rates and time of onset for EPS-related TEAE, categorized by EPS group terms, ie, tremor, dystonia, hyperkinesia, parkinsonism, and dyskinesia, and use of anti-EPS medication. Mean scores over time for the Abnormal Involuntary Movement Scale (AIMS, for dyskinesia), Barnes Akathisia Rating Scale (BARS, for akathisia), and Simpson Angus Rating Scale (SAS, for parkinsonism) were graphed.
Results: Incidence rates for all categories of spontaneously reported EPS-related TEAEs except for hyperkinesia, were numerically lower in pooled LAI studies than in pooled oral studies. Highest rates were observed in the first week of paliperidone-LAI (for all EPS symptoms except dyskinesia) and oral paliperidone treatment (except parkinsonism and tremor). Anti-EPS medication use was significantly lower in LAI (12%) versus oral studies (17%, P = 0.0035). Mean values for EPS scale scores were similar between LAI and oral treatment at endpoint, and no dose response was evident. Mean reductions (standard deviation) from baseline to endpoint in EPS scale scores were larger for LAI (AIMS, −0.10 [1.27]; BARS, −0.09 [1.06]; SAS, −0.04 [0.20]) versus oral studies (AIMS, −0.08 [1.32]; BARS, −0.03 [1.24]; SAS, 0.0 [0.23]). These changes favored LAI for BARS (P = 0.023) and SAS (P < 0.0001), but not for AIMS (P = 0.49), at endpoint for the studies.
Conclusion: In this posthoc descriptive analysis, incidence rates of spontaneously reported EPS-related TEAEs were numerically lower following approximately 90 days of exposure with LAI and approximately 40 days with oral paliperidone at comparable doses.

Keywords: antipsychotic agents, extrapyramidal symptoms, long-acting injectable, movement disorder, second-generation