Weight and metabolic changes in patients with schizophrenia treated with paliperidone palmitate 6-month formulation versus paliperidone palmitate 3-month formulation: a post-hoc analysis.
OBJECTIVE: To determine the effect that paliperidone palmitate 6-month long-acting injectable formulation (PP6M) had on metabolic parameters including body weight (BW), and blood lipid profiles, a post-hoc analysis was conducted to assess changes in BW from baseline to the end of study based on age, body mass index (BMI), and changes in blood lipid profiles during a 12-month, phase 3, double-blind (DB) clinical study. Long term effects of PP6M on BW and BMI were further explored during a 24-month extension study in which participants were treated exclusively with PP6M. METHOD: In the 12-month DB phase, participants were randomized to receive PP6M or paliperidone palmitate 3-month long-acting injectable formulation (PP3M). The mean change in BW and abnormal weight percent change from baseline were calculated at endpoint by age, gender, and BMI. Additionally, treatment-emergent shifts from baseline for the four key lipid parameters (fasting low density lipoprotein [LDL], fasting triglycerides [TG], fasting total cholesterol [TC], and fasting high density lipoprotein [HDL]) during DB were assessed. Following this study, participants were given the opportunity to transition to a 24-month extension study and be treated with PP6M. The mean change and percent change in BW, and the mean change in BMI from DB baseline to the end of the extension study (36 months total) were calculated. RESULTS: Participants who were treated with PP6M showed numerically less weight gain, BMI, waist circumference, and more weight decrease compared to PP3M group during 12-month DB phase, though the proportion of participants reporting an abnormal change (≥7% change) in BW did not significantly differ between PP3M and PP6M. The weight differences were more pronounced in the younger age group (18-25 years) and those who were overweight (BMI: 25 to <30 kg/m2. Numerical differences in favor of PP6M were found in fasting blood lipids (HDL, LDL, TG, and TC). The changes in BW and BMI over time remained consistent throughout the 24-month extension, favoring PP6M in each instance. CONCLUSIONS: This post-hoc analysis demonstrated that PP6M was comparable to PP3M in terms of metabolic parameters; however, it may have a beneficial effect on weight gain, especially in young patients. TRIAL REGISTRATION: Post-Hoc Analysis of Studies NCT03345342 and NCT04072575 (ClinicalTrials.gov). Significant outcomes The findings from this study have highlighted that participants who were treated with the 6-month long-acting injectable formulation of paliperidone exhibited less weight gain during treatment overall, and significantly less weight gain in adolescents and young adults. Importantly, this trend continued over the course of long-term treatment, regardless of age. Participants treated with the 6-month formulation also had fewer shifts in blood lipids outside of the normal range and had more favorable changes in body mass index and waist circumference. These results suggest that when considering metabolic dysregulation as a factor in choosing a long-acting injectable antipsychotic, the 6-month formulation is a viable alternative to the 3-month formulation, particularly in younger patients with schizophrenia. Limitations Because this is a post hoc analysis and the study was not powered to test weight and metabolic changes, most endpoints were summarized descriptively and the statistical test was limited to the main endpoint (abnormal percent weight gain and loss).