Efficacy and safety of paliperidone palmitate 6-monthly long-acting injectable in reduction of relapses in patients with schizophrenia: An Asian subgroup analysis of phase 3, randomized study.

BACKGROUND: Evaluate efficacy and safety of paliperidone palmitate 6-monthly (PP6M) for patients with schizophrenia in the Asian subgroup of a global, multicenter, noninferiority phase-3 study (NCT03345342). METHODS: Patients received paliperidone palmitate 1-monthly (PP1M, 100/150 mg eq.) or paliperidone palmitate 3-monthly (PP3M, 350/525 mg eq.) during the maintenance phase and entered a 12-month double-blind (DB) phase, wherein they were randomized (2:1) to PP6M (700/1000 mg. eq.) or PP3M (350/525 mg eq.). Subgroup analysis was performed for 90 (12.7%) patients from Asia region (India, Taiwan, Malaysia, Hong Kong, and Korea). Primary endpoint was time-to-relapse during DB phase (Kaplan-Meier estimates). Secondary endpoints were changes from baseline in Positive and Negative Syndrome Scale, Clinical Global Impression-Severity scale, Personal and Social Performance (PSP) scale score. RESULTS: In Asian subgroup, 91.9% (82/90) of patients completed DB phase (PP6M: 54/62 [87%]; PP3M: 28/28 [100%]). Median time-to-relapse was "not-estimable" due to low relapse rates in both groups. Estimated difference (95% confidence interval [CI]) between relapse-free patients in PP6M and PP3M groups of Asian subgroup was -0.1% [-8.5%, 8.4%] (global study population: -2.9% [-6.8%, 1.1%]). Mean change from baseline in secondary efficacy parameters was comparable between both groups, similar to the global study population. The incidence of extrapyramidal symptoms was higher in the Asian subgroup than in the global study population. CONCLUSION: Consistent with the global study population, PP6M was noninferior to PP3M in preventing relapse in patients with schizophrenia from the Asia region. Findings suggest the possibility of switching from PP1M/PP3M to twice-yearly PP6M without loss of efficacy and with no unexpected safety concerns.

The Effect of Longer Dosing Intervals for Long-Acting Injectable Antipsychotics on Outcomes in Schizophrenia.

Medication nonadherence in schizophrenia can have serious implications including relapses and hospitalization. Long-acting injectable (LAI) antipsychotics require fewer administrations, while ensuring sustained medication coverage. In this review, we summarize the expected real-world benefits of longer dosing intervals in the management of schizophrenia. LAIs are associated with improved clinical outcomes of less frequent relapses and reduced functional impairment, encouraging patients to regain control of their lives. Aripiprazole lauroxil and paliperidone palmitate three-monthly (PP3M) LAIs have longer dosing intervals of 2-3 months and provide improved outcomes in patients with schizophrenia. Paliperidone palmitate six-monthly (PP6M) LAI provides the longest dosing interval, twice-yearly dosing, among existing LAIs. Decreasing the frequency of LAI administrations has the potential to reduce occurrence of serious outcomes associated with poor medication adherence. By eliminating the need for daily oral antipsychotic dosing, LAIs could increase the likelihood of patient acceptance, decrease stigma, and promote self-esteem. Longer intervals of medication coverage may be desirable for patients with higher risk of relapse including adults with recent-onset schizophrenia, those living in circumstances that may deprive them of regular access (eg, homeless), those that are in transitions between care settings or to reduce interpersonal contact during public health emergencies (eg, COVID-19 pandemic).

Stroke Risk Among Non-Elderly Users of Haloperidol or First-Generation Antipsychotics vs Second-Generation Antipsychotics: A Cohort Study from a US Health Insurance Claims Database.

BACKGROUND: Previous studies have reported an increased risk of stroke in patients taking antipsychotics. However, most of these studies have been conducted in the elderly population. OBJECTIVE: We estimated stroke risk in new users of any first-generation antipsychotic or haloperidol, vs second-generation antipsychotics among patients aged 18-64 years without a recent dementia diagnosis and, separately, regardless of a recent dementia diagnosis. METHODS: Data were obtained from IBM MarketScan® Commercial Database (1 January, 2001-31 December, 2017). Among new users without a recent dementia diagnosis, stroke risk for first-generation antipsychotics (FGAw/oD cohort) or haloperidol (HALw/oD cohort) was compared with second-generation antipsychotics (SGAw/oD cohort). A similar comparison was conducted among new users regardless of dementia diagnosis: first-generation antipsychotics (FGA cohort) or haloperidol (HAL cohort) vs second-generation antipsychotics (SGA cohort). Crude incident stroke rates within each cohort were determined. For hazard ratios, three propensity score matching strategies were used: unadjusted (crude), Sentinel propensity score strategy, and large-scale regularized regression model (adapted propensity score strategy). RESULTS: Each cohort included ≥12,000 patients. The incident rates for stroke per 1000 person-years were 3.10 (FGAw/oD), 5.99 (HALw/oD), 0.85 (SGAw/oD), 3.14 (FGA), 6.12 (HAL), and 0.90 (SGA). Pre-planned analysis with adapted propensity score strategy matching yielded calibrated hazard ratios for stroke: FGAw/oD vs SGAw/oD: 2.05 (calibrated confidence interval 1.13-3.89); HALw/oD vs SGAw/oD: 2.47 (1.14-5.48), FGA vs SGA: 1.64 (0.94-2.97), and HAL vs SGA: 1.98 (0.99-4.00). A post-hoc sensitivity analysis to address potential bias introduced by the 2015 change from the International Classification of Diseases, Ninth Revision to the International Classification of Diseases, Tenth Revision yielded calibrated hazard ratios for FGAw/oD vs SGAw/oD: 1.59 (0.87-3.01), HALw/oD vs SGAw/oD: 2.79 (1.24-6.42), FGA vs SGA: 1.41 (0.79-2.62), and HAL vs SGA: 3.47 (1.63-7.92). CONCLUSIONS: Among adults aged ≤64 years, without a recent dementia diagnosis, stroke risk is higher among those exposed to haloperidol compared with those exposed to second-generation antipsychotics.