BACKGROUNDTV-46000 is a long-acting subcutaneous antipsychotic (LASCA) formulation of risperidone that is approved by the United States Food and Drug Administration for the treatment of schizophrenia in adults. In the phase 3, randomized, double-blind RIsperidone Subcutaneous Extended-release (RISE) study, TV-46000 once monthly (q1m) and once every 2 months (q2m) significantly prolonged time to impending relapse compared with placebo [5.0-fold (q1m) and 2.7-fold (q2m)]. This phase 3, randomized, double-blind Safety in Humans of TV-46000 subcutaneous INjection Evaluation (SHINE) study was designed to evaluate the long-term safety, tolerability, and exposure of TV-46000 in schizophrenia.METHODSPatients who completed RISE without relapse (rollover) or who were newly recruited (de novo) were eligible for the SHINE study. Patients were initially stabilized on oral risperidone for 12 weeks (completed in RISE for rollover, or in SHINE for de novo). Patients in the de novo cohort and patients who received placebo in RISE were randomized 1:1 in SHINE to receive TV-46000 q1m or q2m for up to 56 weeks. Primary endpoint for SHINE was frequency of reported adverse events (AEs); event rates [ER; events per 100 patient-years (PYs)] were calculated for each AE by patients upon general questioning.RESULTSOverall, 336 patients were randomized in SHINE [TV-46000 q1m, n = 174; TV-46000 q2m, n = 162; of these, de novo, n = 109 and rollover, n = 227 (n = 172 patients were treated and n = 55 received placebo)]. A total of 334 patients were evaluated for safety [q1m, n = 172 (PY = 97.8); q2m, n = 162 (PY = 104.5)]. Proportions of patients (ER) with ≥ 1 AE and ≥ 1 treatment-related AE were 37% (180.0) and 21% (84.9) for TV-46000 q1m and 46% (157.9) and 20% (70.8) for TV-46000 q2m, respectively. Frequent treatment-related AEs [≥ 3% of patients in either group; proportion of patients (ER)] were injection site pain [q1m, 5% (24.5); q2m, 4% (22.0)] and injection site nodule [q1m, 2% (9.2); q2m, 6% (12.4)]. The proportions of patients with serious AEs was 5% for TV-46000 q1m and 7% for TV-46000 q2m; serious AEs reported for ≥ 2 patients overall were worsening schizophrenia [q1m, n = 1 (< 1%; ER, 1.02); q2m, n = 2 (1%; ER, 1.91)] and hyperglycemia [q1m, n = 1 (< 1%; ER, 1.02); q2m, n = 1 (< 1%; ER, 0.96)]. Of three reported deaths, none were related to treatment. Overall, eight patients discontinued treatment because of AEs. Similar or somewhat lower rates of AEs were reported for patients who rolled over from TV-46000 treatment compared with those who had no prior TV-46000 treatment (de novo and placebo rollover). Most AEs related to injection site reactions were mild; no patient had a severe reaction.CONCLUSIONResults from this long-term safety study add to the favorable safety profiles of TV-46000 q1m and q2m, consistent with other formulations of risperidone and previous studies with TV-46000.REGISTRATIONClinicalTrials.gov, NCT03893825; 27 March 2019.