Long-term Efficacy and Safety of Paliperidone 6-month Formulation: An Open-label 2-year Extension of a 1-year Double-blind Study in Adult Participants With Schizophrenia.

Abstract

Paliperidone palmitate 6-month (PP6M) demonstrated noninferiority to paliperidone palmitate 3-month (PP3M) in preventing relapse in patients with schizophrenia in a phase-3 double-blind (DB) study (NCT03345342). Here, we report long-term efficacy and safety results from a 2-year single-arm, open-label extension (OLE; NCT04072575) of this DB study. Participants who completed the DB study without relapse were enrolled and followed-up every 3 months up to 2 years. Participants received 4 PP6M gluteal-injections (700/1000mg eq.) at baseline, 6-month, 12-month, and 18-month visits. Efficacy endpoints included assessment of relapse, Positive and Negative Syndrome Scale (PANSS) total score, Personal and Social Performance (PSP) score, and Clinical Global Impression-Severity (CGI-S) scale change from baseline. Safety was assessed by treatment-emergent adverse events (TEAEs), physical examinations, and laboratory tests. Of 178 participants enrolled, 154 (86.5%) completed the OLE; mean age: 40.4 years, men: 70.8%. Mean duration of PP6M exposure during OLE was 682.1 days. Overall, 7/178 (3.9%) participants relapsed between 20-703 days after enrolment. Mean (SD) change from baseline to endpoint: PANSS total score, 0.7 (8.22); CGI-S, 0.0 (0.51); PSP Scale, 0.5 (7.47). Overall, 111/178 participants (62.4%) reported ≥1 TEAE; most common (>5%) TEAEs were headaches (13.5%) and increased blood prolactin/hyperprolactinemia (18.0%); 8/178 (4.5%) participants experienced serious TEAEs, and 6/178 (3.4%) participants withdrew due to TEAEs; no deaths were reported. The relapse rate observed with PP6M during the 2-year OLE was low (3.9%). Clinical and functional improvements demonstrated in the DB study were maintained during OLE and no new safety concerns were identified.