Efficacy and Safety of Paliperidone Palmitate 6-Month versus Paliperidone Palmitate 3-Month Long-Acting Injectable in European Patients with Schizophrenia: A Post Hoc Analysis of a Global Phase-3 Double-Blind Randomized Non-Inferiority Study

Purpose

To examine efficacy and safety of paliperidone palmitate (PP) 6-month (PP6M) vs PP3-month (PP3M) long acting injectable (LAI) in patients with schizophrenia from European sites previously stabilized on PP3M or PP1-month (PP1M).

Methods

This post-hoc subgroup analysis used data from a global phase-3 double-blind (DB) randomized non-inferiority study (NCT03345342). Patients were randomized (2:1, respectively) to receive dorsogluteal injections of PP6M (700 mg eq. or 1000 mg eq.) or PP3M (350 mg eq. or 525 mg eq.) in the 12-month DB phase. Primary endpoint was time-to-relapse during the DB phase, using a Kaplan-Meier cumulative survival estimate (non-inferiority margin 95% CI lower bound larger than prespecified as -10%). Treatment emergent adverse events (TEAEs), physical examinations, and laboratory tests were also evaluated.

Results

A total of 384 patients who entered the DB phase were included in European sites (PP6M, n = 260; PP3M, n = 124) with a mean age similar in both groups (mean age [SD] years: PP6M, 40.0 [11.39]; PP3M, 38.8 [10.41]). Baseline characteristics were similar across both groups. The number of patients who experienced a relapse during DB phase were PP6M: 18 (6.9%) vs PP3M: 3 (2.4%) with percentage relapse-free difference of -4.9% (95% CI: -9.2%, -0.5%), thus achieving non-inferiority criteria. Secondary efficacy endpoints indicated comparable improvements. Incidence of TEAEs was similar between PP6M (58.8%) and PP3M (54.8%) groups. Nasopharyngitis, headache, increased weight, and injection-site pain were the most common TEAEs.

Conclusion

The efficacy of PP6M was non-inferior to that of PP3M in preventing relapse in the European subgroup previously treated with PP1M or PP3M, which was consistent with the global study. No new safety signals were identified.

A Randomized, Double-Blind, Multicenter, Noninferiority Study Comparing Paliperidone Palmitate 6-Month Versus the 3-Month Long-Acting Injectable in Patients With Schizophrenia

BACKGROUND

This double-blind (DB), randomized, parallel-group study was designed to evaluate efficacy and safety of paliperidone palmitate 6-month (PP6M) formulation relative to paliperidone palmitate 3-month (PP3M) formulation in patients with schizophrenia.

METHODS

Following screening, patients entered an open-label (OL) maintenance phase and received 1 injection cycle of paliperidone palmitate 1-month (PP1M; 100 or 150 mg eq.) or PP3M (350 or 525 mg eq.). Clinically stable patients were randomized (2:1) to receive PP6M (700 or 1000 mg eq., gluteal injections) or PP3M (350 or 525 mg eq.) in a 12-month DB phase; 2 doses of PP6M (corresponding to doses of PP1M and PP3M) were chosen.

RESULTS

Overall, 1036 patients were screened, 838 entered the OL phase, and 702 (mean age: 40.8 years) were randomized (PP6M: 478; PP3M: 224); 618 (88.0%) patients completed the DB phase (PP6M: 416 [87.0%]; PP3M: 202 [90.2%]). Relapse rates were PP6M, 7.5% (n = 36) and PP3M, 4.9% (n = 11). The Kaplan-Meier estimate of the difference (95% CI) between treatment groups (PP6M - PP3M) in the percentages of patients who remained relapse free was -2.9% (-6.8%, 1.1%), thus meeting noninferiority criteria (95% CI lower bound is larger than the pre-specified noninferiority margin of -10%). Secondary efficacy endpoints corroborated the primary analysis. Incidences of treatment-emergent adverse events were similar between PP6M (62.1%) and PP3M (58.5%). No new safety concerns emerged.

CONCLUSIONS

The efficacy of a twice-yearly dosing regimen of PP6M was noninferior to that of PP3M in preventing relapse in patients with schizophrenia adequately treated with PP1M or PP3M.

TRIAL REGISTRATION

Clinical Trials.gov identifier: NCT03345342.

Efficacy and Safety of Paliperidone Palmitate 3-Month Formulation for Patients with Schizophrenia: A Randomized, Multicenter, Double-Blind, Noninferiority Study

BACKGROUND

This double-blind, parallel-group, multicenter, phase-3 study was designed to test the noninferiority of paliperidone palmitate 3-month formulation (PP3M) to the currently marketed 1-month formulation (PP1M) in patients (age 18-70 years) with schizophrenia, previously stabilized on PP1M.

METHODS

After screening (≤3 weeks) and a 17-week, flexible-dosed, open-label phase (PP1M: day 1 [150mg eq. deltoid], day 8 [100mg eq. deltoid.], weeks 5, 9, and 13 [50, 75, 100, or 150mg eq., deltoid/gluteal]), clinically stable patients were randomized (1:1) to PP3M (fixed-dose, 175, 263, 350, or 525mg eq. deltoid/gluteal) or PP1M (fixed-dose, 50, 75, 100, or 150mg eq. deltoid/gluteal) for a 48-week double-blind phase.

RESULTS

Overall, 1016/1429 open-label patients entered the double-blind phase (PP3M: n=504; PP1M: n=512) and 842 completed it (including patients with relapse). PP3M was noninferior to PP1M: relapse rates were similar in both groups (PP3M: n=37, 8%; PP1M: n=45, 9%; difference in relapse-free rate: 1.2% [95% CI:-2.7%; 5.1%]) based on Kaplan-Meier estimates (primary efficacy). Secondary endpoint results (changes from double-blind baseline in positive and negative symptom score total and subscale scores, Clinical Global Impression-Severity, and Personal and Social Performance scores) were consistent with primary endpoint results. No clinically relevant differences were observed in pharmacokinetic exposures between PP3M and PP1M. Both groups had similar tolerability profiles; increased weight was the most common treatment-emergent adverse event (double-blind phase; 21% each). No new safety signals were detected.

CONCLUSION

Taken together, PP3M with its 3-month dosing interval is a unique option for relapse prevention in schizophrenia.