Long-Term Use of Paliperidone Palmitate Ensures Stability in Schizophrenia patients: JAMA

Long-acting injectable (LAI) antipsychotics are known for their potential to improve adherence and symptom control in patients with schizophrenia, thereby promoting long-term recovery. Paliperidone palmitate, administered once every six months, is the first LAI antipsychotic with such an extended dosing interval. This study aimed at evaluating the long-term outcomes of PP every 6 months in the adult schizophrenic population over a 3-year period.

This was an open-label extension of a one-year, double-blind RCT between November 20, 2017, and May 3, 2022, involving eligible adults diagnosed with schizophrenia who did not relapse after receiving fixed doses of PP every three or six months in the previous. PP doses of 546 mg were administered on Day 1 and every 6 months until month 30 as a single, once-every-six-month dorsogluteal injection. Major efficacy measures included rate of relapse in each group, and change from baseline to endpoint in the PANSS, PANSS positive, PANSS negative, and PANSS general psychopathology subscale scores, the CGI-S Scale score, the PSP Scale score, and incidence of first relapse or exacerbation, TEAEs, and lump formations at injection sites.

The key findings of the study were:

•  Among the 121 patients (83 [68.6%] male) included in the study, the mean (SD) age was 38.6 (11.24) years, and the mean (SD) duration of illness was 11.0 (9.45) years.

• At the screening of the double-blind study, 101 patients (83.5%) were on an oral antipsychotic, while 20 (16.5%) were on an LAI antipsychotic.

• During the three-year follow-up, only 5 patients (4.1%) experienced a relapse, with reasons including psychiatric hospitalization (2 patients, 1.7%), suicidal or homicidal ideation (2 patients, 1.7%), and deliberate self-injury (1 patient, 0.8%).

• Patients receiving PP every six months maintained clinical and functional stability, as evidenced by stable scores on the PANSS (mean [SD] change, −2.6 [9.96] points), CGI-S (mean [SD] change, −0.2 [0.57] points), and PSP (mean [SD] change, 3.1 [9.14] points) scales over the three-year period.

• 101 patients (83.5%) completed the 2-year OLE study. TEAEs were reported in 97 of 121 patients (80.2%), but no new safety or tolerability concerns emerged.

The study underlines the long-term therapeutic effects of dosiperidone palmitate dosing once every six months in adult patients with schizophrenia. The low rate of relapse in the six-month PP group in this setting, although PALSS, CGIS, and PSP scores were stable for more than 2 years, handsomely demonstrated the effectiveness of the treatment strategy. Moreover, the high completion rate and manageable TEAEs further support the safety and tolerability of PP.

During the 2-year OLE of the 1-year RCT, the safety and positive long-term efficacy of paliperidone palmitate, given every six months for up to 3 years, were demonstrated in adults with schizophrenia. This confirms that PP is a dependable and effective long-term intervention strategy with this illness.

Reference:

Correll, C. U., Johnston, K., Turkoz, I., Gray, J., Sun, L., Doring, M., & Sajatovic, M. (2024). Three-year outcomes of 6-month paliperidone palmitate in adults with schizophrenia: An open-label extension study of a randomized clinical trial. JAMA Network Open, 7(7), e2421495. https://doi.org/10.1001/jamanetworkopen.2024.21495