The US Food and Drug Administration (FDA) approved the first and only antipsychotic for the acute treatment of schizoaffective disorder. Invega (paliperidone) extended-release tablets were approved for the acute treatment of schizoaffective disorder either as monotherapy or adjunctive therapy to mood stabilizers and/or antidepressants. Invega was approved in 2006 for the treatment of schizophrenia. Janssen, Division of Ortho-McNeil-Janssen Pharmaceuticals, Inc, markets Invega in the US.

Differentiating schizoaffective disorder from schizophrenia or a mood disorder can be difficult. Patients with schizoaffective disorder experience the psychosis characteristic of schizophrenia, such as hallucinations or delusions, as well as symptoms of mania and/or depression. Among people who frequently use mental health services, schizoaffective disorder may account for approximately 24 percent of cases.1

"Schizoaffective disorder can be challenging to diagnose because of the broad range of symptoms patients experience," said Nina Schooler, SUNY Downstate Medical Center. "The approval of Invega is exciting as it is the only antipsychotic treatment proven in double-blind, randomized, placebo-controlled trials to be efficacious with a demonstrated tolerable safety profile treating both the psychotic and affective symptoms present in this understudied population."

The approval is based on two international, randomized, double-blind, placebo-controlled studies of patients with an established diagnosis of schizoaffective disorder, who were experiencing acute symptoms. In the first six-week study, patients received flexible doses of Invega (3-12 mg once daily). In the other study, patients were assigned to one of two dose levels of Invega: 6 mg with the option to reduce to 3 mg, or 12 mg with the option to reduce to 9 mg. In addition to study medication, subjects were permitted to receive concomitant treatment with a mood stabilizer and/or antidepressant, provided these medications had been given at a stable dose within 30 days of screening. Approximately half the subjects enrolled received ongoing treatment with a mood stabilizer and/or antidepressant during the studies. The most commonly used mood stabilizers were valproate and lithium. The most commonly used antidepressants were SSRIs and SNRIs.

Efficacy was evaluated using the positive and negative symptom scale (PANSS), a validated multi-item inventory composed of five factors to evaluate positive symptoms, negative symptoms, disorganized thoughts, uncontrolled hostility/excitement, and anxiety/depression. As secondary outcomes, mood symptoms were evaluated using the Hamilton Depression Rating Scale (HAM-D-21) and the Young Mania Rating Scale (YMRS).

The Invega group in the flexible-dose study (dosed between 3 and 12 mg/day, mean modal dose of 8.6 mg/day) and the higher dose group of Invega in the 2 dose-level study (12 mg/day with option to reduce to 9 mg/day) were each superior to placebo in the PANSS. Numerical improvements in mood symptoms were also observed, as measured by the HAM-D-21 and YMRS. In the lower dose group of the 2 dose-level study (6 mg/day with option to reduce to 3 mg/day), Invega was not significantly different from placebo as measured by the PANSS.

The most common adverse events (incidence ³ 5 per cent and at least twice that for placebo) were extrapyramidal symptoms, somnolence, dyspepsia, constipation, weight increase, and naspharygitis.

"Schizoaffective disorder is a chronic, disabling condition," said Husseini Manji, Global Therapeutic Area head, Neuroscience, Johnson & Johnson Pharmaceutical Research & Development. "This new indication for Invega further demonstrates Janssen's commitment to helping people with serious mental illnesses."