The FDA approved Invega (paliperidone), a once-daily extended-release version of Johnson & Johnson’s blockbuster schizophrenia drug, Risperdal.While paliperidone is derived from Risperdal (risperidone), the oral medication qualifies as a new atypical antipsychotic, the FDA said. The tablet is slated to be launched by J&J’s Janssen unit in January.Analysts offered a mixed outlook for the drug, whose label included an unexpected warning that it could increase the risk of a potentially fatal heart side effect, QT prolongation. A similar warning has hampered uptake of Pfizer’s Geodon. Still, Invega’s warning is said to be less severe than Geodon’s, and analysts say J&J hopes to switch a large portion of Risperdal sales to Invega during the 18 months left before Risperdal goes off patent in 2008.A JP Morgan analyst forecasted Invega sales of $488 million in 2007, growing to $1.78 billion by 2009, noted CNNMoney.com.US sales of atypical antipsychotics reached $10.5 billion in 2005, according to IMS Health, with Risperdal accounting for $2.3 billion of that.Janssen also markets a long-acting injection form of risperidone, Risperdal Consta, which is given every two weeks. J&J said Invega is the first new FDA-approved treatment for schizophrenia since 2003 and the first to include information in its labeling about personal and social functioning, which are key issues for these patients and their families.