Janssen (NYSE:JNJ) has won FDA approval for the long-acting atypical antipsychotic Invega Hafyera (paliperidone palmitate), which will be the first six-month injectable on the U.S. market. Titusville, New Jersey–based Janssen announced that patients who intend to obtain Invega Hafyera must receive Invega Sustenna (one-month paliperidone palmitate) four at least four months beforehand. Alternatively, they can…