New clinical data from the wide-ranging CATIE study of schizophrenia drugs suggests that Novartis’ long-in-the-tooth Clozaril is more effective than rival drugs as a second-line therapy.

CATIE first hit the headlines last year after its initial findings suggested that an old, generically-available drug called perphenazine was as effective as newer, more expensive antipsychotics such as Eli Lilly’s Zyprexa (olanzapine), Johnson & Johnson’s Risperdal (risperidone), Pfizer’s Geodon (ziprasidone) and AstraZeneca’s Seroquel (quetiapine).

The $42.6 million study, funded by the US government, is scheduled to generate various other results over the coming months and years to help guide physicians on the selection of drugs to treat schizophrenia.

The latest data, dubbed CATIE phase 2 and published in the April issue of the American Journal of Psychiatry, show that after patients had failed to respond to one drug and were switched to another ‘rescue’ medication at random, Clozaril (clozapine) performed the best, with efficacy measured according to how long the patient remained on treatment with the drug.

The authors note that this is unsurprising, as Clozaril’s efficacy is well-regarded. In fact, drugmakers have been trying for years to develop an antipsychotic that offers Clozaril’s efficacy without its serious side effects, notably neutropenia and myocarditis.

A second study in the AJP also revealed that in patients who chose not to take Clozaril as a second-line option, Zyprexa and Risperdal performed better than Geodon and Seroquel.