Acadia does a nice job not spinning the results. (See the press release below.) The company has another drug, pimavanserin, in trials for psychosis related to Parkinson's. That drug is also being tested for schizophrenia as an add-on to other therapies.

What's interesting is that the failed drug, ACP-104, was a metabolite of Clozapine, a very effective antipsychotic with harsh side effects. In theory, using the metabolite should result in a better drug, but it doesn't always work out this way. Sometimes, as in this case, you get something that's not effective at all.

That's a painful reminder of how little we know about biology and chemistry and how much sheer luck is still involved in inventing new medicines.