FDA tracks rising impact of the 'placebo effect' in antipsychotic trials

One of the big conundrums in the neurosciences branch of drug discovery is the ever-present threat that a therapy that delivered sterling proof-of-concept data in Phase II will go down to defeat in late-stage studies, often because the placebo response suddenly spikes. That placebo wild card helped drive GlaxoSmithKline ($GSK) and others out of CNS. And now a study by the FDA underscores how rising placebo responses have been eroding the treatment benefits that have been recorded in schizophrenia studies over the past two decades.

The investigators set out to see how the second-generation antipsychotics compared to some of the breakthrough medications studied in the early '90s. Dr. Thomas P. Laughren, who runs the agency's division of psychiatry products, concluded that the rising placebo response made it appear that the more expensive second-gen therapies--like Risperdal and Zyprexa--had a smaller effect on patients.

The rising placebo response has had a definite impact on the odds of success in clinical studies, says Laughren, according to a Reuters report. Theoretically, the placebo response could be due to the better relative health of patients being recruited for the studies. But frankly, the FDA doesn't know exactly what caused it. And now Laughren plans to dig deeper, studying the individuals included in trials.

If they are successful, Reuters notes, the FDA researchers could help developers blueprint better trial designs, coming up with better patient selection processes, new standards on trial duration or measuring symptoms that are more likely to highlight the treatment effect.  

- here's the story from Reuters