CNS drug developers face long stretch in the clinic, poor odds of success

The exodus of Big Pharma companies from the CNS drug development field has put a bright spotlight on the hurdles any developer faces when tackling a tricky disease like Alzheimer's. Clinical failures are routine, costs are high and the science often poses a complex riddle for clinical execs. Now the Tufts Center for the Study of Drug Development has quantified just how much more time and effort is required for a CNS program. And the bottom line is daunting.

Looking over the track record of CNS drugs from 1996 to 2010, Tuft's Joe DiMasi found that the mean clinical time required for each treatment was 102.1 months--more than 8 years. That's 40% longer than non-CNS drugs over the same time span. And the mean time needed to gain an approval over that period was 20.3 months, 13% longer than the rest of the disease categories. The combined mean average was 35% longer, a 32-month difference.

DiMasi tells FierceBiotech this morning that he wasn't surprised to find a difference in timelines between CNS drugs and non-CNS treatments, "but the extent of the difference was somewhat surprising."

Not only did the programs take more time, they're also much more likely to fail. Looking at self-originated CNS drugs--treatments that were developed by a single company from start to finish--the success rate was one in 10 between 1993 and 2004, compared to an overall average of one in six. Interestingly, though, despite the added time factor, cost and risk of failure, developers have been steadily upping the ante. DiMasi found a 6 percent annual growth rate for CNS drugs in the pipeline, with the total share swelling to 11%.

"Despite the longer and more costly development associated with CNS drugs, the CNS new product pipeline is among the richest in the R&D-based drug industry," noted DiMasi.He tells us that trend should continue "in the short term because there are a ot of drugs in the pipeline." But high-level pharma departures "suggest in the long-term less development."

- here's the press release on the study