Interesting statistics from article published in Nature Reviews Drug Discovery, 2010, v. 9, p. 1
"We examined the outcomes of 66 FDA panels reviewing new drugs or new indications that took place from 1 January 2008 to 28 March 2010. We assessed whether the panel outcome was a positive, a negative or a mixed recommendation, whether the drugs are approved today, and the timing between the panel recommendation and approval if this occurred. unsurprisingly, the data show that drugs that receive a negative vote do not get approved. Additionally, a significant proportion of drugs still go through a lengthy review timeline and multiple approval cycles, or have not yet been approved after a positive vote. of 49 positive votes in the sample, 11 (22.4%) have not yet been approved and the average number of days to approval from the time of the positive
vote was 162 days (range 15–677 days)."