Drug launch curves in the modern era, a new article in the January 2017 issue of Nature Reviews: Drug Discovery, contains projections of relevance for forecasting pharmaceutical sales in the US market. Relying on unit sales for 61 innovative drugs receiving FDA approval between 2000 and 2002, the authors determined that the median product follows an S-shaped launch-to-peak penetration curve: achieving 11% of peak sales in Year 1, 31% in Year 2, 58% in Year 3, 76% in Year 4, 89% in Year 5, and 100% (i.e. peak sales) in Year 6. On an interquartile basis, time-to-peak (TTP) ranged from 4 to 9 years; the minimum TTP was 2 years and the maximum was 14.
Using data from the Supplemental Materials file we find that the average for TTP for first-in-class drugs is 5.65 years as opposed to 6.93 years for subsequent entrants. Unlike other research on the subject, however, the authors did not that there was a statistically significant relationship between entry order and TTP. But, as they note, TTP is distinct from factors such as market share and revenue potential that may be more indicative of first-mover advantage.