Estimating the Value of Adding 30 Days to the 180-Day Market Exclusivity of the First-to-File Generic Drug...

As an additional incentive to bringing more generic drugs to more markets sooner, our aim was to estimate the value of adding 30 days to the 180 days of market exclusivity currently granted to a qualifying first-to-file (FTF) generic drug entrant after its manufacturer successfully challenges a brand drug's patents.

Using IQVIA's monthly data on drug sales in the U.S. from January 2014 through June 2021, we identified 37 generic drug markets in which one or more generic companies successfully challenged the relevant brand drug patents and began commercial marketing within 75 days of receiving final approval of their Abbreviated New Drug Application (ANDA). We compared each generic drug's sales during the last month of its 180-day exclusive market access (Month 6) with its sales during the first month after their exclusivity expired (Month 7). Our calculation of this change in sales accounted for confounding factors such as the presence of an authorized generic in the market during the exclusivity period and the number of new generic entrants in Month 7. This calculated change represents the value to the FTF manufacturer of extending the 180-day market exclusivity to 210 days.

Our analysis shows that an FTF generic experiences a 13.0% reduction in sales from Month 6 to Month 7, on average. Extending the 180-day exclusivity by 30 days could lower the magnitude of this reduction to 3.1%, resulting in a 9.8% gain in sales by the FTF generic. This gain represents about $870,000 in additional sales during Month 7, on average.

The value of an additional month of exclusivity to a generic firm is sizable and could entice more generic companies on the margin to take on the risk of patent challenges, especially in large markets.