Sales of Brand-Name Products and Generic Competitors Before and After Market Entry of Product Line Extensions in Canada

ABSTRACTWe examined the success of product line extensions (PLEs) in Canada by studying five selected drugs, three with generic competitors (ciprofloxacin, fenofibrate, paroxetine) and two without (clarithromycin, tolterodine). Third-party prescription claims from Canada were used to examine market behavior, which was analyzed using multiple regression and ARIMA. Consistent negative associations indicated high substitutability for all products and their generics. However, this was found only for PLEs with distinct advantages (e.g., increased bioavailability, fewer side effects). PLEs may recapture some market share lost to generics, but success is product-specific and likely depends on the extent of the PLE's therapeutic advantage over the originator.