A new report notes that drugs in the USA experience the greatest degree of brand erosion following patent expiry and exposure to direct generic competition.

The analysis, from Datamonitor, notes that following the USA, brand erosion is next most severe in the UK, Germany, and France, and lowest in Australia, Italy, Russia, Spain, and Japan. It notes that brands tended not to suffer too badly in China following patent expiry since they often face generic competition from the outset "and instead continue to grow both in terms of volume and value.

Brand erosion was greater "in terms of speed and severity" in the hospital setting, the study notes, most likely reflecting the greater brand loyalty among patients in the retail setting. In terms of therapy areas, sales and volume erosion was the greatest among infectious disease, oncology and cardiovascular small molecule brands.

Maura Musciacco, healthcare analyst at Datamonitor says that medicines across the Atlantic, "regarded as the most mature of all generics markets, experienced the greatest degree of brand erosion following patent expiry and exposure to direct generic competition". She notes that on average, sales and volume decline by 72% and 70%, respectively, after six months of generic competition.

Ms Musciacco added that the key driver for the uptake of generics "is the cost-savings they bring, a quality that is undoubtedly even more in demand as the USA contemplates adoption of universal healthcare".