Patent expiry for 2008 provides generic opportunity

Seven blockbuster drugs face patent expiry in the USA during the course of 2008, according to IMS Health data, providing opportunities for generic drugmakers to continue the recent trend of market expansion. In the 2002-2006 period, the proportion of prescriptions dispensed for generic products increased from 40% to 54%, with branded generics falling back from 11% to 9%.

The affected US blockbusters include Anglo-Swedish drug major AstraZeneca's Betaloc/Toprol-XL (metoprolol), a beta blocker, as well as UK-based GlaxoSmithKline's Seretide/Advair (fluticasone propionate/salmeterol), for asthma and chronic obstructive pulmonary disorder, and Lamictal (lamotrigine), for the treatment of epilepsy and bipolar disorder. US drug majors Wyeth and Merck & Co lose market exclusivity for, respectively, Effexor (venlafaxine), a serotonin-norepinephrine reuptake inhibitor, and osteoporosis drug Fosamax (alendronate sodium). US health care majors Johnson & Johnson and Abbott Laboratories both have anti-epileptic drugs coming off patent in the current year: Topamax (topiramate) and Valcote/Depakote (divalproex sodium).

With the USA representing 45% of the global drugs market, the relative impact of generic competition in other countries is less significant. However, the Effexor patent also expires in France, Germany and the UK in 2008. Additionally, AstraZeneca loses market exclusivity for its prostate therapy Casodex (bicalutamide) in both France and the UK. Seretide/Advair faces generic competition in the UK, while Japan-based Eisei's proton pump inhibitor Pariet (rabeprazole) faces competition in France.