The biggest selling inhalable drug for the treatment of asthma and/or chronic obstructive pulmonary disease is GlaxoSmithKline’s (GSK) Seretide/Advair (fluticasone + salmeterol) with sales of GBP 4,977 million (US$7,794 million) in 2009. The next best sellers are AstraZeneca’s Symbicort (budesonide + formoterol), with sales of US$2,294 million in 2009, and Boehringer Ingelheim’s Spiriva (tiotropium), with sales of Euros 2,070 million (US$3,046 million) in 2008.

GSK’s combination patent on Seretide/Advair will expire in the US in September 2010 and in most European markets in 2013. The UK patent has already been revoked. Combination patents covering Symbicort have been revoked in Europe, and AstraZeneca’s data exclusivity will end in August 2010. The US patents for Symbicort begin to expire in 2011. The US patents for Spiriva begin to expire from December 2012, although there are patents running right up to 2023.

The number of patent challenges suggests the opportunities for generic inhalation and nasal spray drugs are worth pursuing, even if this results in lengthy legal battles.

However, collaboration may be the way forward, a case in point when considering AstraZeneca’s Pulmicort (budesonide inhalation suspension). After several years of claims and litigation, between 2005 and 2008, Teva Pharmaceutical Industries’ generic version was finally launched in December 2009 under an exclusive licence from AstraZeneca.

With high-profile inhalable drugs coming off patent, the prospects for the generic sector look promising – but only if companies can overcome production, regulatory and litigation hurdles.

Reference:

Espicom. Emerging Opportunities in Inhalation & Nasal Spray Generic Drugs 2010. 12 March 2010