FDA Approves Generic Tamiflu

Natco Pharma Ltd. has announced the final approval of its abbreviated new drug application filed with the FDA for 30-mg, 45-mg, and 75-mg oseltamivir phosphate oral capsules––a generic version of Genentech’s Tamiflu. Natco and its marketing partner Alvogen, Inc., are the first generic-drug companies to receive this approval.

Natco is located in Hyderabad, India, and Alvogen is based in Pine Brook, New Jersey.

In December 2015, Natco and Alvogen settled a patent infringement suit with Gilead Sciences, Inc., Hoffmann-La Roche Inc., F. Hoffmann-La Roche Ltd., and Genentech, Inc. Under the terms of the settlement, Alvogen will be able to market the oseltamivir phosphate capsules before the expiration of the pediatric exclusivity period listed in the FDA’s Orange Book, which is February 23, 2017.

Tamiflu is an influenza neuraminidase inhibitor indicated for the treatment of acute, uncomplicated influenza A and B in patients 2 weeks of age and older who have been symptomatic for no more than 48 hours. It is also indicated for prophylaxis of influenza A and B in patients 1 year of age and older. Tamiflu was first approved by the FDA in 1999.

Oseltamivir phosphate is an ethyl ester prodrug requiring ester hydrolysis for conversion to the active form, oseltamivir carboxylate. Oseltamivir carboxylate is an inhibitor of influenza virus neuraminidase affecting the release of viral particles.

Cases of anaphylaxis and serious skin reactions, including toxic epidermal necrolysis, Stevens–Johnson Syndrome, and erythema multiforme, have been reported in post-marketing experience with Tamiflu. In addition, there have been post-marketing reports (mostly from Japan) of delirium and abnormal behavior leading to injury, and in some cases resulting in fatal outcomes, in patients with influenza who were receiving Tamiflu.

Sources: Natco Pharma(link is external); August 3, 2016; and Tamiflu Prescribing Information(link is external); June 2016.