Teva Pharmaceutical Industries has suspended testing of its generic version of Rituxan, a $7-billion a year drug, at the third stage of clinical trials.
The company is considering how best to meet the requirements from the U.S. Food and Drug Administration and those necessary for European medical certification.
Rituxan is used in the treatment of cancers such as chronic lymphocytic leukemia and non-Hodgkin lymphoma, as well as rheumatoid arthritis. The generic companies are working on biosimilar versions of the drug, which may differ from the original drug in constitution but have the same biological effect.
Rituxan itself is a monoclonal antibody, a biologically produced protein that is all but impossible to duplicate without precise information from the original maker. The purpose of Phase III clinical trials is to test the efficacy and safety of the drug.
Roche, the Swiss company that developed the brand-name Rituxan, secured global patent protection until the end of 2013, with the exception of the U.S., where the drug is protected from competition until 2018, the company has said. It is Roche's best-selling drug: Sales reached 3.3 billion Swiss francs in the first half of 2012, an increase of 8.4% from the same period of the year before. That works out to about $7.1 billion a year in sales.
Developing a biosimilar generic version of Rituxan (rituximab) is a key goal of the joint venture that Teva, the biggest generic drugmaker in the world, formed in January 2009 with the Swiss company Lonza.
Suspending third-phase clinical testing of the copycat version puts the venture behind rivals Sandoz and Celltrion, which are forging ahead with Phase III tests for oncological indications. The two companies are expected to announce the results of their tests during in the first quarter of 2013.
Assuming success, the companies are expected to receive marketing approval for their copycat version of Rituxan in the last quarter of 2014.
Regarding Rituxan's use for indications of rheumatoid arthritis, Teva is up against the South Korean kobol Samsung, which is partnering with Quintiles Transnational in development.