GlaxoSmithKline (GSK) has entered into an agreement to purchase Shenzhen Neptunus’ stake in a previously formed joint venture between the companies involved in the development and manufacture of influenza vaccines in China, Hong Kong, and Macau. GSK will pay Shenzhen Neptunus $39 million, after which GSK will be the sole owner of the joint venture company, Shenzhen GSK-Neptunus Biologicals (GSKNB).

GSKNB was established by GSK and Shenzhen Neptunus in June 2009, to develop and manufacture seasonal and pandemic influenza vaccines. The joint venture combined GSK’s adjuvant technology and expertise in vaccine development with Shenzhen Neptunus’ experience in the Chinese market. Under the terms of the original agreement, GSK was expected to purchase additional shares and obtain a majority equity interest in the company within two years. Subsequently, in August 2010, GSK increased its equity share in the joint company from 40% to 49%.

According to a statement from GSK, the decision to acquire all the outstanding interest in GSKNB reflects the company’s intention to further expand its vaccines presence in China, which it describes as a “fast growing emerging market.”

“GSK has licensed more vaccines in China than any other global manufacturer and has packaged more than 100 million vaccines at our Shanghai facility,” claimed John Lepore, vice-president and general manager of biologicals and corporate at GSK China, in the statement. “This announcement represents an expansion of GSK’s long-term commitment to vaccine supply, manufacturing and development in China.”