GSK's malaria vaccine trial containing Antigenics’ Stimulon adjuvant enrolls more than 5,000 children

Antigenics, Inc. (NASDAQ: AGEN) today indicated that GlaxoSmithKline’s (GSK) Phase III malaria vaccine clinical trial, containing Antigenics’ QS-21 Stimulon® adjuvant, has enrolled more than 5,000 children to date and is expected to involve up to 16,000 children. The pivotal efficacy study of RTS,S, the world’s most clinically advanced malaria vaccine, is ongoing in seven African countries.

The QS-21 adjuvant is a key component in several of GSK’s prophylactic and therapeutic vaccines, including RTS,S. Under the terms of the license and supply agreements between the companies, Antigenics will receive payments from GSK contingent upon achievement of successful milestones and from royalties on net sales for a period of at least 10 years after the first commercial sale.

“QS-21 has emerged as an important component in 15 vaccine products being tested in clinical trials,” said Garo H. Armen, PhD, chairman and CEO of Antigenics. “QS-21 could become a significant revenue source for Antigenics in the coming years.”

Under current plans, the RTS,S vaccine candidate would be submitted to regulatory authorities in 2012 based on efficacy in children 5-17 months of age. Additional safety and immunogenicity data from the infant population will be submitted soon thereafter, followed by efficacy data for infants once available. Depending on the final clinical profile of the vaccine and the timetable of the regulatory review process, the first vaccine introduction could take place over the next three to five years.

The RTS,S vaccine primarily addresses the malaria crisis in Africa which kills more than 800,000 people every year, the majority of which are children under the age of five.