Sinovac Biotech, a provider of biopharmaceutical products in China, has announced that Phase III clinical trial results for its proprietary Enterovirus 71 (EV71) vaccine have been published online in the February 27 issue of TheNew England Journal of Medicine (NEJM). The clinical results showed the efficacy of the vaccine against EV71-associated hand, foot and mouth disease (HFMD), or herpangina, was 94.8% among infants and young children and an anti-EV71 neutralizing antibody titer of 1:16 was associated with protection against EV71 associated HFMD or herpangina. As outlined in the NEJM article, Sinovac's vaccine also demonstrated a 100% efficacy rate against EV71-associated hospitalization and against HFMD with neurologic complications, the main cause of fatalities.
The article chronicles the results of the phase III clinical trial on 10,077 healthy infants and young children in China (six to 35 months of age) with a randomized, double-blind, placebo-controlled, multicenter trial method. The subjects were randomly assigned in a 1:1 ratio to receive two intramuscular doses of either Sinovac's EV71 vaccine or placebo, 28 days apart. The surveillance period was 12 months. The primary endpoint was the occurrence of EV71-associated HFMD, or herpangina. The results showed the vaccine can provide protection against EV71 associated HFMD in infants and children.
According to the statistics from National Health and Family Planning Commission of China from 2008 to 2013, more than 9 million total cases of HFMD were reported, resulting in around 2,700 reported fatalities in China. According to an epidemiological study for the period of 2008 to 2012, around 80% of the severe cases and over 90% of fatal cases were caused by the enterovirus 71 (or EV71 ) infection.
Fengcai Zhu, M.D., director of Jiangsu Centers for Disease Control and Prevention, co-principal investigator and lead author, said, "This study showed that the EV71 vaccine provides protection to the infants and young children against EV71-associated HFMD and the vaccine candidate has good safety and immunogenicity profile. HFMD has been an increasingly important public health issue among the young children in Asia-Pacific region, including China, and caused a significant social burden. The successful development of the EV71 vaccine is an exciting achievement by Sinovac, as it will provide an effective tool to protect infants and young children against EV71 associated HFMD, especially at the level of severe cases and potential fatalities."
Weidong Yin, chairman, president and CEO, said, "The peer-reviewed publication in NEJM of our phase III clinical trial results shows that our scientific contribution is acknowledged by the academia. The follow-up research is still ongoing. As there is no commercialized vaccine and no EV71 specific treatment available, there are increasing unmet medical needs. We are pleased to see that our vaccine is able to provide protection to infants and children against the EV71-associated HMFD. Sinovac is well prepared for the commercialization of this much needed vaccine. Once the regulatory approval is granted, we will be able to contribute to the overall control and prevention of this devastating disease."
In China, HFMD has become a very serious problem, especially in children, given that no vaccine and specific treatment is currently available to protect against this disease. In March 2008, an EV71 outbreak in Fuyang City of China's Anhui Province caused 23 fatalities, and attracted significant attention from the government and medical communities. In May 2008, the Chinese Ministry of Health identified EV71 as a Class C infectious disease according to prevention and control regulations. EV71 outbreaks have increased over the last five years, with more than 1 million cases identified and 500 to 900 reported fatalities each year.