Positive preliminary results from Sinovac EV71 vaccine phase I trial in adults

Sinovac Biotech Ltd. (Nasdaq: SVA), a leading provider of biopharmaceutical products in China, announced today the unblinding of the Phase I clinical trial results for the adult population for its proprietary inactivated vaccine against human enterovirus 71 (EV71), which causes hand, foot, and mouth disease (HFMD). The preliminary Phase I results for the EV71 vaccine in adults showed a good safety profile and preliminary immunogenicity profile. Sinovac subsequently initiated the inoculations in the young children and infant groups. The results are anticipated to be provided in the coming months.

Sinovac obtained the approval from the China State Food and Drug Administration (SFDA) to commence clinical trials for its EV71 vaccine on December 23, 2010. The Phase I clinical trial was initiated in the Guangxi Province on December 30 2010. The Phase I design is a single center, randomization, double blinded, and placebo controlled study. The Phase I clinical trial is on track to enroll 168 healthy volunteers in three different groups: adults, young children and infants. The study will evaluate the safety and preliminary immunogenicity profile in the different age groups. The Phase I clinical trial is being conducted in the adult group first and followed by the young children group and then the infant group, starting with a lower dosage followed by a higher dosage.

The inoculations with lower and higher dosages in 36 healthy adult volunteers and the safety observation were completed on February 25, 2011.

The unblinding conference for the Phase I clinical data in the adult group was held on the afternoon of March 9, 2011. The data unblinding conference was supervised under the Data Safety and Monitoring Committee (DSMC) and instructed by the experts from the Ministry of Health, China SFDA and China CDC. There is no severe adverse event reported after inoculations, which demonstrated good safety and tolerance profile in adult group.

Dr. Weidong Yin, Chairman and CEO, remarked, "These initial results showed no severe adverse events and demonstrated a positive safety and tolerance profile in the adult population. We were pleased to complete the enrollment, inoculations and safety observation of this first group in just two months and recently commenced administering the EV71 vaccine to the healthy volunteers in the young children and infant groups. We will continue to advance the Phase I trial in the coming months and to provide additional updates on our progress."