Charles River Laboratories International, a Wilmington, Mass.-based CRO, has extended its initial three-year partnership with AstraZeneca for an additional five-year period.

Charles River will retain its position as AstraZeneca’s preferred strategic partner for outsourced regulated safety assessment and development of drug metabolism and pharmacokinetics until 2020.

AstraZeneca Vice President of Global Safety Assessment Stefan Platz said, “Partnering with Charles River to utilize their scientific expertise enabled AstraZeneca to increase our resource flexibility while simplifying the way we work.”