Jovovich and Sanchez join Timothy Olyphant and Steve Zahn in the thriller, which revolves around a newlywed couple on their honeymoon in Hawaii who run into two hikers who turn out to be vicious killers.
Jovovich will play Zahn's new wife, while Sanchez will play Olyphant's companion.
Twohy wrote and is directing the feature, which MGM is distributing.
Production begins March 31 in Puerto Rico and Hawaii.
Relativity Media's Ryan Kavanaugh, Tucker Tooley and Mark Canton are producing along with Robbie Brenner. Bill Block and Kimberly Fox at QED International are exec producing. QED is handling foreign sales.
Sanchez, repped by Gersh and Artistry, is best known for her work on last season's Lost. She recently wrapped the horror thriller Insanitarium.
Jovovich, star of the Resident Evil movies, is repped by ICM and Media Talent Group.