Exeter Chiefs have agreed new contracts with Max Bodilly, Stu Townsend, Ed Holmes and Joe Simmonds.
Full-back Bodily, 22, has signed a two-year contract extension, while scrum-half Townsend and lock Holmes, both 20, have signed deals until 2018.
Fly-half Simmonds, 19, younger brother of Chiefs forward Sam, has agreed three-year first professional contract.
"Obviously we're delighted to secure deals with all of them," said head coach Rob Baxter.
"We still feel there is a lot still to unearth in terms of their overall development."