Neave, who was named on the bench for United's Carabao Cup final victory against Liverpool, joined the club's Academy as a 13-year-old and signed his first professional deal with the club last summer.
He was named in a first-team matchday squad for the first time during Newcastle's Emirates FA Cup fourth round victory against Birmingham City after impressing at youth level, where he scored two minutes into his full Premier League 2 debut for United's under-21 side during a 3-1 away win against Leeds United in November 2024.
Shahar and Sanusi, who are both capped by England at under-18 level, signed their first professional contracts with the club in May 2024 following moves from Wolves and Birmingham City respectively.
Academy Director Steve Harper said: "Sean, Leo and Trevan have shown great promise and we're delighted to see them continue their journey with us.
"Each of them has shown great commitment and potential, and we look forward to supporting their development as they take the next steps in their careers."
Meanwhile, Joe Brayson, Logan Watts and Luke Craggs have signed their first professional contracts with the club.
Sam Alabi, Michael Mills and Sammy Pinnington have agreed first-year scholarships, while Thomas Bryant's scholarship has been extended into a third year.
Harper added: "It's always a proud moment to see young players progress their careers and earn their first professional contracts.
"The challenge now is to keep pushing, keep improving and make the most of the opportunities ahead but they should all take great pride in this recognition and use it as motivation for next season."