Wasps have signed centre Chris Mayor and props Lewis Thiede and Simon McIntyre for next season.
Mayor, 28, who has previously had spells with Sale and Northampton, joins from Italian side Gran Parma.
Thiede, 20, arrives from Championship outfit Doncaster while McIntyre, also 20, makes the switch from Sale, who he played five games for this season.
"We are looking to create long-term strength in depth," said Wasps chief executive Chris Thomas.
"Especially in pivotal positions in the front row, and we have identified these two young players [Thiede and McIntyre] as two for the future.
"Chris Mayor is a player with plenty of Premiership experience and his ability to cover a range of positions in the backs will be a big bonus."
Mayor said: "I've had a great experience with a developing team in Parma over the last year, having wanted to spend a season in a totally different environment.
"I feel I have a good few years left in me at Premiership level. Wasps is a great club with a strong heritage and I am looking forward to being part of a new era there."
Thiede, who will go into the Wasps academy, said: "I'm really pleased to be linking up with a Premiership club and am looking forward to the challenges ahead of me.
"With some great coaches and some experienced players, London Wasps is the perfect place for me to develop and grow."
McIntyre added: "Front row is a position where you are learning all the time as a young player.
"In a new environment I hope can help me take my game to the next level."