22nd August 2017, 19:38 | Hull
Miloudi, 24, a former France Under-20s international full-back, has signed a two-year full-time contract with the Black and Whites after a successful trial period which included a loan spell at Doncaster.
Hull coach Lee Radford said: "Hakim came over originally on trial and really impressed in the two trial games he's played in.
"He's showed some really good signs and he'll offer some great cover at full-back for next year. Jamie Shaul has more or less played every game this year and to have that cover next year with Jake (Connor) as well is really important for us."
Back-row forward Downs, 21, who has made 13 Super League appearances, has signed a one-year contract extension while Sanderson, a full-back or winger who has yet to make his senior bow, has been given a two-year deal.