Cook pasta as directed on package, omitting salt and adding broccoli to the cooking water for the last 3 min. of the pasta cooking time.
Meanwhile, cook and stir chicken and garlic in melted butter in large skillet until chicken is no longer pink. Stir in Alfredo sauce, milk, cheese and basil. Simmer 3 to 4 min. or until heated through, stirring occasionally.
Toss pasta and broccoli with sauce.