COOK pasta as directed on package. Meanwhile, cook and stir chicken in large nonstick skillet on medium heat 8 to 10 minutes or until cooked through. Remove from heat; cover to keep warm.
PLACE cream cheese, Asiago cheese and milk in medium saucepan; cook on low heat until cream cheese is completely melted and mixture is well blended. Add spinach; cook until heated through, stirring frequently.
DRAIN pasta; place in large bowl. Add chicken and cream cheese mixture; toss to coat.