Cook rigatoni to desired doneness as directed on package. Drain; cover to keep warm.
Meanwhile, spray large nonstick skillet with nonstick cooking spray. Add oil; heat over medium-high heat until hot. Add onion and garlic; cook 3 to 4 minutes or until onion begins to brown, stirring frequently.
Stir in tomatoes; simmer 2 minutes. Stir in beans, sage and red pepper flakes; cook until thoroughly heated. Add spinach; mix well. Serve tomato mixture over rigatoni.