Preheat oven to 425 deg. F. Lightly sprinkle heavy large baking sheet with flour. Unfold dough on prepared sheet. Stretch and/or roll dough to 10x13-inch rectangle. Sprinkle clams, then garlic, dried red pepper, parsley and cheese over dough, leaving 1-inch border. Drizzle oil over.
Bake pizza until crust is golden brown and crisp, about 12 minutes. Transfer pizza to work surface. Cut into squares and serve hot.