Pour clam cooking liquid into heatproof bowl, being careful to not pour any grit from bottom of pan into bowl. Rinse saucepan to remove any grit. Return cooking liquid to saucepan. Add garlic; bring to boil. Cook 3 min. or until liquid is reduced to 1 cup. Add cream cheese and butter; cook on medium-low heat 2 to 3 min. or until melted, stirring constantly. Add Parmesan; cook and stir 1 to 2 min. or until melted.