Complex sentence: Raymond Bagatsing and Bing Loyzaga were originally cast for the roles of Alfonso and Maureen, but were later replaced by Tonton Gutierrez and Nikki Valdez.
Split into simpler sentences: Raymond Bagatsing and Bing Loyzaga were originally part of the main cast for the role of Alfonso and Maureen. They were later replaced by Tonton Gutierrez and Nikki Valdez.