How to compose a PHP regular expression so that the preg_replace function only handles exact matches?

Question

PHP

It is necessary that the function

function no_link_current_page( $p ) {
  return preg_replace( '%((current_page_item|current-cat)[^< ]+)[^>]+>([^< ]+)%', '$1$3', $p );
}

processed only EXACT matches of the string "current-cat", now <li>actions are also taking place on the class "current-cat-parent". I would like to avoid this