<?php
$query = new WP_Query( array(
'post_type' => 'case-study',
'paged' => $paged,
'post__not_in' => array( 1, ),
) );
if ( $query->have_posts() ) {
while ( $query->have_posts() ) {
$query->the_post();
// do stuff
} // endwhile;
} // endif;
?>