Find a MS Trial

Array
(
    [posts_per_page] => 6
    [post_type] => post
    [paged] => 1
    [status] => publish
    [trials_display] => 10
    [meta_query] => Array
        (
            [relation] => OR
            [0] => Array
                (
                    [key] => form_of_ms
                    [value] => Primary progressive MS
                    [compare] => IN
                )

        )

)