<?php

$data = '<h5>Mini Biography</h5> 
<p>XXXXXX</p>';

$mini_biography = preg_match('~<h5>Mini Biography<\/h5>\s+<p>(.?+)<\/p>~m', $data, $match) ? $match[1] : 'Biyografi Alınamadı';

echo $mini_biography;

?>