preg_match_all I want to match the regular expression as intended

<p>
<a href="#title1">stack</a>
<br>
<a href="#title2">overflow</a>
<br>
</p>

if(preg_match_all('|<a href="#title.*?">(.*?)</a>br>|mis', $content, $matches, PREG_SET_ORDER)){
    if(!empty($matches)){
        $content=preg_replace('|<a href="#title.*?">(.*?)</a>br>|mis',',',$content);
    }
}