You can try this one:
$string ='<p>LOREM IPSUM!… <a href="http://localhost/post/3" class="read-more">Read More</a></p>';
$string = preg_replace('/<a[^>]*(.*?)<\/a>/s', '', $string);
echo wp_strip_all_tags($string);
//return LOREM IPSUM!…
You can try this one:
$string ='<p>LOREM IPSUM!… <a href="http://localhost/post/3" class="read-more">Read More</a></p>';
$string = preg_replace('/<a[^>]*(.*?)<\/a>/s', '', $string);
echo wp_strip_all_tags($string);
//return LOREM IPSUM!…