$re = '/^(.+?) (.+)$/m';
$str = 'VIA G.VERDI
VIA DOTT. G.BIANCO
PIAZZA ALDO MORO
STRADELLA PRIVATA BRUONO MORO
VIALE MARIA S.SATURNO
';
$subst = "$1";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php