$re = '/(\\\\sOtros:\s(Kit Cumpleaños)(\s\(x[0-9]{1,2}\)){0,1}$)|(\\\\sPastelería:\s(Alfajor de Maicena|Budín de Limón|Muffin|Brownie de Chocolate|Magdalena con Chips de Chocolate|Pasta Frola)(\s\(x[0-9]{1,2}\)){0,1}(,\s(Alfajor de Maicena|Budín de Limón|Muffin|Brownie de Chocolate|Magdalena con Chips de Chocolate|Pasta Frola)(\s(\(x[0-9]{1,2}\))){0,1}){0,4}$)|(\\\\sMinitorta:\s(Chocotorta|Cheescake Oreo|Tiramisú|Bizcochuelo)(\s\(x[0-9]{1,2}\)){0,1}(,\s(Chocotorta|Cheescake Oreo|Tiramisú|Bizcochuelo)(\s(\(x[0-9]{1,2}\))){0,1}){0,4}$)|(\\\\sSouvenirs:\s(Taza de diseño Mandarina|Mate Artesanal Mandarina)(\s\(x[0-9]{1,2}\)){0,1}(,\s(Taza de diseño Mandarina|Mate Artesanal Mandarina)(\s(\(x[0-9]{1,2}\))){0,1}){0,4}$)/m';
$str = '
KITS
Kits individuales:
- 1x KIT ORIGINAL: $ 2.765
Minitorta: Cheescake Oreo (x1), Tiramisú (x2)
Pastelería: Brownie de Chocolate
';
$subst = "";
$result = preg_replace($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