Bullet point entity is shown as  (unknown entity) which have to be captured by Perl program

I have an xml file where the data of the bullet point is shown in the form of box entity  which i am unable to capture using Perl program.Can someone help me on this point !!

Part of Input Data :

<p> Adding Basic Requirements: AU sec. 334 suggests procedures for the auditor's consideration, noting that not all of them may be required in every audit.<\/p>

Expected output :

<p>Adding Basic Requirements: AU sec. 334 suggests procedures for the auditor's consideration, noting that not all of them may be required in every audit.<\/p>

Perl Program :

use strict;
use warnings;
use utf8;
my $filename = $ARGV[0];
my $ext = $ARGV[1];
my $inputfile = $filename . "\." . $ext;
my $document = do {
         local $/ = undef;
         open my $fh,'<',$inputfile or die "Couldn't open the file $inputfile:$!";
       <$fh>;
      };

open my $out,">$filename.sgm" or die "Couldn\'t write to the file $filename.sgm:$!"; 

$document =~ s/?/<i>/isg;

print $out $document;

Output :

Program unable to capture that box type entity and results nothing . No change in the output