If you have random non-base64 chars in the string, maybe it isn't base64encoded? Or else it is a clever attempt at encryption by obfuscation? Anyways, this will do it.

#!/usr/bin/perl 
use warnings;
use strict;

my $str = 'Ton&#x69';
print "$str\n";
$str =~ tr#A-Za-z0-9+/##cd;  # remove non-base64 chars
print "$str\n";
exit;
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