Digits are, in Perl regular expressions, word characters.

If you want to exclude digits, you can use character classes: Either those defined by POSIX (only if you don't have Unicode characters), or using Unicode properties in a recent Perl.

Here's a Unicode-aware example:

use strict;
use warnings;

my $text = "John P5ete Andrew Richard58 Nic4k Le7on5";
my @names = $text =~ /\b\p{Alphabetic}*\d\p{Alphabetic}*\b/g; 
print "@names\n";
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