use warnings;
use strict;
use Data::Dumper;

my $log = 'BACKLOG-123, BACKLOG-124, BACKLOG-125';
my @tickets;
while ($log =~ /([A-Z]+-\d+)/g) {
    push @tickets, $1;
}
print Dumper(\@tickets);

__END__

$VAR1 = [
          'BACKLOG-123',
          'BACKLOG-124',
          'BACKLOG-125'
        ];