.item-list__comma-list, .item-list__comma-list li
{
    display: inline;
}
.item-list__comma-list
{
    margin: 0;
    padding: 0;
}
.item-list__comma-list li::after
{
    content: ", ";
}
.item-list__comma-list li:last-child::after
{
    content: "";
}