Panretin (9-cis-retinoic acid, LGD 1057), is a modified form of vitamin A currently being studied for its anti-KS activity. The drug was originally made in the form of a gel which was applied directly to KS lesions on the skin. However, this method was not practical for people who had extensive lesions, so Panretin has ... been made available in capsule form. Like vitamin A, Panretin and Atragen (see below) can block the growth of some tumours.