Tomcat: Dangerous Desires (1993)

Jacki, a scientist involved in genetic research, meets Tom, a young modern dancer who is suffering from a degenerative nerve disease. Jacki experiments with using genetic material taken from a cat to cure him, but the cure has side effects, and Tom begins to take on feline characteristics that may turn him into a monster. The situation is further complicated by Tom's attachment to Imogen--and Jacki's growing jealousy as she fears the loss of her patient and lover.