Studies on sulfone resistance in leprosy. 2. Treatment with a riminophenazine derivative (B.663).

The first three patients with proven DDS-resistant leprosy infections were treated for one year with the riminophenazine
derivative B.663 (300 mgm. daily for six days a week). All of them showed satisfactory clinical, bacteriologic and histologic
improvement, which at the time of writing has been maintained for a total period of 28 months. The results show that
active leprosy resulting from resistance to one drug can still respond satisfactorily to a different type of drug, as is the case with drug resistance in other bacterial infections. In this limited study B.663 showed no toxicity, but the degree of skin discoloration was disconcerting to Chinese patients.