Chemotherapeutic trials in leprosy. 6. Pilot study of the riminophenazine derivative B.663 in low dosage (100 mgm. twice weekly) in the treatment of lepromatous leprosy.

The riminophenazine deriva tive B.663, first synthesized by Barry et. aZ. (~), was shown by Browne and Hogerzeil in 1962, (5. G) to be effective in the treatment of lepromatous leprosy. This finding has been confirmed by a number of centers (1. 8. ] O. ]3 , 18) . In particular, at the Leprosy Hesearch Unit, Sungei Buloh Leprosarium, considerable experience has been gained in the use of B.663 in the trea tment of relapsed lepromatous leprosy due to the development of sulfone-resistant strains of: Mycobacterium Zeprae (10). All such patients, when treated with B.663 in the dosage of 300 mgm. daily for six days each week, have shown satisfactory clinical, bacteriologic and histologic improvement. A pilot study of B.663, given in the same dosage for five months to previously untreated lepromatous patients (12), produced therapeutic results tha t were comparable to those obtained with standard sulfone therapy. However, this dose of B.663 invariably resulted in marked pigmentation of the skin , more obvious in lighter-skinned patients, many of whom complained strongly of the disco]oratio~ . In addition a small number of patIents suffered from periodic mild diarrhea. It was therefore considered essential to study the effect of B.663 in much lower dosage, both on the rate of therapeutic response and on the degree of skin pigmentation developed. The dose of 100 mgm. twice weekly was chosen, and eight lepromatous patients were included in the pilot trial.