Background: In hyperendemic countries for leprosy, there has been a growing increase in clinical multibacillary "nonresponsiveness" leprosy cases to the fixed-duration treatment recommended by World Health Organization (MDT-MB). There are no defined protocols to treat these patients. Methods: A retrospective, observational case series study was conducted of 4 patients with multibacillary leprosy who presented to a specialized Leprosy health care. Between July 1, 2018, and July 31, 2020, they were treated with moxifloxacin, clarithromycin, minocycline, and clofazimine. A literature review was conducted on the clinical features and treatment of nonresponsiveness leprosy cases to regular MDT-MB. Results: Four patients (3 male; mean [SD] age at treatment, 41 [22.6] years) with nonresponsiveness lepromatous leprosy to regular MDT-MB were successfully treated with daily moxifloxacin, clarithromycin, minocycline and clofazimine for 24 months. There were reduction in the number and size of skin lesions and infiltrations, neural thickening (both visually and by palpation), bacteriological index, and leprosy reactions at 6 to 24 months after initiation of therapy. Conclusions: This case series suggests that daily moxifloxacin, clarithromycin, minocycline and clofazimine association may hold promise as a treatment for refractory lepromatous leprosy to regular MDT-MB.