1359. Clinical Experience and Challenges Utilizing Clofazimine in the Treatment of Nontuberculous Mycobacterial Pulmonary Infections

Abstract Background Nontuberculous mycobacterial (NTM) pulmonary infections are increasingly common and associated with significant morbidity and mortality. Treatment is challenging given high rates of antimicrobial resistance, the need for prolonged therapy with multiple agents, and poor medication tolerability. Clofazimine (CFZ), an antimicrobial available under an investigational new drug (IND) program, has excellent in vitro activity but limited clinical data. We present an 18-month experience of clofazimine as part of a multidrug regimen as salvage therapy for NTM pulmonary infections at the James A. Haley Veterans’ Affairs Hospital in Tampa, FL. Methods We conducted a single-center, retrospective review of the medical records of 11 patients with NTM pulmonary infections who were approved for treatment with CFZ-containing regimens between September 2017 and February 2019. Basic demographics, clinical characteristics, as well as symptomatic, radiologic, and microbiologic responses to therapy were evaluated. Results Approval for the IND program took approximately 15 months. We then treated 8 patients with pulmonary NTM infection with CFZ-containing regimens. Of these, 88% had cavitary disease, 63% were active smokers, and all had underlying pulmonary disease. The most common etiologic organisms were Mycobacterium avium complex and Mycobacterium abscessus. All patients were required to follow up every 3 months while on therapy. For patients who had at least 3 months of follow up, 100% reported symptomatic improvement. 50% achieved negative cultures with an average time to clearance of 25 weeks. All had stable or improved imaging. CFZ was well tolerated with no significant adverse effects. Conclusion Once available, CFZ-containing regimens were moderately effective in treating NTM pulmonary infections with minimal adverse effects. Close patient follow up was necessary to assess response to treatment. Disclosures All authors: No reported disclosures.