The Food and Drug Administration (FDA) has granted Orphan Drug designation to rifaximin, a rifamycin antibacterial, for the treatment of sickle cell disease.

Rifaximin is believed to benefit in sickle cell disease based on its potential to decrease intestinal microbial load, which reduces translocation of intestinal bacteria into the systemic circulation, and subsequently reduces the number of activated neutrophils. The designation is supported by data from a single-arm phase 2 trial that assessed gut decontamination with rifaximin to reduce the frequency of hospital admission due to painful vaso-occlusive crises (VOC) in 13 patients with sickle cell disease. Patients received rifaximin 550mg orally twice a day for up to 1 year. 

Findings from the trial showed that the median number of VOCs decreased from the expected 2.25 per 6 months to 1 per 6 months (range 0-4; P =.003). Additionally, a significant reduction in the number of days needing intravenous opioid analgesia was also observed. Moreover, patients demonstrated an improved quality of life, as measured by the FANLTC (Functional Analysis of Non-life-Threatening Conditions) questionnaire.

“Early data suggests that rifaximin may be beneficial in reducing vaso-occlusive crisis in patients with sickle cell disease, and we are currently finalizing trial protocols to further evaluate its potential in this patient population,” said Joseph C. Papa, chairman and CEO, Bausch Health. “We expect to start a phase 2 trial in the first half of 2021 evaluating a novel rifaximin formulation for a potential sickle cell disease treatment, and we are hopeful to be able to bring this investigational oral formulation forward to help sickle cell patients.”

Related Articles

Rifaximin is currently marketed under the brand name Xifaxan and is indicated for the treatment of traveler’s diarrhea due to noninvasive Escherichia coli (220mg tablet), as well as for irritable bowel syndrome with diarrhea and to reduce the risk of overt hepatic encephalopathy recurrence (550mg tablet).

For more information visit


  1. Bausch Health’s rifaximin receives FDA Orphan designation for sickle cell disease. [press release]. Laval, Quebec, Canada: Bausch Health Companies and Salix Pharmaceuticals; October 29, 2020. 
  2. Lim SH, Dutta D, Moore J. Rifaximin for sickle cell disease. American Journal of Hematology. Published online September 11, 2019. doi: 10.1002/ajh.25637.