A Phase II Study of Rifaximin (Xifaxan) for Patients With Sickle Cell Disease (SCD)

Study point of contact

Judy Moore
[email protected]
Seah Lim, MD PhD
[email protected]


1 United States site


18 to 70 Years




Phase 2

Study type








About the study

In this single-arm, one-stage Phase II study, the investigators hypothesize that gut
decontamination with rifaximin will reduce the frequency of hospital admission due to painful
crisis in patients with SCD. The study will accrue 20 SCD patients who had at least two
hospital admissions in the previous 12 months. These patients will receive rifaximin 550 mg
twice a day for a total of 12 months. This following clinical parameters will be measured: 1.
Changes in the annual rate of hospital admissions due to painful crisis; 2. Changes in the
annual rate of days hospitalized; 3. Annual rates of uncomplicated crises; 4. Annual rate of
acute chest syndrome; 5. Changes in the quality of life; and 6). Toxicities. The following
laboratory parameters will be measured: 1. Changes in the number of circulating activated
neutrophils; 2. Changes in the intestinal microbiome diversity; 3. Changes in the urinary
3-indoxyl sulfate levels; 4. Changes in the serum biomarkers of intestinal permeability
(lipopolysaccharides; zonulin, citrulline, and fatty acid binding proteins).

participation requirements

1. Patients with HbSS, HbSC, or HbS beta thal.

2. Age 18-70 years.

3. More than two hospital admissions for painful VOC in the prior 12 months, whether on
any anti-sickling agents (e.g. hydroxyurea, L-glutamine, or transfusion therapy) or
not. These agents may be continued during the study period. However, subjects are not
allowed to be started on any of these agents during the study period.

4. Ability to comprehend and sign an informed consent. –

participation restrictions

1. Pregnant or lactating. For female subjects of child-bearing potential, the subject
must agree to avoid pregnancy during the rifaximin study period and to practice a
recognized form of birth control during this period (e.g. barrier, birth control
pills, abstinence).

2. Life expectancy of < 12 months. 3. History of allergy to rifaximin. 4. Patients with newly developed abnormal vital signs or abnormal physical examination (outside the signs that are expected in patients with SCD). 5. Patients in active VOC. 6. Patients with a baseline prothrombin time International Normalized ratio (INR) >2.0.

7. Patients who receive any blood products within three weeks of the screening visit.

8. Patients with uncontrolled liver disease or renal insufficiency, colitis, or
inflammatory bowel disease.

9. Patients with HIV, or other concomitant immunodeficiency.

10. Patients on penicillin prophylaxis or antibiotics for treatment of infection.

11. Patients with significant medical condition that require hospitalization (other than
sickle cell VOC) within two months of the screening visit.

12. Patients currently taking or has been treated with an investigational drug within 30
days of the screening visit.


  • Valhalla, New York, United States, Westchester Medical Cancer Cancer Institute, 10532 [Recruiting]