Tafenoquine treatment for chronic babesiosis with severe fatigue

B-FREE Chronic Babesiosis Study: A Phase 2 Open Label Study of Tafenoquine for Treatment of Chronic Babesiosis Patients With Severe Fatigue

Phase 2 Interventional 60 Degrees Pharmaceuticals LLC · NCT06656351

This open-label Phase 2 trial tests tafenoquine 100 mg to see if it reduces severe fatigue and other symptoms in adults with chronic babesiosis who have laboratory evidence of recent Babesia exposure.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment40 (estimated)
Ages18 Years and up
SexAll
Sponsor60 Degrees Pharmaceuticals LLC Industry-sponsored
Locations1 site (New York, New York)
Trial IDNCT06656351 on ClinicalTrials.gov

What this trial studies

This Phase 2 open-label study gives tafenoquine 100 mg to adults with chronic babesiosis who experience severe disabling fatigue and have laboratory evidence of Babesia exposure within the last 12 months. Participants receive oral tafenoquine and undergo regular clinical and laboratory assessments to monitor symptoms and safety. Key exclusions include G6PD deficiency, breastfeeding, unmanaged psychotic disorders, known hypersensitivity to 8‑aminoquinolines, current or planned quinine therapy, and active chronic viral infections. The study is sponsored by 60 Degrees Pharmaceuticals and conducted at the Icahn School of Medicine at Mount Sinai in New York City.

Who should consider this trial

Good fit: Adults 18 or older with chronic babesiosis who have severe disabling fatigue, at least one common babesiosis symptom, laboratory evidence of Babesia exposure within the past 12 months, and no G6PD deficiency are the intended participants.

Not a fit: People with G6PD deficiency, breastfeeding individuals, those with unmanaged psychotic disorders, active chronic viral infections, current quinine treatment, or other significant uncontrolled illnesses are unlikely to be eligible or to benefit from this intervention.

Why it matters

Potential benefit: If successful, tafenoquine could reduce persistent fatigue and other symptoms and provide an effective oral option for people with chronic babesiosis.

How similar studies have performed: Use of tafenoquine for babesiosis is relatively novel with limited clinical data beyond case reports and extrapolation from its approved use against malaria.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Male or female, aged ≥ 18 years
* Severe disabling fatigue
* Have at least one common symptom of babesiosis
* Have laboratory evidence of exposure to babesia in the last 12 months
* Able and willing to give written informed consent
* Able and willing to perform all study assessments
* If female negative urine pregnancy test and
* If female agree to use an acceptable method of birth control

Exclusion Criteria:

* Glucose-6-phosphate-dehydrogenase (G6PD) deficiency
* Breastfeeding
* Unmanaged Psychotic disorder
* Known hypersensitivity reaction to tafenoquine or other 8-aminoquinolines
* Current or planned treatment with quinine
* Uncontrolled cardiopulmonary or endocrine disorders
* Taking OCT2/MATE substrates without appropriate medical oversight
* Medical history of chronic, active viral diseases including HIV/AIDS, hepatitis B, and hepatitis C
* Have a risk factors for relapsing babesiosis
* Anorexia
* Any concomitant significant illness unrelated to babesiosis
* The patient is unable to tolerate medication by the oral route
* The patient has previously taken tafenoquine
* Hemoglobin at baseline is ≤ 8 g/dL

Where this trial is running

New York, New York

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Chronic Babesiosis
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.