60 Degrees Pharmaceuticals Announces Early Enrollment of First Seasonal Patient in Clinical Trial of Tafenoquine for Patients Hospitalized with Babesiosis

60 Degrees Pharma Accelerates Enrollment in Tafenoquine Babesiosis Trial

60 Degrees Pharmaceuticals, Inc. has announced the early enrollment of the first patient for the 2026 tick season in its randomized, double-blind, placebo-controlled clinical trial (NCT06207370) evaluating tafenoquine for babesiosis in hospitalized patients. This enrollment is approximately one month ahead of schedule, potentially allowing minimum enrollment for an interim analysis by early July 2026. The study, conducted at five clinical sites in the Northeastern U.S., aims to assess the efficacy and safety of tafenoquine, with primary endpoints focusing on clinical symptom resolution and parasite clearance. Tafenoquine is already approved in the U.S. for malaria prophylaxis under the product name ARAKODA®.

• 60 Degrees Pharmaceuticals has achieved early enrollment for the 2026 tick season in its babesiosis trial, putting the company approximately one month ahead of schedule. This accelerated pace suggests that the minimum enrollment of at least 24 patients required for an interim analysis could be met as early as July 2026. Following enrollment completion, the company plans to announce the date for the interim analyses of study data, which will separately assess clinical symptom resolution and molecular cure.
• The clinical trial (NCT06207370) is a randomized, double-blind, placebo-controlled study comparing tafenoquine plus standard of care against placebo plus standard of care in patients hospitalized with babesiosis. It is being conducted at five clinical sites across the Northeastern U.S. The two main study endpoints are the time to sustained clinical resolution of babesiosis symptoms and molecular cure, determined using a commercially available PCR assay. These distinct endpoints will undergo separate interim analyses.
• Babesiosis is a severe tick-borne illness, often co-occurring with Lyme disease, which can be life-threatening in vulnerable populations. The Centers for Disease Control and Prevention (CDC) notes historically high tick bite emergency room visits. Tafenoquine, the drug being investigated, is already approved in the U.S. under the product name ARAKODA® for malaria prophylaxis. However, it is not yet approved or proven effective for babesiosis, highlighting the significance of this trial for a new indication.

Addressing the Unmet Needs in Hospitalized Babesiosis

Current treatment options for babesiosis face significant limitations that compromise patient outcomes, particularly in high-risk populations. The available therapeutic arsenal consists primarily of repurposed combination therapies that were not specifically designed for Babesia parasites, leading to suboptimal efficacy and concerning resistance patterns. These challenges underscore the urgent need for targeted therapeutic development in this field.

• Limited and repurposed treatment arsenal - Current therapies rely on combinations of atovaquone with azithromycin or clindamycin with quinine, which were repurposed from other apicomplexan parasites rather than designed based on biological criteria unique to Babesia

• Significant adverse event profile - Existing combination therapies are associated with mild to severe adverse reactions, with the clindamycin-quinine combination demonstrating notably more adverse events compared to azithromycin-atovaquone

• Rapid emergence of drug resistance - Resistance against current drugs including atovaquone, azithromycin, and clindamycin is developing rapidly, with documented cases of babesiosis unresponsive to standard antimicrobial therapy

• High mortality in vulnerable populations - Despite available therapy, mortality rates can reach 20% in high-risk populations, with immunocompromised patients facing particular challenges including persistent relapsing illness

• Prolonged treatment requirements for immunocompromised patients - These patients typically require antibabesial treatment for ≥6 weeks to achieve cure, including 2 weeks after parasites are no longer detectable on blood smear, with some cases requiring 2-10 courses of therapy

• Uncertain management of treatment-refractory cases - The pathogenesis, clinical course, and optimal treatment regimen for patients with babesiosis unresponsive to standard therapy remain poorly defined

• Need for Babesia-specific therapeutic development - Current research emphasizes the critical need for new therapeutic strategies specifically tailored to Babesia parasites, including more specific, fast-acting, and long-lasting drugs designed with knowledge of Babesia genome characteristics

Unpacking the Tafenoquine Babesiosis Trial Design

The provided literature data focuses on babesiosis research but does not contain any trials specifically evaluating tafenoquine for babesiosis treatment. The studies identified examine alternative therapeutic approaches, diagnostic methods, and prevention strategies for babesiosis caused by various Babesia species.

• IVIG Therapeutic Evaluation (2024): Assessed 57 commercial IVIG samples using immunofluorescence assay and 52 samples via ELISA to determine presence of B. microti antibodies, with primary endpoint being antibody detection in commercial preparations

• ELQ-502 Experimental Therapy (2021): Evaluated endochin-like quinolone prodrug ELQ-502 alone and in combination with atovaquone using in vitro models and mouse models of parasitemia and lethal infection, targeting mitochondrial cytochrome bc protein complex inhibition

• Canine Babesiosis Safety Trial (1998): Randomized controlled trial (n=20) comparing diminazene aceturate with antipyrine stabilizer versus antipyrine alone, measuring serum pseudocholinesterase and red blood cell acetylcholinesterase levels at 15-minute intervals over 60 minutes

• Blood Screening Risk Assessment (2019): Applied Alliance of Blood Operators' risk-based decision-making framework to evaluate safety risk, economic impact, and operational considerations for introducing Babesia donation testing, recommending nucleic acid testing using ribosomal RNA template

Tafenoquine's Safety Profile and Potential in Babesiosis

Tafenoquine demonstrates a generally favorable safety profile across its approved indications, with comprehensive data from over 4,000 trial participants supporting its current therapeutic use. The most significant safety consideration remains the absolute contraindication in G6PD-deficient individuals due to risk of severe hemolytic anemia, necessitating mandatory G6PD testing before administration.

• Hemolytic safety profile: The 300 mg single-dose regimen shows similar safety to standard 14-day primaquine therapy, with protocol-defined hemoglobin decreases occurring in 2.4% of tafenoquine patients versus 1.2% with primaquine in the phase 3 GATHER trial

• Neuropsychiatric tolerability: Nervous system adverse events occurred in 11.4% of patients (mainly headache and dizziness) compared to 10.2% with placebo, with psychiatric events (primarily insomnia) occurring in 3.8% versus 2.7% with placebo, and no serious neuropsychiatric events observed

• Gastrointestinal tolerability: Weekly prophylactic dosing increases incidence of gastrointestinal adverse events including diarrhea, nausea, and vomiting compared to placebo, though single-dose therapy shows improved tolerability

• Ocular safety considerations: Prolonged tafenoquine exposure is associated with increased, reversible, asymptomatic vortex keratopathy, with one reported case of serious decreased macular sensitivity in systematic review data

• Drug-related adverse events: Recent multicentre data shows 22.2% of adverse events were considered drug-related with tafenoquine compared to 34.2% with low-dose primaquine and 42.9% with high-dose primaquine regimens

• Contraindication profile: Absolute contraindications include G6PD deficiency, pregnancy, lactation with G6PD-unknown infants, and pediatric use under 16 years, with mandatory G6PD testing required before administration

Tafenoquine's New Frontier: Tackling Relapsing Babesiosis

The swift progress in 60 Degrees Pharmaceuticals' clinical trial for tafenoquine in babesiosis signals a pivotal moment for a drug primarily known for its role in malaria prevention. Tafenoquine, an 8-aminoquinoline with a notably long half-life, is already a valuable tool in the fight against malaria, approved for both prophylaxis and the radical cure of Plasmodium vivax relapse. Now, its investigational use in babesiosis, a tick-borne protozoan infection, opens a new frontier for this established compound.

Babesiosis, particularly severe or relapsing forms in immunocompromised patients, represents a significant clinical challenge. Current treatment options, often combinations of azithromycin and atovaquone or clindamycin and quinine, can be limited by drug resistance or intolerance. The literature indicates that tafenoquine has shown promise in animal models and in a small series of human cases of relapsing babesiosis, often used as an adjunct therapy when standard treatments falter. This trial aims to provide robust data on its efficacy and safety in hospitalized patients, potentially offering a much-needed alternative.

However, the path forward is not without considerations. A critical risk associated with tafenoquine is its contraindication in individuals with G6PD deficiency due to the risk of hemolytic anemia. Implementing mandatory G6PD testing in a hospitalized babesiosis population, who may have complex co-morbidities, will be crucial for patient safety and treatment adherence. Furthermore, while tafenoquine's long half-life is advantageous for adherence, its optimal dosing and role—whether as monotherapy or in combination—will need to be clearly defined, especially given that monotherapy failed in one reported babesiosis case. If successful, this trial could not only provide a new therapeutic option for a growing public health concern but also strategically broaden tafenoquine's market presence, leveraging its existing profile to address another significant parasitic disease.