US-based pharmaceutical company 60 Degrees Pharmaceuticals, Inc. (NASDAQ: SXTP, SXTPW), a developer of medicines for vector-borne disease, said on Wednesday that the first patient to complete its expanded access trial of tafenoquine for relapsing babesiosis in immunosuppressed patients tested negative using both the Mayo RT-PCR and an FDA-licensed RNA amplification blood donation screening test.

The open-label, multi-site study is intended to confirm the high cure rate for tafenoquine in immunosuppressed relapsing patients reported by Yale in a 2024 Clinical Infectious Diseases publication.

60 Degrees recently submitted a Breakthrough Therapy designation request to the US Food and Drug Administration and plans to request a Type B meeting with the FDA in early 2026 to discuss requirements for a supplementary New Drug Application.

The company expects remaining enrolled patients to complete the study between January and October 2026 and said that the data from its tafenoquine trials is expected in the second half of 2026 to support an sNDA.

Tafenoquine is approved in the United States for malaria prophylaxis under the product name ARAKODA and is not currently approved by the FDA for treatment or prevention of babesiosis.