60 Degrees Pharmaceuticals Cures Three Patients of Relapsing Babesiosis

60 Degrees Pharmaceuticals announced that three of three enrolled patients have been cured of babesiosis after completing the tafenoquine regimen in the Company's trial of relapsing babesiosis in immunosuppressed patients. The Company's expanded use trial is an open-label, expanded access, multi-site study evaluating the safety and efficacy of the ARAKODA regimen of tafenoquine combined with atovaquone and other antimalarials/antibiotics administered to patients with risk factors for severe disease with relapsing babesiosis who have previously failed conventional antimicrobial regimens. It aims to confirm the high cure rate from the addition of tafenoquine in these patients, as reported by the Yale School of Public Health in a 2024 Clinical Infectious Diseases publication. For this study, tafenoquine treatment is continued for up to one year until two consecutive negative PCR tests for Babesia parasites are recorded and symptoms of babesiosis are resolved. Sixty to ninety days following clinical resolution and cessation of study drug administration, the study protocol calls for a follow-up visit at which two molecular tests are administered to assess parasite infection status. One test is an RT-PCR from Mayo Clinic. The second is a U.S. Food and Drug Administration-approved RNA amplification test used for blood donation screening that is at least 1,000 times more sensitive than standard commercial RT-PCRs such as the Mayo test. A patient is considered cured if no evidence of infection is detected following treatment. The Yale study reported an apparent treatment success rate of 100 percent in four patients when an atovaquone-containing standard of care regimen was combined with weekly tafenoquine administered until two sequential non-reactive conventional PCRs were noted. The fifth patient in the Yale study was administered weekly tafenoquine monotherapy, then azithromycin/atovaquone; the triple regimen was not sustained until consecutive negative PCRs were noted, and so was not successful. That same final patient in the Yale study was the third patient in the Company's expanded access study, and a quadruple combination of atovaquone/azithromycin/proguanil and weekly tafenoquine sustained until two negative PCRs were noted was ultimately curative as demonstrated through a non-reactive RNA amplification test following treatment. Cure was achieved with a triple combination of tafenoquine, atovaquone, and an antibiotic for the first two patients enrolled in the study. Collectively, in the seven patients evaluated, the data suggest that the cure rate for relapsing babesiosis in immunosuppressed patients approaches 100 percent when weekly tafenoquine is added to a patient's background atovaquone-containing combination regimen and sustained until two negative PCRs are noted. Given the rarity of relapsing immunosuppressed patients and the high cure rate associated with adding tafenoquine, the Company believes it is an appropriate time for widely accepted treatment guidelines to be reviewed in light of the new data.