The Annals of Internal Medicine published a study showing the experimental antifungal olorofim produced clinical improvement in over 70% of 41 patients with disseminated Valley fever who had failed or could not tolerate standard azole therapy. Improvements were seen by day 43, and some patients regained mobility. Olorofim is not FDA-approved, did not fully clear the fungus in this small study, and may require long-term use; larger trials are planned to test earlier use and confirm safety.
Experimental Antifungal Olorofim Shows Promise for Severe Valley Fever, Study Finds
A study published in the Annals of Internal Medicine reports that an experimental antifungal drug, olorofim, produced clinical improvement in a majority of patients with severe, disseminated Valley fever who had exhausted or could not tolerate standard therapies.
Researchers enrolled 41 people whose infection had spread beyond the lungs — a condition known as disseminated Valley fever — and who either no longer responded to conventional azole antifungals or experienced intolerable side effects. Participants received olorofim alone or olorofim in combination with traditional antifungal drugs.
Key results: By day 43 of treatment, more than 70% of patients showed measurable clinical improvement. Several individuals experienced marked functional recovery, with some regaining the ability to walk and drive after receiving the medication.
While promising, the treatment did not fully eradicate the fungus in the study subjects; researchers note that ongoing therapy may be required to prevent relapse. The trial was relatively small, and investigators caution that larger, controlled trials are needed to confirm durability, optimal timing, dosing and safety.
What Is Valley Fever?
Valley fever (coccidioidomycosis) is caused by spores from two Coccidioides fungi that live in dry soils of parts of the Western United States, including California and Arizona. People inhale spores when they are stirred into the air by wind, construction or agriculture.
Most exposed people (about 60%) do not develop symptoms. Roughly 30% get a mild, flu-like illness lasting weeks to months. Between 5% and 10% develop more severe lung disease, and approximately 1% progress to disseminated disease, where the infection spreads to the skin, joints, or central nervous system.
How Olorofim Works And Safety Notes
Olorofim targets fungal cells by inhibiting key processes involved in RNA and DNA synthesis, which leads to fungal cell death. The drug is not yet approved by the U.S. Food and Drug Administration (FDA). Reported benefits in this study are encouraging, but safety, long-term effects and whether olorofim can fully eradicate infection remain uncertain.
Next steps: One researcher is launching a follow-up study to test whether olorofim given earlier in the disease course can achieve complete eradication. Larger randomized trials will be needed to evaluate efficacy, optimal treatment duration and comparative safety versus existing therapies.
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