The investigational metabolic modulator AXA1125 was associated with significantly less physical and cognitive fatigue compared with a placebo in long-COVID patients, according to a small randomized, controlled phase 2 pilot study trial led by researchers from the University of Oxford and AXA1125 maker Axcella Therapeutics, which also funded the study.
The double-blind, single-center study, published late last week in eClinicalMedicine, included 41 adults with fatigue-dominant long COVID who were randomly assigned in a 1:1 ratio to receive 33.9 grams of either AXA1125 or placebo orally in a liquid suspension twice daily for 4 weeks from December 15, 2021, to May 23, 2022. The follow-up period was 2 weeks.
Drug may boost energy production
Magnetic resonance spectroscopy of the patients' calf muscles didn't show significant differences between the 21 AXA1125 recipients versus the 20 placebo recipients, but AXA1125 was tied to a significant reduction in 28-day Chalder Fatigue Questionnaire score relative to placebo (least squares mean difference, -4.30).
Participants who reported less fatigue also showed better mitochondrial health and walked farther in the 6-minute walk test. Mitochondria are organelles that produce energy.
A total of 52.4% of AXA1125 recipients and 20.0% in the placebo group reported adverse events, but none were serious or led to treatment stoppage.
The authors noted that AXA1125 is composed of five amino acids and N-acetylcysteine, which may boost energy production and reduce inflammation. "These findings suggest that AXA1125 might offer therapeutic benefits in patients with Long COVID," the study authors wrote.
There is still some way to go in treating all patients with long COVID.
The researchers said they are planning a larger phase 3 multicenter clinical trial. "There is still some way to go in treating all patients with long COVID—our results focus specifically on fatigue, rather than the breathlessness and cardiovascular issues that other long COVID patients have reported," principal investigator Betty Raman, MBBS, DPhil, said in an Oxford news release. "We also selected patients who had clear signs of mitochondrial function being disturbed—effects of the medication on other symptoms remains to be evaluated in future studies."