A phase 3 trial indicated that a single dose of suraxavir marboxil may significantly shorten the time to alleviation of flu symptoms.

The study, published in Nature Medicine, included 527 participants aged 5–65 years with uncomplicated influenza, predominantly caused by the H1N1 and H3N2 subtypes.

The trial demonstrated that suraxavir, an experimental antiviral, reduced the median time to alleviation of symptoms to 42 hours, compared to 63 hours for the placebo group (P=0.002). Symptoms such as fever, cough, nasal congestion, and fatigue resolved 21 hours faster with suraxavir. Viral load reductions were also more rapid, with a mean change of -2.2 log10 copies/mL 1 day after administration versus -1.3 log10 copies/mL in the placebo group (P<0.001).

Adverse events occurred in 28.4% of suraxavir recipients compared to 23.3% of placebo recipients, and were primarily mild to moderate. The incidence of polymerase acidic protein mutations conferring resistance was less than 1%, underscoring the drug’s low resistance profile.

Participants were randomized in a 2:1 ratio and treated within 2 days of symptom onset, a study limitation that necessitates further research into the drug’s efficacy when administered later or in high-risk populations.

Suraxavir’s ability to inhibit influenza virus replication with minimal resistance suggests potential utility as an alternative to antivirals like baloxavir marboxil.

Full disclosures can be found in the study.