Treating the Flu in Just 24 Hours

Baloxavir marboxil (S-033447) treats influenza A and B in one day, with one dose, reports Shionogi & Co.

crowd of people cheerring

People may soon have another option when treating the flu. And, this new single-dose medicine could work in just 24 hours.

There has not been a new FDA-approved flu medication for many years.

This is important since rare sporadic instances of oseltamivir-resistant and peramivir-resistant influenza A(H1N1)pdm09 viruses and oseltamivir-resistant influenza A(H3N2) viruses have been detected worldwide, said the Centers for Disease Prevention and Control (CDC) in the February Week 5 update.

The CDC recommends antiviral treatment as early as possible for people with confirmed or suspected influenza.

A Japanese pharmaceutical manufacturer completed a phase 3 clinical trial in January 2018, for a medication that is reported to kill the flu virus, within one day.

This late-stage clinical trial on Japanese and American flu patients found that for the people who took, a single dose of Baloxavir marboxil (S-033447) for treatment of influenza A and B, eliminated the flu virus ‘shedding’ in just 24 hours.

That is a much quicker response time than Tamiflu (oseltamivir), a leading flu medicine.

But, this medication will not be available this year in the USA.

Which means, the best defense against influenza remains vaccination.

Baloxavir marboxil, known clinically as S-033447, and produced by Shionogi & Co., Ltd., is a novel small molecule inhibitor of cap-dependent endonuclease that is essential for influenza virus transcription and replication.

This clinical study was a phase 3, multicenter, randomized, double-blind study of a single dose S-033188 Baloxavir Marboxil, compared with placebo or Oseltamivir 75 mg, twice daily for 5 days.

The median time to cessation of viral shedding was 24 hours in patients treated with S-033188, compared to 72 hours in those treated with oseltamivir and 96 hours for placebo.

During October 2017, Shionogi & Co., Ltd. announced the clinical results of the S-033188 Phase 3 study at IDWeek™ in San Diego. This presentation’s highlights included the following:

  • Significant improvement in time to alleviation of symptoms (TTAS) compared with placebo. S-033188 demonstrated superiority to placebo in TTAS; the median TTAS was 53.7 hours in the S-033188 group, compared to 80.2 hours in the placebo group (p<0.0001).
  • TTAS was similar between S-033188 and oseltamivir groups.
  • Significant improvement compared with placebo or oseltamivir for important virological endpoints. The percentage of patients determined to be positive for influenza virus titer was significantly lower in the S-033188 group compared to the oseltamivir group at one, two and four days from the start of treatment.
  • In addition, the time to cessation of viral shedding was significantly decreased in the S-033188 compared with the oseltamivir group.

The researchers involved in this clinical trial were paid by the manufacturer, Shionogi & Co.

No pricing or USA released date was disclosed.

Additional CDC information on recommendations for treatment and chemoprophylaxis of influenza virus infection with antiviral agents is available here.