- New data showed Roche's experimental flu drug shortened the time it took for people to improve from flu symptoms by 28% versus placebo in a Phase 3 trial that focused on patients with a higher risk of developing serious complications from the infectious disease.
- However, the once-daily oral treatment failed to clearly demonstrate superiority in the overall study population over Tamiflu, a Roche flu medication currently on the market. An approximately 10% shorter time to improvement versus Tamiflu was not statistically significant, according to data released Oct. 3 by Roche.
- The drug, baloxavir marboxil, was first developed and commercialized by Shionogi, where it received an OK from Japanese regulators this February and is sold as Xofluza. Roche bought the global rights excluding Japan and Taiwan in 2016. The Japanese pharma conducted this Phase 3 trial.
Roche hopes baloxavir marboxil can fill a big revenue hole left by Tamiflu (oseltamivir) since it began facing generic competition in 2016.
Before facing the patent cliff, Tamiflu was a bona fide moneymaker for Roche in treating the common yet serious infectious disease of influenza, exceeding $3 billion in worldwide sales in 2009 during the H1N1 pandemic.
Five generics have since launched, weighing on the drug's revenue. Market research firm GlobalData anticipated U.S. sales of roughly $200 million in 2018, roughly a quarter the sales from four years ago.
This new Phase 3 data will be another piece of evidence in setting baloxavir marboxil's long-term prospects to grab market share from Tamiflu generics.
While the results were largely positive for baloxavir marboxil, falling short of a statistically significant result versus Tamiflu in the overall study population is a notable miss.
Roche, however, highlighted that baloxavir marboxil did beat out Tamiflu in a subgroup of people with influenza type B, posting a significant reduction in the time to improvement of symptoms.
There are other advantages, too. Patients would only take one pill of baloxavir marboxil compared to a typical 10-pill regimen of twice-daily for five days with Tamiflu.
Against placebo, the study results were compelling in demonstrating baloxavir marboxil's efficacy.
It succeeded in achieving the study's main goal of reducing the time it takes to improve from flu symptoms, posting a median time to improvement of 28% — 73 hours on average instead of 102 hours with placebo.
The drug candidate also reduced the time for viral shedding against placebo as well as reducing the use of antibiotics and incidence of flu-related complications by more than half of placebo rates.
The study, called CAPSTONE-2, enrolled people with higher risk for flu complications, with the most common among the 2,184 participants being asthma or chronic lung disease (39% of the enrolled), endocrine disorders (33%) and being 65 years or older (27%).
Sandra Horning, Genentech's chief medical officer, called it the first Phase 3 study "to demonstrate a significant, clinically meaningful benefit in people at high risk for complications from the flu for which there are no currently approved medications."
Genentech also announced on Oct. 1 a public-private partnership deal with the U.S. government's Biomedical Advanced Research and Development Authority. BARDA will give $43 million over five years to study baloxavir marboxil in treating hospitalized patients with seasonal or pandemic influenza.
CAPSTONE-2 data will be presented on Saturday, Oct. 6 in San Francisco as a late-breaker for IDWeek 2018.
The Food and Drug Administration is expected to make an approval decision on baloxavir marboxil by Dec. 24, based on results from the earlier CAPSTONE-1 study and Phase 2 data.