Roche has unveiled late-stage data showing that its experimental antivrial drug baloxavir marboxil hit efficacy and safety targets in patients with flu.

Baloxavir marboxil is a first-in-class, single-dose investigational oral medicine with a novel proposed mechanism of action designed to target the flu virus, including oseltamivir-resistant strains and avian strains (H7N9, H5N1).

The drug is designed to inhibit the cap-dependent endonuclease protein within the flu virus, which is essential for viral replication, setting it aside from other currently available antiviral therapies.

Data from the Phase III CAPSTONE-2 study showed treatment with baloxavir marboxil significantly cut the time to improvement of influenza symptoms versus placebo (73.2 hours versus 102.3 hours, respectively) in people at high risk of serious complications from the virus.

Results for the overall patient population showed numerically shorter time to improvement of influenza symptoms in the group taking baloxavir marboxil versus those taking oseltamivir, with a median time to improvement of symptoms of 73.2 hours versus 81.0 hours, respectively.

Baloxavir marboxil showed efficacy compared to placebo and oseltamivir for key secondary endpoints, including reducing the time of viral shedding, with ata showing median time of 48.0 hours for the drug versus 96.0 hours for both placebo and oseltamivir.

Also, the trial showed the drug to be well tolerated, with no new safety signals identified, the firm said.

“This is the first Phase III trial to demonstrate a significant, clinically meaningful benefit in people at high-risk for complications from the flu for which there are no currently approved medicines,” noted Sandra Horning, MD, Roche’s chief medical officer and head of Global Product Development.

“This study adds to the growing body of evidence supporting baloxavir marboxil as a potential first-in-class antiviral flu treatment, and we plan to discuss these data with health authorities around the world.”