Significant progress in the Phase III clinical study of Genentech's new influenza drug

Genentech a member of the Roche Group, announced that the CAPSTONE-2, a phase 3 study evaluating the efficacy of the new flu-influenza drug baloxavir marboxil in people with high-risk complication, reached the primary end point.

Significant progress in the Phase III clinical study of Genentech's new influenza drug

The flu is a serious threat to global human health. The annual flu epidemic can cause approximately 3 to 5 million patients to be seriously ill, millions of patients need hospitalization for treatment, and as many as 650,000 people die. The Centers for Disease Control and Prevention (CDC) defines the following populations as people with high-risk flu complications: elderly people 65 years of age or older, people with asthma, chronic lung disease, diabetes, or heart disease. For these patients, the flu may cause them to stay in hospital or even die. They urgently need a new drug to relieve the disease and reduce the incidence of complications.

Baloxavir marboxil was originally developed by Shionogi & Co., Japan. It is a new antiviral drug that inhibits viral replication by inhibiting cap-dependent endonuclease in influenza viruses. The mechanism of action of anti-influenza drugs is to prevent the spread of the virus in the body by targeting neuraminidase. Compared to these drugs, baloxavir marboxil targets the earlier stages of the viral replication cycle and it is effective against influenza viruses that have developed resistance to oseltamivir.


In the Phase 3 study of CAPSTONE-1, baloxavir marboxil has demonstrated significant clinical benefits in healthy populations. The US FDA recently accepted its New Drug Application (NDA) and granted it a priority for single-dose oral therapy for people 12 years of age and older with acute, uncomplicated influenza. The FDA is expected to make a decision on December 24 this year. If approved, baloxavir marboxil will be the first single-dose oral antiviral drug and the first drug in 20 years to have a novel mechanism for treating influenza.

The published CAPSTONE-2 is a phase 3 multicenter, randomized, double-blind study evaluating a single-dose baloxavir marboxil with high-risk complication complications at 12 years of age or older compared with placebo and oseltamivir. The efficacy. Subjects were randomized to receive a single dose of 40 mg or 80 mg baloxavir marboxil, placebo or 75 mg oseltamivir for 5 days. The primary endpoint of the study was to assess the efficacy of a single dose of baloxavir marboxil compared to placebo by measuring the time to improve flu symptoms. Important secondary endpoints were the time to fever, the time to stop the virus from escaping, and the proportion of subjects who were positive for influenza virus titers by time or virus levels in the body, and the incidence of influenza-related complications.

The results showed that baloxavir marboxil improved flu symptoms more effectively at the primary endpoint than placebo. In important secondary endpoints, baloxavir marboxil also showed higher efficacy than placebo and oseltamivir, including reducing the duration of viral release (virus shedding) and reducing viral levels in the body. Baloxavir marboxil also significantly reduced the incidence of influenza-related complications. In addition, baloxavir marboxil is well tolerated and no safety issues have been identified. The full results of the study will be announced at the upcoming medical conference.

“Baloxavir marboxil is the first antiviral drug to show clinical significance in people at risk of flu complications, including the elderly and patients with certain diseases,” said Genentech Chief Medical Officer and Global Product Development Leader Dr. Sandra Horning said: "We plan to submit the positive results of the second phase of this baloxavir marboxil study to the health care regulator and look forward to discussing the next steps as there are no approved antivirals specifically for such high-risk groups. drug."

Reference materials:

[1] Phase III CAPSTONE-2 Study Showed That Baloxavir Marboxil Reduced Symptoms in People at High Risk of Complications From the Flu