Roche's Influenza Drug Xofluza (Baloxavir Marboxil) Approved in China for Patients Aged 12 and Above

On April 29, the official website of the National Medical Products Administration (NMPA) announced that Roche’s influenza drug baloxavir marboxil tablets (brand name: Xofluza), submitted for approval in China, had been granted marketing authorization by the NMPA. The approved indication is for the treatment of influenza in patients aged 12 years and older, including those at high risk of developing influenza-related complications.

Baloxavir is a first-in-class oral antiviral drug that demonstrates efficacy after a single dose and is effective against oseltamivir-resistant influenza strains as well as avian influenza strains. Unlike neuraminidase inhibitor anti-influenza drugs (such as oseltamivir, laninamivir, and peramivir), baloxavir inhibits viral replication by targeting the cap-dependent endonuclease of the influenza virus. By exerting its effect during the early stage of viral self-replication, it blocks influenza progression more rapidly than neuraminidase inhibitors.

Baloxavir, co-developed by Shionogi and Roche, was first approved in Japan in February 2018 and subsequently approved in the United States in October of the same year. It is the first novel-mechanism anti-influenza drug to gain global approval in nearly two decades. Currently, baloxavir tablets are approved in the United States and the European Union for the treatment of influenza in patients aged 12 years and older, including those at high risk for influenza-related complications, as well as for post-exposure prophylaxis of influenza in individuals aged 12 years and older. Furthermore, the oral suspension formulation of this product was approved by the FDA for marketing on November 23, 2020.

The Phase III clinical trial, codenamed CAPSTONE-2, evaluated the efficacy of baloxavir compared with placebo or oseltamivir in treating high-risk adolescent and adult outpatients with uncomplicated influenza. A total of 2,184 patients with risk factors for influenza complications (such as age >65 years) and symptom duration of less than 48 hours were enrolled. Participants were randomized in a 1:1:1 ratio to receive either baloxavir (40 mg or 80 mg, single dose), oseltamivir (75 mg twice daily for 5 days), or placebo.

The study results showed that the median time to improvement in influenza symptoms (TTIIS) was shorter in the baloxavir group than in the oseltamivir and placebo groups, at 73.2 hours, 81.0 hours, and 102.3 hours, respectively. This represented a reduction of 7.7 hours compared with the oseltamivir group and 29.1 hours compared with the placebo group (p<0.0001). Furthermore, the incidence of adverse events in the baloxavir group was comparable to that in the placebo and oseltamivir groups, at 25% (baloxavir), 30% (placebo), and 28% (oseltamivir), respectively. These findings were published in The Lancet in June 2020.

Baloxavir has currently been approved for marketing in Taiwan and Hong Kong, China, and has been included in the third batch of overseas new drugs urgently needed for clinical use. The reasons for its classification as clinically urgent include: involvement in public health, life-threatening severe influenza, and therapeutic advantages over marketed products. On November 2 last year, the marketing application for baloxavir was granted priority review status by the Center for Drug Evaluation (CDE).