MedicalResearch.com Interview with: Mark D. Eisner, MD, MPH Vice President, Product Development Immunology Infectious Disease and Ophthalmology Genentech  MedicalResearch.com: What is the background for this study? Response: CAPSTONE-2 is a Phase III multicenter, randomized, double-blind study that evaluated the efficacy and safety of a single dose of baloxavir marboxil compared with placebo and oseltamivir in people 12 years and older who are at a high risk of complications from the flu. The Centers for Disease Control and Prevention (CDC) defines people at high risk for serious flu complications to include adults 65 years of age or older, or those who have conditions such as asthma, chronic lung disease, morbid obesity or heart disease. A total of 2,184 participants enrolled in the study and were randomly assigned to receive a single, oral dose of 40 mg or 80 mg of baloxavir marboxil (according to body weight), placebo or 75 mg of oseltamivir twice daily for five days. The primary objective of the study evaluated the efficacy of a single dose of baloxavir marboxil compared with placebo by measuring the time to improvement of influenza symptoms. Key secondary endpoints compared outcomes in baloxavir marboxil versus placebo or oseltamivir – these included time to resolution of fever, time to cessation of viral shedding, infectious virus detection in swabs of the nose and throat, prescription of antibiotics and influenza-related complications. Genentech announced initial results from the study on July 16, 2018 but the full data was presented for the first time during a late-breaking oral presentation at the annual IDWeek meeting in San Francisco, CA on October 6, 2018. Baloxavir marboxil is a first-in-class, single-dose investigational oral medicine with a novel proposed mechanism of action designed to target the influenza A and B viruses, including oseltamivir-resistant strains and avian strains (e.g. H7N9, H5N1). Baloxavir marboxil is the first potential influenza treatment to demonstrate a clinically meaningful benefit for people highly vulnerable to serious influenza complications in clinical trials. The FDA accepted a New Drug Application (NDA) and granted Priority Review to baloxavir marboxil as a single-dose, oral treatment for acute, uncomplicated influenza in people 12 years and older. The NDA was based on results from the Phase III CAPSTONE-1 study of a single dose of baloxavir marboxil compared with placebo or oseltamivir 75 mg, twice daily for five days, in otherwise healthy people with the flu. Results from a placebo-controlled Phase II study in otherwise healthy people with the flu were included as supporting data in the NDA. The FDA is expected to make a decision on approval by December 24, 2018. (more…)