This article is more than 5 years old. Information may no longer be current.
IV zanamivir safe, reduced virus load in severe influenza
Intravenous zanamivir was safe and reduced virus load among adults hospitalized with severe influenza, according to recent data.
“Oseltamivir and zanamivir are approved for the treatment and prophylaxis of acute uncomplicated influenza,” the researchers wrote in the Journal of Infectious Diseases. “However, no antiviral treatments have been proven to be effective for complicated or severe influenza in controlled trials, and no parenteral influenza antiviral formulations are licensed outside China, Japan and Korea.”
The researchers conducted an open-label, multicenter, single-arm, phase 3 study in eight countries. From November 2009 to September 2011, 130 patients who were hospitalized with severe or progressive laboratory-confirmed influenza were enrolled. The patients received IV zanamivir (Relenza, GlaxoSmithKline) 600 mg for 30 minutes for 5 days. Some patients could extend treatment at investigator’s discretion. Eighty-seven patients received the treatment for 5 days or less, and 43 patients received it for more than 5 days.
Adverse events were reported in 85% of the patients, and serious adverse events were reported in 34% of patients. The serious adverse events included bacterial pulmonary infections, respiratory failure, sepsis/septic shock and cardiogenic shock. There were protocol-defined liver events in 13% of the patients. There were no fatalities that were considered related to zanamivir. The 14-day all-cause mortality was 13% and the 28-day all-cause mortality was 17%.
For patients with renal impairment, dose adjustments led to similar zanamivir exposure. Among 93 patients positive for influenza by quantitative polymerase chain reaction at baseline, a median decrease in virus load of 1.42 log10 copies/mL was observed after 2 days of treatment.
“Although a potential clinical benefit is difficult to assess without a control group, the safety and clinical outcomes observed in this study are consistent with those expected in patients with severe influenza and reflect a real-life clinical setting,” the researchers wrote.
Disclosure: Some researchers are employees of GlaxoSmithKline. Other researchers have financial relationships with Alnylam, Astellas, Covidien, Gilead, GlaxoSmithKline, Hospal, Kenta Biotech, MSD, Novartis, Pfizer, Sanofi, Talecris and Teva.