Novel antiviral shows promise for those at high risk for flu complications
A phase 3 study of the novel antiviral baloxavir marboxil suggests that it reduces symptoms in people at high risk of flu complications, Roche announced today. The single-dose oral treatment, discovered in Japan and developed by Roche, has a different mechanism of action than neuraminidase inhibitors like oseltamivir (Tamiflu) and was recently granted fast-track approval by the US Food and Drug Administration.
The multicenter study compared a single dose of baloxavir with placebo and oseltamivir in people age 12 and older who are at high risk of flu complications, Roche said in a news release. The trial was conducted globally by Shionogi, the company that discovered the drug.
When compared with placebo, baloxavir showed superior efficacy in time to improvement of flu symptoms. The drug also showed superior efficacy when compared with both placebo and oseltamivir for reducing time of virus shedding and viral load levels. Also against placebo, the medication significantly reduced the incidence of flu complications.
According to the study, the drug was well tolerated, and researchers didn't see any safety signals. Roche said it will present the full results from the study at upcoming medical meeting.
Sandra Horning, MD, Roche's chief medical officer and head of global product development, said in the release that baloxavir marboxil is the first antiviral to show a clinically meaningful benefit in people who are most susceptible to flu complications. "We plan to submit the results of this second positive phase III study for baloxavir marboxil to healthcare authorities, and look forward to discussing next steps since there are no current antiviral medicines approved to specifically treat this high-risk population," she said.
High-risk groups include adults age 65 and older and those with underlying health conditions such as asthma, chronic lung disease, diabetes, or heart disease.
Jul 17 Roche press release
Jun 27 CIDRAP News scan "Novel one-dose antiviral receives FDA priority review"
Study shows evidence of vertical Zika transmission in Aedes mosquitoes
For the first time, researchers demonstrated natural vertical transmission of the Zika virus among field-collected eggs of Aedes aegypti mosquitoes in the Brazilian Amazon. The findings were published yesterday in PLoS Neglected Tropical Diseases.
The scientists conducted the study in the mid-sized city, Itacoatiara, with the goal of determining if larvae from Ae aegyti and Ae albopictus were infected with flaviviruses. From January to April of 2016, they collected 2,057 specimens (1,793 Ae aegypti and 264 Ae albopictus) in 154 larvae pools. The investigators used RNA extraction tests to determine virus status of the larvae, which would indicate vertical transmission.
One pool each tested positive for Zika and chikungunya viruses. The researchers calculated the infection rate per 1,000 mosquitoes to be 0.45 and 0.44 for chikungunya and Zika, respectively, and the minimum infection rate was 0.45 for both viruses.
"We report the first detection of Zika virus vertical transmission in an Ae. aegypti larvae under the natural conditions found in the field," the authors concluded. They explained that this phenomenon may enhance the virus's epidemic potential, "because mosquitoes that emerge as virus-infected adults will have more opportunity to transmit virus than mosquitos that become infected after blood meal in an infected vertebrate."
Jul 16 PLoS Negl Trop Dis study
Antibodies taken from Ebola survivors may offer novel treatments
Scientists supported by the National Institute of Allergy and Infectious Diseases (NIAID), have discovered a new set of broadly neutralizing monoclonal antibodies (mAbs) in the blood of Ebola survivors, which proved protective against disease caused by Zaire, Bundibugyo, and SudanEbola viruses. The findings were published today in the journal Immunity.
In the study, the researchers analyzed plasma from 17 Ebola survivors and found that two survivors produced antibodies that bound to an essential virus protein, called glycoprotein, from Zaire, Bundibugyo, and Sudan Ebola virus species—the most deadly to humans. Those antibodies prevented the viruses from entering host cells.
Antibody therapy is a promising treatment for Ebola, but the current experimental therapy, ZMapp, targets only one of the five known species of the virus—the Zaire strain.
"These mAbs and related clones are promising candidates for development as broadly protective pan-ebolavirus therapeutic molecules," the authors concluded.
Jul 17 Immunity study