CDC Loses Faith In AstraZeneca's Nasal Spray Flu Vaccine
Executive Summary
The US Centers for Disease Control and Prevention has decided not to recommend AstraZeneca PLC's nasal spray flu vaccine FluMist Quadrivalent (known as Fluenz Tetra in Europe) for the upcoming flu season owing to lack of efficacy. AstraZeneca said it would take an $80m write-down on stocks in the second quarter as a result.
The advisory committee on immunization practices (ACIP) of the Centers for Disease Control and Prevention (CDC) has ruled that AstraZeneca PLC's FluMist Quadrivalent live attenuated influenza vaccine (LAIV) should not be used in any setting in the US for the 2016-2017 flu season.
This was on CDC vaccine effectiveness data from the last three influenza seasons in the US, which indicated that the vaccine did not demonstrate significant effectiveness in children 2-17 years of age.
In late May, preliminary data on the effectiveness of LAIV among children 2 years through 17 years during 2015-2016 season became available. The data showed the vaccine to be effective in 3% of recipients. In comparison, IIV (flu shots) had efficacy of 63%. "The data from 2015-2016 follows two previous seasons showing poor and/or lower than expected vaccine effectiveness for LAIV," said the CDC.
AstraZeneca said the CDC data for 2015-2016 season contrast with its own studies "as well as preliminary independent findings by public health authorities in other countries." These findings demonstrate FluMist was 46-58% effective overall against the circulating influenza strains during the 2015-2016 season. As influenza vaccine effectiveness varies from season to season, it is evaluated in annual observational studies.
"AstraZeneca is working with the CDC to better understand its data to help ensure eligible patients continue to receive the vaccine in future seasons in the US," said the company.
Meanwhile, the distribution and use of the vaccine in other countries are progressing as planned for the forthcoming influenza season, "pending the annual release process from relevant regulatory authorities."
UK agencies such as Public Health England (PHE), the Department of Health and NHS England said they remained confident in the effectiveness of the nasal spray flu vaccine.
"We estimate that overall, the vaccine was 57.6% effective in preventing influenza infection amongst children in 2015 to 2016. These findings are encouraging and in line with what we also typically see for the adult flu vaccine," said Dr. Richard Pebody, head of flu surveillance for PHE.
In addition, the National Institute for Health and Welfare in Finland has confirmed that it saw similar effectiveness levels to the UK in 2015 to 2016, and has confirmed the nasal spray flu vaccine will continue to be used in Finland for the forthcoming winter.
Financial Impact
US product sales of FluMist Quadrivalent in 2015 amounted to $206m, the majority of global sales (which were $290m). The ACIP's updated recommendation is expected to result in very limited US demand in the second half of 2016 and AstraZeneca said it would take an inventory write-down of around $80m in the second quarter of 2016. Its financial guidance for 2016 remains unchanged.
FluMist was originally approved in the US in 2003 as a trivalent (three-component) vaccine.
Separately, Europe looks set to get a pandemic LAIV for fighting H5N1-strain bird flu after the EMA's CMHP advisory panel backed use of AstraZeneca's version in children and adolescents earlier this year. The inhaled vaccine is based on the same components used to make FluMist. (Also see "Europe Set To Get Live Pandemic Bird Flu Vaccine Protection " - Scrip, 1 Apr, 2016.)