- In a rare step, French drugmaker Sanofi SA plans to ask medicines regulators around the world to limit use of its dengue vaccine only to people who have previously been infected with the mosquito-borne virus, citing long-term clinical data that showed differences in treatment efficacy depending on past infection history.
- An analysis of up to six years of clinical results found people who were never infected by dengue could in the longer term experience cases of severe disease upon a subsequent infection. For individuals previously infected by the virus and then vaccinated, Dengvaxia conferred persistent protective benefit.
- As a result, Sanofi said it would record a charge in the fourth quarter to reflect depreciation of inventories and other unspecified assets, likely lowering business net income by about €100 million ($119 million) after tax.
While the financial hit may not make much of a dent in Sanofi's fourth quarter earnings, the new data is a setback to the drugmaker's hopes for the vaccine, which was the first treatment ever approved for the virus.
Sanofi said it would ask national regulators to update the label for Dengvaxia to direct healthcare professionals to assess the likelihood of a prior dengue infection in an individual before administering the shot.
For those who had no prior history of a dengue infection, Sanofi believes vaccination should not be recommended in light of the new evidence.
Sanofi noted that between 70% and 90% of people in countries where dengue is endemic will be exposed to the virus at least once by the time they reach adolescence. (In most countries where it is approved, Dengvaxia is currently indicated for individuals aged 9 years or older who live in an endemic area.)
Even so, the proposed label restrictions will limit the potential population treatable by Dengvaxia and add a new step — assessing past infection status — to administration of the vaccine.
Sales of Dengvaxia have been relatively negligible, amounting to only €22 million (about $26 million) through the first 9 months of 2017 as operational hurdles to public vaccination programs and lower disease incidence in Latin America have slowed uptake.
Last year, revenues from Dengvaxia totaled €55 million (about $66 million) across the 14 countries where it received approval.