Wyeth [WYE] and MedImmune's [MEDI] FluMist failed to secure indications for use in key target groups for influenza vaccine in the US. Recently released results suggest that their second generation product may enable the two companies to capitalize on more conventional influenza vaccine sectors.
Five large trials investigating Wyeth/MedImmune's intranasal, cold-adapted trivalent influenza vaccine (CAIV-T) apparently support the product's efficacy, it was revealed at the Fifth International Options for the Control of Influenza Conference in Okinawa, Japan. The Phase III studies included nearly 5,500 individuals from a diverse range of populations, including infants as young as 6 weeks old, children from day care centers, elderly patients and healthy adults from 24-45 years of age.
While no details of the trials were revealed, both companies stated that results were extremely positive, supporting the development plans for the cold-adapted vaccine. CAIV-T has been developed using similar technology to FluMist, recently launched in the US by the same companies. FluMist, however, only gained approval for the 5-49 age group, which is not a key target for immunization programs.
Influenza is a recurrent infectious disease that affects and disrupts the lives of healthy children and adults and has serious health implications for elderly and immunocompromised patients. It results in direct and indirect annual costs of approximately $3-15 billion, including approximately 70 million missed workdays and approximately 38 million missed school days. However, influenza vaccination is currently only recommended for the elderly (over 50s), very young and those at increased risk as a result of medical conditions. As a result, FluMist's approved indications mean that it cannot be used in key immunization programs. Instead, Wyeth and MedImmune have been forced to target their innovative product at relatively healthy and less vulnerable group of patients.
Demonstrating the health-economic value of FluMist to the working population and those with school age children will be key to its initial success. The pain-free intranasal delivery route should support the product's use in such groups but the higher price, relative to injected products, may limit its uptake. These latest results and the potential launch of the second generation product could help Wyeth and MedImmune to benefit from a more conventional influenza market.