Seven senators are questioning why Sanofi and AstraZeneca underestimated the demand for Beyfortus, the first pediatric drug approved for respiratory syncytial virus.
The monoclonal antibody, Beyfortus (nirsevimab-alip), has been in shortage for months, and the CDC released 77,000 doses in mid-November a few weeks after the agency recommended clinicians prioritize 100 milligram doses for patients at the highest risk or RSV.
In a Nov. 17 letter sent to the two pharmaceutical companies, Sen. Tammy Duckworth of Illinois, Sen. Elizabeth Warren of Massachusetts and five other senators asked if Sanofi and AstraZeneca can scale up production.
"Given that we know last RSV season was so severe, we were surprised to hear about the disparity between the estimated and actual demand for nirsevimab this year," the letter says. "What factors led to the significant underestimation of demand for the product and what actions will you take to adjust these estimates going forward?"
The drugmakers were also asked when they became aware of the supply issue and when they notified the FDA.