Regeneron Pharmaceuticals (REGN) reported Q1 adjusted earnings Tuesday of $8.22 per diluted share, down from $9.55 a year earlier.
Analysts polled by FactSet expected $8.62.
Revenue for the quarter ended March 31 was $3.03 billion, compared with $3.15 billion a year earlier.
Analysts surveyed by FactSet expected $3.25 billion.