Alnylam Pharmaceuticals (ALNY) shares tumbled 22% pre-bell after it reported second-quarter non-GAAP earnings Thursday of $1.84 per diluted share, compared with $0.28 a year earlier.

Two analysts surveyed by FactSet expected $2.03.

Revenue for the quarter ended June 30 was $1.29 billion, compared with $773.7 million a year earlier.

Analysts surveyed by FactSet expected $1.32 billion.

The company lowered its full-year 2026 net product revenue guidance to a range of $4.70 billion to $5.10 billion from previous guidance of $4.90 billion to $5.30 billion.