CSL shares plunged to an eight-year low on Wednesday after reporting first-half underlying profit fell 7% to A$1.9 billion, while reported profit collapsed 81% to A$401 million due to restructuring charges and impairments.

Revenue declined 4% to A$8.3 billion, hit by lower immunoglobulin and albumin sales following Medicare reforms in the US and policy changes in China. The company booked A$1.1 billion in after-tax impairments, largely related to intellectual property at its Vifor and Seqirus units, reflecting generic competition and lower demand for COVID-related vaccine technology.

The plunge also came after the company announced the appointment of interim CEO Gordon Naylor the day before, replacing Paul McKenzie. Despite the weak result, CSL maintained full-year guidance and expanded its share buyback program to A$750 million.

This significant drop reflects investor concern over CSL's ability to navigate market headwinds and regulatory pressures in its core therapeutic areas.