Chiron Corporation / PathoGenesis Corporation

Pseudomonas aeruginosa lung infection in cystic fibrosis

$86M TOBI worldwide sales in the year preceding the 2000 acquisition

Disease Overview

Cystic fibrosis is an autosomal-recessive CFTR-mutation disease causing thick airway mucus, chronic bacterial colonization and progressive lung damage. Chronic Pseudomonas aeruginosa lung infection is nearly universal — by age 18, roughly 80% of classic-CF patients are colonized — and is the leading driver of pulmonary exacerbations, hospitalization and respiratory failure, historically capping life expectancy in the 30s before modern CFTR modulators.

Competitive Landscape

At the time of Chiron's August 2000 acquisition of PathoGenesis, TOBI (tobramycin solution for inhalation, FDA-approved 1997) was the first and only inhaled antibiotic specifically approved for chronic Pseudomonas suppression in CF and was generating roughly $86M in worldwide sales. Standard-of-care competitors at the time were limited to off-label inhaled colistin (colistimethate) and IV/oral aminoglycosides — neither tailored for chronic outpatient suppression. The deal anchored Chiron's anti-infectives franchise and pre-positioned a pipeline that later produced Cayston (aztreonam lysine inhalation, Gilead, FDA 2010) and the dry-powder TOBI Podhaler (Novartis, FDA 2013) as direct successors. Chiron also acquired ~275 PathoGenesis employees, an inhaled-antibiotic discovery engine, and the Seattle research site. The deal preceded — and was effectively rolled up into — Novartis's 2006 acquisition of Chiron, after which TOBI/TOBI Podhaler became a Novartis brand. The advent of CFTR modulators (Kalydeco 2012, Trikafta 2019) has since reshaped CF economics, but inhaled tobramycin remains a guideline-standard chronic-suppression therapy.