Pfizer has agreed to acquire Swiss biotechnology firm Therachon for a total consideration of $810m to support its rare disease portfolio.

The deal involves an upfront payment of $340m and a further $470m when certain milestones are achieved in the development and commercialisation of TA-46.

This investigational, soluble recombinant human fibroblast growth factor receptor 3 (FGFR3) decoy. It is intended to address the overactive FGFR3 signalling pathways related to bone development abnormalities in achondroplasia, a genetic type of dwarfism that can cause serious cardiovascular, neurological and metabolic complications. The condition currently lacks approved treatments.

TA-46 is being developed as a weekly subcutaneous injection to treat children and adolescents. The product has completed Phase I development and holds orphan drug designation from both the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA).

“Pfizer’s existing research programmes for paediatric growth disorders provide a complementary setting for this potential breakthrough therapy.”

Therachon’s pipeline also features apraglutide for rare gastrointestinal (GI) diseases, TA-46 LCM for skeletal dysplasias, and TA-100 FGFR3 Decoy for achondroplasia and other rare skeletal dysplasias.

Prior to the acquisition, Therachon will spin off the apraglutide development programme into a separate, independent company. Apraglutide is a once-weekly GLP-2 analogue currently in Phase II development for short bowel syndrome. Pfizer’s venture capital arm will continue to hold a stake in this new company.

Pfizer’s rare disease research unit senior vice-president and chief scientific officer Seng Cheng said: “Through the acquisition of Therachon, we believe that we have a significant opportunity to transform the lives of young people with achondroplasia who courageously endure lifelong complications from short-limb dwarfism.

“Pfizer’s existing research programmes for paediatric growth disorders provide a complementary setting for this potential breakthrough therapy.”

Therachon expects Pfizer’s rare disease expertise and global footprint to drive TA-46’s development.