Pfizer expands rare disease pipeline with $820m buyout

The deal sees Pfizer pay $370m (€330m) upfront for Therachon, with a further $470m reserved for milestone payments on development and commercialisation targets.

The therapeutic candidate at the heart of the deal is TA-46, which is a soluble recombinant human fibroblast growth factor receptor 3 (FGFR3) decoy.

TA-46 has completed Phase I trials as a weekly subcutaneous injection for children and adolescents living with achondroplasia, the most common form of short-limbed dwarfism.

In those living with achondroplasia, the FGRF3 pathway is overactive and inhibits the development of bones, TA-46 is being investigated as a means to normalise the pathway.

Therachon’s CEO, Luca Santarelli said, “With its rare disease expertise and worldwide reach, Pfizer is well positioned to accelerate the development of TA-46 and fulfil Therachon’s vision of addressing the complications suffered by children with achondroplasia by targeting the molecular root causes of this condition.”​

Therachon worked with Catalent Biologics​ to get its development of TA-46 into Phase I trials, with the manufacture currently taking place at the latter’s facility in Wisconsin, US.

Therachon estimates that the rare disease affects approximately one in 25,000 live births and there are currently no specific treatments for the condition. TA-46 has already been provided orphan drug designation by both the US Food and Drug Administration and the European Medicines Agency.

BioMarin Pharmaceuticals has a potential rival treatment for achondroplasia going through Phase III trials, which is expected to read out later this year.

As well as its candidate for achondroplasia, Therachon has also developed apraglutide, a GLP-2 analog that is in Phase II development for the treatment of short bowel syndrome.

However, Pfizer did not pursue the inclusion of this candidate as part of its acquisition and will instead use its venture capital arm, Pfizer Ventures, to invest in the spin-out company created by Therachon that will focus on the further development of apraglutide.

Apraglutide is currently in Phase II trials and Pfizer Ventures will hold a minority stake in the newly-formed business.