Under the terms of the deal, Pfizer will pay $340 million upfront with another $470 million in payments contingent on milestones for the development and commercialization of TA-46 for the treatment of achondroplasia. Achondroplasia is a genetic condition that is the most common form of short-limbed dwarfism. The disorder can also cause serious cardiovascular, neurological and metabolic problems for about 250,000 people worldwide. There are currently no approved treatments for achondroplasia.
TA-46 is a soluble recombinant human fibroblast growth factor receptor 3 (FGFR3) decoy. It is believed it can normalize the overactive FGFR3 signaling pathway that is implicated in bone development abnormalities linked to achondroplasia. Therachon is developing it as a weekly subcutaneous injection for children and adolescents with the disorder.
The drug has finished Phase I trials. The European Medicines Agency (EMA) and the U.S. Food and Drug Administration (FDA) have both granted the drug Orphan Drug Designation.
Before the deal closes, Therachon plans to spin-off its apraglutide development program into an independent company. The drug is a once-weekly GLP-2 analog. It is currently in Phase II trials for short bowel syndrome. Pfizer Ventures, the drug company’s venture capital arm, holds a minority stake currently and will continue to have an equity stake in the spin-off company.
“At Pfizer, our strategy is focused on advancing the most promising science in the world, regardless of whether it is found inside or outside of our labs,” stated Mikael Dolsten, Pfizer’s chief scientific officer and president, Worldwide Research, Development, and Medical. “By acquiring Therachon, we hope to leverage Pfizer’s leading scientific and development capabilities to more rapidly advance this potentially promising therapy for people with achondroplasia.”
Pfizer intends for the acquisition to bolster its rare diseases portfolio, which includes several research programs for pediatric growth disorders.
In addition to headquarters in Switzerland, Therachon has research laboratories in Nice, France and business operations in the New York area.
On March 25, Therachon presented data from the Phase I trial of apraglutide in short bowel syndrome at the ASPEN 2019 Nutrition Science & Practice Conference organized by the American Society for Parenteral and Enteral Nutrition in Phoenix, Ariz. Short bowel syndrome (SBS) is caused by extensive intestinal resection as the result of chronic inflammatory bowel disease (IBD), acute events such as mesenteric infarction or congenital abnormalities. Symptoms include diarrhea, dehydration, malnutrition and weight loss.
Apraglutide is designed to increase the intestine’s ability to absorb nutrients and decrease the need for parenteral support (PS), which is the intravenous delivery of essential nutrients, calories and fluids. The drug is currently being studied in two Phase II clinical trials in SBS patients in Denmark.
For its part, Pfizer’s acquisition of the achondroplasia will set them on a path to compete with BioMarin Pharmaceutical, which is developing vosoritide for the disorder. In 2015, BioMarin announced positive Phase II proof-of-concept data for the drug, with data from 26 children in the trial showing a favorable safety profile and efficacy at the 15 micrograms/kilogram/daily dose.
In June 2018, BioMarin dosed the first patient in a global Phase II trial of the drug. The drug has also been granted Orphan Drug Designation in the U.S. and Europe. The trial will study the drug in about 70 infants and young children with achondroplasia in newborns and children less than 5 years old for 52 weeks. There will then be an open-label extension. The primary objectives of the study are safety, tolerability, and the effect of vosoritide on height Z-scores. It also plans to augment that score with data on proportionality, functionality, quality of life, sleep apnea, and foramen magnum dimension in addition to the beginning of major illnesses and surgeries.