The agreement expands upon the previously established partnership with PRX-102’s developer, Protalix BioTherapeutics, which had granted Chiesi the development and sales rights to the therapy in all countries outside the U.S.
Under the terms of the new agreement, Protalix will continue to be the manufacturer of PRX-102 for all clinical development and commercial purposes.
Protalix will receive an upfront payment of $25 million from Chiesi and additional payments in development costs up to $20 million. If the drug is approved by regulatory agencies as a treatment for Fabry disease, Protalix will also be entitled to receive additional payments and royalties on net sales.
“We are very pleased to expand our collaboration with Chiesi, a growing global company with well-established global commercial infrastructure with a fast growing commercial presence in the U.S.,” Moshe Manor, president and CEO of Protalix, said in a press release.
“[The combined global investment] in the two agreements reflects Chiesi’s true commitment to the Fabry space,” Manor added.
PRX-102 is a genetically engineered version of the human alpha-galactosidase A (alpha-GAL-A) enzyme that is involved in the breakdown of globotriaosylceramide (Gb3), and whose deficiency is responsible for the development of Fabry disease.
It was designed by Protalix as an enzyme replacement therapy (ERT) for Fabry disease, replacing the faulty alpha-GAL-A enzyme and restoring its normal function.
In preclinical studies, PRX-102 has demonstrated significantly better and higher enzyme activity in disease-affected organs when compared to currently available versions of the molecule, such as Sanofi Genzyme’s Fabrazyme (agalsidase beta) or Shire’s Replagal (alpha-galactosidase A).
PRX-102 has been shown to slow the progression of damage to small nerve fibers in mice with Fabry disease. It reduced by 53% the levels of Iba1, a biomarker of inflammation affecting the peripheral nerve system, whereas other therapies failed to do so.
Data collected in a Phase 1/2 clinical trial (NCT01678898), and its extension studies (NCT01981720, NCT01769001), have demonstrated the experimental compound can prevent the decline of kidney and heart function in Fabry disease patients. The trial also showed that PRX-102 is safe and well tolerated.
The treatment is currently being evaluated in three Phase 3 trials in Fabry patients. All trials — taking place across the U.S., Europe, and occasionally other international sites — are currently recruiting participants.
The BRIGHT study (NCT03180840) is exploring the safety, effectiveness, and general properties of PRX-102, administrated every four weeks over a year, in Fabry patients who were previously treated with approved ERTs.
Interim data announced in June 2018 revealed the superior stability and enhanced activity of the investigative therapy in slowing kidney and heart damage due to Fabry disease.
Another Phase 3 study (NCT03018730) is an open-label switch trial assessing the safety and effectiveness of PRX-102 in Fabry patients who were treated for at least two years with Replagal (agalsidase alfa).
“The more we work with Protalix and see the progress made in the development and the product’s characteristics, it becomes abundantly clear the significant role PRX-102 could have in the underserved Fabry market and to potentially change the treatment paradigm,” said Ugo Di Francesco, the CEO of Chiesi.
PRX-102 was granted Orphan Drug Designation by the European Commission for the treatment of Fabry disease, and Fast Track status by the U.S. Food and Drug Administration for the same indication. These designations are expected to support and facilitate its clinical development and regulatory review.