Protalix BioTherapeutics Gets $20 Million Milestone Payment from Chiesi

Rare Daily Staff

Protalix BioTherapeutics said it is eligible to receive $20 million from its commercial partner Chiesi Global Rare Diseases after the U.S. Food and Drug Administration’s approval of their Fabry disease therapy Elfabrio triggered a milestone payment.

“Receiving this milestone payment resulting from the FDA’s approval of Elfabrio is an important step for Protalix as it further to strengthens our financial position,” said Dror Bashan, Protalix’s president and CEO.

Fabry disease is an X–linked inherited disease that results from deficient activity of the lysosomal α–Galactosidase–A enzyme resulting in progressive accumulation of abnormal deposits of a fatty substance called globotriaosylceramide (Gb3) in the lysosomes throughout a person’s body. Fabry disease occurs in one person per 40,000 to 60,000 people. Fabry patients inherit a deficiency of the α–Galactosidase–A enzyme, which is normally responsible for the breakdown of Gb3. The abnormal storage of Gb3 increases with time and Gb3 accumulates, primarily in the blood vessel and tissues. The ultimate consequences of Gb3 deposition range from episodes of pain and impaired peripheral sensation to end-organ failure.

Elfabrio is a PEGylated enzyme replacement therapy. It is a recombinant human α–Galactosidase–A enzyme expressed in plant-cell culture that is designed to provide a long half-life.

In July 2018, the two companies entered into an exclusive license and supply agreement to commercialize Elfabrio in the United States. This followed a similar agreement for ex-U.S. rights for the drug in 2017.

Under the two agreements, Protalix has already received a total of $95 million in upfront payments and to cover development costs. In addition, under the two agreements, the company is entitled to up to $1 billion in potential regulatory and commercial milestone payments, tiered royalties ranging from 15 percent to 40 percent of Chiesi’s net sales in the United States and tiered royalties ranging from 15 percent to 35 percent of Chiesi’s net sales outside the United States, as consideration for product supply.

Photo: Dror Bashan, Protalix’s president and CEO