Dive Brief:
- Italian biopharma Chiesi Farmaceutici has acquired U.S. rights to an experimental Fabry disease drug developed by Protalix BioTherapeutics, expanding an existing partnership with the Israeli biotech for the late-stage candidate.
- Per deal terms, Protalix will receive an upfront payment of $25 million, with Chiesi funding development costs of the drug, called pegunigalsidase alfa or PRX-102, for up to $20 million.
- The real payoff for Protalix, however, is if the drug is successfully commercialized. Chiesi lined up regulatory and commercial milestone payments of up to $760 million, with tiered royalties ranging from 15% to 40% of future net sales. Pegunigalsidase alfa is currently in Phase 3 testing.
Dive Insight:
Protalix has focused its development efforts on recombinant therapeutic proteins, securing U.S. approval of Elelyso (taliglucerase alfa) for Gaucher disease in 2012 before outlicensing the drug to Pfizer.
Pegunigalsidase alfa is now Protalix's lead candidate, with Fabry patients enrolled in three pivotal Phase 3 studies that are expected to begin reading out data in the first half of next year.
Protalix had already collaborated with Cheisi before, agreeing in October 2017 to hand ex-U.S. rights to the Italian company. But the expansion of the deal to include the U.S. came as a surprise to some.
Peter Welford, an analyst at Jefferies, described the deal as "an unexpected, albeit positive update, given impressive deal terms," in a July 24 note to clients.
Taken together, the two agreements have handed Protalix $95 million in upfront cash and lined up over $1 billion in potential milestone payments for the biotech to cash in on if all goes well.
"Taking into consideration a $25 million upfront payment and shared development expenses, we expect our cash runaway to take us through the read outs of all of the Fabry clinical trials," said Protalix CEO Moshe Manor.
Protalix will continue to manufacture the drug candidate for both clinical and commercial use under the terms of the expanded partnership.
Fabry disease is a rare inherited disorder leading to a build up of a particular type of fat in the cells. This leads to pain, skin, eye and hearing problems, and patients can develop gastrointestinal disorders, kidney damage, heart attack and stroke.
For Jefferies' Welford, pegunigalsidase alfa is a long-term growth opportunity. The analysts models a 60% probability that the candidate reaches $250 million in peak annual sales with a projected launch in the latter half of 2021.
There are other treatments in development for Fabry patients. Amicus Therapeutics already markets migalastat as Galafold for certain Fabry disease patients in Europe, and is awaiting a decision from the Food and Drug Administration on approval in the U.S.