Protalix, Chiesi fire up accelerated approval pitch for Fabry disease treatment
When Protalix BioTherapeutics reported its 2018 results this March, it spent much of its time talking up the potential of nabbing an accelerated approval for its Fabry disease treatment pegunigalsidase alfa.
Weeks later, the Israeli biotech — which has an unappetizing penny stock valuation $PLX — and partner Chiesi are going for it, optimistic after months of discussion with the FDA. The BLA filing is scheduled for Q1 2020.
Like Shire’s Replagal, which it’s being compared against in a pair of late-stage trials, pegunigalsidase alfa (or PRX-102) is an enzyme replacement therapy designed to break down the excess fat molecules building up in Fabry patients. Synthesized from plants, this particular recombinant alpha-galactosidase A enzyme can be infused every four weeks instead of Replagal’s two.
An initial glimpse of the Phase III study showed that high levels of the drug circulated in the bloodstream after 28 days, with a mean concentration 138 ng/mL among 15 evaluable patients. In contrast, Fabrazyme — another ERT developed by Sanofi Genzyme — had historically shown a mean concentration of 20 ng/mL at 10 hours post infusion, HC Wainwright analysts added in a February note.
But those are not the only competitors Protalix will face. Amicus has traveled down its own winding path to an approval for Galafold, an oral drug that works by addressing some misfolded α-GalA enzymes. New therapies to introduce healthy copies of the GLA gene, which encodes for the enzyme, are coming up in the pipeline, with a notable effort from Avrobio.
“This regulatory approval path is a significant achievement as it means that we can start the application process and potentially attain market approval significantly earlier than the initial plan of data from our ongoing phase III BALANCE clinical trial,” CEO Moshe Manor said in a statement. “We plan to continue the BALANCE study to further strengthen the profile of pegunigalsidase alfa.”
Chiesi holds the US rights to the drug from a deal that looped in $760 million in regulatory and commercial milestones. Protalix currently has one approved product for Gaucher disease, marketed by Pfizer.
That 2012 approval, though, has done little to lift Protalix’s suffering stock after a confounding decision in 2007 to price a secondary offering at an 85%. Shares plummeted from $35 to $5 overnight and has barely gone over $10 since, trading way below $1 these days.