Protalix BioTherapeutics: Overcoming Regulatory Hurdles to Unlock Rare Disease Market Potential

Protalix BioTherapeutics' Elfabrio faces regulatory hurdles in Europe, with the EMA rejecting a less frequent dosing schedule for Fabry disease. This setback does not impact FDA approval in the US or broader adoption. The company's growth potential and Chiesi partnership are key to its investment narrative, but regulatory progress remains uncertain.

Protalix BioTherapeutics Inc. (AMEX: PLX) experienced a significant market setback on Friday, September 12, 2025, after the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) rejected an alternative dosing regimen for its Fabry disease therapy, Elfabrio. The CHMP's decision, which was based on an insufficient data review, led to a 20.8% plunge in the company's stock price in premarket trading, according to an InvestorsHub report.

The rejected proposal was for a 2 mg/kg body weight infusion every four weeks (E4W) as an alternative to the currently approved 1 mg/kg every two weeks (E2W) regimen. The submission included data from the BRIGHT trial and its ongoing extension study, which had a median patient exposure of nearly six years. However, the CHMP concluded that the evidence was "not deemed sufficient to conclude on similar efficacy," the InvestorsHub article reported.

Despite this regulatory hurdle, Protalix and its partner Chiesi Global Rare Diseases expressed their commitment to continuing efforts to reduce the treatment burden for Fabry disease patients. Elfabrio remains approved for Fabry disease treatment in the EU, and the companies plan to support the Fabry disease community despite the setback, as noted by InvestorsHub.

The EMA's decision does not impact the FDA approval of Elfabrio in the US or its broader adoption. Protalix's growth potential and the partnership with Chiesi remain key aspects of its investment narrative. However, regulatory progress in Europe remains uncertain, which could potentially affect the company's overall growth trajectory, according to a TradingView post.