Israel-based Protalix BioTherapeutics has started enrolling patients in its Phase IIa clinical trial of oral glucocerebrosidase (GCD), or oral GCD (PRX-112) for treatment of Gaucher disease.
Oral PRX-112 is the company's proprietary plant cell expressed form of an active glycosylated glucocerebrosidase enzyme (GCD) that is naturally encapsulated within carrot cells and administered orally.
The 28-day, sequential dose escalation Phase IIa trial is designed to assess the safety of oral PRX-112, as well as study the dose dependant pharmacokinetics of Oral GCD in ten naive adult Gaucher patients.
The trial is expected to be complete during the third quarter of 2014, with patients given once-daily oral administrations of oral GCD for five consecutive days at each dose, with a two-day washout period between doses.
In a Phase I trial carried out in 2013, oral GCD was found to be safe and well-tolerated in all 16 patients across all of the three doses tested, and there were no drug-related serious adverse reactions reported as well as no patient discontinued the study prematurely.
The company said that presence of the GCD enzyme was detected in patients' blood circulation and the enzyme showed biological activity.
By administering oral GCD daily, the company expects to achieve a steady state level of active GCD enzyme in the blood circulation of patients similar to the physiological state in healthy individuals.
Protalix president and chief executive officer David Aviezer said: "We believe oral delivery of GCD has the potential to improve patients' quality of life and possibly clinical maintenance while maintaining the efficacy and safety of an enzyme treatment."