Dose-ranging Study of PRX-102 in Adult Fabry Disease Patients

A Phase 1/2, Open Label, Dose Ranging Study to Evaluate the Safety, Tolerability, Pharmacokinetics and Exploratory Efficacy Parameters of PRX-102 Administered by Intravenous Infusion Every 2 Weeks for 12 Months to Adult Fabry Patients

This is the first human treatment with PRX-102, an enzyme being developed as a long-term enzyme replacement therapy in patients with a confirmed diagnosis of Fabry disease (alpha galactosidase deficiency). The safety, tolerability, and exploratory efficacy will be evaluated in this study of increasing doses. Patients will be treated with infusions every two weeks for 12 months.

Under the PB-102-F01 study protocol, patients will be enrolled into one of three PRX-102 dosing groups (0.2 mg/kg, 1.0 mg/kg, 2.0 mg/kg) and receive PRX-102 as an intravenous infusion every 2 weeks for 12 weeks (3 months). Patients who finish the PB-102-F01 study will be enrolled in the PB-102-F02 extension study and receive the same dose they had received in the PB-102-F01 study for an additional 38 weeks (9 months).

Inclusion Criteria:

• Symptomatic adult Fabry patients (≥18 yrs)
• Males: plasma and/or leucocyte alpha galactosidase activity (by activity assay) less than lower limit of normal (LLN in plasma=3.2 nmol/hr/ml, LLN in leucocytes=32 nmol/hr/mg/protein)
• Females: historical genetic test results consistent with Fabry mutations
• Globotriaosylceramide (Gb3) concentration in urine > 1.5 times upper normal limit
• Patients who have never received enzyme replacement therapy (ERT) in the past, or patients who have not received ERT in the past 6 months and have a negative anti alpha galactosidase antibody test
• eGFR ≥ 60 mL/min/1.73m2
• The patient signs informed consent
• Female patients and male patients whose co-partners are of child-bearing potential agree to use a medically acceptable method of contraception, not including the rhythm method

Exclusion Criteria:

• Participation in any trial of an investigational drug within 30 days prior to study screening
• Chronic kidney disease stages 3-5 (CKD 3-5) (Appendix 7)
• History of dialysis or renal transplantation
• Angiotensin converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) therapy initiated or dose changed in the 4 weeks prior to screening
• Severe myocardial fibrosis by MRI (≥2 late-enhancement [LE] positive left ventricular segments) (Weidemann et al. 2009)
• History of clinical stroke
• Pregnant or nursing
• Presence of HIV and/or HBsAg and/or Hepatitis C infections
• Known allergies to ERT
• Known allergy to Gadolinium based contrast agents
• Presence of any medical, emotional, behavioral or psychological condition that, in the judgment of the Investigator and/or Medical Director, would interfere with the patient's compliance with the requirements of the study