Study of the Safety and Efficacy of PRX-102 Compared to Agalsidase Beta on Renal Function

Inclusion Criteria:

- Symptomatic adult Fabry disease patients, age 18-60 years

1. Males: Plasma and/or leucocyte alpha galactosidase activity (by activity assay)
less than 30% mean normal levels and one or more of the characteristic features
of Fabry disease

i. neuropathic pain

ii. cornea verticillata

iii. clustered angiokeratoma

2. Females:

a. historical genetic test results consistent with Fabry pathogenic mutation and
one or more of the described characteristic features of Fabry disease:

i. neuropathic pain

ii. cornea verticillata

iii. clustered angiokeratoma

b. or in the case of novel mutations a first degree male family member with Fabry
disease with the same mutation, and one or more of the characteristic features of
Fabry disease

i. neuropathic pain

ii. cornea verticillata

iii. clustered angiokeratoma

- Screening eGFR by CKD-EPI equation 40 to 120 mL/min/1.73 m²

- Linear negative slope of eGFR based on at least 3 serum creatinine values over
approximately 1 year (range of 9 to 18 months, including the value obtained at the
screening visit) of ≥ 2 mL/min/1.73 m²/year

- Treatment with a dose of 1 mg/kg agalsidase beta per infusion every 2 weeks for at
least one year and at least 80% of 13 (10.4) mg/kg total dose over the last 6 months.

- Female patients and male patients whose co-partners are of child-bearing potential
agree to use a medically accepted method of contraception, not including the rhythm
method.

Exclusion Criteria:

- History of anaphylaxis or Type 1 hypersensitivity reaction to agalsidase beta

- Known non-pathogenic Fabry mutations

- History of renal dialysis or transplantation

- History of acute kidney injury in the 12 months prior to screening, including specific
kidney diseases (e.g., acute interstitial nephritis, acute glomerular and vasculitic
renal diseases); non-specific conditions (e.g, ischemia, toxic injury); as well as
extrarenal pathology (e.g., prerenal azotemia, and acute postrenal obstructive
nephropathy)

- Angiotensin converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB)
therapy initiated or dose changed in the 4 weeks prior to screening

- Patient with a screening eGFR value between 91-120 mL/min/1.73 m², having an
historical eGFR value higher than 120 mL/min/1.73 m² (during 9 to 18 months before
screening)

- Urine protein to creatinine ratio (UPCR) > 0.5 g/g and not treated with an ACE
inhibitor or ARB

- Cardiovascular event (myocardial infarction, unstable angina) in the 6 month period
before randomization

- Congestive heart failure NYHA Class IV

- Cerebrovascular event (stroke, transient ischemic attack) in the 6 month period before
randomization

- Known history of hypersensitivity to Gadolinium contrast agent that is not managed by
the use of pre-medication

- Female subjects who are pregnant, planning to become pregnant during the study, or are
breastfeeding

- 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