This is a Phase 1, double-blind, placebo-controlled, single ascending dose study in participants with elevated uric acid levels. This study will be conducted in approximately 64 adult male and female participants in the dose escalation phase.

Participants will be assigned to 1 of 8 sequential dosing cohorts, each composed of 8 participants (6 active + 2 placebo) who will receive a single dose of PRX-115 or placebo by intravenous (IV) infusion.

Inclusion Criteria:

1. Males or females 18 to 65 years of age, inclusive.
2. Serum uric acid greater than 6.0 mg/dL (0.35 mmol/L) at the Screening visit.
3. Body mass index within the range 18.5 to 40 kg/m^2, inclusive, at the Screening visit.
4. Women of childbearing potential may be included only if they have a negative beta human chorionic gonadotropin (β-hCG) test result at Screening.
5. Men and women of childbearing potential and their partners should use double barrier contraception.

Exclusion Criteria:

1. Has any condition known to have arthritis as a clinical manifestation
2. Had greater than or equal to 1 gout flare in the last year prior to either Screening or Day -1.
3. Has clinical evidence of subcutaneous tophi at either Screening or Day -1.
4. Estimated glomerular filtration rate (eGFR) value less than or equal to 60 mL/min/1.73m^2
5. History of significant renal disease, and/or presence of renal stones at either Screening or Day -1.
6. Has a history of anaphylaxis, severe allergic reactions, or severe atopy.
7. History of autoimmune disorders, and/or participant is immunocompromised or treated with immunosuppressive medications.
8. Has evidence of cardiovascular or cerebrovascular disease.
9. History of congestive heart failure, New York Heart Association Class III or IV.
10. BP outside the range of 90 to 150 mm Hg for systolic or 50 to 95 mm Hg for diastolic.
11. Participants with hypertension who are not on stable medication for at least 6 months.
12. Has uncontrolled type 2 diabetes
13. Concurrent treatment with urate lowering drugs (ULDs).
14. Prior exposure to any experimental or marketed uricase (eg, rasburicase [Elitek, Fasturtec], pegloticase [Krystexxa®], pegadricase [SEL-212]).
15. Glucose-6-phosphate dehydrogenase (G6PD) deficiency or known catalase deficiency.