A Sequential Phase 2/3 Study of APL2 in Patients With Focal Segmental Glomerulosclerosis

Inclusion Criteria:

* Age

  * Phase 2: adults aged ≥18 years
  * Phase 3: adults aged ≥18 years; if and where approved, adolescents (aged 12--17 years) at the time of signing the informed consent and assent form
* Weight ≥30 kg and ≤100 kg at screening
* FSGS diagnosis

  * Phase 2: primary, genetic, or undetermined FSGS diagnosed by kidney biopsy
  * Phase 3: primary, genetic, or undetermined FSGS diagnosed by kidney biopsy or by recognized podocyte genetic mutation
* At least 1.5 g/day of proteinuria on a screening 24-hour urine collection and a uPCR of at least 1.5 g/g in at least 2 FMU samples collected during screening
* Estimated glomerular filtration rate (eGFR) ≥25 mL/min/1.73 m2
* Stable regimen for FSGS treatment for at least 12 weeks prior to randomization, with no planned or anticipated adjustments or dose changes to the stable treatment regimen

Exclusion Criteria:

* Previous exposure to APL2
* Evidence of improving kidney disease in the 8 weeks prior to screening or during the screening period according to available data
* FSGS secondary to another condition (eg, infectious, diabetic, drug-induced, obesity, prematurity, sickle-cell, vesicoureteral reflux, congenital anomalies of the kidney, and urinary tract)
* Type 1 or uncontrolled (HbA1C ≥8%) type 2 diabetes mellitus
* History of kidney transplant
* Current or prior diagnosis of HIV, hepatitis B, or hepatitis C infection or positive serology or viral load during screening that is indicative of active infection with any of these viruses
* Hypersensitivity to APL2 or to any of the excipients
* Significant other kidney disease that would, in the opinion of the investigator, confound interpretation of study results
* Use of rituximab, belimumab, or any approved or investigational anticomplement therapy within 5 half-lives of that product prior to the screening period