Baseline uPCR value was calculated as the average of the uPCR measurements from at least 6 of the 9 first-morning spot urine (FMU) samples collected between the start of screening and Day 1, inclusive. The uPCR values used to calculate baseline included those from the samples collected on Day -2, Day -1, and before dosing on Day 1. In situations where less than 6 samples or more than 9 samples were collected, the average of all collected samples was used for baseline derivation. The difference between treatment groups using a composite contrast of equal-weighted average over Weeks 24, 25, and 26 was estimated.

Baseline was the average of measurements recorded before taking the first dose of pegcetacoplan, which included local and central laboratory values during the screening period. Analysis excluded data before the RCP and was censored for transfusions.

Area under the concentration-time curve limited to the end of the dosing interval. The samples included in the calculation of AUC0-tau were collected at the following times: on dosing Days 1, 3 and 5, PK samples were taken up to 30 minutes pre-dose and at 15 minutes (± 5 min), 30 minutes (± 5 min), 1 hour (± 10 min), 4 hours (± 10 min), 8 hours (± 30 min), and 24 hours (± 30 min) post-dose as well as on Day 8 pre-dose.

Maximum observed serum concentration. Determined using the samples collected post-dose on dosing Days 1, 3 and 5.

Time of maximum measured serum concentration. Determined using the samples collected post-dose on dosing Days 1, 3 and 5.

Observed serum concentration pre-dose. From Day 8 (Week 1) and onwards, PK samples were taken pre-dose at each visit.

C3c staining intensity is semi quantitatively graded on a scale of 0 to 3, in which negative, 1+, 2+ and 3+ staining corresponds to scores of 0 to 3, with 0 being absent and 3 being the highest intensity seen on immunofluorescence. Higher scores indicate worse outcome. Reduction in C3c staining was defined as decrease of at least 2 orders of magnitude of intensity from baseline. Baseline was defined as the most recent non-missing measurement prior to first administration of study drug for Group 1 subjects or randomization for Group 2 subjects.

TEAEs were defined as adverse events (AE) that occurred after dosing on Day 1 and up to 30 days after the last dose of study drug. A treatment-related TEAE was defined as a TEAE with a relationship to study drug of possible, probable, or definite. TEAEs were graded according to the Common Terminology Criteria for Adverse Events (v4.03) based on: Grade 1: Mild, Grade 2: Moderate, Grade 3: Severe, Grade 4: Life-threatening, Grade 5: Death related to AE.

Serum chemistry assessments of LDH were made at the last measurement prior to the first dose of pegcetacoplan (baseline) and periodically throughout the treatment period.

Serum chemistry assessments of haptoglobin were made at the last measurement prior to the first dose of pegcetacoplan (baseline) and periodically throughout the treatment period.

Hematology assessments of Hb were made at the last measurement prior to the first dose of pegcetacoplan (baseline) and periodically throughout the treatment period.

The square root GA lesion size (i.e. transformed area of GA) was measured by FAF photographs. Baseline was defined as the last available, non-missing observation prior to first study drug administration.

A TEAE was defined as any adverse event (AE) that commenced or worsened on or after time of first study drug administration up to 60 days beyond last dose of study drug. A treatment-related TEAE was defined as a TEAE with a relationship to study drug of possibly related or probably related or not reported. Severity of TEAEs were categorized as mild; moderate; severe; life-threatening or death related to TEAE, according to Common Terminology Criteria for AEs v4.03. A TEAE of special interest (TEAESI) was defined as a TEAE of scientific and medical concern specific to pegcetacoplan, whether serious or non-serious.

Serum chemistry assessments of LDH were made at the last measurement prior to the first dose of pegcetacoplan (baseline) and periodically throughout the different parts of the treatment period. LDH results were summarized for Cohort 2 only.

Serum chemistry assessments of LDH were made at the last measurement prior to the first dose of pegcetacoplan (baseline) and periodically throughout the different parts of the treatment period. LDH results were summarized for Cohort 2 only.

Serum chemistry assessments of haptoglobin were made at the last measurement prior to the first dose of pegcetacoplan (baseline) and periodically throughout the different parts of the treatment period. Haptoglobin results were summarized for Cohort 2 only.

Serum chemistry assessments of haptoglobin were made at the last measurement prior to the first dose of pegcetacoplan (baseline) and periodically throughout the different parts of the treatment period. Haptoglobin results were summarized for Cohort 2 only.

Hematology assessments of hemoglobin were made at the last measurement prior to the first dose of pegcetacoplan (baseline) and periodically throughout the different parts of the treatment period. Hemoglobin results were summarized for Cohort 2 only.

Hematology assessments of hemoglobin were made at the last measurement prior to the first dose of pegcetacoplan (baseline) and periodically throughout the different parts of the treatment period. Hemoglobin results were summarized for Cohort 2 only.

TEAEs were defined as AEs that developed or worsened after first dose of study drug (Day 1), and up to 30 days after last dose of study drug. The Investigator assessed AEs for severity and relatedness to study drug. AEs were graded according to the Common Terminology Criteria for Adverse Events (CTCAE, v4.03) based on: Grade 1: Mild; Grade 2: Moderate; Grade 3: Severe; Grade 4: Life-threatening; Grade 5: Death related to AE.

TEAEs were defined as AEs that developed or worsened after first dose of study drug (Day 1), and up to 30 days after last dose of study drug. The Investigator assessed AEs for severity and relatedness to study drug. AEs were graded according to CTCAE, v4.03 based on: Grade 1: Mild; Grade 2: Moderate; Grade 3: Severe; Grade 4: Life-threatening; Grade 5: Death related to AE.

Assessment of AUC0-t of pegcetacoplan over the multiple dosing phase, estimated using a non-compartmental approach and calculated by the linear-log trapezoidal method. Pegcetacoplan pharmacokinetic (PK) parameters were summarized for Cohort 4 only.

Assessment of Ctrough,max of pegcetacoplan over the multiple dosing phase, estimated using a non-compartmental approach. Pegcetacoplan PK parameters were summarized for Cohort 4 only. Ctrough,max was calculated for both 270 mg/day and 360 mg/day where subjects received both doses. Note: 1 subject in Cohort 4 who was receiving 360 mg/day was granted Sponsor and institutional review board approval to increase the dose further to the equivalent of 440 mg/day and Ctrough,max is also reported for this dose.

Safety was assessed throughout the study. A TEAE was defined as any AE that started on/after the IVT injection of pegcetacoplan.

The occurrence of any of the following AEs were considered DLTs: intraocular inflammation (vitritis or uveitis), endophthalmitis, sustained elevation of intraocular pressure ≥30 millimeters (mm) of mercury, and/or sustained loss of visual acuity ≥15 letters not attributable to the injection procedure or progression of disease.

The AUC(0-t) was measured using the linear trapezoidal method when concentrations were increasing and the logarithmic trapezoidal method when concentrations were decreasing. The median AUC(0-t) is presented for each cohort.

The AUC(0-t) was measured using the linear trapezoidal method when concentrations were increasing and the logarithmic trapezoidal method when concentrations were decreasing. The dose normalized AUC(0-t) was calculated for each subject by dividing the parameter by the subject's respective dose in milligrams. The median dose normalized AUC(0-t) is presented for each cohort.

The median Cmax is presented for each cohort.

The dose normalized Cmax was calculated for each subject by dividing the parameter by the subject's respective dose in milligrams. The median dose normalized Cmax is presented for each cohort.

The median Tmax is presented for each cohort. If the maximum value occurred at more than 1 time point, Tmax was defined as the first time point with this value.