A Study Evaluating the Efficacy, Safety, Pharmacokinetics and Pharmacodynamics of Crovalimab in Pediatric Participants With Atypical Hemolytic Uremic Syndrome (aHUS)

Participants were considered to be on dialysis at baseline or at Week 25 if dialysis occurred within 5 days prior to the first crovalimab administration or prior to the end date of the primary treatment period, respectively. The percentage of participants who required dialysis at baseline and Week 25 has been reported here. Percentages have been rounded off.

Participants were considered as being on dialysis at baseline or at Week 25 if dialysis occurred within 5 days prior to the first crovalimab administration or prior to the end date of the primary treatment period, respectively. Percentages have been rounded off.

GFR is an index of kidney function that describes the flow rate of filtered fluid through the kidneys. It was categorized according to chronic kidney disease (CKD) staging criteria. eGFR was calculated using the creatinine-based bedside Schwartz equation. eGFR (milliliters per minute per 1.73 square meter [mL/min/1.73 m^2])=0.413*(height [ht]/serum creatinine [sCr]), if height is expressed in centimeters, or 41.3*(ht/sCr), if height is expressed in meters.

GFR is an index of kidney function that describes the flow rate of filtered fluid through the kidneys. It was categorized according to CKD staging criteria. eGFR was calculated using the creatinine-based bedside Schwartz equation. eGFR (mL/min/1.73 m^2])=0.413*(ht/sCr), if height is expressed in centimeters, or 41.3*(ht/sCr), if height is expressed in meters.

CKD stage was assessed using eGFR, calculated from central serum creatinine using Creatinine-based bedside Schwartz equation \& classified according to National Kidney Foundation CKD staging criteria as follows: G1 (≥90 mL/min/1.73 m²; normal or high kidney function), G2 (60-89 mL/min/1.73 m²; mildly decreased kidney function), G3a (45-59 mL/min/1.73 m²; mildly to moderately decreased kidney function), G3b (30-44 mL/min/1.73 m²; moderately to severely decreased kidney function), G4 (15-29 mL/min/1.73 m²; severely decreased kidney function), \& G5 (<15 mL/min/1.73 m²; kidney failure). Change in CKD stage from baseline to Week 25 was categorized as improved (participants who improved in CKD stage from Baseline to Week 25 were based on the number of participants who completed 24 weeks and were not Stage 1 at baseline), stable (no change), or worsened (participants with CKD Stage 1 to 4 at baseline) among participants who completed 24 weeks of treatment. Percentages have been rounded off.

This event was confirmed at two separate assessments obtained at least 4 weeks (a minimum of 26 days) apart and any measurement in between.

Percentage has been rounded off.

Percentage has been rounded off.

cTMAr was defined by meeting all of the following criteria at two separate assessments, obtained at least 4 weeks (a minimum of 26 days) apart, and any measurement in between: Platelet count ≥ LLN; LDH ≤ ULN; and ≥ 25% decrease in serum creatinine from baseline. Kalpan-Meier (K-M) method was used to estimate median time to cTMAr. Data for participants who did not reach cTMAr during PTP were censored at the date of their last visit when cTMAr was assessed during the primary treatment period or prior to the treatment discontinuation, whichever was earlier. Data for participants who received a prohibited therapy during the PTP were censored at the date of the first received prohibited therapy during the primary treatment period or prior to the treatment discontinuation, whichever was earlier.

cTMAr=meeting following criteria at 2 separate assessments, obtained at least 4 weeks (minimum of 26 days) apart \& any measurement in between: Platelet count ≥LLN; LDH ≤ULN; \& ≥25% decrease in serum creatinine from baseline. Duration of cTMAr was calculated as time from start of cTMAr to end of cTMAr. End of cTMAr=when all of following criteria were met during same visit \& confirmed at assessment that took place at least 4 weeks (minimum of 26 days) later: Platelet count <LLN; LDH >ULN; \& ≥25% increase in serum creatinine from baseline \& ULN. K-M method was used to estimate the median duration of cTMAr. Data for participants with no observed end of cTMAr at CCOD were censored at the date of their last visit when cTMAr was assessed before CCOD or before treatment discontinuation, whichever was earlier. Data for participants who received prohibited therapy before CCOD were censored at date of first receiving prohibited therapy or before treatment discontinuation, whichever was earlier.

cTMAr at Week 25 was defined by meeting all of the three cTMAr criteria at Week 25: Platelet count ≥ LLN; LDH ≤ ULN; and ≥ 25% decrease in serum creatinine from baseline. Percentage has been rounded off.

mTMAc was considered not maintained if all of the following criteria were met during one of the visits between baseline and Week 25, and were confirmed at an assessment that took place at least 4 weeks (a minimum of 26 days) later: Platelet count < LLN; LDH > ULN; and 25% increase in serum creatinine from baseline.

An AE is defined as any untoward medical occurrence in a clinical investigation participant administered a pharmaceutical product, regardless of causal attribution. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product.

An AE is defined as any untoward medical occurrence in a clinical investigation participant administered a pharmaceutical product, regardless of causal attribution. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product.

An AE is defined as any untoward medical occurrence in a clinical investigation participant administered a pharmaceutical product, regardless of causal attribution. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product.

Crovalimab and eculizumab bind distinct epitopes on complement component C5, and formation of DTDCs comprising crovalimab, eculizumab, and C5 are formed when participants switch treatment. DTDCs will be characterized using size exclusion chromatography (SEC) coupled with enzyme-linked immunosorbent assay (ELISA).

Participants will be considered to be ADA positive if they were ADA negative at baseline but developed an ADA response following stuy drug exposure (treatment-induced ADA response), or if they were ADA positive at baseline and the titer of one or more post-baseline samples is at least 4-fold greater than the titer of the baseline sample (treatment-enhanced ADA response).