Clinical Benefits Associated With Evinacumab in Pediatric Patients With Homozygous Familial Hypercholesterolemia

Background Homozygous familial hypercholesterolemia (HoFH), characterized by extremely elevated low‐density lipoprotein cholesterol (LDL‐C) due to severely impaired LDL‐C clearance from circulation, remains challenging to treat. Here, we investigated clinical benefits of monoclonal antibody, evinacumab, inhibiting angiopoietin‐like 3, recently approved in children with homozygous familial hypercholesterolemia. Methods This retrospective, observational study included 13 children with homozygous familial hypercholesterolemia on oral lipid‐lowering therapy and assessed their attainment of LDL‐C goal, need for lipoprotein apheresis (LA), and cardiac plaque formation at initiation of evinacumab and at follow‐up of 2.0 (1.3–3.0) years. Results Evinacumab, initiated at age 11 (8.5–13.5) years, increased number of patients reaching LDL‐C goal from none before initiation to 9 of 13 (69%; P =0.004) at follow‐up. Mean±SD LDL‐C at follow‐up was 111 (44) mg/dL, compared with 206 (61) mg/dL before evinacumab (mean difference, −95 mg/dL [95% CI, −142 to −47]; P <0.001). Before initiation of evinacumab, 11 of 13 children received LA with average interval of 7.8 days. At follow‐up, LA frequency decreased in 7 of 11 children with average interval of 18.9 days; increase between LA sessions was 11.0 days (3.5–18.5; P =0.008), 42% longer session interval. For 3 (15%) children, due to evinacumab initiation, LA remained dispensable over the course of treatment. Coronary computed tomography angiography showed plaque stabilization (n=5), regression (n=3), and no formation (n=2), in 10 of 13 (77%) children, and plaque progression in 3 (23%) children. Conclusions Add‐on evinacumab increased number of children with homozygous familial hypercholesterolemia reaching and maintaining LDL‐C goal, concomitant reduction in LA frequency, and in most patients, stabilization or improvement in coronary computed tomography angiography findings.