ESPE Abstracts

Background: The EU-IGFD registry was established to monitor the safety and effectiveness of recombinant human IGF-I (rhIGF-I) (mecasermin (rDNA origin) injection; Increlex^®) for short stature in children with SPIGFD, including those with Laron syndrome (LS).

Objective: To report patient characteristics, effectiveness and safety data in clinically relevant patient subgroups.

Methods: Data were compiled from this ongoing observational study (NCT00903110; 10-May-2017 cut-off) for three treatment-naïve prepubertal (NPP) cohorts: LS (irrespective of treatment-response status); non-LS with treatment response (non-LS-responder; responder=year-1 height SDS change ≥0.3); non-LS with poor treatment response (non-LS-poor-responder). Two cohorts who were not treatment-naïve or who were pubertal (non-NPP) were additionally characterized (LS and non-LS).

Results: Characteristics: Of 246 patients enrolled, 213 were included in the analysis (NPP: 21 LS, 50 non-LS-responder, 38 non-LS-poor-responder; non-NPP: 17 LS, 87 non-LS). Of 33 patients excluded: 29 missing treatment-response status; four missing pubertal status and/or missing previous treatment. Cohorts had more males than females (NPP cohorts: LS 12/21 vs non-LS-responder 30/50 vs non-LS-poor-responder 27/38; non-NPP cohorts: LS 10/17 vs non-LS 59/87). At first rhIGF-I intake, mean (S.D.) ages for NPP cohorts were 6.07 (3.49) vs 7.00 (3.11) vs 10.28 (3.53) years, respectively, and for non-NPP cohorts were 12.78 (3.73) vs 11.43 (3.58) years, respectively. Mean (S.D.) height SDS in NPP cohorts were −5.62 (1.95) vs −3.49 (1.15) vs −3.44 (0.90) and in non-NPP were −4.63 (1.51) vs −3.61 (1.20). At first rhIGF-I intake, mean (S.D.) height velocities (HVs) in NPP cohorts: 5.67 (1.10) vs 4.99 (1.66) vs 4.19 (1.98), and in non-NPP: 4.43 (1.23) vs 4.70 (1.84). Effectiveness (year 1): Mean (S.D.) height SDS changes from baseline in NPP cohorts: 0.70 (0.56) vs 0.64 (0.26) vs 0.01 (0.21), and in non-NPP: 0.19 (0.50) vs 0.24 (0.47). All year-1 HVs (cm/year) improved (mean (S.D.) for NPP: 8.25 (2.54) vs 8.06 (1.69) vs 5.66 (1.36); non-NPP: 5.50 (2.88) vs 6.48 (2.37)). Safety: Targeted adverse events (TAEs) occurred in NPP cohorts for 15/21 (71.4%) vs 24/50 (48.0%) vs 14/38 (36.8%) patients and in non-NPP for 13/17 (76.5%) vs 38/86 (44.2%). The TAE reported in the greatest proportion of patients was hypoglycemia, except in non-LS-poor-responders (headache).

Conclusions: NPP responded better to treatment than non-NPP at year 1. Among NPP, patients with LS were younger and shorter than non-LS at first IGF-I intake, but showed a slightly better response at year 1. Safety is consistent with the known profile of mecasermin.