First-year response to rhGH therapy in children with CKD: a National Cooperative Growth Study Report.

A clear definition of the appropriate growth response during recombinant human growth hormone (rhGH) treatment has never been established in the pediatric chronic kidney disease (CKD) population. We present here data from Genentech's National Cooperative Growth Study (NCGS) on the first-year growth response in prepubertal children with CKD. Using NCGS data, we constructed response curves for the first year of rhGH therapy in 270 (186 males, 84 females) naïve-to-treatment, prepubertal children with CKD prior to transplant or dialysis. Data from both genders were combined because gender was not significantly related to height velocity (p = 0.51). Response to rhGH was expressed as height velocity (HV) in cm/year. Mean, mean + or - 1SD, and mean - 2SD for HV during the first year of rhGH treatment as well as pretreatment HV were plotted versus age. Age-specific HV plots for rhGH-treated children with CKD are presented. At all ages, the first-year mean HV was greater than the mean pretreatment HV. The mean - 2SD for HV in children on rhGH treatment was similar to the mean pretreatment HV. These growth plots will be useful to clinicians for assessing a patient's first-year growth response. We propose that a HV below the mean - 1SD is an inadequate response. These curves may help identify patients with a suboptimal growth response due to confounding medical factors and/or non-compliance.