This study is an open-label, multi-center clinical trial to evaluate the safety and effectiveness of rhIGF-I/rhIGFBP-3 to increase rate of growth when administered once daily for 12 months in children and adolescents with growth hormone insensitivity syndrome (GHIS) such as Laron Syndrome. At the end of the initial twelve-month treatment period, additional safety and long-term efficacy data will be assessed in a second 12 month treatment period.