Babies that are born extremely prematurely are at higher risk of developing chronic (long term) lung disease (CLD) and other complications (problems). The purpose of this study is to test the safety and effectiveness of an investigational drug called mecasermin rinfabate (rhIGF-1/rhIGTBP-3) or OHB-607. The researchers want to find out if OHB-607 can help reduce the risk of chronic lung disease in babies born prematurely and if it can help reduce the risk of other complications.