The Master PRAM is a Phase II, multicenter, randomized, open-label trial of a standard therapeutic regimen in current use versus experimental therapies administered over 48 weeks. It is designed to allow new therapeutic arms to be studied as "rolling screens" through multiple generations of PRAM. Each PRAM generation compares 2 novel therapeutic arms with a linking arm that allows for an indirect comparison of included therapies. Once accrual to PRAM-1 is complete a new treatment comparison opens for accrual (PRAM-2). The linking arm to be used in PRAM-2 is decided by the Pediatric Primary Scientific Committee. PRAM-2 will continue to accrue patients while PRAM-1 patients continue therapy.