Little patients, losing patience: pediatric cancer drug development.

The December 2004 Food and Drug Administration (FDA) approval of clofarabine (Clolar, Genzyme) for refractory pediatric acute lymphoblastic leukemia was a milestone in the history of pediatric cancer drug development. A rare occurrence, it represented approval of a new cancer drug for a pediatric cancer indication without prior approval for an adult cancer indication. This is a major exception, as approval of new cancer drugs for pediatric patients is typically an afterthought to their development and approval for treating adult cancers. In fact, of the 120 new cancer therapies for adults approved by the FDA between 1948 and January 2003, only 30 have shown use in children. Of those 30 drugs, only 15 acquired any labeling for pediatric use during that same 55-year period (1, 2). This disparity in the number of oncology drugs labeled for use in adults versus children is a manifestation of the many challenges faced in pediatric cancer drug development. So, why has pediatric drug development been the poor stepchild of cancer drug development? What are the major challenges currently confronting pediatric cancer drug development? What are pediatric oncologists and other children’s advocates doing to overcome these barriers? Despite these challenges, how have pediatric oncologists managed to make extraordinary strides in improving outcomes for children with cancer?