Cord Blood for Cerebral Palsy: 1st publication of controlled trial
A group led by Dr. MinYoung Kim at CHA Bundang Medical Center in South Korea is the first to publish results of a placebo-controlled, double-blind clinical trial on the efficacy of cord blood stem cells for the treatment of cerebral palsy. The 96 children in this trial did not have their own cord blood in storage, so they were treated with cord blood from donors that were matched on at least 4 of 6 key antigens (HLA types). The study found that the children who received cord blood therapy had significantly better outcomes than control groups, in terms of both motor skills and cognitive function. Families of children with cerebral palsy should regard this study as an important validation that the benefits of cord blood therapy are not just anecdotal, they have been validated against controls.
The full story of this trial is more complicated, because the 96 participants were divided among 3 study arms:
1. The first control group of 32 children received only rehabilitation, an intensive program of physical and occupational therapy.
2. The second control group of 33 children received rehabilitation plus the hormone erythropoietin (EPO) that stimulates the bone marrow to produce stem cells.
3. The study group of 31 children received rehabilitation, plus EPO, plus a matched cord blood donation.
Unfortunately, the biggest flaw in this trial is that there is no study arm that measures the effect of cord blood alone. The participants in the study were evaluated by 4 different outcome measures at intervals of 1, 3, and 6 months post-treatment.
The most important take away description of the trial results is that the children who received cord blood and EPO had better outcome scores in all categories than the other two groups, with the benefit growing over the study period. At the 6 month mark, most of the score differences exceed the measurement uncertainty, so there is negligible chance there is a statistical error.
The study data can be sliced and diced different ways to yield even more provocative results. One finding is that younger patients responded better to this therapy. Not surprisingly, a bigger cord blood stem cell dose led to better outcome. An intriguing fact is that the improvements with cord blood were more dramatic when the donor was a closer match to the patient. That is a very important clue for competing studies, because it suggests that the trials in which children receive their own cord blood or bone marrow may show better results than this trial which used donated cord blood.
The research community can also learn a lesson from this study, about the importance of pushing out results in a competitive field with major implications for vulnerable patients. The use of cord blood to treat cerebral palsy was pioneered by Dr. Joanne Kurtzberg's group at Duke Medical Center in the United States. According to a survey by Verter (in preparation for ISCT 2013), since 2005 more children have received cord blood therapy at Duke for acquired neurological disorders than at all other reporting hospitals combined. Yet, nothing has ever been published by the Duke group about the efficacy of cord blood for cerebral palsy. Now, Dr. MinYoung Kim's group in South Korea is the first to publish controlled data on the efficacy of cord blood for cerebral palsy. Quite frankly, this paper is a scientific coup and a stark demonstration of the global nature of research today.