Potential Market of Cord Blood Therapy for Cerebral Palsy
There should be thousands of children worldwide who already have a cerebral palsy diagnosis and have their own cord blood in storage, based on the epidemiology of the disorder and the inventory of cord blood in family banks. If autologous cord blood therapy for cerebral palsy is accepted as a standard of care, those children are the immediate potential market for therapy. If therapy with matched cord blood donations is also accepted, even more children will potentially have access, but the cost of therapy will go up dramatically, and the search for a matching cord blood unit will complicate their ability to access this therapy.
The overall incidence of cerebral palsy has not changed in more than four decades, despite significant advances in the medical care of newborns. In developed nations, the incidence of cerebral palsy among all births is about 2 cases per 1000 (CDC, Medscape). However, cerebral palsy is over ten times more common among premature babies that are born before 34 weeks gestation. For these high risk infants, improved care has lowered the cerebral palsy rate to 2 per 100 or 2% (van Haastert et al. 2011).
In the United States, a CDC study showed that the average prevalence of CP is 1 in 303 among eight year old children. The total number of US children who have cerebral palsy and display evidence that it was triggered by an acquired brain injury is under 200,000, qualifying for the FDA's orphan disease status.
The impact of cerebral palsy on affected families is severe. According to the charity Cure CP, 1 in 3 children with cerebral palsy cannot walk; 1 in 4 cannot feed themselves; and 1 in 4 cannot dress themselves.
A study published in the Morbidity and Mortality Weekly Report in 2003 (ref) examined the direct and indirect medical expenses associated with developmental disabilities. They found that the total cost of cerebral palsy to the nation is $11.5 billion in 2003 dollars! Average lifetime costs per person were estimated at $921,000 for cerebral palsy. This consists of 9.2% direct medical costs (therapies, medication, etc.), 10.2% direct non-medical costs (special education, modifications), and 80.6% indirect costs such as lost productivity of the patient and caregivers. Clearly, if a stem cell infusion that can be delivered for under ten thousand dollars per person can provide lasting benefit to cerebral palsy patients, it is a worthwhile investment of national health care resources to reduce the current lifetime cost of cerebral palsy per person that is nearly 100 times higher.
At Duke University Medical Center, the current therapy for cerebral palsy requires the child to have his or her own cord blood (Sun et al. 2010). So far they have treated hundreds of children with some form of cerebral palsy from around the world. The Parent's Guide to Cord Blood Foundation inventory for the end of 2013 counts over 3 million children worldwide that have their cord blood stored in family banks. If 3.3 out of every 1000 of these children have cerebral palsy, then there are 9,900 potential patients worldwide who are eligible for treatment.
At CHA University Medical Center in South Korea, the current therapy for cerebral palsy relies on matched cord blood donations (Kim et al. 2012). So far they have treated over 160 Korean patients with matched cord blood units from their affiliated public bank whose inventory was 162 thousand in February 2013.
In theory the use of donated cord blood could open the door to therapy for many more cerebral palsy patients who do not have their own cord blood in storage. In practice, allogeneic therapy with donated cord blood introduces two steep hurdles. The first hurdle is that the patient must take immunosuppressive drugs for the duration of therapy, in order to prevent the patient's body from immediately rejecting the donor cord blood. This in turn makes it necessary to take extra precautions against infection while the patient is immune compromised. The current treatment protocol in Korea requires the patient to stay in the hospital for about three weeks. This patient management is significantly more complicated and expensive than the autologous therapy which only requires medical supervision on the day of infusion.
Another hurdle is the process of finding a matched cord blood unit. This hurdle has many components - genetic, political, and financial. Patients from ethnic minorities and mixed racial backgrounds will have a harder time finding matched donors. But what can be even harder than finding the matching unit, is convincing a public cord blood bank to release that unit for a therapy that is not a traditional hematology or oncology indication. Even if they are willing to release it, at what cost? The current financial model of public banks is built on the assumption that they only release 1-3% of their inventory for transplants, and because of that low release rate the cost of a public unit is over $30,000 in the US. That would be a staggering burden for a family pursuing a clinical trial that is not covered by insurance.
Families will probably find that the easiest way to access a cord blood unit for a child who does not have his or her own cord blood in storage, is to use sibling cord blood. The odds of a perfect match naturally occurring with a full sibling are 25%, but a match can be engineered with preimplantation genetic diagnosis. The cost to a US family to provide privately banked sibling cord blood is about $2,000 to bank the cord blood, about $125 per year in storage fees, plus any shipping costs that are not covered by the bank when the cord blood is released.
In summary, the potential market of patients who could benefit from cord blood therapy for cerebral palsy numbers in the thousands and is distributed worldwide. Someday our approach towards all cord blood banking may be modified by the realization that a certain fraction of infants will need to use their cord blood stem cells for therapy. Dr. Kurtzberg of Duke has suggested that the cord blood donated to public banks should be "embargoed" for the first year of storage, in case the donor needs it back.