Cord blood for cerebral palsy: mostly discouraging new trial data

umbilical cord blood
Cropped Flickr image labeled for reuse
umbilical cord blood
Cropped Flickr image labeled for reuse of cord blood unit

Some notable newly published Phase II data from the Duke cord blood for cerebral palsy trial unfortunately doesn’t give much reason for optimism that this approach is going to have a substantial positive effect for these kids.

The double-blinded, placebo-controlled study did not find a meaningful benefit overall from infusions of autologous cord blood (ACB) for children with cerebral palsy. It didn’t meet its primary endpoint. The study was published in Stem Cells Translational Medicine and was entitled, “Effect of Autologous Cord Blood Infusion on Motor Function and Brain Connectivity in Young Children with Cerebral Palsy: A Randomized, Placebo-Controlled Trial.”

This finding is discouraging overall. I can’t say I’m too surprised as to me at least there is no obvious mechanism by which this would work. Yes, investigational therapies based on non-obvious hypothesized mechanisms can rarely give surprisingly good outcomes anyway, but with the publication of the new data in this case that future possibility seems pretty remote at this point.

cord blood cerebral palsy
Figure 2A, Sun, et al. Stem Cells Translational Medicine

Some hold onto a bit of hope from specific aspects of the new study data because the higher dose (>=20 million ACB/kg) produced some moderate significantly different (better) outcomes than either lower dose or placebo. I feel mostly skeptical about that. I’m no expert on ACB or on cerebral palsy, but I’m looking at the data as a stem cell scientist just based on common sense.

I also found it discouraging that for some key measures the lower dose of ACB may have made patients slightly worse off than placebo, although I’m not sure that change downward was meaningful (see Figure 2A at right, potential low-dose worsening more evident in panels 2B-D). I don’t see significant safety issues based on that and overall this kind of therapy when provided by a proper clinical trial appears safe. Longer term follow up is needed as well.

The authors, including senior author Joanne Kurtzberg and first-author Jessica Sun, focused on the hopeful dosing effect, but more data would be needed to make clear meaning of that. The phase II trial had some limitations too pointed out by the authors that may have impacted the findings including patient family socioeconomic factors and in turn patients receive other kinds of therapies concurrently.

Overall, there just isn’t much evidence to date that stem cells or related cellular therapies can benefit specific pediatric brain conditions examined so far such as cerebral palsy and autism (see recent post on autism including regarding another ACB Duke trial).

I find the mostly discouraging data to be frustrating as pediatric regenerative medicine is an area of research interest for me more broadly and was hoping for better news. There is still reason for hope in general. Cord blood won’t solve everything, but it remains a very promising, powerful resource. We just need to learn where and how it can be best used beyond current indications. Along the way there are going to be both successes and not so great outcomes too, which is a natural progression with clinical science even if it can be discouraging at times.

5 Comments


  1. “People generally see what they look for, and hear what they listen for.” – Harper Lee

    SIGNIFICANCE STATEMENT

    Results of this trial suggest that when adequately dosed, an intravenous infusion of autologous umbilical cord blood improves whole brain connectivity and motor function in young children with cerebral palsy

    CONCLUSION

    Results of this trial suggest that when dosed >= 2×10(7) cells per kg, an IV infusion of ACB improves whole brain connectivity and motor function in young children with CP. These findings have important implications for the treatment of children with CP and should be further explored in future studies. As it is not feasible for every child to have an available ACB unit, studies of allogeneic cord blood should also be pursued.


  2. My sense is that the authors were looking on the optimistic side, whereas I was trying to be more neutral-to-skeptical like a reviewer. Potential negative effect of low dose cord blood was similar in magnitude to potential positive effect of high dose, which probably should have been discussed in the pub Discussion section.


  3. Did you see this contemporaneous publication, which appears to support the Sun paper? https://goo.gl/XZtLmk Sorry, Paul, but your bias in analysis of this paper appears to perpetuate the divide between the iPS camp and those of us working in the perinatal field.


  4. I am not a stem cell scientist but I am a co-parent (Aunt Cindy) to a cerebral palsy child who was a recipient in the Phase ll stem cell clinical trial. You skeptically pointed out Dr. Kurtzberg conveyed there were limitations including socioeconomic factors and other kinds of current therapies that may have impacted her findings. I can tell you firsthand that the parents of this child including myself have very little income but with the support of our family and friends we managed to purchase round-trip tickets for my niece and me to fly to North Carolina from California at a reasonable amount, saving each year for the next years flight, three flights in total.

    Duke Medical Center also referred us to a hotel which provided discounted rates to medical patients including shuttle service to and from the hospital. As for the other ‘current’ kinds of therapies my niece was 3 years of age on our first visit and was not attending therapy sessions of any kind. It was the hospital staff at Duke Medical that introduced us to physical therapy options and specialize doctors that were available to cerebral palsy children for families with low income.

    At birth doctors told us that our little girl would most likely be immobile, unable to talk or hold her head upward on her own. She still has her daily challenges with CP but fast forward 5 years since her stem cell infusion and she can hold her head up high, communicate, walk with a walker, and use “both” hands to play on her I-Pad.

    Dr. Joanne Kurtzberg and her team of researchers as well as my favorite nurse, Anne, helped make our impossible, possible. Cord Blood Registry (CBR) was also instrumental. My step-father succumbed to ALS and it was him whom first believed in Christopher Reeve’s tireless fight to advance stem cell research. If it were not for him my mother would not have insisted on storing the cord blood at CBR. Everyone has their purpose in this world!

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