by Christopher Scott
In July 2007 I did a quick rundown of stem cell clinical trials found in the world’s largest registry, ClinicalTrials.gov. Then the registry contained information on 45,000 federally and privately supported clinical trials in 140 countries. Since then the database has exploded to over 70,000 records in 165 countries. The website was launched by the National Institutes of Health on the heels of legislation calling for a comprehensive, publicly accessible repository for clinical trials. In 2004, a group of medical journals published a consensus statement in the New England Journal of Medicine that essentially said to anyone conducting clinical research: “if you want to publish in our journals, then you need to put your trials in a public registry (and, by the way, ClinicalTrials.gov is the place to put them).”
Not surprisingly, the number of records skyrocketed soon after. Here’s a rough curve of the growth of the number of records (taken from the published literature at various timepoints and in some years extrapolated).
According to ClinicalTrials.gov, how many stem cell trials might there be?
I ran the search again using the site’s advanced search algorithm. Note that most are hematology/oncology studies, and that each hit may not be a true stem cell trial. The parenthetical number is the first result, followed by the percent increase.
- aggregate increase in clinical trials records = 70,000 (45,000) +55%
- trials with a mention of “stem cell” = 2319 (709) +227%
- “heart disease” + “stem cell” = 118 (56) +110%
- diabetes + “stem cell” = 21 (11) +91%
- Parkinsons + “stem cell” = 0 (1) -100%
- “stem cell” + China =17 ( 7) +143%
- “stem cell” + Germany = 128 (73) +75%
- “cord blood stem cell” = 18 (59) -69%
- trials using cells made from embryonic stem cells = 0
- trials with “gene therapy” as the intervention = 334
- trials with “stem cells” as the intervention = 1861
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8 Comments
March 22, 2009 at 7:20 am
Thank you for an interesting analysis of the stem cell clinical trials. I have linked your posting here: http://watchdogonscience.blogspot.com/2009/03/stem-cell-clinical-trials.html
Watchdogonsicence
March 22, 2009 at 7:52 am
great analysis! thanks!
I think if you exclude all of trials in hematology-oncology (which take more then 80% of results in search “stem cell” key words in this database) you can get quite different numbers, but probably the same trends.
All of trials in leukemia clinic using term “stem cell transplantation” and back on 5 years they were only ” stem cell” trials in indicated database.
March 22, 2009 at 9:05 am
Thank you Alexy. You’re right. I changed the word “many” to “most”. The interesting thing is that Hem/Onc trials have appropriated the words “stem cell” when a few years ago they simply would have been variations on bone marrow transplantation studies.
March 22, 2009 at 12:41 pm
Monya Baker, editor of Nature Stem Cell Reports, comments on The Stem Cell Clinical Trial Index (2) and wonders what the database has to say about fetal stem cells http://blogs.nature.com/reports/theniche/2009/03/clinical_trials_mentioning_ste.html. Searching entire records or the interventions field for “fetal stem cells” yields no hits. “Fetal cells” brings up two records, and both appear to be diagnostic/observational studies. One trial uses fetal stem cells for Batten disease but doesn’t mention them in the registry: http://clinicaltrials.gov/ct2/show?cond=Batten%27s+Disease&spons_ex=Y&rank=2
March 22, 2009 at 4:10 pm
Interesting. According to this link http://is.gd/l6B0 there were almost 26,000 HSC transplants in the EU in 2007. If that number is correct, I suspect ClinicalTrials.gov underestimates the true value. I doubt the EU did more than 50% of all transplants in 2007. Or maybe there are just a lot more clinical trials than approved transplants?
March 22, 2009 at 5:24 pm
A good catch, thanks.
Looks like from the journal article behind your link http://is.gd/l6B0 (Bone Marrow Transplantation) that these are numbers of_patients_receiving a transplant in the EU, including procedures administered as clinical care, not numbers of experimental trials. That might explain the 26K. And, each clinical trial listed in a registry can have hundreds of subjects, depending on the phase. Lastly, ClinicalTrials.gov is one of several registries, though by far the biggest.
March 22, 2009 at 7:18 pm
That’s very interesting, and unfortunate, that the known fetal stem cell trials are hard to catch. This kind of analysis is quite interesting. There should be a move to standardize nomenclature to make it easier. (Any moves in that direction?) Even with the available tools, though, this is insightful.
March 23, 2009 at 3:12 pm
[...] 118 to 56); Parkinson’s disease fell by 100% last year (from 1 to 0). That’s according to an index of clinical trials just posted by Stanford’s Chris [...]