Cell Trials

Starting from 2014, I was trying to capture results of clinical studies in cell therapy. Today, Id like to share some results of this attempt. I decided to narrow down my analysis to regenerative medicine, since most of cell-based therapies with published results belong to this category.

Inclusion criteria and definitions

Exclusion criteria

Search strategy I set very loose filter for search of clinical studies results by using PubMed database with query stem cell. I receive notifications about new publications from this query via RSS feed. Stem cell query captures about 50-100 publications daily, <1% of them are clinical studies. I did random check to assess RSS feed accuracy and confirmed that it captures everything. I find that such filter allows to capture the most (if not all) clinical studies, related to cell-based therapies (by any type of cells) in regenerative medicine. I also compared stem cell filter with cell therapy and some others. A stronger filter in PubMed stem cell + clinical trial (check box), misses >90% of clinical studies.

Total number of studies and data capture

Demographics A great variety of countries published results of clinical studies in 2014. The biggest number of reports came from China. US was the second biggest contributor. I summarized major contributing countries (more than 4 reports) in this figure:

Cell types As one may predict, Mesenchymal Stromal Cells (MSC) was the major cell type (35%) in cell-based regenerative medicine clinical studies. Mobilized hematopoietic stem/progenitor cells (HPC-A) and bone marrow mononuclear cells (BM MNC) were another popular type of cells for tissue regeneration. Interestingly, 2 reports were about results of studies, involved embryonic stem cell-based (ESC) products. Few studies used 2 different types of cells cell simultaneously or concurrently.

Results interpretation I loosely judged all results of clinical studies as (1) positive, (2) mixed/ inconclusive and (3) failed. Positive are the results, reported no safety and feasibility concerns and/or provided at least some evidence of efficacy. Mixed/ inconclusive results included:

Failed studies were considered, based on termination of studies due to safety issues, lack of feasibility and/ or lack of efficacy. Failed efficacy usually reported by authors as lack of difference between control group (example: placebo) and experimental (cells) group. Few trials were not described as failed by authors, but judged as such by me, based on lack of significance between groups and missed end points.

The first figure shows total number of positive, mixed/ inconclusive and failed studies from analysis of all reported studies (116):

Next, I looked at only registered clinical trials and broke it down by phases 1, 1/2, 2, 2/3 and 3:

Only one trial is failed in phase 1 and almost 90% of them reported as positive. The only trial, which failed in phase 1 was designed with efficacy end points. There were no trials, which failed safety. A number of mixed/inconclusive and failed trials were increased from phase 1 to 2/3. Because efficacy of therapy is usually assessed in phase 2 trials, studies labeled as phase 1/2 are not necessarily included efficacy end points. Despite lack of any controls many studies concluded by authors as positive or promising. Placebo control was very rare. Most controls include: (i) historic, (ii) baseline and (iii) standard therapy.

Limitations of analysis

It was a snapshot of some data that I was able to capture in 2014. Please feel free to give me feedback and discuss these data in comments. Im open to suggestions and collaboration.

How to cite: Bersenev Alexey. Results of regenerative medicine clinical studies from 2014. CellTrials blog. March 1, 2015. Available: http://celltrials.info/2015/03/01/results-regenmed-studies-2014

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Cell Trials