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Published on: January 4, 2015
Positive and negative cell therapy in randomized control trials for central nervous system diseases
Di Chen1, Hongyun Huang1, Hooshang Saberi2
1Beijing Hongtianji Neuroscience Academy, Beijing, P.R. China.
Abstract:
Neurorestorative cell therapies have been tested to treat patients with nervous system diseases for over 20 years. Now it is still hard to answer which kinds of cells can really play a role on improving these patients' quality of life. Non-randomized clinical trials or studies could not provide strong evidences in answering this critical question. In this review, we summarized randomized clinical trials of cell therapies for central nervous diseases, such as stroke, spinal cord injury, cerebral palsy (CP), Parkinson's disease (PD), multiple sclerosis (MS), brain trauma, amyotrophic lateral sclerosis (ALS), etc. Most kinds of cell therapies demonstrated negative results for stoke, brain trauma and amyotrophic lateral sclerosis. A few kinds of cell therapies showed neurorestorative effects in this level of evidence-based medicine, such as olfactory ensheating cells for chronic ischemic stroke. Some kinds of cells showed positive or negative effects from different teams in the same or different diseases. We analyzed the possible failed reasons of negative results and the cellular bio-propriety basis of positive results. Based on therapeutic results of randomized control trials and reasonable analysis, we recommend: (1) to further conduct trials for successful cell therapies with positive results to increase neurorestorative effects; (2) to avoid in repeating failed cell therapies with negative results in same diseases because it is nonsense for them to be done with similar treatment methods, such as cell dosage, transplanting way, time of window, etc. Furthermore, we strongly suggest not to do non-randomized clinical trials for cells that had shown negative results in randomized clinical trials.
Insights
Randomized trials reveal limited success for most cell therapies in treating central nervous system diseases. Olfactory ensheathing cells show promise for chronic ischemic stroke, warranting further investigation.
Area of Science:
- Neuroscience
- Regenerative Medicine
- Clinical Trials
Background:
- Cellular therapies have been explored for over two decades to treat nervous system diseases, yet definitive evidence of efficacy remains elusive.
- Non-randomized studies often lack the robust data needed to determine which cell types genuinely improve patient quality of life.
Approach:
- This review systematically analyzes randomized clinical trials (RCTs) investigating cell therapies for various central nervous system disorders.
- The analysis includes conditions such as stroke, spinal cord injury, cerebral palsy, Parkinson's disease, multiple sclerosis, brain trauma, and amyotrophic lateral sclerosis.
Key Points:
- Most cell therapies demonstrated negative outcomes in randomized trials for stroke, brain trauma, and amyotrophic lateral sclerosis.
- A subset of cell therapies, notably olfactory ensheathing cells for chronic ischemic stroke, exhibited neurorestorative effects supported by high-level evidence.
- Variability in results across different research teams and disease indications highlights the complexity of cell therapy efficacy.
Conclusions:
- Further RCTs are recommended for cell therapies showing positive neurorestorative effects to optimize outcomes.
- Repeating failed cell therapies with similar methodologies (dosage, delivery, timing) in the same diseases should be avoided.
- Non-randomized trials for cell types with previously negative RCT results are strongly discouraged to prevent wasted resources and misleading conclusions.
