The therapeutic potential of stem cells has so profoundly changed the landscape of medical research that it has spawned an entirely new field — regenerative medicine.
There is indeed a great deal of promise, but also a tendency to think that a cure is just around the corner. The path from research to the clinic is often long and complicated, with many small advances. Our aim is to present an objective view of the most important advances, to provide a foundational knowledge against which to read and evaluate new research as it emerges.
A recent Canadian report examined the state of “novel” stem cell clinical trials around the world.
Four Approaches to Clinical Research for Stem Cell Derived Therapies
Generally, it is helpful to understand four different approaches to using stem cells for clinical benefit, in addition to their still critical role in understanding the disease process.
Stem cell transplantation
Stem cell transplantation exploits the special characteristics of stem cells to multiply indefinitely and to become other cells required by the body. For example, stem cells that reside in the bone marrow or are plentiful in cord blood are removed and used to generate new blood cells. These are then transplanted back into the body, thereby restoring a patient’s immune system and capacity to fight disease.
Cellular therapy relies on stem cells’ ability to regenerate indefinitely and to evolve from one kind of cell to another based on elaborate codes and cues. Stem cells residing in our own tissues may be re-programmed, or new ones manufactured artificially through therapeutic cloning, to replace the cells damaged by disease or injury. Then, these can be generated in large enough quantities for transplantation.
While stem cells help scientists to understand the mechanisms and pathways that initiate and perpetuate disease, it is now evident that they can also be mobilized to reverse this process. By manipulating growth factors that enhance stem cell activity and silencing the genes that drive disease, scientists are already demonstrating that stem cells will be able to regenerate tissue and restore lost function.
By manipulating stem cells, scientists are now able to recreate human disease in animal models. Furthermore, they can isolate and multiply the cells that are responsible for the disease process and decode the critical messages.
Not only is this leading to the discovery of new drugs, but new technology allows scientists to generate large quantities of patient-specific cells on which to test them.
Articles about this research go into considerable detail about the most promising approaches for each disease. You may wish to consult the About Stem Cells section to gain familiarity with the concepts and terminology that are used in presenting the latest research specific to each disease.
Although there are occasional references to clinical trials that are envisioned or underway, we neither endorse nor evaluate these trials. For more information on clinical trials consult the Patient Handbook on Stem Cell Therapies, published by the International Society of Stem Cell Research.
Medical research studies involving people are called clinical trials. Clinical trials are intended to explore
- Disease prevention — using drugs, vitamins, foods to reduce risk
- Treatments — new drugs or combinations of drugs; new ways of giving treatment, new types of treatment
- Diagnosing disease — new tests or scans
- Controlling symptoms — new drugs or complementary therapies
Trials aim to find out if a new experimental drug or procedure
- Is safe
- Has side effects
- Works better than the currently used treatment
- Helps you feel better
New treatments must be thoroughly tested. A new drug, for example is investigated first in the laboratory. If it looks promising, it is carefully studied in people. There are three different types of clinical trials. These are called Phase 1, 2 and 3.
Phase 1 is the earliest trials in the life of a new drug or treatment. They are usually small trials, recruiting up to 30 patients.
About 70% of new treatments tested at Phase 1 make it to Phase 2 trials. Phase 2 trials are often larger than Phase 1. There may be up to 50 people taking part. If the results of Phase 2 trials show that a new treatment may be as good or better than existing treatment, it then moves to Phase 3.
Phase 3 trials compare new treatments with the best currently available treatment (the standard treatment). Phase 3 trials are usually much larger than Phase 1 or 2. This is because differences in success rates may be small, so many results are required to show the difference. Sometimes Phase 3 trials involve thousands of patients in many different hospitals and even different countries. Phase 3 trials are usually randomized. This means the researchers put the people taking part into two groups at random. One group gets the new treatment and the other the standard treatment.
You should first consult your physician or specialist about trials or therapies available in your area. For clinical trials, you will need to meet the entry criteria, which are put in place to safeguard the participants and ensure the integrity of the research results.
To find out about registered clinical trials for a particular disease, select from the list below. The trials are drawn from ClinicalTrials.gov, an international database sponsored by the U.S. National Institutes of Health.
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