A Stem Cell scientist using a microscope

There is huge excitement over the potential of stem cells to treat currently incurable diseases and researchers worldwide are developing new therapies. But this research can take many years, even decades to go from the lab to the clinic. This often isn’t reflected in the stories you read (you can learn more about stem cells and the media here)[link to relevant page].

Scientific research can be a slow process and you don’t always get the result you hoped. But over time this research generates sufficient evidence to believe your proposed treatment will work. This doesn’t mean you can start using it on people. Once you have data from lab experiments (called in vitro experiments), these findings need proving in a living organism (called in vivo experiments). This first involves testing therapies in animals (often called pre-clinical testing), usually small animals such rats or mice, but occasionally larger animals.

The results of these in vitro and in vivo studies are usually published in peer-reviewed scientific journals, which allows other scientists to check that they have been performed well and allows scientists to perform similar experiments or learn from the original work.

Once in vitro data has been confirmed in vivo during animal testing, it can be trialled on humans. These trials involve 4 phases, each involving larger numbers of volunteers.

Phase 1 clinical trials are the most risky. They involve only small numbers of patients (say 10-15) and are used to check that the treatment is safe and has no major side-effects.

Phase 2 clinical trials repeats the trial, using information gained in phase 1, on a larger number of patients. Again it is used to prove the treatment is safe.

Phase 3 clinical trials are performed on larger numbers of patients and are used to prove that the treatment works. The treatment is usually compared to existing treatments to prove that at works as least as well as, or better than, what is currently done.

Phase 4 clinical trials are the final stage and can only be performed if all the other phases have been passed. It checks the safety and efficacy on the treatment on a large number of patients and allows the treatment to be licensed.

These trials take many years to complete and are hugely expensive, costing millions of pounds. However, they are important to prove that a treatment works and isn’t harmful.Importantly these trials allow treatments to be licensed by regulatory authorities around the world.

Importantly, clinical trials need volunteers and if you would are happy to be involved in trials you can apply to be involved. This can be done through your doctor, or you can apply yourself. You can find more information on how clinical trials work, what is involved and what trials are currently on-going by clicking here.


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