Patient information and safety notice: extracellular vesicles/exosomes and unproven therapies

Published  2020 August 8

This document is meant to answer questions about the use of extracellular vesicles and exosomes to treat patients and the uncertainties surrounding their effects on patients’ wellbeing. This information is provided by the Regulatory Affairs Task Force of the International Society for Extracellular Vesicles (ISEV), an international society of more than 1500 scientists and clinicians who study extracellular vesicles. This document is for information only and does not take the place of communicating with your healthcare practitioner.

1. What are extracellular vesicles and exosomes? 
Extracellular vesicles are a type of small particle that all cells release. They can be used to carry molecules, such as proteins and DNA, from one cell to another. In this way they are used by cells to communicate with one another. As such, extracellular vesicles play a role in many biological processes, including the function of the immune system and normal ageing. You can learn more about extracellular vesicles in this video.
There are different types of extracellular vesicles, and you may hear them being called: EVs (short for extracellular vesicles), exosomes, microvesicles, ectosomes, apoptotic bodies, oncosomes and more. Although we’ve learnt a lot about extracellular vesicles over the past two decades, there is still a great deal we don’t yet understand about them.

2. How are they prepared?
There are currently several methods used to collect extracellular vesicles. Researchers who study extracellular vesicles in the laboratory apply very strict measures to isolate and identify them. They have learnt that unless done appropriately, it is easy to introduce impurities and contaminants during this process. While some clinics may claim that they are using ‘conditioned media containing extracellular vesicles’ or that the extracellular vesicles are “purified” before administering them to patients, this may very well not be the case. As such, there may be significant safety issues and risk of adverse reactions without having any beneficial effect on your condition. 
This is true even if the extracellular vesicles are prepared using your own cells, as they are exposed to a lab environment in the clinic, which can result in contamination and subsequent infections, inflammations or other unwanted effects to your body. Some of these bad outcomes have already been reported by healthcare regulators.

3. Can extracellular vesicles be used for treatment of disease?
As of June 2020, there are currently no approved extracellular vesicle or exosome-based therapies worldwide. There is ongoing research to establish the safety of administering any type of experimental therapy to patients, and to check whether that therapy is effective for the treatment of a specific condition. We emphasize that all extracellular vesicle or exosome-based therapies are experimental at this stage, and that you should consult with your doctor or other healthcare professional before considering taking one.

4. What are ‘unproven therapies’ and ‘clinical trials’?
Unproven therapyAny potential therapy that has not been tested in an appropriately regulated clinical trial to confirm safety and beneficial therapeutic effects. In addition, any new potential therapy should be approved by an appropriate healthcare regulatory agency such as the Food and Drug Administration (FDA) in the US or the European Medicines Agency (EMA) in the European Union.  
Clinical trials: The best way to find out whether a treatment is safe and effective is through scientific testing via rigorous clinical trials, often involving a large number of people and regulated by appropriate agencies such as the FDA or the European National Authorities. The purpose of clinical trials is to investigate in a rigorous scientific manner whether any new therapy is safe and works better than placebo (dummy drug) and at least as well as current available treatments (if there are any). Clinical trials also test for side effects and to ensure that the advice on dosage is correct. 

5. What are the risks of undergoing unproven extracellular vesicle or exosome-based treatments?

  • You could be exposing yourself to dangerous products containing impurities and pathogens like bacteria or viruses. 
  •  There is no scientific proof that these therapies can treat or alleviate the symptoms of your disease, and by taking part in unproven treatment, you may disqualify yourself from receiving a licensed medicine or taking part in a regulated clinical trial.
  • As many of these therapies are expensive and some are offered only abroad in parts of the world that don’t have strict medical regulations, it is worth noting that the money you spend on these treatments can very well be a waste. This is especially important if you are reassured that ‘if it is expensive, it must be good’ or if you fundraise to receive this type of treatment. 


6. How to spot unproven therapy?
Approach new treatments with a wary eye, especially if you’re parting with money. As with most things, if it seems too good to be true, it probably is. Here are some warning signs:

  • It is marketed as a cure-all 
  • It is marketed online or in media only
  • It is supported by patient testimonials only
  • Claims that there are no risks
  • Your doctor doesn’t know about it
  • It is experimental but not being offered to you in a clinical trial (patients can ask for registration number of trial or ask whether a registration of the study at regulatory agencies is available)
  • It is experimental but you do not get an informative document about expected effects and potential risks to help you decide if you should take the treatment (this is known as ‘informed consent’)
  • It has not been tested for your condition in clinical trials (if something is tested for other conditions it does not mean that it will be effective for your condition or harmless to you) 

7. How to report adverse effects/unproven therapy clinics?
If you know of a company or clinic offering unproven treatments, you should report your suspicion to your doctor, and you can also report them to your national regulatory body.
A list of regulatory bodies with the links to their websites can be found here.

8. Trusted sources/ how to find clinical trials for your condition?
It is important to discuss any new potential treatment you consider with your doctor. They will be able to check further and determine if there are any clinical trials that you could take part in. 
Several organizations including the International Society for Cell and Gene Therapies (ISCT) and the International Society for Stem Cell Research (ISSCR) have web-based resources where you and your doctor can find further information:
ISCT: Information on Unproven Cellular Therapies
ISSCR: A Closer Look at Stem Cells

Always talk with your healthcare practitioner first before taking part in any treatments or enrolling in any trials.