Gene and advanced cell therapies are the most heavily regulated interventions a sport and exercise medicine (SEM) clinician is likely to be asked about, and also the ones most often misrepresented in marketing. They are genuine medicines that have transformed care in a small number of serious conditions, and they have no established role in routine musculoskeletal practice. For the clinician the important content is threefold: what these therapies actually are and how they differ from the orthobiologics covered elsewhere, how they are classified and regulated as an advanced therapy medicinal product (ATMP), and how they intersect with anti-doping, since gene and cell doping is a prohibited method in its own right. The general orthobiologics regulatory framework is set out in the related material and is not repeated here.
What are gene and advanced cell therapies?
The term advanced therapy medicinal product covers three groups that are worth being able to distinguish. A gene therapy medicinal product contains a recombinant nucleic acid used to regulate, repair, replace, add or delete a genetic sequence, with the therapeutic effect relating directly to that sequence or its expression product; delivery is usually by a viral or non-viral vector. A somatic cell therapy medicinal product contains cells or tissues that have been substantially manipulated, so that their biological characteristics or function are altered, or that are used for a different essential function in the recipient than in the donor. A tissue-engineered product contains engineered cells or tissues and is presented as regenerating, repairing or replacing human tissue, and cartilage repair products are the example most relevant to musculoskeletal practice. Some products combine cells with a device and are regulated as combined advanced therapies.
Advanced therapy medicinal products divide into gene therapy products, somatic cell therapy products and tissue-engineered products, distinguished by whether genetic material, substantially manipulated cells, or cells on a scaffold are the active component.
The distinction that matters clinically is between these products and the orthobiologics discussed elsewhere in this category. Platelet-rich plasma and a centrifuged marrow concentrate involve non-substantial processing and are used within a single procedure, which generally keeps them outside the medicines framework. Culture expansion, enzymatic digestion, genetic modification or use for a different essential function move a preparation towards advanced therapy classification. Classification is product-specific rather than obvious from the description, and where there is doubt a classification view should be sought from the medicines regulator rather than assumed. Unlicensed products reach patients only through narrow routes: a marketing authorisation, an authorised clinical trial, or for unlicensed products the hospital exemption for non-routine preparation for a named patient in a hospital, or the specials route, both requiring an appropriate manufacturing licence.
How do these therapies intersect with anti-doping?
Gene and cell doping is a prohibited method and it is prohibited at all times, both in and out of competition, which distinguishes it sharply from the in-competition restrictions that apply to glucocorticoids. The prohibition has two limbs. The first covers the use of nucleic acids or nucleic acid analogues that may alter genome sequences or gene expression by any mechanism, explicitly including gene editing, gene silencing and gene transfer technologies. The second covers the use of normal or genetically modified cells. From the 2026 list, the use of cell components, with mitochondria and ribosomes given as examples, has been added to that second limb. Throughout, the prohibition applies where there is the potential to enhance sport performance, which is the qualifier that makes the rule workable rather than absurd.
Gene and cell doping is prohibited at all times and covers nucleic acid technologies and the use of normal or modified cells and cell components, where there is potential to enhance performance. Non-transformed stem cells used alone for healing that restores normal function are not prohibited.
Two clarifications prevent the most common errors. First, the World Anti-Doping Agency has stated that non-transformed stem cells used alone, with no growth factors or other hormones added, for healing an injury are not prohibited, provided they return the functioning of the affected area to normal and do not enhance it. That is a narrow permission resting on restoration rather than enhancement, and it should not be read as a general licence for cell therapy in athletes. Second, the addition of cell components brings preparations such as exosomes, which are cell-derived vesicles, within scope where they have performance-enhancing potential, and this is a live issue because such products are marketed directly to athletes. The practical rule is unchanged from the rest of this category: establish exactly what a preparation contains and how it was processed, check it against the current list and the relevant checking tools, and treat a product whose contents cannot be established as one that cannot be assumed permitted. It is also worth knowing, and reassuring to patients, that the anti-doping authorities have stated they are not presently aware of athletes using gene doping, despite periodic media claims.
Exam Tips
•Advanced therapy medicinal products (ATMP) divide into gene therapy products, somatic cell therapy products and tissue-engineered products, with some combined products including a device.
•A gene therapy product contains recombinant nucleic acid whose therapeutic effect relates to that sequence or its expression product, usually delivered by a vector.
•Culture expansion, enzymatic digestion, genetic modification or use for a different essential function push a preparation towards advanced therapy classification; classification is product-specific and can be confirmed with the medicines regulator.
•Gene and cell doping is prohibited at all times: nucleic acids or analogues altering genome sequences or gene expression, including gene editing, silencing and transfer, and the use of normal or genetically modified cells.
•From the 2026 list, cell components such as mitochondria and ribosomes were added, which brings preparations such as exosomes within scope where they have performance-enhancing potential.
•Non-transformed stem cells used alone, with nothing added, for healing an injury are not prohibited provided they restore normal function rather than enhance it.