Cells are the building blocks for all tissues in the body, including organs and blood. As a result of damage from infections, genetics, or nutritional imbalances, cells may die, which can lead to disease. In cell therapy, physicians administer healthy cells with the aim of restoring the activity in a specific tissue or organ.
Cell Therapy 101
A New Approach
to Treat Diseases
Did you know? Replacing lost cells is being explored to treat a growing number of diseases.
Cell therapy is an innovative approach to medicine that uses healthy cells to replace a patient’s cells, which have been lost due to disease. Researchers are exploring novel cell therapies to treat a broad range of diseases, with more than 100* clinical trials underway in the U.S. alone. Building on decades of scientific advances, new cell therapies are continuing to be reviewed and approved by the U.S. FDA and other regulatory authorities.
*Data as of October 2025.
Cell Therapy 101: How It Works
Replacing Lost Cells to Potentially Restore Cell Function: The Process Explained
By introducing healthy, living cells into the body, cell therapy aims to replace cells that have been lost due to disease. Often, the replacement cells come from healthy donors and can be used in multiple patients.
This is a “one-for-many” approach, referred to as allogeneic therapy. The cells received from donors have been specially modified to become what are known as precursor cells. These precursor cells are then developed into the specific type of cell to be replaced in a patient.
A second approach takes cells directly from the patient and modifies them before reintroducing them back into the same patient. This is a “one-for-one” approach and is called autologous therapy.
Instead of focusing on symptom management, cell therapy aims to change the course of disease by replacing the cells that have been lost due to the disease, with the hope to restore activity in a specific tissue or organ.
Cell Therapy Holds Great Potential
Potential New Treatments are in Clinical Trials Right Now
More than , including for blood stem cell transplants, leukemia and lymphoma, type 1 diabetes, sickle cell disease, and graft-versus-host disease.
Credible cell therapy clinical trials are reviewed by regulatory authorities, such as the U.S. FDA, and many trials are happening now, not in the distant future. They offer hope for potential new treatment options for people living with serious diseases.
These clinical trials are how researchers test whether a therapy can be considered safe and effective in people. Providing the results of the trials to the U.S. FDA and other regulatory authorities is a key step required for a treatment to be approved for use in patients.
Many patients and caregivers find that understanding and participating in clinical research is an important way that they can be a part of advancing science. If you want to learn more or may be interested in participating in a clinical trial, speak with your health care provider.
Frequently Asked Questions
There are different sources of cells for different types of cell therapy.
For many types of cell therapy, cells come from a healthy donor (skin or blood cells, for example) and are then modified to become what scientists call “induced pluripotent stem cells,” or iPSCs. These iPSCs are precursor cells that can then be further developed into the specific type of cell being replaced in the patient.
Another source is from “embryonic stem cells” (ESCs), which can be derived from in vitro fertilization embryos donated for research. Researchers can turn ESCs into the specific type of cell being replaced in the patient.
Donors can be healthy individuals, or even the patient themselves.
Replacement cells derived from a healthy individual (ie., one donor) may be used in multiple patients. This is called a “one-for-many” approach, also referred to as allogeneic therapy. For each patient receiving the cells, the replacement cells will be made and stored before being administered.
Cells taken directly from the patient are referred to as autologous therapy (“auto” indicating “from oneself”). This is a “one-for-one” approach; the autologous cells are modified after removal and then delivered back to the patient.
Researchers study cell therapies by testing them in rigorously controlled clinical trials. These therapies undergo extensive testing needed to help determine safety and effectiveness in patients. Trial results are submitted to the U.S. FDA and regulatory authorities in other countries as a key step in gaining approval for use in patients.
Yes, cell therapies have been approved in the U.S. by the FDA for certain diseases, and many other cell therapies are being tested in clinical trials. It is hoped that new cell therapies will be approved to address an ever-broadening range of diseases to benefit patients.
People with Parkinson’s disease have lower levels of dopamine due to the loss of neurons that produce dopamine; this results in a range of movement-related symptoms that patients experience. Compared to current therapies that only treat symptoms, cell therapy for Parkinson’s disease seeks to restore vital cell functions by replacing lost neurons with healthy cells. This approach is currently investigational and being tested in clinical trials.
Inherited retinal diseases (IRDs) are a group of rare genetic conditions that affect the retina — the layer of tissue at the back of your eye that senses light and sends corresponding signals to your brain. IRDs include retinitis pigmentosa (RP), Usher syndrome (a form of RP with associated deafness), Stargardt disease, and cone-rod dystrophy (CRD). Cell therapy seeks to restore function by replacing cells lost to the disease with healthy cells. Clinical trials requiring an injection in the eye are currently underway in patients.
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