Are stem cells drugs?

stem cell treatmentAre stem cells a drug?

Should the FDA regulate them?

Technically, the FDA calls stem cells “biologics”, but the FDA regulates stem cell products with the goal of ensuring safety and efficacy much the same as traditionally define chemical “drugs”. You can learn more about the FDA’s view of and concerns about stem cells here and here.

Some for-profit proponents of stem cell-based therapies want the FDA to stop regulating stem cell-based therapies. An example of such a company is CellTex, but there are others.

The bottom line is that they want the FDA off their backs. The key word we are hearing more and more is “deregulation”. Republicans say they like deregulation. So it is perhaps not surprising that these stem cell companies have allies in the Republican Party. Look for the national Republican leadership, some who themselves have links to stem cell companies, to start pressing hard for deregulation of autologous stem cell therapies and for them to pressure the FDA to back off.

So should stem cells  be regulated by the FDA even in the case of autologous transplants?

Before I attempt to provide some answers, let’s concisely go over some background.

Cell therapy and stem cell-based regenerative medicine therapies are two highly related approaches to treating human disease.

In each case, doctors give patients cells as the treatment rather than or in addition to conventional chemical drugs.

When giving patients cells as medicine, there are two main possibilities: autologous or allogeneic.

Autologous cell transplants are treatments that use a patient’s own cells.

Allogeneic cell transplants are treatments that use cells that are not the patient’s for treatment.

Of course one key difference is that at least in theory autologous transplants do not stimulate an immune response and may not need immunosuppression therapy.

So should autologous or allogeneic stem cells be regulated by the FDA in much the same way that it regulates drugs?

As a stem cell scientist, I  say ‘yes’, even with autologous therapies. 

Right now stem cells are sometimes being used as treatments without vetting by science or the FDA and that is dangerous. We’ve seen in some cases that the FBI stepped in with indictments and arrests, and two months ago I called for dubious stem cell providers, who I know read my blog, to shut down.

Advocates of deregulation argue that it is illogical for stem cells from a patient’s own body being used for autologous therapy to be regulated by the FDA. However, there are two reasons why I think they are wrong.

First, in almost all cases, the doctors involved are somehow “processing” the sample taken from the patient before giving it back to them. For example, they may be “purifying” stem cells from adipose (fat) tissue. That processing step in my mind makes the end product a biological product requiring regulation, some might even call them “drugs”.

Second, the people doing the transplant are taking cells or tissue from one part of the body, and then they inject the processed sample into another part of the body. There is a reason that Mother Nature does not let our cells do massive migrations around our body. We don’t spontaneously have our belly fat move up to our shoulder for example or our neck. By taking cells from part of the body and putting them elsewhere, I believe such cells become a therapeutic product that some might call a biological drug that process needs regulation.

However, many companies are trying to avoid FDA regulation.

I support the letter by Associate Professor Leigh Turner of the University of Minnesota to the FDA asking for them to look into the CellTex situation. The safety of patients must be the primary consideration, and as I pointed out in a previous post a doctor working with CellTex recently  naively said that the worst-case scenario for patients receiving their treatment is that it won’t work, when in reality the end result of any cell therapy theoretically can be the death or injury of patients.

Nature magazine just published a powerful editorial raising these concerns about stem cell therapies.

Recently, Carl Elliott, Professor at the University of Minnesota also had published an informative article at Slate on the situation with CellTex and Glenn McGee, who was in the leadership of CellTex, but just a few days ago resigned.

Apparently when reportedly faced with litigation, sadly Slate retracted Carl’s article. You can read more about this situation and what it means here in a piece by William Heisel and also here in an interesting piece by the wonderful writer Doug Sipp.

In the end the semantics of what a medical product is called (drug, biological, etc) is indeed important because the government views these in different ways, but the bottom line is the level of regulation required.

In some sense it is even more essential that the FDA regulate stem cells than say a traditional chemical drug like aspirin because stem cells are alive. As a result their behavior in a transplant recipient is less predictable and in theory the stem cells and their progeny may persist in the patient for the patient’s lifetime. That’s right. Forever.

So whether you call stem cells a “drug”, a “biologic”, or more broadly a “medicine”, I believe there is compelling cause to regulate them including autologous stem cells.


  1. Your “First” and “Second” arguments might equally apply to many surgical procedures and in vitro fertilization? All sorts of medical procedures (even the type of food you eat) can modify cells (DNA methylation, for example). You have not convinced me that it generally makes sense to regard an autologous mesenchymal stem cell therapy to belong to the same category as a manufactured drug. Depending upon the specific way they are being used, it may be much more like surgery than the manufacture of some mass-produced drug. To this layman, the FDA seems to be re-badging a shovel as a kitchen sink?

    • Brian, I disagree. Even with the very small subset of surgeries that involve taking one body part and moving it to another place in the body (e.g. cardiac bypass, tendon autologous transplant, etc), the tissue in question is not processed and certain subpopulations of cells are not “purified” to enrich for certain cell types like stem cells.
      You do have a point about my second point regarding moving the tissue from one place to another in the body not necessarily making something a “biological” or drug, but I still believe the ways in which this is being done for “adult stem cell transplants” is fundamentally different than say a cardiac bypass or tendon transplant because in those cases the tissues are intended to perform the same functions in their new homes. In the case of the stem cells, the medical goal is to artificially induce a new function for that tissue after transplant.

      • I’d be the last person to argue that such things should be unregulated. But I am concerned that regulations be sensible, otherwise they will do more harm than good. How would you see the following (not autologous) use of MSC in a kidney transplant?
        Here, both the kidney and stem cells are isolated from the donor. The patients cells are additionally manipulated (in vivo, with radiation). Then the donor cells and kidney are put into the patient. I’d argue that this is the practice of medicine and should be regulated as such. Of course, I would hope that the FDA would play a constructive role — and I think they sometimes do — perhaps by helping develop good practice protocols for cell culture, eg:

        We live in a world of super-specialization… We need many more people to think across the broader span of disciplines and human experience. It’s encouraging to find at least one researcher who will stick his neck out a little bit outside of his box.

  2. Paul,

    I fear that in failing to refer to the different levels of regulation a reader may believe that either the FDA regulates all “stem cells” similarly or that you believe they should.

    As we know, not all autologous stem cells products/treatments are designated or regulated the same way by the FDA or EMA. The regulatory agencies have made room for a less burdensome regulatory pathway for stem cell products/treatments where they meet certain criterion which have been determined to make them ‘low-risk’. I’m assuming you agree with this approach or are you suggesting all autologous stem cell products/treatments be regulated similarly?

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