Understanding Stem Cells Part 2: Ready for the Clinic?

With advances in research and technology, using stem cells for their regenerative potential has become a reality. But many stem cell treatments on the market have been marketed to the public and applied clinically without scientific evidence of efficacy. Worse, some treatments with stem cells have caused serious adverse events.

Provided that cell and tissue products fall into the “minimally manipulated” classification established by the Food and Drug Administration (FDA) under Title 21 of the Code of Federal Regulations Part 1271, studies to prove efficacy and safety are not required. This makes it possible to promote stem cell treatments for any use, without scientific or medical evidence that they work. Medical practitioners and patients alike must be aware that stem cell treatments are generally not “FDA approved.”

Draft guidance for industry was issued by FDA in 2017, proposing guidelines for evaluating and approving regenerative therapies which have demonstrated safe and efficacious use in serious conditions. These products could achieve a designation of “Regenerative Medicine Advanced Therapy” or “RMAT” in several ways. While the actual policy is still being formulated, this guidance initiated discussion with industry stakeholders and signaled increasing attention by FDA to regulating products touted as “regenerative,” including stem cells.

Cells for stem cell treatments are often autologous, extracted from the patient through bone marrow aspiration, a blood draw and centrifuge process, or liposuction (for adipose stem cells). There are also stem cell products available commercially that are allografts (cells or tissue from a human donor), including umbilical cord blood stem cells, allograft fat, and cell-based bone grafts. The number and type of stem cell varies based on the tissue of origin and the processing of the product, and both of these factors can be expected to affect outcomes.

Stem cell clinics often charge very high prices for stem cell treatments, from $1,500 for a joint injection to $25,000 for a systemic treatment. Insurance typically does not cover these treatments because they are considered experimental. Patients range from injured athletes and weekend warriors who want to avoid surgery, to desperate and terminally ill patients who are struggling with incurable conditions.

One unfortunate example of stem cell treatment gone wrong occurred at a Florida clinic. Three elderly women received stem cell injections to treat age-related macular degeneration and were blinded by the procedure. One of the women was apparently misled into believing that she was taking part in a clinical trial. The clinic which performed the injections, Bioheart Inc., had not conducted any pre-clinical or clinical trials. Today, Bioheart Inc. is doing business as US Stem Cell, which received a warning letter from FDA in August 2017, citing a multitude of deviations from current good manufacturing processes as well as inappropriate marketing claims and clinical uses. Read about it here.

Yet, there are many reasons to be excited about stem cells which are produced, processed, and applied appropriately. The California Institute for Regenerative Medicine (CIRM) has pioneered stem cell treatments to cure children afflicted with Severe Combined Immunodeficiency Disease (SCID), and they are now entering Phase 2 clinical trials for this clinical application. CIRM has over 40 trials running at this time, all targeting devastating medical problems.

In more common clinical scenarios, studies have shown that stem cell injections can improve osteoarthritis symptoms, and many sports medicine and orthopedic specialists are using them to help patients avoid surgery.

Future cardiac applications may become possible, too. In an article published in Nature Communications by Shadrin and colleagues (2017), scientific work investigated the development of a scaffold composed of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), which are heart cells derived from adult human stem cells. The scientists developed a “cardiopatch”, essentially a network of organized heart cell tissue, and conducted experiments in a rodent model. The cardiopatches became vascularized, showed specific characteristics of adult heart tissue, and conducted the heart’s electrical charge. The researchers believe that their 4x4cm cardiopatches could eventually be scaled to create larger sections of functioning tissue for myocardial repair.

Validated treatments using stem cells have the potential to improve countless lives. But, for most conditions, we are years away from establishing proper protocols and doses. It’s appropriate for practitioner and patient alike to weigh the risks and benefits of any treatment, including (and, perhaps, especially) those promising stunning disease reversals and health advancements. Meanwhile, research continues to bring the promise of stem cells closer into focus and, step by step, safely into the clinic.



Begley, Sharon. (2017, March 15). Three patients blinded by stem cell procedure, physicians say. STAT. Retrieved from https://www.statnews.com/2017/03/15/stem-cell-patients-blind-macular-degeneration/.

Doheny, Kathleen. (2017, April 14). Stem cells for knees: promising treatment or hoax? WebMD. Retrieved from https://www.webmd.com/osteoarthritis/news/20170407/stem-cells-for-knees-promising-treatment-or-hoax#1.

GEN News Highlights. (2018, January 29). Stem cells: On your mark, get set, don’t go. Genetic Engineering & Biotechnology News. Retrieved from https://www.genengnews.com/gen-news-highlights/stem-cells-on-your-mark-get-set-dont-go/81255432.

McFarling, Usha Lee. (2016, February 8). FDA moves to crack down on unproven stem cell therapies. STAT. Retrieved from https://www.statnews.com/2016/02/08/fda-crackdown-stem-cell-clinics/.

Shadrin, Ilya Y., Allen, Brian W., Qian, Ying, Jackman, Christopher P., Carlson, Aaron L., Juhas, Mark E., & Bursac, Nenad. (2017, November 28). Cardiopatch platform enables maturation and scale-up of human pluripotent stem cell-derived engineered heart tissues. Nature Communications, 8: 1825. doi:10.1038/s41467-017-01946-x

Uygur, Aysu, & Lee, Richard T. (2016, February 22). Mechanisms of cardiac regeneration. Developmental Cell, 36: 362-374. https://doi.org/10.1016/j.devcel.2016.01.018