There has been a flood of reports in the news recently regarding vaccines and experimental treatments for COVID-19, including trials for treatments involving stem cells that could possibly change the way we treat this virus, and other viruses in the future. But the mix of optimism, a multitude of clinical trials, and technical language usually reserved for the laboratory has left many of us wondering how hopeful we should be about these reports and what information can and should be trusted.
Can stem cells really be used to treat viral infections like COVID-19?
What do we know about these clinical trials so far?
There are a number of trials being conducted around the world that are displaying early promise for an effective stem cell treatment. Celularity, an American company that is frequently in the news for stem cell research, has partnered with Seattle’s Infectious Disease Research Institute and have been cleared by the FDA for a clinical trial to use their CYNK-001 therapy to treat adults with COVID-19. This therapy uses placental stem cells to form “Natural Killer” (NK) cells, white blood cells that have been used in trials to fight cancer and other viral infections.
This particular trial will focus on patients who may be at risk for the most severe symptoms. The hope is that NK cells will “flatten the viral titer curve” of the virus inside the patient by destroying cells in the body that have become infected with the virus, preventing them from creating more viral cells, helping patients fight off the infection on their own before it has the opportunity to become more severe.
The FDA recently approved a trial to treat COVID-19 patients with Athersys’ stem cell product MultiStem®. This stem cell therapy was already in the clinical trial phase to treat acute respiratory distress syndrome (ARDS), a dangerous condition that, in COVID-19 cases, can be caused by “cytokine storms”, where the body’s immune system actually exacerbates the symptoms of coronavirus by attacking the lungs.
MultiStem® had substantially lowered mortality rates from ARDS in one study, before it was approved for this study involving COVID-19 patients. The Biomedical Advanced Research and Development Authority (BARDA), a government office in the Department of Health and Human Services, designated this product as “Highly Relevant” for the treatment of COVID-19, providing further hope that we are closer to effective stem cell treatments.
International research is also promising, and beginning to impact experimental treatment in the United States. Mesoblast, an Australian company that also operates in the U.S., has been approved by the FDA for a trial to treat 240 patients in 20 hospitals across the U.S. with a stem cell product made from mesenchymal stem cells (MSCS), the same kind of stem cell that can be collected in cord and placental tissue. This trial is also focusing on ARDS, using learnings from another Mesoblast trial focused on the treatment of acute graft-versus-host disease, a similar immune reaction. The goal is for the infusion of stem cells to calm the hyperactive immune system response, so that the virus can still be targeted by the body, without damaging the lungs.
An Israeli trial using stem cells derived from placental tissue is also showing great promise. Pluristem Therapeutics has shared data on a compassionate use trial for seven intensive care COVID-19 patients on ventilators due to severe ARDS. Like the Mesoblast trial, this therapy also attempts to harness the immunomodulatory properties of the stem cells to prevent or reverse over-activation of the immune system in order to protect the vulnerable lungs. Four of the patients began to improve within a week, leading to plans for an expanded clinical trial. Pluristem also provided this stem cell product to a hospital in New Jersey, where doctors are hoping another patient on a ventilator, in similar condition to the patients in Israel, will also see improvements in his health.
Two European hospitals, one in Denmark, and another in France, have also announced clinical trials using MSCs. The Danish trial is utilizing stem cells obtained from adipose tissue, while the French trial sourced stem cells from umbilical cord tissue. Both trials are focusing on patients severely affected by the condition, with the stated goal of measuring clinical improvements in lung function from initial treatment to seven days after treatment. Similar to the trials above, the hope is for the immunomodulatory properties of the stem cells to demonstrate positive outcomes for the immune system and to reduce damaging inflammation in the lungs.
Can stem cells from the placenta still be obtained safely?
As a number of these treatments utilize stem cells taken from the placenta, it is worth asking if it is still safe to bank this tissue with ongoing concerns about COVID-19. The Society for Maternal-Fetal Medicine and Centers for Disease Control both report that COVID-19 has not been detected in amniotic fluid, umbilical cord blood, and placental tissue, meaning banking stem cells from these sources is still considered to be safe at this time.
It is important to understand that it is still unlikely that banking stem cells at your newborn’s birth would provide a treatment for this virus in the immediate term. In the event that effective treatments are established through these trials, it is almost certain that any benefits from banking these stem cells would be for the treatment of future viral infections, not COVID-19 in 2020.
What are the realistic takeaways from these reports?
As with clinical trials for the treatment of any condition, there are never guarantees that success will be found. Nonetheless, these developments are exciting, and also demonstrate how broad the scope of stem cell treatments truly is, as there are multiple trials and approaches for the treatment of this one condition.
It is important to continue to monitor these trials for demonstrated safety and for researchers to determine why approaches are effective, so any improvements in the health of these patients can be learned from and applied to help treat patients suffering from COVID-19 now, and hopefully for future medical needs if and when they arise.