Melbourne-based biotech company Mesoblast announced earlier this week that it’s begun enrolling up to 300 patients for a randomized, controlled study of its stem cell therapy remestemcel-L in the treatment of COVID-19 patients experiencing acute respiratory distress syndrome. Over 20 hospitals will participate in the study, which is anticipated to last 3-4 months.
The announcement came about a week after the company reported that treatment with remestemcel-L in a group of 12 COVID-19 patients with ARDS at Mt. Sinai hospital in New York had a survival rate of 83%. The purpose of the randomized, controlled clinical trial is to test that survival rate on a larger scale.
“We were very pleased with preliminary data demonstrating the cells seem to have benefitted some of these patients,” says CEO Silviu Itescu. “If the cells work in COVID-19 ARDS, we’re in a position to provide products to as many patients as possible.”
For coronavirus patients, ARDS is one of the deadliest complications of the disease, and often ends up requiring the use of ventilators in order to ensure they’re getting sufficient oxygen. It’s caused by what’s known as a “cytokine storm” - an overreaction of the immune system in which the body ends up damaging the lungs in an attempt to destroy the coronavirus and the lung cells that it has infected.
“The cytokines these cells make destroy lung tissue,” says Itescu. “It’s a trade-off being trying to get rid of the virus and trying to limit destruction to your own lung tissue.”
According to the CDC, between 20-42% of hospitalized COVID-19 patients develop ARDS, with as many as 85% of patients admitted to intensive care having this complication. Among those ICU patients who develop ARDS, over 40% die (some studies show that number as high as 72%) and those who survive spend an average of 10-13 days in the hospital.
Mesoblast’s remestemcel-L treatment is derived from allogenic mesenchymal stem cells, which when infused into the body can slow down an immune response and prevent the body from damaging itself. Its technology originally spun out of a research collaboration between Columbia University and Australian scientists, leading to the founding of the company in 2004.
One of the diseases the company has been working to treat is graft-vs-host disease, a condition that arises in patients who receive bone marrow transplants. In that disease, the donated bone marrow begins to see its new host as “foreign” and directs the immune system to attack it in a manner similar to that of the cytokine storm seen in ARDS.
The company is one of several biotech firms aiming to use mesenchymal stem cells as a potential COVID-19 treatment. Cleveland-based Athersys, which is working on stem cell therapies for strokes, heart disease and other conditions, is also expected to begin clinical trials soon. Haifa, Israel-based Pluristem, which is developing stem cell treatments as well, secured 50 million Euro (about $55.4 million) in financing this week from the European Investment Bank to support its COVID-19 trials.
So far, says Itescu, Mesoblast’s treatment has been tested in clinical trials in over 1,100 graft-vs-host patients. On April 1, the FDA accepted a priority review filing for use of the treatment against graft-vs-host disease. On April 6, the FDA gave clearance for an investigational new drug application for remestemcel-L in COVID-19 patients, which paved the way for this clinical trial.
Using Mesoblast’s treatment for coronavirus patients with ARDS “has a rationale behind it” says Dr. Wayne Marasco, who’s studied a number of coronavirus diseases and is currently researching potential antibody treatments for COVID-19. “That would be in line with how it works with graft-versus-host disease.”
Itesecu says that his company is focused on the next phase of its clinical research in the midst of this pandemic, and hopes it proves to be part of a number of effective therapies against the disease.
“We’re going to do our best to provide a solution to those patients in greatest need: those who are in intensive care on ventilators, where I think a safe and effective way to reduce severe inflammation is needed,” says Itescu. “We hope that what we’re doing is complementary to what folks who are developing vaccines and antivirals are doing.”