Researchers at the Medical University of South Carolina are testing a possible treatment for multisystem inflammatory syndrome, MIS-C, a rare but serious complication of COVID-19 in children. The syndrome can cause inflammation in the heart, lungs, kidneys, brain, skin, eyes, and gastrointestinal organs. One MUSC Health pediatrician described MIS-C as an immune response to the virus “gone haywire.”
The syndrome has only affected seven children in South Carolina since the start of the pandemic. All have recovered. But MIS-C is blamed for killing children in other states, including Louisiana and Colorado.
The Regenerative Therapy
The treatment was developed by the company Mesoblast for another purpose: to try to help people who have had bone marrow transplants by keeping their bodies from rejecting the transplanted tissue. This regenerative therapy could be an MIS-C fighter because, like the body’s reaction to a bone marrow transplant, MIS-C is a harmful immune system reaction to a perceived enemy. Research suggests remestemcel-L is safe for children, one of the important thresholds in clinical research. A very small study indicates it may also be effective in the fight against COVID. Twelve adults with COVID who were on ventilators because their immune systems were overreacting to the infection, causing acute respiratory distress syndrome, were given the treatment.
The current treatment for MIS-C is similar to how doctors care for kids with a condition called Kawasaki disease. “The standard of care normally is to give large amounts of very non-specific anti-inflammatory drugs — steroids, immunoglobulin,” Eckard said. “But I think the advantage of the treatment we’re testing is that it’s more specific, really focusing just on the tissues that are more affected — the blood vessels, the heart and the lungs rather than just everything. Because there are side effects with steroids, we find them very safe, we give them all the time, but this may be advantageous because it’s more directed toward the damaged tissue,” Eckard said.
The Clinical Trial
In the Mesoblast International sponsored clinical trial at MUSC, children with MIS-C who meet certain criteria will get an IV treatment called remestemcel-L, which goes by the brand name Ryoncil. It uses mesenchymal stromal cells from the bone marrow of healthy people that have been expanded in a lab to try to help sick people. The hope is that they’ll help kids with MIS-C by getting their overactive immune systems under control and repairing some of the damage the syndrome has caused. To qualify for the MUSC trial, a child’s MIS-C must be causing heart trouble and affecting at least one other organ. The kids also have to be 17 or younger and have either tested positive for COVID-19 or been exposed to the coronavirus within a few weeks of showing MIS-C symptoms. This is an expanded access study, meaning everyone in the study gets the treatment—no one gets the placebo.
MUSC PI POV
Allison Eckard, M.D., a pediatric infectious disease specialist at MUSC Children’s Health and an associate professor in the College of Medicine, is helping lead MUSC’s part of the trial. “The safety profile looks very safe, with very few side effects or concerns. As a parent, I would 100% want to give this to my child because it may improve outcomes and there’s very little downside to giving it,” she said.
The remestemcel-L trial is one of several studies underway at MUSC, focusing on COVID-19, including one testing a possible antibody treatment. Eckard is pleased to see that the growing list includes potential options for kids. “Hopefully, we won’t see many children with MIS-C, but you want to have good treatments for them.”
Publicly traded (ASX: MSB; Nasdaq: MESO), Mesoblast is developing and commercializing cellular medicines to treat serious and life-threatening inflammatory diseases with significant, unmet medical needs. The Company’s Phase 3 off-the-shelf mesenchymal lineage cell product candidates are:
· RYONCIL™ (remestemcel-L) for steroid-refractory acute graft versus host disease (acute GVHD)
· Remestemcel-L for moderate to severe acute respiratory distress syndrome (ARDS) due to COVID-19 infection
· REVASCOR® for advanced chronic heart failure, and
· MPC-06-ID for chronic low back pain due to degenerative disc disease.
The US FDA has accepted for priority review Mesoblast’s BLA to seek approval of RYONCIL to treat acute GVHD in children and set a PDUFA action date of September 30, 2020. The Company’s proprietary manufacturing processes yield industrial-scale, cryopreserved, off-the-shelf, cellular medicines. With defined pharmaceutical release criteria, these cell therapies are planned to be readily available to patients worldwide.
Allison Eckard, M.D., a pediatric infectious disease specialist at MUSC Children’s Health and an associate professor in the College of Medicine.