When four-year-old KJ Griffin’s mother rushed him to a hospital in South Carolina, with his body limp, she didn’t think he had COVID-19, let alone that he would eventually be treated with an experimental Australian drug that would save his life.
KJ had caught the highly infectious virus weeks earlier and, like most children his age, his symptoms were mild to nonexistent. But the coronavirus had left its mark in the form of multisystem inflammatory syndrome in children (MIS-C), a rare and potentially lethal complication from COVID-19.
MIS-C develops two to four weeks after a COVID-19 infection and triggers an immune response that attacks vital organs, including the heart, lungs, kidneys and brain.
“I like to think of it as the immune system going haywire,” said Dr Allison Eckard, associate professor of paediatrics and medicine at Medical University of South Carolina (MUSC).
“It’s the body’s reaction to the (COVID-19) infection that takes the immune system on a pathway of overstimulation and causes a lot of inflammation and immune dysfunction in the child.”
Dr Eckard treated KJ at MUSC’s Shawn Jenkins Hospital in Charleston. When he arrived at the hospital’s emergency department his body was in shock, unable to get enough blood flow to his vital organs.
Dr Eckard was able to save his life after securing access to Mesoblast’s remestemcel-L, a drug the ASX-listed company is currently trialling in the US to treat severe complications from COVID-19.
The drug was initially developed to treat children with steroid-refractory acute graft versus host disease (aGVHD), which has a similar immune response seen in patients with severe complications from the coronavirus.
Dr Eckard initially treated KJ with “all of the standard treatments”, including antibody therapies using immunoglobulins, high-dose steroids and aspirin, which has anti-inflammatory properties and reduces the chance of clotting.
“We gave him all of the standard treatments and it didn’t help. That’s why we decided to treat him with the Mesoblast product.
“On the day we were due to give him the first infusion (of remestemcel-L), his cardiac function had improved but it was still quite abnormal and his inflammatory markers — especially one called d-dimer, which is a marker of coagulation — was particularly high. Those two things together made us move forward with remestemcel-L.”
And KJ responded almost instantly.
“Within one day of giving him the first infusion, his cardiac function returned to normal. His d- dimer was decreasing and by the time of the second infusion those numbers had improved even more in a very short period of time.”
KJ had two infusions of remestemcel-L, which Dr Eckard said was the standard protocol, and was discharged a week and a half later, making a full recovery.
“MIS-C, although rare, is very serious and often life-threatening. There have been 11 cases of children who have died of MIS-C across the US.”
But Dr Eckard said if treated quickly with the right medication children could often recover.
“Kids are very resilient. It always amazes me how quickly they turn around compared to adults with similar problems. They’re young and have good healing, and he (KJ) was no different.
“In tertiary care hospitals when you get those children in quickly and get them started on appropriate medication, and in his case remestemcel-L, they do very well. We are so fortunate to be part of this expanded access program and thrilled to have been able to give him remestemcel-L and see his full recovery.”
Mesoblast has made remestemcel-L available to doctors for treatment of COVID-19-infected children with multisystem inflammatory syndrome under the company’s Expanded Access Program.
Already the US Food and Drug Administration’s advisory committee has voted in favour of the drug’s efficacy 9:1 for treating children with steroid-refractory acute graft versus host disease. The FDA is set to make its final decision on approving the drug later this month.
Mesoblast chief executive Silviu Itescu hopes to also gain duallabelling approval for its treatment on COVID-19 patients. The company is trialling it on 300 patients in the US and is expected to reveal their initial results in coming weeks. If the results strongly support its hypothesis, Mesoblast will then seek to have it approved as a treatment for COVID-19 as well as graft-versus-host disease.
This week it also expanded its study to Australia after it received ethics approval to include Australian hospitals in the phase three randomised controlled trial of remestemcel-L in ventilator-dependent COVID-19 patients with acute respiratory distress syndrome.
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