24 April 2020, Written by Matt Ogg

An Australian-developed stem cell treatment has drastically increased survival rates in trials for ventilator-dependent patients suffering from acute respiratory distress syndrome (ARDS) due to Covid-19.

Melbourne-based regenerative medicine company Mesoblast (ASX: MSB, NASDAQ: MESO) has been engaged in trials with New York City's Mt Sinai hospital to intravenously infuse its product remestemcel-L in patients, and the early signs are promising.

The sample size of 12 patients may be small, but 83 per cent (10) of them have survived after the stem cell treatment compared to a 12 per cent survival rate for ventilator-dependent Covid-19 patients with the condition at a major referral hospital network in the city.

Mesoblast reports 75 per cent of the patients (nine) were able to come off ventilator support within a median of 10 days, compared to a 9 per cent rate for patients treated with standard of care during March and April.

Seven of the patients, who were given remestemcel-L within five days under emergency compassionate use, have been discharged from the hospital.

Using bone marrow aspirate from healthy donors, Mesoblast's proprietary technology is currently used to treat a condition called acute graft versus host disease (aGVHD), which many suffer after receiving a bone marrow transplant (BMT).

But as the Covid-19 pandemic took centre stage, the company hypothesised Remestemcel-L would be able to treat what is known as a cytokine storm - a kind of hyperinflammatory syndrome - in the lungs that often occurs with serious Covid-19 cases.

The company then quickly mobilised plans for trials in the US, Australia, China and Europe.

"The remarkable clinical outcomes in these critically ill patients continue to underscore the potential benefits of remestemcel-L as an anti-inflammatory agent in cytokine release syndromes associated with high mortality, including acute graft versus host disease and Covid-19 ARDS," says Mesoblast chief executive Dr Silviu Itescu.

"We intend to rapidly complete the randomized, placebo-controlled Phase 2/3 trial in COVID-19 ARDS patients to rigorously confirm that remestemcel-L improves survival in these critically ill patients.

The company's chief medical officer Dr Fred Grossman emphasises a significant need to improve the "dismal survival outcomes in COVID-19 patients who progress to ARDS and require ventilators".

"We have implemented robust statistical analyses in our Phase 2/3 trial as recommended by the US Food and Drug Administration (FDA) in order to maximise our ability to evaluate whether remestemcel-L provides a survival benefit in moderate/severe COVID19 ARDS," he says.

MSB shares in the company rose by more than 22 per cent this morning to $2.40 each.

Updated at 11:14am AEST on 24 April 2020.