Pluristem Therapeutics has reported topline results from its Phase II studies of PLX-PAD cells to treat acute respiratory distress syndrome (ARDS) associated with Covid-19.

The two Phase II dose escalation studies have assessed the efficacy and safety of intramuscular injections of PLX-PAD cells to treat severe ARDS.

Pluristem CEO and president Yaky Yanay said: “Pluristem joined the global effort to fight the evolving and unexpected Covid-19 pandemic. We chose to focus on the most severe intubated patients suffering from ARDS associated with Covid-19, that have no viable treatment to date and are challenging healthcare systems worldwide.

“With the new coming wave of the Omicron variant, we intend to explore the opportunities based on the efficacy trends obtained from the Studies.”

The company noted that the results were based on the analysis of 89 participants enrolled in two clinical studies conducted in the US, and Europe and Israel.

The multicentre, double-blind, placebo-controlled, randomised, parallel-group study in the US enrolled 66 participants.

This US study had three treatment groups of PLX-PAD cells – with single administration of 300 million cells, single administration of 600 million cells, or 300 million cells twice in an interval of one week.

It also had two placebo control groups with single administration, and two administrations in a one-week interval.

In addition to standard medical care according to local practices, all groups in the US study received a study treatment.

The multicentre, randomised, controlled, parallel-group EuropeanIsraeli clinical trial enrolled 23 patients in Bulgaria, Germany, and Israel.

The European/Israeli clinical study had a single treatment group with a single dose of 300 million PLXPAD cells, besides best standard medical care as per the local practices, and a control group, which was given the best standard medical care as per the local practices.

The number of ventilator free days (VFD) during the day 1 to day 28 of the studies was the primary efficacy endpoint.

All-cause mortality at days 28 and 60, and VFD at day 60 were some of the two studies’ secondary efficacy endpoints.

Pluristem stated that the clinical trials did not meet the primary endpoint of significant improvement of VFD at 28 days.

After considering the baseline risk factors of the ARDS patients, the company stated that there were no differences in the safety profile between PLX-PAD and placebo.

Last year, Pluristem started dosing Covid-19 patients in Israel with PLX cells under a compassionate use programme.