Israeli immunotherapy company Enlivex Therapeutics said Wednesday that 16 severe and critical COVID-19 patients who received its experimental treatment had survived a 28-day Phase II clinical trial period.
Two of the patients, who were critical cases at the start of the trial when they received the company’s Allocetra treatment, were still in intensive care and on ventilators at the end of the trial.
The other 14 patients recovered, were discharged from the hospital by the end of the trial and were reported to be healthy. The average duration of hospitalization after receiving Allocetra, for those who were discharged, was 5.3 days, the company said.
At the start of the trial, nine of the patients were in severe condition and seven were critical.
The company did a preliminary trial of five COVID-19 patients last fall. All of those patients, who were in severe to critical condition when they received the drug, were released from the hospital with an average stay of under 10 days after getting Allocetra.
The two trials together, therefore, had a mortality rate of zero percent in 21 severe to critical cases, although the fate of the two patients still in the ICU remains uncertain.
The majority of patients in both trials had preexisting risk factors including obesity and hypertension, the company said.
In the Phase II trial, 12 of the patients were at Hadassah Medical Center in Jerusalem, three at Barzilai in Ashkelon and one at Ziv in Safed. The first trial was held at Hadassah.
Following the successful Phase II trial, the company will submit the data for review by regulators later this month in the hopes of using the drug widely for the treatment of severe and critical COVID-19.
Allocetra treats the over-response of the immune system and inflammatory response that is sometimes seen in COVID-19 patients, called a cytokine storm. The phenomenon can cause severe immune system attacks on the body’s own organs, leading to organ failure and sometimes death.
Cytokine storms are difficult to treat because they are complex responses involving multiple biological systems reacting, and interacting, at the same time. Cytokines are proteins used in cell signaling that summon immune cells during an immune response.
Allocetra uses the body’s own regulation mechanisms to tamp down the storm without hampering the immune system, the company said. The treatment infuses billions of early apoptotic cells, or dying cells, into the bloodstream.
Macrophages and dendritic cells, the body’s first responders, feed on these apoptotic cells, releasing fewer cytokine alert signals and calming the storm.
The company first demonstrated the drug’s safety in treating a small group of sepsis patients.
Enlivex, based in Ness Ziona, is a clinical stage immunotherapy drug company, focused on balancing the immune system. It was founded in 2005. Allocetra is the firm’s leading treatment and the furthest along in trials.