Promethera Biosciences SA, a global innovator in cell-based medicines and liver diseases, today announced clinical data from the ongoing phase 2a study of its lead product candidate HepaStem® in patients with Acute-on-Chronic Liver Failure (ACLF) or acute decompensation (AD) at high risk of developing ACLF. The data was presented in an oral presentation during the late breaker session at The International Liver Congress^™ (ILC) 2019 on April 13, 2019, in Vienna, Austria by Promethera’s principal investigator Prof. F. Nevens, KULeuven, BE.

Currently, liver transplant is the only rescue treatment for patients suffering of ACLF and to a lesser degree for AD patients. There are no other existing therapies that can rescue the end-stage-liver failure. Promethera is developing HepaStem as an alternative to transplant; it consists of liver stem cells that are obtained from ethically donated healthy human organs and expanded in GMP culture conditions. These liver stem cells migrate through the blood and reach the liver, where they settle and support the tissue regeneration function.

In the trial, HepaStem cells have been infused intravenously in single or repeated infusions in multiple ascending doses in patients to assess the tolerability and the safety profile of the treatment. The trial recruited a total of 19 patients with a mean CLIF-ACLF score of 50 (12 patients) and a mean CLIF-AD score of 54 (7 patients) – both parameters used as a disease severity score and predict the 28-day mortality.

With two repeated doses at 0.5 million cells per kilogram of body weight and one infusion of 1 million cells per kilogram of body weight, no adverse events related to HepaStem occurred and no clinically significant changes were shown in platelet count, fibrinogen levels, and coagulation factors following HepaStem infusion. In addition to this positive safety profile, the study has been showing trends in efficacy with improvement in three indicators of liver disease severity; Model for End Stage Liver Disease score (MELD), Child-Pugh score and bilirubin levels, at day 28 and up to three months after treatment initiation.

“Pioneering the use of liver stem cells for the treatment of ACLF, we are excited to pass this first major hurdle of establishing a well-defined safety profile, as we continue to advance HepaStem through the clinic,” said Etienne Sokal, M.D., Ph.D., Promethera’s Chief Scientific & Medical Officer. “HepaStem has a broad therapeutic potential, being a possible first alternative to organ transplant for an ever-growing patient population in dire need, and we are relentless in our drive to bring it to patients in the safest and fastest way possible. The next stages of our development plan will be to conduct a larger trial in ACLF focusing on clinical efficacy to restore better liver function, and potentially decrease mortality and need for transplantation.”

Prof. Nevens added, “We are happy to report we have developed a safe dosing protocol with HepaStem for patients with Acute-on-Chronic Liver Failure (ACLF) or acute decompensation (AD) at risk of developing ACLF. While these are early results, our preliminary data point to liver function improvement. We can only hope this treatment will not only prove to be efficacious in the future, but also help the numerous patients with ACLF and AD and bring them to a stage where organ transplantation can again be considered, or behavioral changes can start helping again.”