Betting on its stem cell therapy for end-stage liver disease, Belgium-based Promethera Biosciences has got €39.7 million (about $44.4 million) in the bank to develop the drug as an alternative to often hard-to-procure transplants.
Established in 2009, Promethera’s lead drug is an experimental stem cell therapy called HepaStem for patients with a deadly syndrome called acute-on-chronic liver failure, or ACLF, for whom transplants are the only existing rescue treatment. Derived from human livers, the therapy is formulated using mesenchymal stem cells (MSCs) replete with liver markers and liver features. At the International Liver Congress last month, Promethera presented data from an ongoing dose-escalation Phase IIa study, which showed the treatment is safe and suggested “trends in efficacy.”
“The hope is to develop the technology as an alternative to liver transplantation in ACLF patients — not all of them are getting transplants because a lot of the patients are alcoholics,” company chief John Tchelingerian said in an interview with Endpoints News.
“Our cells have these natural features — they are coming from the liver and going back into the liver — after their intravenous administration in patients. They are producing highly potent factors that are necessary for liver balance and liver maintenance…these factors are tailored to act specifically on liver cells and repair the lesion or act against the inflammation occurring in the liver.”
In 2016, Promethera acquired the assets of Durham-based Cynotet, who had over a decade of experience dealing with US-based organ procurement organizations (OPOs). This established infrastructure makes Promethera the second port of call for the OPOs — if the liver is non-transplantable, Tchelingerian said.
Once the donation is procured — the liver is processed at a GMP-compliant US Promethera facility, which produces a liver cell suspension that is enriched with hepatocytes — this constitutes the starting materials to produce HepaStem. This suspension is put into sealed bags, frozen and shipped to the company’s Belgium factory, where HepaStem is then formulated and cryo-preserved, he explained. “The process takes about two months — to produce a batch of billions of stem cells from a single bag that contains a few hundred millions cells. We have many runs per year. From one liver today — we can treat about 300 to 350 patients suffering from ACLF.”
“We’re the opposite of the CAR-Ts — who went from bench to patient very quickly showing efficacy…we have done the reverse, I think that’s a very good way to bring our products to the maximum number of patients worldwide, because we control the full value chain from the donor to the end product.”
Novartis’ $NVS pioneering CAR-T therapy Kymriah was approved amidst great fanfare in 2017, but sales have suffered due to manufacturing issues. In the fourth quarter, the drug generated a paltry $28 million. However, Novartis is doing its best to shore up manufacturing, having bought cell and gene therapy manufacturer CellforCure.
Promethera’s ongoing HepaStem Phase IIa will be completed this summer — and if the positive findings are confirmed, that data will provide the ground to launch a Phase IIb trial. That study is expected to kick off by the end of 2019, with about 200+ patients and should take 2.5 years to complete.
Meanwhile, Promethera intends to initiate a NASH trial in very late-stage patients sometime this year and will make a decision on whether to pursue HepaStem in less-severe patients, based on the results of other NASH readouts expected this year.
So far, the company has raised roughly €110 million — including the Tuesday series D raise, which was co-led by new Japanese investors Itochu and Shinsei Capital Partners.
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