By the end of the year, a British biotech plans to start testing a new kind of cell therapy based on macrophages, a roaming immune system sentinel known for gobbling up dead and dying cells throughout the body.
The startup, Resolution Therapeutics, is engineering macrophages to tamp down on inflammation and break up fibrotic scars — and prevent more from forming — in the liver. On Thursday, it announced $85 million (£63.5 million) in Series B financing to pay for its upcoming Phase 1/2 study of 25 patients with end-stage liver disease.
“The only treatment option today for these patients is a liver transplant,” CEO Amir Hefni told Endpoints News in an interview. Resolution’s initial goal is to prevent or reduce the likelihood of death and liver failure, he added.
“We’re not looking for incremental benefits,” he said. “We’re looking for transformative benefit.”
The new raise, led by the British life science investor Syncona, will keep Resolution running into mid-2027, Hefni said. It’s a big bet on a unique approach at a time when many venture capitalists are shying away from cell and gene therapies.
To make the therapy, Resolution will collect and isolate white blood cells called monocytes from a patient’s veins. Scientists will then coax the monocytes to turn macrophages with “pro-regenerative” properties, Hefni said. The cells are then treated with an mRNA molecule encoding two proteins — Hefni won’t say what they are — to enhance the macrophage’s natural anti-inflammatory and anti-fibrotic powers.
Resolution is based on more than a decade’s worth of research from liver biologist Stuart Forbes, who leads the regenerative medicine research center at the University of Edinburgh. Forbes has already tested macrophage therapies without the mRNA engineering in two academic-led studies, including a Phase 2 trial of 50 people with liver cirrhosis.
The study’s primary endpoint was a change in a common scale for liver disease severity called the MELD score. Although the difference wasn’t statistically significant, Hefni was encouraged by the “downward trend.” But more importantly, he thinks that the survival data suggest a real and durable benefit.
At the European Association for the Study of the Liver (EASL) conference in June, the Edinburgh team reported that 30 months into the study, there were only two deaths and no liver transplants among the 26 patients who got the macrophage therapy. There were seven deaths, two liver transplants, and one person waitlisted for a liver transplant in the 24 patients who received standard care. Data from the three-year follow-up are expected soon, Hefni said.
So far, the treatment looks safe. The cells haven’t caused the overwhelming and dangerous immune reactions that have plagued some CAR-T therapies for cancer. And recipients don’t require the lymphodepletion that cancer patients need to make room for their cell transplants.
Resolution’s upcoming study, the first clinical test of its engineered macrophages, will enroll about 25 patients in the UK and Spain. Hefni expects an interim analysis in the first quarter of 2026 and the full readout in December of that year. If the results are positive, the company will start work on a pivotal trial.
In the meantime, Resolution will work on improving and scaling its manufacturing process, which includes freezing the cells so patients can receive multiple doses. It will also conduct preclinical studies of its macrophage therapies in other conditions, including graft-versus-host disease and lung fibrosis.