Resolution Therapeutics has treated the final patient in its Phase 1/2 EMERALD trial of engineered macrophage therapy RTX001 in end-stage liver disease, with interim data expected in Q4 2026.

EMERALD completes patient dosing

The EMERALD trial is evaluating the safety and efficacy of RTX001 in patients with end-stage liver disease and a history of decompensated liver cirrhosis.

A total of 15 patients have been dosed with RTX001 in the study, which is being conducted at hepatology centres across the UK and Spain. The trial is a multicentre, single-arm, open-label, first-in-human study.

The primary focus is on evaluating the safety and tolerability of RTX001, alongside measures of clinical efficacy. The study is also assessing clinical events and biomarkers associated with liver disease severity.

RTX001 is an autologous engineered macrophage cell therapy designed to address inflammation and fibrosis in damaged liver tissue. The cells are engineered with interleukin-10 (IL-10) and matrix metalloproteinase-9 (MMP-9) to enhance their anti-inflammatory and anti-fibrotic activity.

Resolution received UK regulatory approval to begin the EMERALD study in 2024, with the programme subsequently expanded to clinical centres in Spain. The first patient was dosed in 2025.

RTX001 targets inflammation and fibrosis

Macrophages are immune cells involved in inflammation and tissue repair. Resolution’s approach is designed to modify these cells so they can support the resolution of inflammation and fibrosis in diseased tissue.

RTX001 is administered as an intravenous infusion without the pre-conditioning or lymphodepletion commonly used with some other cell therapies. Resolution says the outpatient infusion takes less than 10 minutes.

The company is developing RTX001 for patients with end-stage liver disease who have experienced hepatic decompensation. Liver transplantation remains an important treatment option for suitable patients, but access to donor organs limits the number of people who can receive a transplant.

Resolution said interim clinical data from EMERALD are expected in the fourth quarter of 2026.

Amir Hefni, CEO of Resolution Therapeutics, said: “Dosing the final patient in the EMERALD trial marks a significant milestone for Resolution Therapeutics and reflects our progress toward a potential new treatment paradigm for end-stage liver disease.”

He added: “Patients with this condition face very limited options beyond transplantation and symptom management, and RTX001 has the potential to offer a differentiated, transformational therapeutic approach.”

The company has said that the EMERALD programme will provide clinical data to support the further development of RTX001 in end-stage liver disease. The trial is currently listed as active but not recruiting.

Next-stage study planned for 2027

Resolution plans to discuss the development programme with the US Food and Drug Administration before initiating a later-stage study in the US.

The company has said it plans to begin a pivotal study in end-stage liver disease in 2027, subject to discussions with the FDA and finalisation of the study design.

Beyond RTX001, Resolution is also developing additional regenerative macrophage therapy programmes for inflammatory and fibrotic diseases, including lung fibrosis. It is separately investigating an in vivo approach designed to engineer macrophages inside the body, with those programmes remaining at the preclinical stage.

For EMERALD, the next key development will be the interim clinical data expected later this year. These data will provide the first substantive clinical evidence on the safety and potential activity of RTX001 in patients with advanced liver disease.