Resolution Therapeutics has expanded its regenerative macrophage therapy pipeline with a new in vivo programme designed to deliver therapeutic mRNA directly to immune cells using lipid nanoparticle technology.

The clinical-stage biotechnology company said it has signed Material Transfer Agreements with multiple lipid nanoparticle technology providers to evaluate delivery systems for its proprietary regenerative macrophage therapy payloads.

The programme is intended to complement RTX001, Resolution’s lead autologous engineered macrophage therapy, which is currently being evaluated in the Phase 1/2 Emerald trial in patients with end-stage liver disease and a history of decompensated liver cirrhosis.

The company is developing regenerative macrophage therapies as a potential treatment for inflammatory and fibrotic diseases, an area of significant unmet medical need where treatment options remain limited.

Unlike conventional anti-inflammatory therapies that target individual disease pathways, Resolution’s approach seeks to restore macrophage function to support the body’s natural tissue repair processes.

Macrophages play a central role in regulating inflammation and tissue healing. Resolution believes that restoring these functions could help address both chronic inflammation and fibrosis, potentially supporting tissue regeneration across multiple disease areas.

The newly announced programme will focus on identifying lipid nanoparticle formulations capable of efficiently delivering mRNA payloads to cells within the myeloid compartment in vivo. According to the company, successful delivery would require efficient encapsulation, targeted cellular uptake and expression of the therapeutic payload without triggering an inflammatory macrophage response.

Resolution expects preliminary results from the evaluation programme later this year.

The company said it is using a parallel assessment strategy to compare multiple lipid nanoparticle technologies simultaneously, with the aim of accelerating development timelines and identifying the most suitable delivery platform.

Amir Hefni, chief executive officer of Resolution Therapeutics, said: “This programme marks a decisive inflection point for Resolution Therapeutics — an acceleration of ambition to match the urgent patient need. EMERALD, our autologous programme, is in the clinic with interim data expected later this year. We are building an in vivo platform to bring Regenerative Macrophage Therapy to more patients.”

The expansion reflects growing industry interest in combining advances in mRNA technology with targeted delivery systems to develop treatments that can be administered directly within the body rather than through personalised cell manufacturing processes.

While lipid nanoparticles have become widely established as delivery vehicles for nucleic acid-based medicines, efficiently targeting specific immune cell populations remains a significant scientific challenge.

Lara Campana, scientific co-founder and senior vice president, head of research and translational science at Resolution Therapeutics, said: “Resolution’s deep expertise in RMT biology, and how it mechanistically correlates with its clinical potential, offers a unique vantage point in building an in vivo RMT platform.”

She added: “A successful encapsulation and expression readout would directly lead to candidate nomination studies and, critically, demonstrate that mRNA payloads can be delivered via an established, scalable modality.”

The company believes the in vivo programme could ultimately broaden access to regenerative macrophage therapies by extending treatment beyond patient-specific cell therapy approaches. If successful, the platform could support the development of therapies for a range of chronic inflammatory and fibrotic diseases.