A new in vivo program could help bring regenerative macrophage therapy to more patients with chronic inflammatory and fibrotic diseases.
For patients with end-stage liver cirrhosis, time is often measured by waiting lists. Once the liver reaches a point where it can no longer repair itself, transplantation is usually the only option and donor organs remain painfully scarce.
Resolution Therapeutics believes there may be another path as the clinical-stage biotech has announced a new in vivo Regenerative Macrophage Therapy (RMT) program that sits alongside its existing lead candidate, RTX001, with the ambition of making regenerative medicine more widely available [1]. Rather than engineering a patient’s own cells in a lab, the new approach aims to reprogram key immune cells directly inside the body using messenger RNA (mRNA) delivered by lipid nanoparticles (LNPs).
If that sounds familiar, it is because lipid nanoparticles are the tiny fat-based carriers that helped make mRNA COVID-19 vaccines possible. Think of them as delivery vans: instead of carrying parcels, they carry genetic instructions to specific cells. In Resolution’s case, the destination is macrophages, immune cells that can either fan the flames of inflammation or help tissues heal.
The company has signed Material Transfer Agreements with several independent developers of best-in-class LNP technologies, allowing it to evaluate multiple delivery systems simultaneously. Early findings are expected later this year.
From personalized medicine to scalable medicine
Resolution’s flagship therapy, RTX001, remains at the center of the company’s clinical strategy.
Currently in the Phase 1/2 EMERALD trial, RTX001 is being tested in patients with end-stage liver disease caused by decompensated cirrhosis, where transplantation is often the only remaining treatment option. The therapy works by collecting a patient’s own macrophages, reprogramming them outside the body and returning them to encourage tissue repair. It is a highly personalized process and one that comes with the manufacturing complexity common to many advanced cell therapies.
The new in vivo program takes a very different route. Instead of removing cells from the body, modifying them in a laboratory and infusing them back into patients, Resolution hopes to send genetic instructions directly to macrophages through a simple injection. If successful, the body’s own immune cells would receive new instructions in place, eliminating several manufacturing steps and potentially making treatment available to far more people.
It is the difference between repairing every individual engine in a workshop and sending a software update remotely. The destination is the same; the journey becomes considerably simpler.
“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,” said Amir Hefni, CEO of Resolution Therapeutics.
Failing faster to move faster
Rather than betting everything on a single proprietary delivery system, Resolution plans to test several leading LNP formulations in parallel. The company describes this as a “deliberate fast-fail” strategy – identifying weak approaches early so resources can be concentrated on the combinations that perform best.
In biotech, companies often spend years optimizing one platform before discovering its limitations. Resolution is attempting to compress that timeline by asking multiple questions at once.
Alongside evaluating delivery vehicles, researchers are refining the company’s own mRNA payloads. The challenge is not simply reaching macrophages, but ensuring the genetic instructions switch the cells into repair mode without accidentally provoking more inflammation.
“This fail-fast approach is precisely what this scientific programme needs today,” said Lara Campana, Scientific Co-Founder and SVP, Head of Research and Translational Science at Resolution Therapeutics. “ 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.”
Why macrophages matter beyond the liver
Macrophages rarely receive the same attention as stem cells or gene editing, yet they quietly orchestrate many of the body’s repair processes.
When functioning properly, they help clear damaged tissue, calm excessive inflammation and support healing. However, in chronic disease – and increasingly during aging – that balance can break down. Instead of resolving damage, persistent inflammation lingers, while scar tissue, known as fibrosis, gradually replaces healthy tissue.
Resolution’s strategy is to restore those immune cells to their regenerative role rather than targeting a single disease in isolation. That matters because inflammation and fibrosis underpin not only liver disease but a growing list of age-related conditions affecting organs throughout the body. By focusing on the biology driving tissue decline instead of one specific diagnosis, regenerative macrophage therapy hints at something larger: a platform that could eventually be applied across multiple diseases.
The next generation of regenerative therapies will not be judged solely on whether they work in carefully controlled clinical trials. They will also be judged on whether they can be manufactured efficiently, delivered at scale and reach the millions of patients who stand to benefit.
If therapies like Resolution’s eventually transform advanced liver disease into something treatable with an injection rather than a transplant, the implications would extend far beyond one company. If its fast-fail strategy proves successful, it could encourage a more collaborative model for drug development in an industry often defined by closely guarded platforms.
Finally, with both interim EMERALD data and early in vivo platform results expected later this year, investors will soon have two very different visions of regenerative medicine to evaluate: one built around personalized cell therapy already in the clinic, the other around a scalable platform that could dramatically broaden patient access.
