Marble Therapeutics was a biotechnology company with a mission to develop treatments sourced from the human microbiome. The company’s goal was to harness the complex communities of microorganisms residing in the gut to create new therapies. Its work centered on modulating the gut’s microbial environment to address the underlying factors of serious diseases. This approach placed the company within a growing field of research looking to gut health as a pathway for treating a range of conditions. The company’s work was eventually absorbed into a larger entity, continuing its scientific vision under a new name.
Microbiome-Based Therapeutic Focus
The company’s strategy was to develop therapies known as oral live biotherapeutics (LBPs), which are specifically selected consortia of beneficial bacteria designed to restore balance to an unhealthy gut. This method was an evolution of Fecal Microbiota Transplantation (FMT), a procedure that involves transferring fecal matter from a healthy donor to a patient. While FMT has shown effectiveness, it can have variability and challenges with standardization. The company aimed to overcome these issues by creating a more controlled and scalable product.
Their process involved identifying specific strains of bacteria believed to have therapeutic effects, growing them in a lab, and combining them into a precisely formulated consortium delivered in a capsule. The delivery mechanism itself was a component of their technology. They utilized a capsule-in-capsule system designed to protect the live bacteria from stomach acid and ensure they reached the lower gastrointestinal tract intact. This targeted delivery was intended to maximize the potential for the bacteria to colonize the gut and exert their therapeutic effects directly where needed. This approach represented a more pharmaceutical-grade and reproducible version of microbiome therapy.
Primary Disease Target
The primary focus of this therapeutic platform was Ulcerative Colitis (UC), a chronic inflammatory bowel disease (IBD) that causes inflammation and ulcers in the lining of the colon and rectum. UC is characterized by an overactive immune response in the gut, and growing evidence suggests a connection between the disease and a dysbiotic, or imbalanced, gut microbiome. In patients with UC, there is often a decrease in microbial diversity and a loss of beneficial bacteria that help regulate immune responses.
By introducing specific strains of bacteria known to have anti-inflammatory properties or that support a healthy gut barrier, the therapy was designed to help modulate the immune system and reduce the inflammation that drives UC symptoms. The lead therapeutic candidate developed from this program was originally designated MB-107.
This specific formulation contained a consortium of bacterial strains selected for their potential to impact pathways related to UC. It was engineered as an oral capsule intended for patients to take regularly, providing a non-invasive method for continuously managing the microbial environment of the gut.
Acquisition by Assembly Biosciences
Marble Therapeutics ceased to operate as an independent entity after it was acquired by Assembly Biosciences, a clinical-stage biotechnology company. This acquisition integrated Marble’s research pipeline and its underlying technology into Assembly Bio’s broader development portfolio. The move was a strategic step by Assembly to build out its own capabilities in the microbiome space.
Following the acquisition, the lead program, MB-107, was renamed ABI-M201 and its development was continued by Assembly Biosciences. The company advanced the program into a Phase 1b clinical trial to evaluate its safety and efficacy in patients with mild to moderate UC.
The legacy of Marble Therapeutics’ vision is represented by the continuation of its science within Assembly Biosciences and beyond. In 2020, Assembly regained full worldwide rights to its microbiome programs from a collaboration partner. Subsequently, in 2022, the ABI-M201 program was acquired from Assembly by Xbiome, a company specializing in AI-driven microbiome therapeutics, ensuring that the development of this novel approach for Ulcerative Colitis would proceed.