Mammoth Biosciences to Present Preclinical Data on MB-111

Mammoth Biosciences to Present Preclinical Data on MB-111 at the European Society of Gene & Cell Therapy 32nd Annual Congress

BRISBANE, Calif. -- Mammoth Biosciences, Inc., a biotechnology company harnessing its proprietary next-generation in vivo CRISPR gene editing platform to create potential one-time curative therapies, today announced new preclinical data on its first clinical development candidate, MB-111, to be presented at the European Society of Gene & Cell Therapy (ESGCT) 32nd Annual Congress in Seville, Spain, on October 8, 2025.

MB-111 leverages CasPhi – a proprietary ultracompact CRISPR nuclease that is significantly smaller than Cas9-based systems. Encapsulated and delivered within a lipid nanoparticle along with the gRNA, MB-111 disrupts the expression of the APOC3 gene – a key regulator of triglyceride metabolism – in the liver.

Persistent chylomicronemia is a metabolic disorder characterized by extremely elevated triglyceride levels (>1000 mg/dL), resulting in recurrent and potentially life-threatening episodes of acute pancreatitis. MB-111 offers a potentially one-time, curative intervention aimed at lowering high triglyceride levels in affected patients.

The oral presentation shows that MB-111 substantially reduced APOC3 gene expression and disrupted apoC-III protein production in multiple animal models, further supporting its continued development for clinical use. The findings from this presentation include:

·      In a humanized transgenic mouse model of hypertriglyceridemia, MB-111 administration led to substantial reductions in apoC-III protein and serum triglyceride levels.

·      In nonhuman primates (NHPs), MB-111 administration resulted in saturating liver editing and sustained reductions in serum apoC-III protein.

·      MB-111 administration was well tolerated in NHPs, with only transient elevations in liver function tests at higher dose levels.

“Our data showcase the strong foundation we envisioned when developing MB-111,” said Trevor Martin, Ph.D., co-founder and chief executive officer of Mammoth Biosciences. “With the ability to safely and effectively reduce apoC-III protein in NHPs and triglycerides in mouse models that closely reflect the diseases of hypertriglyceridemia, we see a clear line of sight towards the clinic in 2026 and, ultimately, to transforming care for patients who currently have limited options.”