Lumen Bio Reports Positive Phase 2 Results from the RePreve Clinical Trial (LMN-201 for C. difficile Infection)

- Global cure observed in 83.3% of LMN-201 recipients versus 36.4% randomized to placebo

- LMN-201 treatment plus standard-of-care antibiotics demonstrated a six-fold reduction in C. difficile infection recurrence compared to standard-of-care antibiotics and placebo (9.1% versus 55.6%)

- Results to be featured in a late-breaking oral presentation at IDWeek 2026

SEATTLE, Oct. 21, 2026 /PRNewswire/ -- Lumen Bioscience today announced positive results from the RePreve Clinical Trial of oral LMN-201, an investigational biologic cocktail drug, that demonstrate a statistically significant global cure and recurrence reduction versus placebo in patients with C. difficile infection (CDI).

LMN-201 is an oral biologic cocktail, delivered in capsules, intended for use with and following antibiotics to improve clinical outcomes for CDI. LMN-201 is made with Lumen's proprietary spirulina-based GMP manufacturing system. In the Phase 2 RePreve Trial (NCT05330182), participants diagnosed with CDI (total n=45 (Part B 23; Part A 22)) were given LMN-201 or placebo during and after standard-of-care antibiotic treatment, with the goal of both improving primary treatment outcomes and preventing CDI recurrence (together, "global cure").

Global cure was observed in 83.3% of LMN-201 Part B recipients (10 of 12) versus 36.4% receiving placebo (4 of 11). The 47-percentage-point risk difference (odds ratio, 8.75) is statistically significant in accordance with the prespecified Bayesian statistical analysis plan. Part B was placebo-randomized (1:1) and double-blinded, with participants stratified by standard-of-care antibiotic and age.

In addition, LMN-201 reduced primary cure failure by more than 50% relative to standard-of-care alone in Part B (odds ratio, 0.425), a directionally favorable trend on a secondary endpoint that did not reach statistical significance. LMN-201 was well tolerated, with a favorable safety profile and adverse event rates similar to placebo and consistent with the underlying infection and initial antibiotic treatment. There were no drug-related serious adverse events or deaths.

"These data support LMN-201's potential as a first-in-class oral biologic for C. difficile infection, one that could both improve primary treatment outcomes and prevent recurrence," said Carl Mason, MD, Lumen's VP, Clinical. "We are incredibly grateful to the participating patients and their families for generously agreeing to participate in the RePreve Trial, to the clinical research teams who facilitated the study, and to the Department of War's CDMRP program for supporting this important work."

"Every recurrence we prevent is an opportunity to spare a patient a second, third, or subsequent C. difficile episode," said Kole Krieger, Lumen's SVP, Business Development. "LMN-201 could expand hospital and primary care access, potentially becoming a routine part of C. difficile care and improving outcomes for millions of patients."

Additional details of the RePreve Trial results will be featured in a late-breaking oral presentation at the IDWeek 2026 conference in Washington, DC. Dr. Carl Mason, Lumen's head of clinical research, will present on October 24 at 1:30 p.m. ET. IDWeek is the annual joint meeting of leading infectious disease organizations designed to highlight the latest advances in infectious disease prevention, diagnosis, and treatment.

About LMN-201
LMN-201 combines three toxin-binding proteins and an antibacterial enzyme, all produced in engineered spirulina, together in conveniently administered oral capsules. LMN-201 is orally delivered and highly scalable, allowing for much broader potential use in routine CDI management. It is among the most advanced cocktail biologic drugs in development, and the first that implements the principle of rationally designed synthetic avidity to be tested in a clinical trial. Lumen previously released a preprint with LMN-201's preclinical data. Manuscripts are in preparation for this study and an earlier trial that assessed LMN-201's safety, tolerability, and gastrointestinal pharmacokinetics (NCT04893239).

Background on C. difficile infection
CDI remains a serious and costly problem. Nearly half a million cases occur in the U.S. each year, leading to an estimated 29,000 deaths and ~$5 billion in hospital costs annually. Recurrent CDI drives much of this burden: patients who relapse often require extended hospital care and may suffer multiple recurrences. Antibiotic resistance also remains a significant concern. The U.S. Centers for Disease Control and Prevention lists CDI as an antimicrobial resistance "Urgent Threat," and researchers worry about growing resistance to vancomycin, the main antibiotic used to treat CDI. Until now, efforts to improve CDI outcomes have had limited impact, due in part to high costs and inconvenient administration of other preventive therapeutics (chiefly fecal microbiota transplants and injected monoclonal antibodies).

About Lumen Bioscience
Seattle-based Lumen Bioscience has developed a new spirulina-based drug discovery, manufacturing, and delivery platform for highly prevalent diseases that have been difficult to address with conventional biopharmaceutical tools. The company's unique platform has the potential to transform the biologics industry through faster development, straightforward assembly of cocktail therapeutics, mass-market scale, and exponentially lower costs than legacy approaches. Visit www.lumen.bio.

About the Funding Source: Congressionally Directed Medical Research Program (CDMRP)
The work was supported by the Assistant Secretary of War for Health Affairs endorsed by the Department of War, in the amount of $16,288,194 through the Peer Reviewed Medical Research Program under Award No. HT9425-23-1-0959. Opinions, interpretations, conclusions, and recommendations are those of the author and are not necessarily endorsed by the Assistant Secretary of War for Health Affairs or the Department of War.

SOURCE Lumen Bioscience