In vitro studies, undertaken by two leading microbiology centers, confirm RHB-204's killing capability on Mycobacterium avium subspecies paratuberculosis (MAP) and its MAP-killing comparability to RedHill's RHB-104 in both long-term intracellular culture and spot and phage assays

The two sets of studies, showing confirmed MAP-killing effect and comparability to RHB-104, led by Professor Tim Bull from City St George's University of London, and Prof Irene Grant, Professor of Microbiology and Food Safety, Queen's University Belfast and Dr Hannah Dane, further support development of RHB-204's potential in MAP-related Crohn's disease

In its positive Phase 3 study, RHB-104 met the primary endpoint with statistical significance, showing RHB-104 plus standard of care (SoC) to be 64% more effective than SoC alone in treating Crohn's disease, compared to the placebo (standard of care only) group (p = 0.0048)1

RHB-2042, a proprietary next-generation oral optimized formulation of RHB-1043, designed for reduced toxicity and side effects and enhanced patient adherence, employs a differentiated, MAP-targeted approach to the treatment of Crohn's disease

RALEIGH, N.C. and TEL AVIV, Israel, Nov. 2, 2026 /PRNewswire/ -- RedHill Biopharma Ltd. (NASDAQ: RDHL) ("RedHill" or the "Company"), a specialty biopharmaceutical company, today announced the confirmation of RHB-204's killing capability on Mycobacterium avium subspecies paratuberculosis (MAP), and RHB-204's comparability to RHB-104 MAP-killing, following two sets of in vitro studies, undertaken by leading microbiology centers, in both long-term intracellular culture and spot and phage assays.

The two sets of studies led by Professor Tim Bull from City St George's University of London, and Prof Irene Grant, Professor of Microbiology and Food Safety, Queen's University Belfast and Dr Hannah Dane, support the potential for RHB-204's role in MAP-related Crohn's disease (CD) through demonstrated RHB-204 comparability to RedHill's RHB-104, which met the primary endpoint with statistical significance of its positive Phase 3 clinical trial, showing RHB-104 plus standard of care (SoC) to be 64% more effective than SoC alone, in treating CD compared to the placebo (standard of care only) group (p = 0.0048).

In vitro studies, undertaken by Professor Tim Bull, confirm RHB-204's MAP-killing capability MAP in long term intracellular culture4 and further demonstrate RHB-204's comparability to RedHill's RHB-104's MAP-killing effect. The positive results were seen across a range of MAP strains, taken from both human Crohn's disease patients and animal carriers of Johne's disease, sometimes referred to as "animal Crohn's", which were suggestive of both potential human and veterinary utility. The studies also showed that RHB-204 did not induce tolerance in the strains during the short exposure periods used in the studies (6 days max), suggesting that further consecutive dosing could add to the effect.

Tim Bull, Professor of Cell and Molecular Biology at City St George's University of London said: "RHB-204 demonstrated a significant MAP-killing effect, similar to RHB-104, against multiple strains of MAP, both human and animal, whilst intracellularly persistent. MAP is remarkably difficult to kill and test against due to its unique biological structure, intracellular lifestyle, and slow growth rate. This data gives a valuable insight into the potential of RHB-204 to treat MAP-related Crohn's disease involving either human or animal derived MAP strains."

Prof. Bull's work adds to the in vitro work undertaken by Rapid-myco Technologies, a world leader in the field and developer of a transformative diagnostic platform for the rapid detection of important and often life-threatening mycobacterial infections of humans and livestock. This work, led by Prof Irene Grant, Professor of Microbiology and Food Safety at Queen's University Belfast and Dr Hannah Dane, showed in vitro that RHB-204 demonstrated comparable MAP killing to RHB-104 in both spot and phage assays. Importantly, MAP killing efficacy was achieved with lower doses of two of the active ingredients compared to RHB-104, indicative of potential for reduced toxicity and side effects5.

"We know from previous published positive Phase 3 clinical testing that RHB-104 delivered a statistically significant 64% improvement over placebo in efficacy in treating Crohn's disease using a MAP-targeted approach. In vitro confirmation of RHB-204's MAP-killing effect and comparability to RHB-104 is another step forward in the development of RHB-204 for MAP-related CD," said Reza Fathi, PhD, Senior VP, R&D at RedHill. "We believe Phase 2-ready RHB-204 could be among the first treatments to be evaluated in an adequately controlled study in a specifically defined MAP-positive Crohn's disease patient population."

There is a significant body of peer reviewed published research supporting the scientific rationale that MAP may be a root cause of CD6, however, a major hurdle in previous clinical studies for new therapies directed at MAP has been the ability to rapidly and accurately detect MAP, one of the slowest growing and hardest to detect bacteria known.

We believe that RedHill's existing collaborations for the provision of cutting-edge MAP detection diagnostics, with two leading European research organizations, may provide the right conditions for a well-designed study in a specifically defined MAP-positive Crohn's disease patient population. Such a study could provide key evidence that could transform CD management and, if RHB-204 is approved, support a therapy addressing both the suspected cause of the disease and its symptoms.

New safe and effective orally administered therapeutic approaches are needed to help improve outcomes in the treatment of Crohn's disease. Up to 40% of CD patients fail to respond to anti-TNF treatment, and over time a similar proportion of responders lose response and have disease flare-ups7. Many existing treatment options are both expensive and intravenously administered, further increasing the cost burden. Moreover, several of these existing therapies have known safety issues, including Black Box Warnings. The CD market is expected to expand significantly, with sales in the United States, Japan, and five major European markets expected to grow at a compound annual growth rate (CAGR) of 3.87% to $19.1 billion by 20335.

RHB-204 is patent protected through 2041 and has been granted FDA Fast Track, Orphan Drug and QIDP and EU Orphan designations. Where applicable, the Company intends to explore the potential for additional designations, including FDA breakthrough therapy and pediatric orphan drug designations, which may provide a potential avenue for receiving a priority review voucher (PRV).

RedHill is actively pursuing partnerships and collaborations for this program, including through innovation development grant applications.

About RHB-204

RHB-204 is a proprietary, fixed-dose oral capsule containing a combination of clarithromycin, rifabutin and clofazimine, at specific doses designed to safely and effectively treat Mycobacterium avium subspecies paratuberculosis-positive (MAP-positive)-related Crohn's disease.

RHB-204 is a next-generation formulation of RHB-104 with an optimized formulation for the treatment of CD. It contains the same three antimicrobial agents with potent intracellular, anti-mycobacterial and anti-inflammatory properties, and with an optimized dosing profile, RHB-204 provides the potential for enhanced tolerability, safety and compliance with a 40% pill burden reduction. RHB-204 is supported by clinical data from the positive safety and efficacy results achieved in the Phase 3 clinical study of RHB-104 in CD8, with its potential further demonstrated using mucosal healing imaging, which is widely used in the evaluation of efficacy in CD.

Originally developed for the treatment of pulmonary non-tuberculous mycobacteria (NTM) disease caused by Mycobacterium avium complex (MAC), RHB-204 was granted FDA Fast Track and Orphan Drug Designation, in addition to QIDP Designation under the Generating Antibiotic Incentives Now Act (GAIN Act), extending U.S. post-approval U.S. market exclusivity to a potential total of 12 years. RHB-204 has additionally been granted EU Orphan Designation, providing eligibility for 10 years EU post-approval market exclusivity.

About Crohn's Disease

Crohn's disease (CD) is a form of Inflammatory Bowel Disease (IBD) causing inflammation of digestive tract tissue that can lead to abdominal pain, severe diarrhea, fatigue, weight loss and malnutrition. CD can be highly debilitating and remains a serious burden for both patients and healthcare systems: significantly impairing quality of life and, in some cases, leading to life-threatening complications. There is no known cure for Crohn's disease. It is estimated that 1 million Americans9 and approximately 6-8 million people globally have Crohn's disease10.

Commonly used FDA-approved therapies in the treatment of CD include: Abbvie's Humira® (adalimumab), Janssen's Remicade® (infliximab) and Stelara® (Ustekinumab), BMS's Zeposia® (ozanimod) and Pfizer's Xeljanz® (tofacitinib).

About RedHill Biopharma

RedHill Biopharma Ltd. (NASDAQ: RDHL) is a U.S. specialty biopharmaceutical company primarily focused on the development and commercialization of proprietary drugs for gastrointestinal diseases, infectious diseases and oncology. RedHill promotes the FDA-approved gastrointestinal therapies Rebyota®, for the prevention of recurrent C. diff infection (rCDI), and the bowel preparation treatment, Clenpiq®. RedHill's key clinical late-stage development programs include: (i) opaganib (ABC294640), a first-in-class, orally administered sphingosine kinase-2 (SPHK2) selective inhibitor with anticancer, anti-inflammatory, antiviral and metabolic activity, targeting multiple indications with a track record of U.S.