Gastroenterology First Half Recap: 2025

The first half of 2025 saw significant progress in gastroenterology, highlighted by US Food and Drug Administration (FDA) approvals of mirikizumab and guselkumab for Crohn’s disease (CD)—marking important expansions for IL-23-targeted therapies in inflammatory bowel disease (IBD). Beyond IBD, fecal microbiota transplantation (FMT) continued to gain traction with new data supporting its potential as a first-line treatment for primary C. difficile infection (CDI).

In ulcerative colitis, promising phase 2b results for icotrokinra signaled another pipeline contender, while early-phase data for EBX-102-02 showed microbiome-based innovation in irritable bowel syndrome with constipation (IBS-C). Additionally, updated US Multi-Society Task Force on Colorectal Cancer (USMSTF) guidance on bowel prep emphasized the continued importance of optimizing colonoscopy quality amid the growing landscape of noninvasive screening tools.

Here’s a recap of what made headlines in the first half of 2025:

FDA Approves Mirikizumab (Omvoh) for Crohn’s Disease

Starting Q1 off strong, on January 15, 2025, the FDA approved Lilly’s mirikizumab (Omvoh) for the treatment of adults with moderately to severely active CD, marking the IL-23p19 antagonist’s second approval in IBD since 2023, when it was approved as a first-in-class treatment for moderately to severely active ulcerative colitis (UC).

Related: Marla Dubinsky, MD: Ushering In a New Era of Crohn’s Disease Treatment with Mirikizumab

FDA Approves Guselkumab (Tremfya) For Crohn Disease

In the second CD approval of Q1, the FDA approved Johnson & Johnson’s guselkumab (Tremfya) based on data from multiple phase 3 trials, including the GALAXI trials, which found guselkumab outperformed ustekinumab (Stelara) for multiple endoscopic endpoints. Like mirikizumab, the approval of guselkumab for CD marked the agent’s second approval for IBD, building upon a previous indication for UC.

Fecal Microbiota Transplantation Shows Promise for First-Line Primary C Diff Treatment

Findings from a randomized, open-label, noninferiority phase 3 trial suggest FMT may be a viable first-line treatment for primary CDI, highlighting its noninferiority to standard-of-care vancomycin. The trial, which was conducted at 20 hospitals in Norway, found clinical cure and no disease recurrence within 60 days without additional treatment occurred in 66.7% of patients with FMT versus 61.2% with vancomycin.

ANTHEM-UC: Icotrokinra (JNJ-2113) Shows Promise for Ulcerative Colitis

On March 10, 2025, Johnson & Johnson announced positive topline results from the phase 2b ANTHEM-UC study of icotrokinra (JNJ-2113) in adults with moderately to severely active UC. The study met its primary endpoint of clinical response in all icotrokinra dose groups evaluated and demonstrated clinically meaningful differences versus placebo in key secondary endpoints of clinical remission, symptomatic remission, and endoscopic improvement at week 12.

EBX-102-02, A Full-Spectrum Microbiome Drug, Shows Promise for IBS-C in Phase 2a Trial

Phase 2a data from the from the Treating IBS with an Intestinal Microbiota Product for Health (TrIuMPH) trial presented at Digestive Disease Week 2025 suggest EBX-102-02, a next-generation oral full-spectrum microbiome drug, is safe, tolerable, and leads to improvements in IBS-Symptom Severity Scale (IBS-SSS), abdominal pain, and stool consistency in patients with IBS-C.

USMSTF Guidance on Optimizing Bowel Preparation for Colonoscopy

Even with the advent of several new noninvasive testing options, 3 of which were approved by the FDA in 2024 alone, colonoscopy remains the preferred approach for colorectal cancer screening and prevention. However, its effectiveness relies heavily on adequate bowel preparation, with inadequate preparation potentially leading to missed lesions, prolonged procedures, and the need for repeat exams.

New 2025 guidance from the USMSTF provides clinical recommendations to address challenges related to bowel preparation for colonoscopy, focusing specifically on outpatients at low risk for inadequate bowel preparation. In this HCPLive RX Review, Brian Jacobson, MD, MPH, and Joseph Anderson, MD, discuss the nuances of the guidance, potential barriers to its implementation, and areas for future research.