Tremfya reimbursed for inflammatory bowel disease

Its dual mechanism of action a strength…seeks endoscopic and histologic healing

Secures long-term clinical data in clinical trials… expectations rise for deep remission

As treatment goals for inflammatory bowel disease (IBD) continue to evolve beyond symptom control toward endoscopic and histologic healing, reimbursement for the interleukin (IL)-23 inhibitor Tremfya has expanded therapeutic options for patients.

Despite the introduction of various biologic therapies, experts noted that many patients still fail to achieve optimal disease control, underscoring the need for new treatment strategies aimed at achieving deep remission and long-term disease control.

On June 30, Janssen Korea held a press briefing to commemorate the reimbursed launch of Tremfya(guselkumab), an IL-23-targeting biologic, for the treatment of IBD.

Since the 1st, Tremfya has been reimbursed under the National Health Insurance system for patients with moderately to severely active Crohn's disease and ulcerative colitis. The therapy can now be used as a first-line biologic treatment option in patients who have shown an inadequate response or intolerance to conventional therapy, or for whom standard treatment is contraindicated.

Professor Sung Ae Jung, Department of Gastroenterology and Hepatology, Ewha Womans University Seoul Hospital

IL-23 is a cytokine known to play a key role in the inflammatory processes underlying both Crohn's disease and ulcerative colitis. As a result, several antibody therapies have been developed to block IL-23 activity, all of which target IL-23’s p19 subunit.

Tremfya’s strength lies in its dual-action mechanism, which adds additional immune cell targeting to its existing mechanism of action.

It is the only IL-23 inhibitor that directly targets CD64-positive immune cells, which produce IL-23. The antibody's Fab region binds to the p19 subunit of IL-23 to block inflammatory signaling, while its Fc region binds to receptors on CD64-positive immune cells, suppressing their activation and function.

In other words, Tremfya not only blocks the inflammatory signaling molecule itself but also inhibits the activity of the cells responsible for producing it. According to experts, this dual mechanism represents a unique advantage not shared by other IL-23 p19 inhibitors.

Inflammatory bowel disease, which includes Crohn's disease and ulcerative colitis, is a chronic inflammatory disorder of unknown cause affecting the gastrointestinal tract. The disease is characterized by chronic and recurrent relapses, and due to the nature of the disease, it presents in various forms and severities.

Although advances in medical technology have improved the treatment landscape through the introduction of multiple biologic therapies, the chronic nature of IBD and its need for long-term management means that a substantial need for new therapeutic options remains.

Sung Ae Jung, Professor of Gastroenterology and Hepatology at Ewha Womans University Seoul Hospital (President, Korean Association for the Study of Intestinal Diseases), said, "Treatment goals for IBD have evolved from simply improving symptoms to achieving deep remission, including endoscopic and histologic healing, and ultimately modifying the course of the disease. However, despite the introduction of various therapies, approximately half of patients still fail to reach optimal treatment outcomes."

She added, "Novel therapies with new mechanisms of action like Tremfya are expected to play a significant role in addressing these unmet medical needs."

Professor Seong Noh Hong, Department of Gastroenterology, Samsung Medical Center

In the Phase II/III GALAXI study, Tremfya demonstrated superiority over Stelara (ustekinumab) across multiple endoscopic endpoints in patients with Crohn's disease. In particular, the therapy achieved deep remission, meeting both clinical remission and endoscopic remission endpoints.

In the Phase III QUASAR study, Tremfya also demonstrated clinical value in ulcerative colitis by achieving not only endoscopic remission but also histologic healing.

Tremfya also demonstrated durable efficacy in the long-term results of both studies.

Specifically, in the QUASAR study, approximately 95% of patients remained on treatment through Week 92. At that time, clinical remission rates were 74% in the Tremfya 200 mg group and 71% in the 100 mg group. Endoscopic remission rates were 34% and 35%, respectively, while histologic remission rates reached 66% and 67%.

The long-term GALAXI extension study also confirmed a safety profile consistent with that observed in the drug's previously approved indications.

Seong Noh Hong, Professor of Gastroenterology at Samsung Medical Center (Chair, IBD Research Committee, KASID), said, "Tremfya achieved deep remission by simultaneously demonstrating meaningful endoscopic and clinical remission rates in Crohn's disease. It has also met key efficacy endpoints in ulcerative colitis, garnering attention as a promising new treatment option for IBD."

Hong added, “The recently reported long-term extension data also demonstrated consistent efficacy over time. These findings suggest that Tremfya could contribute to treatment strategies aimed at achieving deep remission from the early stages of disease management."