IBD Treatment Landscape: From 5-ASA to Advanced Therapies

Inflammatory bowel disease (IBD) treatments range from older anti‑inflammatory pills to targeted biologics and small molecules. Therapy choice depends on disease severity, location, and risk of complications. Modern care favors clear targets and timely escalation when needed. This overview explains each medication class and how clinicians sequence them to reach and maintain remission. It aligns with recent U.S. guidelines and approvals.

Key takeaways

• For moderate to severe ulcerative colitis (UC), guidelines favor early use of advanced therapies rather than slow step‑up after failure. (gastro.org)

• For Crohn’s disease, mesalamine is not effective; many patients benefit from early advanced therapy. (gi.org)

• Steroids calm flares but should be short term, with a plan to transition to steroid‑free maintenance. (medscape.com)

• Multiple advanced classes are available: anti‑TNF, anti‑integrin, IL‑12/23 and IL‑23 inhibitors, JAK inhibitors, and S1P modulators. Recent U.S. approvals expanded options. (gastro.org)

• Care follows treat‑to‑target: symptom control plus healing on labs and scope, checked on a schedule. (pubmed.ncbi.nlm.nih.gov)

The medication classes at a glance

How therapies are sequenced

1) Start with disease severity and risk

• Mild UC often begins with oral and rectal 5‑ASA. If targets are not met within weeks, escalate to systemic therapy. For moderate to severe UC, the American Gastroenterological Association (AGA) favors starting an advanced therapy rather than waiting through multiple failures. (gastro.org)

• For Crohn’s, mesalamine is discouraged. Mild ileocecal disease may use budesonide for induction. Many with moderate to severe or high‑risk Crohn’s start an advanced therapy earlier to prevent complications. (gi.org)

2) Choose a class that fits the person and the problem

• Anti‑TNF agents have broad effectiveness and can work quickly. Combining infliximab with a thiopurine lowers immunogenicity and can raise remission rates compared with either alone. Subcutaneous infliximab is FDA‑approved for maintenance after IV induction. (pubmed.ncbi.nlm.nih.gov)

• Vedolizumab is gut‑selective, useful when infection risk is a concern. Subcutaneous maintenance is available after IV induction for UC and Crohn’s. (takeda.com)

• IL‑23 pathway therapies expanded rapidly. Mirikizumab is approved in UC and Crohn’s. Guselkumab is approved in UC and Crohn’s, including subcutaneous options. Risankizumab is approved in Crohn’s and, as of 2024, in UC. These offer effective, often durable control. (investor.lilly.com)

• JAK inhibitors are oral and fast. Tofacitinib is for UC. Upadacitinib is approved for UC and Crohn’s and can induce remission within weeks. These require screening and risk discussion for infections, clots, and cardiovascular events. (fda.gov)

• S1P modulators are oral options for UC maintenance. They need first‑dose heart checks and eye exams in selected patients. (gastro.org)

3) Induction, then maintenance

• Steroids (prednisone or budesonide) induce control but should be tapered and stopped. A maintenance therapy must be in place to stay well without steroids. (medscape.com)

• Maintenance is usually with the same advanced agent used for induction. Some agents switch from IV induction to subcutaneous maintenance for convenience. (takeda.com)

4) If response is inadequate, adapt quickly

• Use therapeutic drug monitoring with biologics to decide between dose optimization, adding an immunomodulator, or switching. If failure is pharmacokinetic, optimize the same class; if mechanistic, switch to a different class. (See the separate TDM article.)

• Switching within or across classes is common. Biosimilars, including subcutaneous infliximab, expand options and access. (prnewswire.com)

5) Treat‑to‑target and safety steps

• Targets include symptom relief, normalized biomarkers, and endoscopic healing, checked on a timeline, then monitored long term. (pubmed.ncbi.nlm.nih.gov)

• Before immunosuppression, update vaccines and screen for infections such as tuberculosis and hepatitis B. (See the Infection Prevention Vaccinations guide.)

FAQs

When is 5‑ASA used

Primarily for mild UC. It is not effective for Crohn’s disease and is no longer recommended there. (gi.org)

What does “step‑up” versus “top‑down” mean

Step‑up starts with simpler drugs, then escalates. Top‑down starts earlier with advanced therapy in higher‑risk disease. Newer Crohn’s guidance supports earlier advanced therapy in appropriate patients. (gi.org)

Which advanced therapies are oral

Upadacitinib and tofacitinib (JAK inhibitors) and the S1P modulators ozanimod and etrasimod are oral. Upadacitinib is approved for both UC and Crohn’s. The others are approved for UC. (fda.gov)