Meds & Biologics
If your gastroenterologist has recommended a biologic for ulcerative colitis, you are probably staring at a list of drug names and wondering how to make sense of it all. The biologic options for UC have expanded significantly in recent years, with the FDA approving several new therapies in 2024 and 2025 alone. The best biologic for ulcerative colitis depends on your treatment history, disease severity, lifestyle preferences, and how your body responds. No single drug is universally superior. This guide breaks down the major biologic classes, explains what the latest guidelines say about choosing between them, and covers the practical details of infusions, injections, biosimilars, and switching.
How Biologics Work: Four Mechanism Classes
Biologics for UC fall into four main categories based on which part of the immune system they target. Understanding these classes helps you make sense of why your doctor might recommend one drug over another.
Anti-TNF agents (infliximab, adalimumab, golimumab) block tumor necrosis factor-alpha, a protein that drives inflammation. Infliximab (originally branded as Remicade) was the first biologic approved for UC and remains one of the higher-efficacy options for treatment-naive patients according to the AGA's 2024 living guideline. Adalimumab (Humira) and golimumab (Simponi) also target TNF but are classified as intermediate or lower efficacy for UC compared to infliximab.
Anti-integrin therapy (vedolizumab/Entyvio) blocks alpha-4-beta-7 integrin, preventing inflammatory white blood cells from migrating into the gut. Because it acts specifically on gut-homing immune cells, vedolizumab has a favorable safety profile and is also classified as higher-efficacy for biologic-naive patients.
Anti-IL-12/23 therapy (ustekinumab/Stelara) blocks both interleukin-12 and interleukin-23. The 2025 ACG guidelines recommend ustekinumab for induction of remission in moderately to severely active UC, and it performs particularly well in patients who have already tried and lost response to an anti-TNF.
Anti-IL-23 agents (risankizumab/Skyrizi, mirikizumab/Omvoh, guselkumab/Tremfya) selectively block only IL-23. This is the newest and fastest-growing class. Risankizumab received FDA approval for UC in June 2024, mirikizumab was the first in class with approval in October 2023, and guselkumab received FDA approval for UC with a fully subcutaneous regimen in September 2025.
What "Best" Means for Different Patient Profiles
The AGA's living guideline divides biologics into efficacy tiers, and your treatment history changes which tier applies to you. For patients who have never taken a biologic, infliximab, vedolizumab, risankizumab, and guselkumab all fall into the higher-efficacy category. Ustekinumab and mirikizumab are classified as intermediate efficacy in this group. Adalimumab ranks lower.
The picture shifts for patients who have already been exposed to one or more advanced therapies. In that scenario, ustekinumab and upadacitinib (a small molecule, not a biologic) move into higher-efficacy positioning, while vedolizumab drops to lower efficacy. Network meta-analyses published in Clinical Gastroenterology and Hepatology confirm that prior biologic exposure, particularly anti-TNF failure, significantly affects how well subsequent therapies perform.
Other factors beyond efficacy data also shape the choice:
Patients with extraintestinal manifestations (joint pain, skin conditions) may benefit from anti-TNF or anti-IL-23 agents that address inflammation beyond the gut
Patients prioritizing safety and a targeted mechanism may prefer vedolizumab for its gut-selective action
Patients who want to avoid infusion centers entirely can now choose from several self-injectable options, including adalimumab, the subcutaneous formulations of vedolizumab and guselkumab, and the single-injection maintenance regimen for mirikizumab
When Switching Biologics Makes Sense
Switching biologic treatments is common. Research shows that more than half of IBD patients switch their initial biologic within one year. The two main reasons are primary non-response, where the drug never achieves adequate control, and secondary loss of response, where the drug works initially but effectiveness fades over time.
Before switching, your gastroenterologist will likely check drug levels and antibodies through therapeutic drug monitoring. If your blood levels of the biologic are adequate but inflammation persists, the drug mechanism itself may not be right for your disease, and switching to a different class is typically recommended. If drug levels are low because of antibody formation, dose optimization or switching within the same class may be appropriate.
A 2025 retrospective study in Clinical Gastroenterology and Hepatology found reassuring data about switch timing: overlapping switches, where you start the new biologic before the old one has fully cleared, were not associated with increased infection risk compared to non-overlapping transitions.
Biosimilars: Same Drug, Lower Cost
Biosimilars are near-identical copies of biologic drugs that have lost patent exclusivity. For UC patients, biosimilars are now available for three major biologics:
Infliximab biosimilars (Inflectra, Renflexis, Avsola, and others) have been on the market since 2016, with extensive real-world evidence confirming equivalent safety and efficacy
Adalimumab biosimilars (Hadlima, Hyrimoz, Cyltezo, Simlandi, and others) became widely available after Humira's patent exclusion, with newer citrate-free formulations designed to reduce injection-site pain
Ustekinumab biosimilars (Yesintek, Steqeyma, Selardsi, and others) entered the market in late 2024 and throughout 2025, with seven FDA-approved biosimilars creating new pricing competition
Clinical trials and real-world switching studies consistently show that biosimilars perform the same as their reference products. If your insurance or pharmacy switches you to a biosimilar, the evidence supports that this is a safe transition.
What to Expect During Infusions and Injections
Your practical experience with a biologic depends largely on how it is administered. Infliximab requires intravenous infusions, typically lasting two to four hours at a certified infusion center. You will sit in a chair, have an IV line placed, and be monitored throughout. The initial loading schedule involves infusions at weeks 0, 2, and 6, then every eight weeks for maintenance. Fewer than 5% of patients experience infusion reactions such as flushing, itching, or changes in blood pressure, and pre-medication with antihistamines can reduce this risk.
Vedolizumab is also given as a 30-minute IV infusion on a similar schedule, though a subcutaneous self-injection option now exists for maintenance. The IL-23 inhibitors offer the most flexibility: risankizumab starts with IV induction doses and transitions to subcutaneous maintenance injections every eight weeks, while guselkumab and mirikizumab can now be administered entirely by subcutaneous injection from induction through maintenance.
Self-injectable biologics like adalimumab, golimumab, and the subcutaneous formulations of newer drugs are administered at home using prefilled pens or syringes, typically every two to eight weeks depending on the drug and phase of treatment.
Making the Decision With Your Care Team
Choosing a biologic is not a one-time event. It is an ongoing conversation between you and your gastroenterologist, shaped by your disease severity, treatment history, personal preferences about infusions versus injections, insurance coverage, and how your body responds over time. The good news is that the field has moved well beyond a single class of drugs. If the first biologic you try does not work or stops working, there are multiple alternatives across different mechanisms.
Starting or switching a biologic? Track your symptoms from day one with Aidy. Having clear before-and-after data helps your GI evaluate response and adjust treatment if needed.