When you’re living with Crohn’s disease or ulcerative colitis, the goal isn’t just to manage symptoms-it’s to get your life back. For many, conventional treatments like steroids or immunomodulators just don’t cut it. That’s where IBD biologics come in. These aren’t your everyday pills. They’re precision-targeted drugs designed to shut down specific parts of your immune system that are attacking your gut. And since the first one, infliximab, hit the market in 1998, they’ve changed the game for millions.
How IBD Biologics Work
Your immune system is supposed to protect you. But in IBD, it gets confused. It sees your intestinal lining as a threat and launches a constant attack. That’s what causes the pain, diarrhea, bleeding, and fatigue. Biologics don’t suppress your whole immune system like steroids do. Instead, they target one specific molecule involved in the inflammation process.
There are three main types of these targeted drugs:
- Anti-TNF inhibitors block tumor necrosis factor-alpha, a key inflammation signal.
- Anti-integrin therapies stop immune cells from traveling to your gut.
- IL-12/23 inhibitors interrupt the interleukin pathways that drive chronic inflammation.
Each works differently. And each has its own pros, cons, and best-use cases.
Anti-TNF Agents: The First Line, But Not Always the Best
Infliximab (Remicade), adalimumab (Humira), golimumab (Simponi), and certolizumab pegol (Cimzia) were the first biologics approved for IBD. They’re still the most widely used-making up about 65% of the market. If you’ve heard of one biologic, it’s probably one of these.
Infliximab is given as an IV infusion, usually at a clinic. You get doses at weeks 0, 2, and 6, then every 8 weeks after that. Each session takes 2 to 4 hours. Adalimumab, on the other hand, is a self-injected shot you can give yourself every other week after an initial loading phase.
But here’s the catch: while they work fast-often showing results in 2 to 4 weeks-they come with bigger risks. Serious infections, including tuberculosis and fungal infections, are more common with anti-TNFs than with other biologics. The FDA requires special monitoring programs (REMS) for these drugs because of the risk of lymphoma and other cancers.
Studies show infliximab has slightly better efficacy than adalimumab in people who’ve never used a biologic before. One meta-analysis found infliximab was more likely to induce remission and heal the gut lining. But in real life, many patients choose adalimumab because it’s easier to take at home. Convenience matters.
Biosimilars like Inflectra and Cyltezo are now available. They’re nearly identical to the originals but cost 15% to 30% less. That’s a big deal when a single dose of infliximab can run $5,000 or more.
Anti-Integrin Therapies: Gut-Selective, Safer, Slower
Vedolizumab (Entyvio) is the only anti-integrin approved for IBD in the U.S. It works differently. Instead of blocking inflammation everywhere, it stops immune cells from entering the gut. Think of it like a bouncer that only checks IDs at the intestinal door.
This targeting means fewer systemic side effects. No increased risk of brain infections like PML (which happened with natalizumab, another integrin drug used in MS). No higher cancer risk. No need to screen for TB before starting.
But there’s a trade-off: it takes longer to work. Most people don’t feel better until week 6 to 10. That’s tough if you’re in a flare. Still, in patient surveys, vedolizumab gets the highest satisfaction ratings-4.1 out of 5 stars. Why? Because once it kicks in, it works reliably. And side effects? Only 18% of users report them, compared to over 50% with adalimumab.
It’s given as an IV infusion every 8 weeks, same as infliximab. But many patients prefer it because they don’t have to worry about the systemic risks. It’s especially recommended for people with a history of multiple sclerosis, latent TB, or those who’ve had bad reactions to anti-TNFs.
IL-12/23 and IL-23 Inhibitors: The New Kids on the Block
Ustekinumab (Stelara) was the first IL-12/23 inhibitor approved for IBD, hitting the market in 2016 for Crohn’s and 2019 for ulcerative colitis. It blocks two inflammatory proteins-IL-12 and IL-23-that play a big role in chronic gut inflammation.
It’s injected under the skin, either every 8 or 12 weeks depending on your weight. Many patients like it because it’s convenient and has a clean safety profile. It’s often used after anti-TNFs fail.
But the real breakthrough came in 2024 with the FDA approval of risankizumab (Skyrizi) for ulcerative colitis. It’s the first IL-23 inhibitor approved for both Crohn’s and UC. It targets just IL-23-the key driver of inflammation in IBD-without touching IL-12. That makes it even more precise.
Results from the ADVENT trial showed nearly 3 out of 10 patients achieved clinical remission at 52 weeks with risankizumab, compared to just 1 in 10 on placebo. And side effects? Minimal. No major safety red flags.
Mirikizumab (Omvoh), another IL-23 inhibitor, was approved for UC in 2022 and is now being studied for Crohn’s. These drugs are the future. They’re safer, they’re effective, and they’re growing fast-25% annual market growth.
Which One Is Right for You?
There’s no one-size-fits-all answer. Your doctor will look at your disease severity, previous treatments, lifestyle, and personal risks.
Here’s how experts break it down:
- If you have severe, active disease and need fast results: Infliximab is still the top choice. It works quicker than the others.
- If you’re worried about infections or have TB or MS risk: Vedolizumab is safer. No systemic immune suppression.
- If you hate infusions and want to inject at home: Adalimumab or ustekinumab might be better. But be ready for injection site reactions.
- If you’ve tried anti-TNFs and they didn’t work: Switch to vedolizumab or an IL-23 inhibitor. Many patients respond even after failing TNF blockers.
- If you have psoriasis along with IBD: Avoid anti-TNFs-they can make psoriasis worse. Vedolizumab or ustekinumab are preferred.
And here’s something most patients don’t realize: you don’t have to stay on the same drug forever. About 30% of people need to switch to a different biologic class within five years. That’s why knowing your options matters.
Cost, Convenience, and Real-Life Challenges
These drugs are expensive. A single dose of vedolizumab can cost $5,500. Ustekinumab runs around $7,200. But most patients pay far less thanks to manufacturer assistance programs. Janssen, AbbVie, and Takeda all offer co-pay cards and free drug programs for eligible patients. Many end up paying $0 to $5 per infusion or injection.
Still, 41% of patients say out-of-pocket costs are a major burden-even with insurance. And 63% would switch therapies just to avoid going to a clinic for infusions.
Infusion therapy means 3 to 5 hours every 8 weeks. That’s time off work, childcare arrangements, transportation. Self-injectables give you control-but they come with their own stress. About 22% of patients develop injection anxiety. Some need counseling to get through it.
Another issue: losing response over time. About 6% to 25% of people on anti-TNFs develop antibodies that make the drug stop working. The fix? Increasing the dose or adding an immunomodulator like azathioprine. The SONIC trial showed combining them cuts antibody formation by half.
What’s Next?
The future of IBD treatment is personalization. Researchers are looking at biomarkers-blood tests or stool markers-that can predict which drug will work best for you before you even start.
Upcoming drugs like etrolizumab (another anti-integrin) are in late-stage trials. Early data shows 35% of UC patients achieved remission after a year. That’s promising.
By 2028, IL-23 inhibitors like risankizumab could make up 30% of the biologic market. But anti-TNFs won’t disappear. They’re still the go-to for the most aggressive cases.
What’s clear is this: we’re moving away from trial-and-error. We’re moving toward choosing the right drug for the right person at the right time.
What You Should Do Now
If you’re on a biologic:
- Keep up with vaccinations. Get your flu shot, pneumonia vaccine, and shingles vaccine before starting-or if you’re already on one.
- Track your symptoms. Use an app like MyTherapy. 68% of users say it helps them stick to their schedule.
- Know the signs of infection: fever, chills, cough, unusual fatigue. Call your doctor right away.
- Ask about financial help. Don’t assume you can’t afford it. Most manufacturers have programs that cut costs drastically.
If you’re considering a biologic:
- Ask your doctor: “Which drug has the strongest evidence for my type of IBD?”
- Ask: “What are the risks specific to my health history?”
- Ask: “How will this affect my daily life?” Infusions? Injections? Monitoring?
IBD biologics aren’t magic. But for many, they’re the difference between being stuck at home and being able to travel, work, or play with your kids again. The right one can give you back your life. And with new drugs coming every year, the best is yet to come.
What are the most common side effects of anti-TNF biologics?
The most common side effects include infections (like colds, sinus infections, or urinary tract infections), injection site reactions (for adalimumab and certolizumab), and infusion reactions (for infliximab and golimumab). More serious risks include tuberculosis reactivation, fungal infections, lymphoma, and worsening heart failure. These are rare but require monitoring before and during treatment.
Can I switch from one biologic to another if the first one stops working?
Yes, switching is common. About 30% of patients need to switch to a different biologic class within five years. If an anti-TNF stops working, switching to vedolizumab or an IL-23 inhibitor like risankizumab often works well-even if you’ve failed a TNF blocker before. The mechanism is different, so your body may respond.
Why is vedolizumab considered safer than anti-TNF drugs?
Vedolizumab only blocks immune cells from entering the gut, not the whole body. That means it doesn’t increase the risk of serious infections like TB, or cancers like lymphoma, which are linked to anti-TNFs. It also doesn’t cross the blood-brain barrier, so there’s no risk of PML-a rare but deadly brain infection seen with another integrin drug used for MS.
How long does it take for biologics to start working?
Anti-TNFs usually start working in 2 to 4 weeks. Vedolizumab and ustekinumab take longer-typically 6 to 10 weeks. IL-23 inhibitors like risankizumab may show improvement around week 8, with full effects at 12 to 16 weeks. Patience is key. Don’t stop treatment just because you don’t feel better right away.
Are biosimilars as good as the original biologics?
Yes. Biosimilars like Inflectra and Cyltezo are highly similar to the original drugs-infliximab and adalimumab-with no meaningful differences in safety or effectiveness. They’ve been studied in thousands of patients and approved by the FDA. The main advantage is cost: they’re 15% to 30% cheaper, which helps patients and the healthcare system.
Can I get vaccinated while on a biologic?
Yes-but timing matters. You should get all age-appropriate vaccines (flu, pneumonia, shingles, HPV, etc.) before starting a biologic. Live vaccines (like MMR or varicella) are not safe once you’re on treatment. Inactivated vaccines are fine and recommended. Always check with your doctor before getting any shot.
What’s the difference between IL-12/23 and IL-23 inhibitors?
Ustekinumab blocks both IL-12 and IL-23, two related proteins involved in inflammation. Risankizumab and mirikizumab block only IL-23. Since IL-23 is the main driver of IBD inflammation, targeting it alone may be more precise and potentially safer. Early data suggests IL-23 inhibitors have even lower infection rates and better long-term outcomes.
Do I need to take biologics forever?
Most people stay on biologics long-term because stopping often leads to flare-ups. Some patients who achieve deep, sustained remission may try to taper under close supervision, but relapse rates are high. For now, ongoing treatment is the standard. Research is ongoing into whether certain biomarkers can predict who might safely stop.
