Tysabri and Omvoh represent very different positions in the Crohn's biologic landscape. Omvoh (mirikizumab) is the newest IL-23 p19-selective biologic for Crohn's, approved in January 2025 based on VIVID-1. Tysabri (natalizumab) is an integrin-blocking biologic restricted by the TOUCH program due to progressive multifocal leukoencephalopathy (PML) risk and typically reserved for refractory cases. This guide walks through the tysabri vs omvoh crohn's comparison.
Integrin vs IL-23 p19 Mechanism
Tysabri binds alpha-4 integrin, blocking lymphocyte trafficking to both gut and brain tissue. Omvoh binds the p19 subunit of interleukin-23, selectively blocking IL-23 signaling while preserving IL-12. IL-23 is a central driver of Th17-mediated inflammation in Crohn's. The natalizumab vs mirikizumab distinction is foundational: Tysabri's broad integrin mechanism creates PML risk, while Omvoh's selective IL-23 blockade produces a favorable safety profile.
Crohn's Efficacy
Omvoh's Crohn's efficacy rests on VIVID-1, a three-arm trial comparing mirikizumab with placebo and with ustekinumab (Stelara). VIVID-1 showed mirikizumab superior to placebo on co-primary endpoints of clinical remission and endoscopic response, with a key secondary endpoint establishing non-inferiority to Stelara. Tysabri's Crohn's efficacy rests on ENACT-1, ENACT-2, and ENCORE. No head-to-head trial has directly compared Tysabri with Omvoh in Crohn's. Indirect comparisons suggest Omvoh produces strong response in biologic-naive and biologic-experienced Crohn's patients. Tysabri is typically reserved for patients refractory to Omvoh and other biologic classes.
PML Risk and TOUCH Program
Tysabri carries a black-box warning for PML. The TOUCH program requires enrollment, JC virus antibody testing, routine monitoring, and prescriber/pharmacy/infusion center certification. Most gastroenterologists reserve Tysabri for Crohn's patients who have failed multiple other biologic classes and who test negative for JC virus antibodies. Omvoh has no such restricted access program.
Omvoh Safety Profile
Omvoh's Crohn's safety data from VIVID-1 has been favorable, consistent with IL-23 p19 class effects. Long-term data for IL-23 p19 biologics consistently shows low rates of serious systemic infection and malignancy. For tysabri vs omvoh side effects, Omvoh is the clear winner for patients with infection concerns, cancer history, or complex comorbidities.
Refractory Crohn's Biologic
For refractory Crohn's patients who have failed anti-TNFs, Stelara, and other biologic classes, both Tysabri and Omvoh can be considered. Omvoh is generally tried first because of its favorable safety profile and head-to-head data against Stelara in VIVID-1. Tysabri is reserved for patients who have failed Omvoh and who test JC virus antibody negative. For refractory crohn's biologic selection, treatment algorithms typically place Tysabri last.
Administration and Dosing
Tysabri is administered as a 300 mg IV infusion every 4 weeks at a TOUCH-certified infusion center, per Biogen's prescribing information. Omvoh for Crohn's uses IV induction at 900 mg every 4 weeks for three doses (weeks 0, 4, and 8), followed by subcutaneous maintenance at 300 mg every 4 weeks (administered as two 150 mg injections), per Lilly's prescribing information. Omvoh transitions patients to SC maintenance after IV induction, eliminating ongoing infusion center visits. Tysabri requires lifelong monthly IV infusions at a TOUCH-certified center.
When Tysabri Might Be Considered
For Crohn's patients who have failed multiple biologic classes including Omvoh, Tysabri may be considered, particularly in patients who test negative for JC virus antibodies. This is a narrow population, and shared decision-making with a gastroenterologist experienced in refractory Crohn's is essential.
Anti-TNF Experienced Patients
For Crohn's patients with prior anti-TNF exposure, Omvoh's VIVID-1 included biologic-experienced patients and showed meaningful response. Tysabri also has efficacy in biologic-experienced patients, but the PML risk typically drives clinicians to try mechanism-class alternatives like Omvoh, Skyrizi, Tremfya, Stelara, or Entyvio before Tysabri.
Biosimilar Availability
Omvoh is branded with no biosimilar. Tysabri has a biosimilar (Tyruko) approved in 2023, though real-world utilization in IBD remains low given TOUCH program requirements apply equally to biosimilars.
Practical Access
Omvoh can be administered at a variety of infusion centers for induction, and SC maintenance can be self-administered at home. Tysabri requires infusion at a TOUCH-certified center. For patients with complex schedules or geographic barriers, Omvoh's accessibility is a practical advantage.
Choosing With Your GI
For a Crohn's patient deciding between Tysabri and Omvoh, Omvoh is preferred for most patients because of its established efficacy (including head-to-head data against Stelara in VIVID-1), favorable safety profile, SC maintenance after IV induction, and absence of TOUCH program restrictions. Tysabri is a niche option reserved for patients who have exhausted other biologic classes including Omvoh and who test JC virus antibody negative. If you are considering Tysabri, ask your GI about JC virus antibody status, prior treatment history, and the specific risk-benefit rationale. A log of stool frequency, urgency, abdominal pain, and any new neurological symptoms between visits is particularly important for patients on Tysabri.
This article is for educational purposes and is not medical advice. It is researched against current AGA clinical guidelines and peer-reviewed sources. Always discuss treatment decisions with your care team.