Biosimilars for Stelara: An IBD Patient Guide

Stelara treatment for Crohn's disease uses an intravenous induction dose followed by subcutaneous maintenance injections. A biosimilar transition can therefore affect the infusion order, the self-injected prescription, or both. FDA-approved biosimilars must be highly similar to Stelara, with no clinically meaningful differences in safety or effectiveness. The practical work is identifying the exact ustekinumab product, keeping the correct dose and schedule, and making sure both phases of treatment are authorized.

The eight Stelara biosimilars and their manufacturers

As of August 2026, the FDA biosimilar product list names eight ustekinumab biosimilars referencing Stelara: Wezlana, Selarsdi, Pyzchiva, Otulfi, Imuldosa, Yesintek, Steqeyma, and Starjemza. Their FDA applicants are Amgen, Alvotech, Samsung Bioepis, Fresenius Kabi, Accord BioPharma, Biocon, Celltrion, and Bio-Thera Solutions, respectively. Applicant names may differ from the company that markets or distributes a product, so use the brand name and four-letter suffix when checking a prescription or claim.

FDA approval and local inventory answer separate questions, and each infusion center or specialty pharmacy chooses what it stocks. The Purple Book record for Imuldosa, for example, lists both an intravenous vial and subcutaneous prefilled syringes. Ask which brand will be used for induction and maintenance, because a plan or provider may handle those presentations through different channels.

What remains the same after a switch

The reference drug and its biosimilars target the same biological pathway and provide the same expected clinical benefits for approved uses. The FDA patient guide explains that an approved biosimilar has the same strength, dosage, treatment benefits, and potential side effects as its reference product. For adult Crohn's disease, the Imuldosa prescribing information uses a weight-based intravenous induction dose followed by a 90 mg subcutaneous dose eight weeks later and every eight weeks thereafter.

Interchangeability is a separate FDA designation governing substitution under applicable state law. Every biosimilar follows the same FDA standard of clinical quality. Imuldosa, Otulfi, and Starjemza are examples with interchangeable designations in their current Purple Book records. The live database should be checked for the exact presentation because regulatory status can change.

What the early switching evidence shows

Ustekinumab biosimilars arrived later than infliximab and adalimumab biosimilars, so the real-world IBD evidence base is younger. A 2025 prospective study of 81 patients with IBD followed a switch from originator ustekinumab to a biosimilar. The researchers reported stable clinical and laboratory measures and 95 percent treatment persistence at 24 weeks. Longer follow-up and experience with more products will add detail. The study is consistent with the FDA standard of no clinically meaningful difference.

Keep a pre-switch record of bowel symptoms, recent biomarkers, dose timing, and any drug-level testing ordered by the gastroenterology team. After the change, record the full product name, injection dates, device experience, and any new symptoms. Compare the delivery label with the prescription before the first maintenance injection. If the syringe or injector changes, request training from the specialty pharmacy and review the manufacturer instructions. Refill planning is especially important when an authorization change coincides with the eight-week dosing interval. The ustekinumab label includes warnings about infections, malignancies, hypersensitivity reactions, and certain neurologic and pulmonary conditions, so urgent or unusual symptoms should be discussed with the treating clinician.

Insurance implications of Stelara biosimilars

The intravenous induction and injected maintenance dose may be billed differently. Medicare Part B generally covers biological products administered incident to a physician's service, and CMS publishes separate biosimilar payment information. A self-injected maintenance product may instead be managed by a pharmacy benefit and specialty pharmacy. Commercial plan rules vary, so confirm the benefit, provider, pharmacy, billing code, and authorization for each phase.

A plan may prefer a biosimilar while the infusion center or specialty pharmacy stocks another. Before a transition, ask whether both prescriptions need new prior authorizations, whether the maintenance device or concentration changes, and what the deductible, copay, or coinsurance will be. The Crohn's & Colitis Foundation biosimilar guide recommends confirming the effective date, cost, supply source, and appeal options. Coordinating the medical and pharmacy sides before the next scheduled dose helps prevent an administrative gap in treatment.

Request written confirmation for both the induction or re-induction order and the maintenance prescription when relevant. The insurer should identify its preferred brand, the authorized provider or pharmacy, the approval dates, and the patient's expected share. Share the response with the gastroenterology office so it can reconcile a mismatch before the dose is due. Keep call reference numbers and shipment records with the authorization because two-benefit coordination can otherwise leave each party waiting for another to act.