Drug Update · Rheumatology

FDA Approves Immgolis for RA and UC: 59% ACR20 in Trial RA

August 09, 2026

Drug

Immgolis (golimumab-sldi)

Regulatory action

FDA approval as interchangeable biosimilar to Simponi and Simponi Aria (May 2026)

Primary trial result

ACR20 59% versus 25% (SIM PONI ARIA + MTX vs placebo + MTX) at Week 14 [Trial RA]

Clinical Perspective

This approval affects rheumatologists, gastroenterologists, pharmacists, and other clinicians who treat adult patients with moderately to severely active rheumatoid arthritis and with moderately to severely active ulcerative colitis because Immgolis is now an FDA-designated interchangeable biosimilar to Simponi and Immgolis Intri is interchangeable with Simponi Aria ^[7]^[8]. The source-confirmed data and FDA review indicate analytical, functional, and pharmacokinetic similarity to the reference products, supporting interchangeability determinations for these biosimilars ^[7]. How interchangeability will be implemented locally—by pharmacy substitution policies, payer formularies, and institutional protocols—remains an operational question for clinicians and health systems?

Dr. Deepak Nair · Rheumatology

The FDA approved Immgolis (golimumab-sldi) as an interchangeable biosimilar to Simponi and Immgolis Intri as an interchangeable biosimilar to Simponi Aria for indications that include moderately to severely active rheumatoid arthritis (in combination with methotrexate) and moderately to severely active ulcerative colitis in May 2026 ^[7]^[8]. The decision was supported by analytical and pharmacokinetic similarity data and informed by prior clinical trial evidence for the golimumab program, including Trial RA showing an ACR20 of 59% versus 25% with placebo + MTX at Week 14 ^[7]^[9].

Clinical Context

Golimumab products are human monoclonal antibodies that bind to tumor necrosis factor alpha (TNFα) and inhibit its biological activity, thereby blocking inflammatory signaling described for this class of agents ^[7]^[9]. The FDA has approved Immgolis and Immgolis Intri as the first interchangeable biosimilars to Simponi (subcutaneous golimumab) and Simponi Aria (intravenous golimumab), respectively; the approvals designate interchangeability with those reference products for the indicated adult uses noted by the agency ^[7]^[8]. The regulatory decision was based on the totality of analytical, functional, and pharmacokinetic data showing similarity to the reference products, together with existing clinical data for golimumab products ^[7]. Simponi and Simponi Aria labeling describe approved uses across rheumatology and gastroenterology indications and list safety considerations and common adverse reactions observed with golimumab products ^[2]^[3]^[9].

Key Findings

Trial RA showed SIMPONI ARIA + MTX achieved an ACR20 of 59% versus 25% with placebo + MTX at Week 14 in the multicenter randomized, double-blind, controlled Trial RA (primary endpoint ACR20 at Week 14) ^[9].
The FDA stated that multiple lots and a broad range of product quality attributes confirmed similarity in structural and functional features between Immgolis and Simponi and that a pharmacokinetic similarity study showed comparable exposure and immunogenicity results supporting interchangeability ^[7].
The FDA approval covers Immgolis for the same adult Simponi indications currently approved for the reference product, including moderately to severely active rheumatoid arthritis in combination with methotrexate and moderately to severely active ulcerative colitis ^[7]^[8].

Safety & Tolerability

Serious infections (including tuberculosis, bacterial sepsis, and invasive fungal infections) have occurred with golimumab products and are listed as a boxed warning in the reference product labeling ^[2]^[3]^[4]^[5]^[6].
Malignancy (including reports of lymphoma) has been observed with TNF blockers and is included in boxed warnings and warnings in the reference labeling ^[2]^[3]^[4].
Upper respiratory tract infection is listed among the most common adverse reactions (incidence > 5%) in golimumab labeling and was cited by the FDA as a common expected side effect for Immgolis/Immgolis Intri ^[7]^[2].
Nasopharyngitis is listed among common adverse reactions in reference labeling and mentioned by the FDA for Immgolis/Immgolis Intri ^[7]^[2].
Injection site reactions are listed among common adverse reactions in reference labeling and mentioned by the FDA for Immgolis ^[7]^[2].
Headache is named as an adverse event in clinical sources ^[1]^[9].
Anemia is named as an adverse event in clinical sources ^[1].
Neutropenia is named as an adverse event in clinical sources ^[1]^[3].
Pyrexia is named as an adverse event in clinical sources ^[1].

Study Design

The regulatory approval was granted after FDA review of analytical comparisons, multiple-lot product quality testing, and a pharmacokinetic similarity study showing comparable exposure and immunogenicity for Immgolis versus Simponi; the FDA described the totality of these data as supporting approval and interchangeability ^[7]. Trial RA (a multicenter, randomized, double-blind, controlled trial, NCT00973479) enrolled 592 adult patients with moderately to severely active rheumatoid arthritis despite MTX and used the percentage of patients achieving an ACR20 response at Week 14 as the primary endpoint, with 59% ACR20 in the active group versus 25% with placebo + MTX at Week 14 ^[9].

FAQ

Q1 What is Immgolis (golimumab-sldi) approved for?

Immgolis is approved as an interchangeable biosimilar to Simponi for the treatment of adult patients with moderately to severely active rheumatoid arthritis in combination with methotrexate and for adults with moderately to severely active ulcerative colitis. The FDA also approved Immgolis Intri as an interchangeable biosimilar to Simponi Aria for certain indications. These approvals reflect the agency's determination of biosimilarity and interchangeability for the listed adult indications.

Q2 How does Immgolis (golimumab-sldi) work?

Immgolis is a golimumab product; golimumab is a human monoclonal antibody that binds to both soluble and transmembrane forms of tumor necrosis factor alpha (TNFα). By binding TNFα, golimumab prevents TNFα from interacting with its receptors and inhibits downstream inflammatory signaling that contributes to disease activity in rheumatoid arthritis and ulcerative colitis.

Q3 What is the recommended dose of Immgolis (golimumab-sldi)?

Dosing information for Immgolis was not available in the provided source excerpts. The FDA approval establishes Immgolis as an interchangeable biosimilar to Simponi and Immgolis Intri as an interchangeable biosimilar to Simponi Aria; clinicians should consult the current prescribing information for the biosimilar and reference-product labeling to confirm dosing for specific indications and formulations. Clinicians should consult current prescribing information for full dosing guidance.

Q4 What are the most common side effects of Immgolis (golimumab-sldi)?

The most common expected side effects for Immgolis/Immgolis Intri, consistent with those observed with Simponi and Simponi Aria, include upper respiratory tract infection, nasopharyngitis, and injection site reactions (incidence > 5%). Golimumab products can also cause serious adverse events including serious infections and malignancy; these risks are described in the boxed warnings and safety sections of the reference-product labeling and were cited by the FDA in the approval announcement.

Clinicians should consult current prescribing information for full dosing guidance.

FDA Approves Immgolis for RA and UC: 59% ACR20 in Trial RA

Direct Clinical Takeaway & Evidence Summary

FDA Approves Immgolis for RA and UC: 59% ACR20 in Trial RA

Clinical Perspective

Clinical Context

Key Findings

Safety & Tolerability

Study Design

FAQ

References

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