Adalimumab Biosimilar ZRC-3197 Improves Difficult-to-Treat Ankylosing Spondylitis

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Patients who received the biosimilar reported early and significant improvements in areas of pain, NSAIDs requirement, and function.

A 10-week course of an adalimumab biosimilar, ZRC-3197, showed significant early improvement in pain and function in patients with difficult-to-treat ankylosing spondylitis that lasted for up to 1 year, according to a study published in Cureus.1

“Cost and drug toxicity frequently deter the long-term use of anti-tumor necrosis factor (TNF) agents in AS,” a team of Indian investigators stated. “Therefore, this study was conducted to observe long-term relief after the short-term administration of an anti-TNF agent.”

AS, a chronic condition that is often difficult to treat effectively, is usually treated with nonsteroidal anti-inflammatory drugs (NSAIDs). However, biological disease-modifying antirheumatic drugs (bDMARDs) and TNF have been shown to be more effective and better suited for long-term use.2

A prospective, interventional, uncontrolled, single-center trial enrolled 50 TNF-naïve adult patients (42 men and 8 women) with symptomatic active chronic AS currently receiving treatment between June 2016 and July 2018. Patients received 40 mg of ZRC-3197 subcutaneously every 2 weeks for 10 weeks. Most patients were taking etoricoxib (60 mg and 90 mg) prior to enrollment and were allowed to continue treatment during the study. Although patients were responsible for their own medication costs, the biosimilar was provided free of charge to 13 patients and was given to the remainder at a nearly 50% concessional market rate.

Patients who did not achieve the Assessment in Ankylosing Spondylitis Response Criteria (ASAS 20) index response by week 12 either received 2 additional ZRC-3197 injections or continued with routine follow-up. Efficacy was assessed using ASAS response, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Ankylosing Spondylitis Disease Activity Score (ASDAS), and the Indian version of the Health Assessment Questionnaire (HAQ).

The average age of patients was 31.2 years with a disease duration of 99.5 months. Human leukocyte antigen (HLA) B27 was exhibited in most (86%) patients. Patients who received the biosimilar reported early and significant improvements in areas of pain, NSAIDs requirement, and function. At 8 weeks, fewer than 15% of patients required daily NSAIDs and at week 12, 4 of the 9 patients taking daily NSAIDs had an ASAS20 index response.

They also had significant improvements in ASAS20, ASAS40, ASAS partial remission, BASDAI, BASFI, and ASDAS after discontinuing the initial injections. At week 12, 84% achieved ASAS20 improvement and 34% had partial remission. At week 48, 52% retained ASAS20 and 24% had partial remission. At all time points, over half of all patients were able to achieve an ASAS20 response. Continued improvement was observed regarding ASAS20 at week 12, 24, and 36. At week 12, 56% of patients were categorized as inactive or low disease activity and major improvement was observed in 28% of patients at week 48.

Although 10 patients experienced mild adverse events, which were resolved with standard care, there was no adverse event-related treatment discontinuation. The most common adverse events were nasopharyngitis, dermatophytosis, aches and pains, mild uveitis, and itchy eczema.

Investigators noted that the uncontrolled study design, performed at a single center with a small sample size, may have limited the findings. Further, early results may have been partially affected by the placebo effect.

“Short-term use of [the biosimilar] is viable for treating difficult AS in resource-constrained settings like ours,” investigators concluded. “However, more research is needed before it can be accepted as a standard treatment modality for AS.”


  1. Chopra A, Khadke N, Saluja M, Kianifard T, Venugopalan A, Gharia M. The Long-Term Effects of Short-Period Adalimumab Biosimilar Usage in Ankylosing Spondylitis. Cureus. 2023;15(3):e36444. Published 2023 Mar 20. doi:10.7759/cureus.36444
  2. Ward MM, Deodhar A, Akl EA, et al.: American College of Rheumatology/Spondylitis Association of America/Spondyloarthritis Research and Treatment Network 2015 Recommendations for the Treatment of Ankylosing Spondylitis and Nonradiographic Axial Spondyloarthritis. Arthritis Rheumatol. 2016, 68:282-98. 10.1002/art.39298