Adalimumab Biosimilar Improved Symptoms for up to 48 Weeks in Ankylosing Spondylitis

In a real-world study in India, patients with ankylosing spondylitis (AS) who were treated with the adalimumab biosimilar Exemptia for 10 weeks showed improvements in disease activity that persisted through 48 weeks.

According to the authors of the study, anti-tumor necrosis factor alpha (TNF) drugs are effective for AS, an autoimmune inflammatory disease affecting the joints of the spine, but their high cost and the risk of infections such as tuberculosis have prevented more widespread use of these biologics in India. The reference adalimumab (Humira) is unavailable in India; however, the biosimilar adalimumab product Exemptia (Zydus) has been marketed there since 2014. The authors conducted the study with the help of a donation of Exemptia by the manufacturer.

Clinical observations of prolonged symptom relief in patients with AS following a shorter-than-standard treatment period with other anti-TNF drugs (infliximab or etanercept) led to the current study. The authors noted that the shorter duration of therapy was effective as well as safer and more acceptable to patients compared to the standard duration when preliminary findings using this short-term protocol were presented at the 2005 Asia Pacific League of Associations for Rheumatology Congress.

The study was an uncontrolled, prospective investigation of a 10-week, 6-injection protocol of adalimumab biosimilar treatment of active chronic symptomatic AS in 50 patients at a community rheumatology clinic in India. None of the patients had been previously treated with anti-TNF drugs. Patients were an average age of 31 and had average disease duration of 99.5 months. Six injections of the biosimilar were administered, once every 2 weeks, and patients were followed for a total of 48 weeks.

Disease activity was evaluated using standard AS questionnaires, such as Ankylosing Spondylitis Response Criteria (ASAS 20), Ankylosing Spondylitis Disease Activity Score, and Bath Disease Activity Index (BASDAI). Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), TNF-alpha, interleukin (IL)-6, and IL-17 were also measured.

Improvement in Pain and Disease Activity, Reduction in NSAID Use

Statistically significant improvements at week 4 were observed in pain Visual Analog Scale (VAS), patient global assessment, Health Assessment Questionnaire, ESR, and CRP. These improvements were significantly different from baseline also at weeks 8, 12, and 48. For example, mean (SD) pain VAS was 5.9 (2.0) at baseline, 3.7 (1.7) at week 4, and 3.9 (2.2) at week 48.

All 50 patients received daily nonsteroidal anti-inflammatory drugs (NSAIDs)for the first 4 weeks, followed by a pro-re-nata regimen determined by their rheumatologist. During weeks 8-12, 9 patients were using NSAIDs daily, and 15 using them as needed. The lowest NSAID use was observed during the week 12 to 24 period, with 4 patients using NSAIDs daily and 14 using them as needed. By week 48, 17 patients were using NSAIDs daily, and 11 used them as needed.

The primary efficacy measure, ASAS 20, indicates at least 20% improvement in 3 of 4 of the following domains and no worsening: patient global assessment, overall pain, function (Bath Functional Index-10 items), and inflammation (mean of BASDAI questions of morning stiffness). ASAS 20 was achieved in 41 (82%) patients at 12 weeks, and ASAS 40 by 35 (70%) patients. The authors reported that more than half of patients achieved an ASAS 20 response at each time point (4, 8, 12, 24, 36, and 48 weeks), and that 21 patients (42%) demonstrated continued improvement in ASAS 20 index from 12 to 36 weeks. Overall, the greatest improvements in efficacy endpoints were observed at week 12. These improvements “persisted, albeit with some decline, until the study’s completion at 48 weeks,” the authors wrote.

None of the patients reported a serious adverse event, and no patients developed symptoms of TB. Ten patients experienced mild adverse events, which “were resolved with standard care.” Eleven patients withdrew from the study, most due to a poor therapeutic response. None of the patients withdrew due to adverse events. One patient required hip arthroplasty after 30 weeks of follow-up.

The authors concluded that 6 injections of biosimilar adalimumab over 10 weeks “demonstrated significant early improvement that often lasted for 24 weeks.” They added that this shorter-term protocol could be economically valuable and “merits further confirmation and acceptance, especially in resource-constrained contexts.”

Reference

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. doi:10.7759/cureus.36444