Efficacy and Safety of Tofacitinib Compared to Cyclophosphamide in Early Diffuse Cutaneous Systemic Sclerosis: A Randomized Controlled Trial

OBJECTIVE: This study aims to determine the efficacy of tofacitinib in the treatment of early diffuse cutaneous systemic sclerosis. MATERIALS AND METHODS: This open-label randomized controlled clinical trial was conducted at the Department of Rheumatology, Bangabandhu Sheikh Mujib Medical University, Dhaka. The trial was registered at ClinicalTrials.gov (identifier: NCT06044844). Consecutive sampling was used in this study. Forty-six patients were randomized to groups A and B using block randomization, with 23 patients in each group. In group A, tofacitinib (5 mg) was administered twice daily. Group B received cyclophosphamide (500 mg/m² monthly). Primary efficacy was assessed by the change in the Modified Rodnan Skin Score (mRSS) from baseline after 24 weeks. Secondary efficacy was assessed by the change in the Disease Activity Score for 28 joints (DAS28) in response to changes in C-reactive protein (CRP) level and erythrocyte sedimentation rate (ESR). The Bangla version of the Health Assessment Questionnaire-Disability Index (B-HAQ) response from baseline to 24 weeks was analyzed. Oral prednisolone (≤10 mg/day), calcium channel blockers, and phosphodiesterase 5 inhibitors (sildenafil and tadalafil) were administered. Follow-up was performed at four, 12, and 24 weeks. History, physical examination, and relevant investigations were used to assess adverse effects. Changes in acute-phase reactants and composite measures within the groups from baseline to 24 weeks were also analyzed. Adverse effects were assessed through patient history, physical examination, and relevant investigations. RESULTS: Per-protocol analysis showed a significantly greater reduction in mRSS in group A compared with group B at 12 weeks (7.0 ± 2.89 vs. 5.26 ± 2.42; p = 0.03) and 24 weeks (10.17 ± 2.92 vs. 8.0 ± 4.08; p = 0.04). DAS28-ESR and DAS28-CRP reductions were significant between the groups from baseline to weeks 12 and 24 (p < 0.05). The reduction in functional status (measured by B-HAQ) was 2.11 ± 4.91 and 0.96 ± 0.53 in groups A and B, respectively (p = 0.43). FVC change was 9.17 ± 8.33 in group A and 3.43 ± 8.1 in group B. Within the other core set of outcomes, composite measures were significantly improved in group A. Two patients (8.7%) in group A and six patients (17.4%) in group B developed nausea. Two patients (8.7%) in both groups developed respiratory tract infections and urinary tract infections. Taeniasis developed in three patients (13%) in group B. Two cyclophosphamide-treated patients (8.7%) developed hemorrhagic cystitis. CONCLUSIONS: Tofacitinib demonstrated significant efficacy in reducing skin thickness (mRSS) in early dcSSc, showing both numerical and statistical advantages over cyclophosphamide at 24 weeks, along with a more favorable safety profile. These findings support further evaluation of tofacitinib as a potential therapeutic option in this patient population.