Efficacy and safety evaluation of tocilizumab in adult systemic sclerosis

Systemic sclerosis is a rare disabling autoimmune disease with few treatment options. Recently, Khanna D of the University of Michigan in the United States conducted a phase II randomized double-blind placebo-controlled trial (faSScinate) to evaluate tocilizumab (IL-6 receptor alpha inhibitor) in patients with systemic sclerosis (SSc) In the efficacy and safety.

Researchers conducted a double-blind, placebo, controlled study in 35 hospitals in Canada, France, Germany, the United Kingdom and the United States, recruiting from the first signs or symptoms of non-Raynaud phenomenon to progressive systemic behavior within 5 years Adult patients with sclerosis. Patients were randomly assigned (1:1) to receive weekly subcutaneous injections of tocilizumab 162 mg or placebo. The primary endpoint was the difference in the mean change of the modified Rodnan skin score from baseline at 24 weeks.

The results showed that 87 patients were included in the study: 43 patients were treated with tocilizumab, and 44 patients were treated with placebo. At 24 weeks, the least squares mean change of the modified Rodnan skin score in the tocilizumab group was -3.92, and that of the placebo group was -1.22 (difference -2.70, 95% CI -5.85～0.45; P=0.0915). At 48 weeks, the least squares mean change of patients in the tocilizumab group was -6.33, and that of the placebo group was -2.77 (treatment difference -3.55, 95% CI -7.23～0.12; P=0.0579). Exploratory analysis showed that at 48 weeks, fewer patients in the tocilizumab group had a decreased percentage of forced vital capacity than the placebo group (P=0.0373). However, the researchers did not observe significant differences between the two groups in terms of the severity of disability, fatigue, itching, and overall clinical disease. Adverse events occurred in 42 patients (98%) in the tocilizumab group and 40 patients (91%) in the placebo group. Serious adverse events occurred in 14 patients (33%) and 15 patients (34%), respectively. Serious infections in the tocilizumab group (7 cases, 16%) were more common than the placebo group (2 cases, 5%). The death of one patient was related to tocilizumab treatment.

The study showed that tocilizumab did not significantly reduce skin thickening. However, the difference in modified Rodnan skin scores in the tocilizumab group was greater than that in the placebo group, and the researchers found some evidence of reduced forced vital capacity. Before reaching a clear conclusion on the risks and benefits of tocilizumab, its efficacy and safety should also be observed in phase III clinical trials.