Abstract: Objective: The spectrum of GCA includes various vascular phenotypes. Tocilizumab (TCZ) is the only biologic therapy currently approved, regardless of phenotype. We aimed to assess the effectiveness of TCZ in various phenotypes.
Methods: This is a multicentre observational study of GCA patients treated with TCZ. They were divided into three phenotypes: (i) cranial (cGCA), (ii) extracranial GCA (ecGCA) and (iii) mixed GCA (mixGCA). Outcomes included clinical remission, EULAR complete remission, relapses, absence of inflammation as shown using imaging techniques, and safety.
Results: We studied 471 patients (342 women; mean age 74.0 ± 9.0 years). The phenotypic distribution was: cGCA (n = 217; 46%), mixGCA (174; 37%) and ecGCA (80; 17%). Patients with ecGCA were younger (66.5 ± 10.1 years) than those with cGCA (74.8 ± 8.1) and those with mixGCA (71.4 ± 8.5), and had a longer delayed GCA diagnosis {median [interquartile range (IQR) [6 (1-14)] vs 1 (1-3) vs 2 (1-6) months, respectively}. Systemic manifestations were similar in the three groups, while ischaemic manifestations were more frequent in cGCA. Combined TCZ, in addition to glucocorticoids, was used more frequently in ecGCA (36%). Clinical remission was observed in 51%/43%/47% in cGCA/ecGCA/mixGCA, respectively, after the first month, and in 79%/81%/89% after 24 months. Complete EULAR remission in 35%/27%/28% (after 1 month) and 72%/73%/67% (after 24 months). Absence of inflammation being shown in the imaging techniques was 15%/26% after 12 months, and 22%/7% (ecGCA/mixGCA) (after 24 months). Relevant adverse events were observed in 109 (23.1%) patients.
Conclusion: TCZ shows rapid and maintained effectiveness in all GCA phenotypes in clinical remission and EULAR complete remission. By contrast, absence of inflammation as shown using imaging techniques was much lower in ecGCA and mixGCA.
