SAT0531 Acute phase reactant levels and prednisone doses at disease flare in patients with giant cell arteritis: prospective data from the giacta trial
Authors: J.H. Stone, K. Tuckwell, S. Dimonaco, M. Klearman, M. Aringer, D. Blockmans, E. Brouwer, M.C. Cid, B. Dasgupta, J. Rech, C. Salvarani, H. Schulze-Koops, G. Schett, R. Spiera, S.H. Unizony, N. Collinson
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> The relationship between acute phase reactant levels and giant cell arteritis (GCA) disease flares is not known, particularly in the era of interleukin-6 receptor blockade with tocilizumab (TCZ). Prednisone doses at which GCA flares can occur have not been studied thoroughly in prospective clinical trials. <h3>Objectives</h3> Investigate prednisone doses and acute phase reactant levels at the time of disease flare in patients with GCA. <h3>Methods</h3> Secondary analyses of prednisone doses, C-reactive protein (CRP) levels, and erythrocyte sedimentation rate (ESR) were performed for patients who experienced GCA flare after achieving remission during 52 weeks of treatment with TCZ-weekly or -every-other-week+26 week prednisone taper (TCZ-QW or TCZ-Q2W) or placebo +26 week or 52 week prednisone taper (PBO+26 or PBO+52). The last CRP and ESR values before first disease flare were used if values on the day of first flare were missing. Analyses are descriptive and were performed post hoc. <h3>Results</h3> GCA flare after remission was reported in 23% (23/100) of TCZ-QW patients, 26% (13/50) of TCZ-Q2W patients, 68% (34/50) of PBO +26 patients, and 49% (25/51) of PBO +52 patients.<sup>1</sup> Median CRP levels and ESR at the time of flare were lower in the TCZ groups than in the PBO groups (Table). In the TCZ groups, 92% (33/36) of flares were associated with normal CRP levels (≤1 mg/dL) and 89% (32/36) were associated with normal ESR values (&lt;30 mm/h). In the PBO groups, 34% (20/59) of flares were associated with normal CRP values and 31% (18/59) with normal ESR. Median (min–max) prednisone doses at the time of disease flare in the combined TCZ and combined PBO groups were 5.5 (0.0–310.0) and 9.0 (0.0–55.0) mg/day, respectively. Among 149 patients in the TCZ groups, 10 (7%) had disease flares while receiving prednisone doses greater than 10 mg/day, accounting for 28% of all disease flares in the TCZ groups. Among 101 patients in the PBO groups, 23 (23%) had disease flares while receiving prednisone doses&gt;10 mg/day, accounting for 39% of all disease flares in the PBO groups. Thus, 33 of the 95 disease flares in GiACTA (35%) occurred while the patient was receiving ≥10 mg/day prednisone. <h3>Conclusions</h3> Acute phase reactants are not reliable correlates of disease flare in TCZ-treated patients, but approximately one-third of all PBO +prednisone patients also had normal acute phase reactants at the time of disease flare. Median prednisone dose at the time of disease flare for TCZ-treated patients was numerically lower than that of patients treated with PBO +prednisone. One-third of all disease flares in GiACTA occurred while the patient was receiving &gt;10 mg/day prednisone. <h3>Reference</h3> [1] Stone JH, et al. N Engl J Med2017;377:317–328. <h3>Acknowledgements</h3> This study was sponsored by F. Hoffmann-La Roche Ltd. <h3>Disclosure of Interest</h3> J. Stone Grant/research support from: Roche, Genentech, Xencor, Consultant for: Roche, Genentech, Xencor, K. Tuckwell Shareholder of: Roche, Employee of: Genentech, S. Dimonaco Employee of: Roche, M. Klearman Employee of: Genentech, M. Aringer Consultant for: Chugai, Roche, Speakers bureau: Chugai, Roche, D. Blockmans: None declared, E. Brouwer Grant/research support from: Roche, M. C. Cid Consultant for: Roche, Novartis, Boehringer-Ingelheim, B. Dasgupta Consultant for: Roche, GlaxoSmithKline, J. Rech: None declared, C. Salvarani: None declared, H. Schulze-Koops: None declared, G. Schett Grant/research support from: AbbVie, BMS, Celgene, Chugai, GSK, Lilly, Novartis, Roche, Sanofi, UCB, Consultant for: AbbVie, BMS, Celgene, Chugai, GSK, Lilly, Novartis, Roche, Sanofi, UCB, R. Spiera Grant/research support from: Roche/Genentech, Consultant for: Roche/Genentech, S. H. Unizony: None declared, N. Collinson Employee of: Roche