OP0283 LONG-TERM EFFICACY OF TOCILIZUMAB MONOTHERAPY AFTER ULTRA-SHORT GLUCOCORTICOID ADMINISTRATION TO TREAT GIANT CELL ARTERITIS: THREE YEAR FOLLOW-UP OF THE GUSTO TRIAL
Authors: L. Christ, L. Seitz, G. Scholz, F. Kollert, S. Reichenbach, P. Villiger
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> The GUSTO (Giant cell arteritis (GCA) treatment with Ultra-Short glucocorticoids (GC) and TOcilizumab (TCZ)) trial was set up to evaluate the efficacy and safety of a 52-week TCZ-monotherapy after a 3-day GC-pulse in new-onset GCA [1]. <h3>Objectives:</h3> The presented data show the maintenance effect of the GUSTO protocol over 3 years of drug-free remission and the effectiveness or retreatment with TCZ after relapse. Data up to week 208 are presented. <h3>Methods:</h3> Eighteen patients with newly diagnosed GCA were enrolled in this investigator-initiated, single-arm, single-center, open-label clinical trial. Patients received 500 mg methylprednisolone intravenously for 3 consecutive days. Thereafter, GC treatment was discontinued and TCZ (8 mg/kg bodyweight) was administered intravenously, followed by weekly subcutaneous TCZ injections (162 mg) from day 10 until week 52. Patients in clinical remission stopped TCZ at week 52 and entered the follow-up study. Maintenance of efficacy at week 208 included the proportion of patients with complete lasting remission of disease at week 208, and time to first relapse after week 52. <h3>Results:</h3> Median age was 72 (range 67-75) years at inclusion and 12/18 patients were female. Fifteen out of 18 patients complained of cranial symptoms (10/18 jaw claudication, 6/18 visual symptoms), 10/18 suffered from polymyalgia rheumatica symptoms, 16/18 had positive ultrasound findings of the cranial arteries, and in 13/18 patients temporal arterial biopsies showed a characteristic histopathology. At week 52, 13/18 patients were in relapse-free remission and entered the follow-up study. One out of 13 patients presented with a minor relapse at week 72 and another minor relapse at week 187. In both cases, remission was achieved after restart of TCZ-monotherapy. A second patient presented with a minor relapse at week 200. Remission was achieved after restart of TCZ-monotherapy. At week 208, 11/18 patients were in relapse-free remission. <h3>Conclusion:</h3> After a 3-days pulse of methylprednisolone followed by 52 weeks of TCZ monotherapy, drug-free remission was maintained until week 208 in all but two patients entering long-term extension (11/13, 85%). This relapse rate is substantially lower than reported in the randomised-controlled trials [2,3]. Patient characteristics (exclusively new diagnoses), and the intensive initial treatment consisting of a 3-day GC pulse, immediately followed by TCZ may explain the lasting remission. The data argue for the use of TCZ in newly diagnosed cases and they propose larger studies to define the effect of a treatment start with pulse GC therapy. <h3>REFERENCES:</h3> [1] Christ, et al. Lancet Rheumatology, 2021. [2] Villiger, et al. Lancet, 2016. [3] Stone, et al. NEJM, 2017. <h3>Acknowledgements:</h3> We thank Sabine Hasler, Andrea Ziörjen Kipfer, Barbara Strehler, and Astrid Zbinden for their outstanding support in conducting of the study. We would like to thank Lukas Bütikofer for his excellent statistical support. <h3>Disclosure of Interests:</h3> Lisa Christ Vifor, Gilead Sciences and F. Hoffmann-La Roche Ltd, Bristol-Myers Squibb and Novartis, Gilead Sciences, F. Hoffmann-La Roche Ltd, and Pfizer, Luca Seitz: None declared, Godehard Scholz: None declared, Florian Kollert Roche, Roche, BMS, Actelion, Boehringer-Ingelheim, Pfizer, Roche, Gilead, Pfizer, Stephan Reichenbach: None declared, Peter Villiger F. Hoffmann-La Roche, F. Hoffmann-La Roche, MSD, Abbvie, Grünenthal, Vifor, GSK and Astra-Zeneca.