THU0584 RHEUMATOLOGICAL IMMUNE-RELATED ADVERSE EVENTS ASSOCIADTED WITH IMMUNOTHERAPY IN SOLID ORGAN TUMOR. STUDY OF 102 CASES FROM A REFERRAL SINGLE CENTER FOR LAST 4 YEARS

Background Immune checkpoint blockade therapy (ICBT) currently is one of the most used therapies against cancer. The activation of the immune system can lead to different immune-related adverse events (irAEs), being the rheumatological side effects among the most common. Objectives Our aim was to assess the rheumatological irAEs in patients who received immunotherapy. Methods We set up an observational study of patients treated with Nivolumab and Pembrolizumab (anti-PD1), Atezolizumab (anti-PD-L1) and Ipilimumab (antiCTLA-4) for solid organ tumors. All these patients were followed in a single reference University Hospital from March-2015 up to December-2018. The main outcome was to determinate the incidence of rheumatological irAEs. Results We studied 102 patients (63♂/39♀) with a mean age of 60.6±9.7 with different solid organ tumors. Only 7 patients (6.8%) had a previous diagnosis of an immune-mediated disease: psoriasis (n=2), psoriatic arthritis (1), systemic lupus erythematosus (1), spondyloarthitis (1), rheumatoid arthritis (1) and skin lupus (1). Rheumatological side effects were observed in 15 patients (14.7%): inflammatory arthralgia (8), arthritis (6), myositis (2) and aortitis (1). The time of appearance of the rheumatological irAEs was of 6.36 months (±5.81). From the 7 patients with previous diagnosis of an immune-mediated disease, only 1 patient with psoriasis suffered a worsening of skin symptoms and another one with psoriatic arthritis had a monoarthritis episode. Among the 14 patients who suffered from arthralgia/arthritis, the most frequent pattern was oligoarticular (40%), followed by poly (30%) and monoarticular (30%). The most affected joint was the knee (n=4), followed by wrist (3), hands (3), ankle (2), shoulder (2) and foot (1). Apart from the articular disease, 2 patients suffered from myositis in lower limbs, with weakness of legs and arthralgia in their knees. A patient was diagnosed of aortitis through a PET, although the patient did not have any symptom. Immunology tests with RF, ACCP and ANA were done in 8 out of the 15 patients with musculoskeletal irAEs, being negative in all cases. Interviewing 40 of the patients who received ICBT, 7 of them (17.5%) referred xerophthalmia. 6 of them (15%) had a positive Schrimer test, and 3 (7.5%) had a reduced tear break-up time. None patient met Sjogren criteria. In 6 out of the 15 patients with rheumatological irAEs (all of them with arthralgia/arthritis) the ICBT was removed, temporary in all cases, and could be reintroduced after a mean of 33 ± 18.9 days. 6 patients were treated with NSAIDs and 5 with oral prednisone (2 of them also required intra-articular corticoids). Conclusion Rheumatological irAEs are common in clinical practice. Arthralgia-Arthritis and dry-syndrome are the most frequent adverse events. Disclosure of Interests Lara Sanchez Bilbao: None declared, Inigo Gonzalez-Mazon: None declared, Rosalia Demetrio-Pablo: None declared, Jose Luis Martin-Varillas: None declared, Marina Delgado Ruiz: None declared, Isabel Bernat Pina: None declared, Belen Atienza-Mateo: None declared, Monica Calderon-Goercke: None declared, D. Prieto-Pena: None declared, Almudena Garcia Castano: None declared, Miguel A Gonzalez-Gay Grant/research support from: Prof. MA Gonzalez-Gay received grants/research supports from Abbvie, MSD, Jansen and Roche., Speakers bureau: Consultation fees/participation in company sponsored speaker’s bureau from Pfizer, Lilly, Sobi, Celgene, Novartis, Roche and Sanofi., Ricardo Blanco Grant/research support from: Abbvie, MSD, and Roche, Consultant for: Abbvie, Pfizer, Roche, Bristol-Myers, Janssen, Speakers bureau: Abbvie, Pfizer, Roche, Bristol-Myers, Janssen DOI: 10.1136/annrheumdis-2019-eular.7386