LAUSR

Background There is evidence that fibromyalgia (FM) can increase the burden of disease in patients affected with psoriatic arthritis (PsA) and interfere with the assessment of clinical disease activity, but studies focusing the impact of FM on long-term clinical outcomes are lacking. Objectives We aimed at evaluating the impact of FM on the achievement of clinical remission or minimal disease activity (MDA) in naïve PSA patients on treatment with a first biologic drug in real life settings. Methods We retrospectively assessed PsA patients, fulfilling CASPAR criteria, from 1st January 2010 through 30th June 2017, starting a first biologic drug or apremilast. At baseline and at each visit thereafter, DAPSA, PASI, MDA, ASDAS-CRP, and HAQ were evaluated. Rate of patients achieving DAPSA based low disease activity (LDA) was assessed at 3 months, and MDA or DAPSA-remission at 12 months. LOCF method was carried out for those patients who did not reach 12 months follow-up or discontinue the treatment before 12 months. The persistence on the first treatment was evaluated by Kaplan-Mayer survival curves. Estimated hazard ratios (HRs) of discontinuing therapy or achieving remission or MDA at last observation were assessed by a multivariate stepwise backward Cox regression model, adjusting for patient demographics (gender, age, BMI, comorbidities) and disease characteristics (co-therapy with MTX or glucocorticoids, DAPSA). Results Upon excluding pure axial PsA without peripheral involvement, 238 patients (126 female) with mean age 51 years (95% CI, 40-59), BMI 26 (95% CI, 23-30), disease duration 24 (95% CI, 10-60) months were analyzed. At baseline, 120 had polyarticular involvement (≥ 5 joints), 118 had oligoarticular pattern, and 64 had concomitant spine involvement. One hundred-fifteen begun a treatment with anti-TNF-receptor, n.106 with anti-TNF-mAb, n.9 with ustekinumab, n.6 with apremilast, and n.2 with secukinumab. FM was diagnosed, according to both 1990 and 2019 ACR classification criteria, in 58 (female 74%) patients. Crude drug survival rate was significantly lower in FM-PsA patients (50%) (mean survival time (MST, 95% CI) 32 (25-38) months than in PsA patients without FM (74%) MST 42 (38-45) months (log rank=15.6, p=0.0001) (Figure 1a). This large difference was also seen estimating drug survival by ineffectiveness, FM-PsA 58.6% (MST 35 (28-42) months) vs PsA 82% (MST 45 (42-48) months) (log rank=18.5, p=0.0001) (Figure 1b), but not by adverse events (data not shown). LDA at 3 months was reached by 78% of PsA patients and by 21% of FM-PsA patients (p=0.0001). At 12 months, MDA was achieved by 62% of PsA and only by 2% (1 out of 58) of FM-PsA (p=0.0001), and likewise remission was seen in 47% of PsA and in 2% of FM-PsA p=0.0001) Figure 2. FM was the only independent factor associated to drug discontinuation (HR 2.5, 1.6-4.1 (95% CI), or to the achievement of either MDA (HR 0.23, 0.1-0.5 (95% CI) and clinical remission (HR 0.26, 0.1-0.6 (95% CI), with the first biologic drug within the time span of the study. Conclusion Our findings clearly demonstrate the FM has a striking negative impact on clinical outcomes in PsA, as early as 3 months of treatment. Clinicians should be aware that treating PsA patients with comorbid FM is demanding, and appropriate patient shared strategies should be adopted in these settings.Figure 1 Kaplan-Mayer curves of crude drug survival (left) and by ineffectiveness in PsA patients with or without fibromyalgia.Figure 2 Percentage of PsA patients with or without fibromyalgia achieving LDA-DAPSA at 3 months, and MDA or DAPSA-remission at 12 months. Disclosure of Interests Florenzo Iannone Consultant for: F Iannone has received consultancy fees and/or speaker honoraria from Pfizer, AbbVie, MSD, BMS, Novartis, Lilly, UCB outside this work, Speakers bureau: F Iannone has received consultancy fees and/or speaker honoraria from Pfizer, AbbVie, MSD, BMS, Novartis, Lilly, UCB outside this work, Mariangela Nivuori: None declared, Giuseppe Lopalco Speakers bureau: SOBI, BMS, Maria Grazia Anelli Speakers bureau: BMS, Abbvie, Laura Coladonato: None declared, Gaetana Laselva: None declared, Crescenzio Scioscia Speakers bureau: Abbvie