Background Biological treatments have provided new opportunities for disease control for patients with psoriatic arthritis. However, it is important to evaluate their safety, since they expose them to an increased risk of developing malignant tumors and serious infections.

Objectives To examine the rate of solid tumors and serious infections among patients diagnosed with psoriatic arthritis (PsA) treated with biological drugs (BD) in 2011–2015.

Methods We included all PsA patients (CASPAR criteria) under treatment with BD followed in our regional registry (reference population 2.055.000) between January 2011 and December 2015. In order to capture the incidence of new malignancy we excluded patients with a prior history of malignancy. Medical records were fulfilled for patients and were recorded solid tumors diagnosed (date of diagnosis and histology information) and all serious infections (requiring hospitalization or intravenous antibiotics) in this time. Incidence rates (IRs) were calculated per 1000 Person-year (py). We used for this analysis sex, age, disease duration, current BD with or without current DMARD associated. Continuous variables were reported as mean ± standard deviation (SD). Categorical variables were reported as percentages and frequencies. Differences were considered statistically significant if p<0.05 (two-tailed).

Results Among 604 patients 329 (54.5%) of whom were men, with a mean age of 53.3±12.6 years and a time since the diagnosis of PsA of 12.4±8.7 years. There were 14 cancers diagnosed during treatment (2.3%), with an IR of 0.48 cases per 1000 patient-years. Patients who developed cancer had a higher age, 63.4±10.0 years vs 53.1±12.6, than those who did not developed (p=0.010). Etanercept was the most used (42%) and no differences were observed among BDs (p=0.214) or between naïve and non-naïve to BD (p=0.384). Current DMARD associated (56.2%) had not differences in tumors (p=0.429). Prostate tumor was the most frequent (21.4%). There were 42 had serious infection (6.2%), with an IR of 13.9 cases per 1000 patient-years, and was more common in men (4.7% vs 8.8%, p=0.049). Severe infections were more frequent in patients non-naïve to BD (10.4% vs 5.4%, p=0.026). Pneumonia (28.6%), varicella-zoster virus infection (16.6%) and soft tissue infections (14.3%) were most frequent. Latent tuberculosis infection was positive in 133 patients (22.0%) and 3 developed tuberculosis.

Conclusions Patients older than 60 years with psoriatic arthritis treated with BDs had a higher incidence of tumor development. Most of patients were men and prostate tumor was the most frequent. Pneumonia was the most frequent serious infection and non-naïve to BD patients had a higher IR of serious infections.

References

1. Malignancy incidence in patients with psoriatic arthritis: a comparison cohort-based incidence study. Wilton KM, Crowson CS, Matteson EL.Clin Rheumatol. 2016 Oct; 35(10):2603–7.

References

Acknowledgements The authors are grateful for the support of the members of the Galician Society of Rheumatology (SOGARE).

Disclosure of Interest None declared