Switching to second, third TNFi tied to lower drug survival, response rates in PsA patients

Patients with axial and peripheral psoriatic arthritis (PsA) who switch to a second or third tumour necrosis factor inhibitor (TNFi) have significantly lower drug survival and response rates, a recent study has found.

The authors performed Kaplan-Meier analysis for first-, second- and third-line TNFi in PsA patients. Responses included European League Against Rheumatism (EULAR) criteria, Disease Activity Index for Psoriatic Arthritis (DAPSA), minimal disease activity (MDA), and Ankylosing Spondylitis Disease Activity Score (ASDAS) at 3 and 6 months.

Cox and multivariable multinomial/logistic regression models were generated to assess the baseline predictors of discontinuation and response.

A total of 750 PsA patients had drug retention of 4.1±3.4 years (follow-up, 5.8±3.8 years) for first TNFi, but drug survival further decreased by 1.1 years after switching to a second (n=189) or third (n=50) TNFi. Discontinuation of first TNFi was predicted by the following: female sex, higher baseline 28-joint count Disease Activity Score and infliximab.

Of the patients, 48.7 percent achieved a good EULAR criteria response and 20.9 percent were in DAPSA remission after 6 months of the first TNFi. Additionally, 11.4 percent of patients had MDA and 56.4 percent had a good ASDAS.

Responses to the second TNFi, however, were much poorer than responses to the first TNFi. Female sex and higher baseline Health Assessment Questionnaire–Disability Index negatively correlated with good EULAR response at 3 months. Obesity also decreased the response rate at 6 months.

“More successful therapeutic approaches will require considering the effect of sex and obesity on TNFi effectiveness,” the authors said.