Survival rates of biologics and other novel immunomodulatory drugs vary substantially across chronic inflammatory diseases, and rates are highest for rituximab in rheumatoid arthritis (RA) and golimumab in axial spondyloarthritis (axSpA), but with similar rates seen for most drugs used in the treatment of psoriasis and psoriatic arthritis (PsA), according to findings from a study of two Danish registries.
Drug survival refers to “the probability that patients will remain on a given drug, and is a proxy for efficacy as well as safety in daily clinical practice,” wrote Alexander Egeberg, MD, PhD, of the department of dermatology at Copenhagen University Hospital–Bispebjerg, and colleagues. Although the use of biologics has expanded for inflammatory diseases, real-world data on drug survival in newer agents such as interleukin (IL)-17, IL-23, and Janus kinase inhibitors are lacking, they said.
In a study published in Seminars in Arthritis and Rheumatism, the researchers reviewed data from the DANBIO and DERMBIO registries of patients in Denmark with inflammatory diseases including rheumatoid arthritis (RA), axial spondyloarthritis (AxSpA), psoriatic arthritis (PsA), and psoriasis.
The study population included 12,089 adults: 5,104 with RA, 2,157 with AxSpA, 2,251 with PsA, and 2,577 with psoriasis. Patients’ mean age at the time of first treatment for these conditions was 57.8 years, 42.3 years, 49 years, and 45 years, respectively. Participants were treated with biologics or novel small molecule therapies for RA, AxSpA, PsA, or psoriasis between January 2015 and May 2021 (from the DANBIO database) and November 2009 to November 2019 (DERMBIO database).
In adjusted models, drug survival in RA was highest for rituximab followed by baricitinib, etanercept, and tocilizumab. Drug survival in AxSpA was highest for golimumab, compared with all other drugs, followed by secukinumab and etanercept. Survival was lowest for infliximab. In PsA, drug survival was roughly equal for most drugs, including golimumab, secukinumab, and ixekizumab, with the lowest survival observed for tofacitinib and infliximab, compared with all other drugs. Drug survival in psoriasis was highest with guselkumab, followed by ustekinumab and IL-17 inhibitors.
However, the number of treatment series “was low for some drugs, and not all differences were statistically significant, which could influence the overall interpretability of these findings,” the researchers noted in their discussion.
Notably, the high treatment persistence for rituximab in RA patients needs further confirmation, the researchers said. “In Denmark, rituximab is often the biologic drug of choice in RA patients with a history of cancer while there is a reluctancy to use TNF [tumor necrosis factor] inhibitors in such patients; this may have prolonged the drug survival for rituximab treated patients due to limited treatment alternatives,” they said.
The findings were limited by several factors, including the observational study design and changes in guidelines over the course of the study, the researchers noted. Other limitations included the inability to adjust for certain variables, such as antibody status, body weight, and smoking, because of missing data, and a lack of data on the underlying reasons for drug discontinuation, they said.
However, the results were strengthened by the large number of patients and completeness of the registries, the researchers emphasized. The range in responses to different drug types across diseases supports the need for individualized treatments with attention to underlying disease, patient profile, and treatment history, they concluded.
The study received no outside funding. Eight coauthors reported financial ties to a number of pharmaceutical companies.