Etanercept, combination therapy superior to methotrexate alone in PsA
Etanercept alone, or in combination with methotrexate, has greater efficacy than methotrexate monotherapy in patients with psoriatic arthritis, both in terms of ACR20 and minimal disease activity responses, as well as radiographic progression, according to recent study findings.
“A key unaddressed question [in the field has been] in an early PsA population naïve to methotrexate treatment, how does methotrexate monotherapy compare with etanercept monotherapy or combination of methotrexate and etanercept in controlling arthritis?” Philip J. Mease, MD, of the Swedish Medical Center at the University of Washington School of Medicine, told Healio Rheumatology. “In other words, conducting a trial like the TEMPO trial in RA in PsA; there had never been such a trial in PsA to truly assess methotrexate in a head-to-head manner with a biologic such as etanercept.”
To determine the efficacy of monotherapy with either methotrexate or etanercept (Enbrel, Amgen), as well as combination therapy, among patients with PsA, Mease and colleagues conducted the Study of Etanercept and Methotrexate in subjects with Psoriatic Arthritis (SEAM-PsA) trial, a 48-week, phase 3 international study.
A total of 851 adult patients with PsA were recruited from 124 hospitals across 17 countries, and randomly selected to receive weekly doses of either oral methotrexate 20 mg plus placebo, etanercept 50 mg plus placebo or etanercept 50 mg plus oral methotrexate 20 mg. Both monotherapy groups included 284 participants, with 283 in the combination group.
Following the 48-week double-blind period came a 30-day safety follow-up. The primary endpoint was ACR20 response at week 24, with patients’ minimal disease activity responses during the same period acting as the secondary endpoint. Mease and colleagues also examined inflammatory arthritis, radiographic progression and nonarticular disease manifestation measures.
According to the researchers, patients’ ACR20 and minimal disease activity responses at week 24 were significantly greater among those in the etanercept monotherapy group, compared with those treated with methotrexate alone. Specifically, 60.9% of participants in the etanercept group achieved the ACR20 response, compared with 50.7% in the methotrexate group (P = .029). Similarly, 35.9% of those treated with etanercept alone achieved the minimal disease activity response, compared with 22.9% of the methotrexate monotherapy group (P = .005).
“Etanercept was statistically superior to methotrexate in the primary endpoint and key secondary endpoint, thus supporting the conclusion of the recently published ACR-NPF PsA treatment guidelines which suggest that a TNF inhibitor should be used ahead of methotrexate based on network meta-analysis of these medications’ efficacy and safety,” Mease said.
In addition, 65% of patients who received combination therapy demonstrated ACR20 responses, compared with 50.7% of those treated with methotrexate along (P = .005). Participants in the combination group also achieved the minimal disease activity response at greater rates, with 35.7% compared to 22.9% among those who received only methotrexate (P = .005).
“The combination of etanercept and methotrexate was no better than etanercept monotherapy in most endpoints, which was different than the finding in TEMPO where the combination was better than etanercept monotherapy,” Mease said. “This new finding should reassure the physicians and patients who may not want to use methotrexate in the background of etanercept that the combination really doesn’t add anything over etanercept monotherapy.”
The researchers also noted that patients’ ACR70, very low disease activity score and psoriatic arthritis disease activity scores were also consistent with these results. By week 48, participants treated with etanercept, whether in monotherapy or in combination with methotrexate, demonstrated less radiographic progression compared with those who received methotrexate alone. The researchers reported no new safety results.
“In a thorough assessment of the varied clinical domains of PsA — arthritis, enthesitis, dactylitis, skin and nail disease, function, quality of life and X-ray — we found that etanercept worked better than methotrexate,” Mease said. “We now have a more complete understanding of the effectiveness of these medications in these clinical domains, and — for the first time — in a very early population of patients. The median disease duration was 6 months! No previous PsA study has looked at patients this early in disease.” – by Jason Laday
Disclosure: Mease reports consulting fees, speaking fees and/or honoraria from AbbVie, Amgen, Bristol Myers Squibb, Celgene, Janssen, Eli Lilly, Novartis, Pfizer, Galapagos, Genentech, Sun and UCB. Please see the study for all other relevant financial disclosures.