MADRID – within the next 12 months than were patients on their first tumor necrosis factor (TNF) inhibitor, in a large retrospective national propensity score-matched study.
Bruce Jancin/MDedge News
Dr. David L. Kaplan
“This was surprising to us,” David L. Kaplan, MD, admitted in presenting the study findings at the annual congress of the European Academy of Dermatology and Venereology.
The surprise came because apremilast, a phosphodiesterase 4 (PDE4)-inhibitor, is less potent than the injectable biologics at driving down Psoriasis Area and Severity Index (PASI) scores.
“This is real-world data. And this is what patients are saying at 1 year: that they’re actually happier [with apremilast] and they’re not interested in changing,” said Dr. Kaplan, a dermatologist at the University of Kansas and in private practice in Overland Park, Kan.
He and his coinvestigators tapped the IBM Watson MarketScan health insurance claims database for 2015-2016 and identified 1,645 biologic-naive adults with psoriasis who started on apremilast therapy and an equal number of biologic-naive psoriasis patients who initiated treatment with a biologic, of whom 1,207 started on an TNF inhibitor and 438 began on an interleukin inhibitor, which was ustekinumab in 81% of cases. The TNF inhibitor cohort was split 80/20 between adalimumab and etanercept. The three groups – new users of apremilast, a TNF inhibitor, or an interleukin inhibitor – were propensity-matched based upon age, prior usage of systemic psoriasis therapies, Charlson Comorbidity Index scores, and other potential confounders.
The primary endpoint was the switch rate to a different psoriasis treatment within 12 months. The switch rate was significantly lower in patients who had started on apremilast than in those on a TNF inhibitor by a margin of 14% to 25%, while the 11% switch rate among patients on an interleukin inhibitor was not significantly different from the rate in the apremilast group.
“I think this data kind of gives us pause,” the dermatologist said. “As a clinician myself, when patients come back in the first question I always ask is, ‘How’re you doing? Are you happy?’ And at the end of the day, the data in terms of switch rates shows where patients are at. And that doesn’t really follow what we see with PASI scores.”
A secondary endpoint was the switch rate through 24 months. The same pattern held true: 24.9% in the apremilast starters, which was similar to the 22.9% in patients initiated on an interleukin inhibitor, and significantly less than the 39.1% rate in the TNF inhibitor group.
Among patients who switched medications within the first 12 months, the mean number of days to the switch was similar across all three groups.
The study had several limitations. Propensity score–matching is not a cure-all that can eradicate all potential biases. And the claims database didn’t include information on why patients switched, nor what their PASI scores were. “This is real-world data, and clinicians don’t do PASI scores in the real world,” he noted.
Audience member Andrew Blauvelt, MD, a dermatologist and president of the Oregon Medical Research Center, Portland, rose to challenge Dr. Kaplan’s conclusion that patients on apremilast were happier with their care.
“How can you rule out that it’s just practices that don’t use biologics, and they’re keeping patients on apremilast regardless of whether they’re better or happy because they’re not using biologics?” inquired Dr. Blauvelt.
Dr. Kaplan conceded that might well be a partial explanation for the results.
“Reluctance to use biologics is out there,” he agreed.
Dr. Kaplan reported serving as a consultant and paid speaker for Celgene, the study sponsor, as well as several other pharmaceutical companies.
SOURCE: Kaplan DL. EADV Abstract FC04.04.