MADRID – To date, an adalimumab biosimilar has proven itself in a large, phase III trial of patients with psoriasis, including a subset with mild to moderate psoriatic arthritis (PsA).
The biosimilar, known as CHS-1420, cleared psoriatic plaques and improved health-related quality of life just as well as adalimumab after 12 weeks of treatment, Barbara Finck, MD, said at the European Congress of Rheumatology. It also suppressed high-sensitivity C-reactive protein (CRP) as well as the originator molecule, she said.
Dr. Finck, the chief medical officer of Coherus Biosciences, the developer of CHS-1420, reported results from the first 16-week phase of the 48-week study. Data are still to come on a 6-week period during which half those taking adalimumab switched to CHS-1420 in a blinded fashion, and 26 weeks of open-label CHS-1420 for all patients.
The study’s primary endpoint was a 75% reduction in the Psoriasis Area and Severity Index (PASI) score (PASI 75) Two additional endpoints were evaluated in patients with PsA: change in the Health Assessment Questionnaire-Disability Index (HAQ-DI) and changes in CRP.
Dr. Finck bemoaned the lack of the clinical rheumatologic endpoint, tender and swollen joint count. “I advocated for this but was unable to convince our dermatology colleagues” to conduct this exam, she said. “I think we have a ways to go to educate our colleagues in this regard.”
The study comprised 545 patients with mild to moderate psoriasis; of these, 127 had PsA. They received subcutaneous injections of either CHS-1420 or adalimumab at identical doses (80 mg at week 1, followed by 40 mg every other week). They were a mean of 44 years o
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Dr. Barbara Finck
In the entire study population, treatment with CHS-1420 and adalimumab followed almost identical response curves. By week 4, 22% of the CHS-1420 group and 20% of the adalimumab group had reached a PASI75 response. By week 8, those numbers were 57% and 61%, respectively, and by week 12, they were 69% and 72% – not significantly different.
Response was similar in the subgroup of PsA patients: By week 12, 82% of the CHS-1420 group and 77% of the adalimumab group had reached a PASI 75. PsA patients also responded equally well to both medications on the HAQ-DI by week 12. At baseline, the mean HAQ-DI was about 1 in each group. At 12 weeks, it was reduced by about half a point in both groups. High-sensitivity CRP decreased similarly in the CHS-1420 and adalimumab groups as well (reductions of 8.9 mg/L and 6.3 mg/L, respectively).
Adalimumab, a tumor necrosis factor blocker, is a highly immunogenic molecule, and as such, many patients developed antibodies to both it and to CHS-1420. By week 12, 84% of both treatment groups had developed anti-drug antibodies and 32%, neutralizing antibodies. Among those with PsA, 82% taking CHS-1420 and 88% of those taking adalimumab developed antidrug antibodies. Neutralizing antibodies developed in 33% and 30%, respectively. Neither of these differences was statistically significant.
Other adverse events were similar, Dr. Finck noted. These included nasopharyngitis (9% of both groups), upper respiratory tract infection (6%), injection site reaction (4%), headache (3%), and worsening of psoriasis (1% for CHS-1420, and 3% for adalimumab).
If the switching study data are similarly positive, Coherus expects to file a Biologics License Application with the Food and Drug Administration in early 2018, Dr. Finck said.
msullivan@frontlinemedcom.com
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