Bimekizumab efficacy and safety through 3 years in patients with moderate-to-severe plaque psoriasis: long-term results from the BE RADIANT phase IIIb trial open-label extension period.

BACKGROUND

Overexpression of interleukin (IL)-17A and IL-17F significantly influences psoriasis pathology. Until recently, biologics targeting IL-17A alone, like secukinumab, were used to treat psoriasis. Bimekizumab is a monoclonal IgG1 antibody that targets both IL-17A and IL-17F. BE RADIANT was the first phase III trial to investigate switching from selective inhibition of IL-17A to dual inhibition of IL-17A and IL-17F. Bimekizumab has previously shown superior achievement of complete skin clearance [100% improvement from baseline in Psoriasis Area and Severity Index (PASI 100)] vs. secukinumab through 48 weeks. Switching from secukinumab to bimekizumab resulted in improved clinical responses. Over 2 years, no new safety signals were observed.

OBJECTIVES

To report the 3-year efficacy and safety of bimekizumab in patients with moderate-to-severe plaque psoriasis receiving continuous bimekizumab or switching from secukinumab after 1 year.

METHODS

The BE RADIANT phase IIIb randomized controlled trial had a 48-week double-blinded period, in which patients received bimekizumab [320 mg every 4 weeks (Q4W)] or secukinumab (300 mg weekly to week 4, then Q4W). At week 16, patients randomized to bimekizumab underwent re-randomization to receive Q4W or Q8W maintenance dosing. From week 48 onward (open-label extension), all received bimekizumab.

RESULTS

In total, 336 patients randomized to bimekizumab and 318 randomized to secukinumab at baseline entered the open-label extension. More patients randomized to bimekizumab achieved PASI 100 (modified nonresponder imputation) at year 1 (74.9%) vs. those randomized to secukinumab (52.8%). PASI 100 response rates were maintained over 3 years in patients treated with bimekizumab (68.8%) and increased in those randomized to secukinumab switching to bimekizumab (68.8%). Bimekizumab was well tolerated to 3 years. In patients who received ≥ 1 bimekizumab dose, the most common treatment-emergent adverse events (TEAEs) over 3 years were nasopharyngitis, oral candidiasis and upper respiratory tract infection (exposure-adjusted incidence rates 12.2, 10.0 and 5.5/100 patient-years, respectively). Rates of TEAEs of interest, including serious infections, inflammatory bowel disease, and suicidal ideation and behaviour, did not increase with longer exposure to bimekizumab from 1 to 3 years.

CONCLUSIONS

More than two-thirds of patients randomized to bimekizumab and those who switched from secukinumab to bimekizumab achieved and maintained complete skin clearance over 3 years of treatment. Over 3 years, bimekizumab was well tolerated and TEAE rates did not increase with longer exposure.

TRIAL REGISTRATION: NCT03536884.