Bimekizumab shows dual efficacy in patients with psoriatic arthritis
medwireNews: Research shows that patients with psoriatic arthritis (PsA) gain substantial improvements in both musculoskeletal and skin symptoms with bimekizumab, highlighting the benefits of its ability to neutralize both interleukin (IL)-17A and 17F.
“Bimekizumab is a monoclonal antibody that potently and selectively neutralizes both IL-17A and IL-17F […] both of which are expressed at sites of inflammation and independently cooperate with other cytokines to mediate inflammation in humans,” Christopher Ritchlin (University of Rochester Medical Center, New York, USA) explained at the EULAR 2019 congress in Madrid, Spain.
For the BE ACTIVE phase IIb randomized trial in PsA, 206 patients were assigned to receive subcutaneous bimekizumab at varying doses or placebo every 4 weeks for a double-blind period of 12 weeks. The doses of bimekizumab included 16 mg, 160 mg, 160 mg with a 320 mg loading dose (LD), or 320 mg. At week 12, patients receiving placebo or 16 mg of bimekizumab were re-randomized to receive 160 mg or 320 mg bimekizumab for the remaining 36 weeks.
At week 12, significantly more of the 164 patients receiving bimekizumab had achieved an ACR50 response, with rates of 26.8% at the 16 mg dose, 41.5% at the 160 mg dose, and 46.3% at the 160 mg (320 mg LD) dose, compared with 7.1% with placebo. The 24.4% ACR50 response rate in patients taking the 320 mg dose was not significantly different to placebo, which Ritchlin suggested may be due in part to this group having more active skin and joint disease than the other groups.
By week 48, however, ACR50 response rates in the 320 mg dose group, including those re-allocated at 12 weeks, had improved in line with those of the other groups.
Specifically, Ritchlin reported an increase in ACR50 response rates between weeks 12 and 24 that was “persistent through week 48,” across all drug doses. At this point, the rates were 63.4% in patients who had taken bimekizumab 320 mg throughout the trial, 56.8% in those who took 160 mg (320 mg LD), and 55.0% in those who took 160 mg.
Resolution of enthesitis response rates were high at 48 weeks, at between 56.5% and 70.0% in these same dosing groups. And with regard to skin efficacy, PASI100 response rates among patients taking bimekizumab ranged from 17.2% to 50.0% at week 12 versus 7.1% in those taking placebo. These rates continued to increase, reaching up to 61─73% at week 48.
At baseline, the patients had an average tender joint count of 21.7 points, an average swollen joint count of 11.5 points, and 66.5% had a psoriasis body surface area of 3% or above. Ritchlin emphasized that the dropout rate for the study was low, at “only 8% of patients.”
The safety profile of bimekizumab was consistent with previous reports, said Ritchlin, commenting that “there was no apparent relationship between dose and treatment-emergent adverse events, that the majority of adverse events were of mild or moderate intensity, and that oral candidiasis was reported by 4.9% of patients and all cases reported during [bimekizumab] treatment were of mild or moderate intensity and did not lead to treatment discontinuation.”
There were also no deaths and no cases of inflammatory bowel disease or major cardiovascular events during the study.
Ritchlin confirmed that “bimekizumab is currently being evaluated in phase III studies.”
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