Bimekizumab Maintains Efficacy for PsA Up to 2 Years Among Week 16 Responders

Jessica A. Walsh, MD

Credit: University of Utah

Bimekizumab treatment of psoriatic arthritis (PsA) demonstrated robust maintenance of response at the 2-year mark, new findings suggest, and specifically among those who responded to at the 16-week mark who were either disease-modifying antirheumatic drug (DMARD)-naïve or had TNF-inhibitor inadequate response/intolerance (TNFi-IR).¹

These data were highlighted in ‘Bimekizumab Maintained Efficacy Responses in Patients with Active Psoriatic Arthritis: Up to 2-Year Results from Two Phase 3 Studies,’ an abstract presented at the American College of Rheumatology (ACR) Convergence 2024 in Washington, DC. Jessica Walsh, MD, is an Associate Professor at the University of Utah School of Medicine and George E. Wahlen Veteran Affairs Medical Center.

“Here, we report the proportion of [Week] 16 responders maintaining their response in joint, skin, and composite efficacy outcomes up to 2 years in [bimekizumab]-treated [patients] with PsA,” Walsh and colleagues wrote.¹

Trial Design and Notable Findings

The drug itself is a monoclonal IgG1 antibody designed to selectively inhibit interleukin-17F (IL-17F) alongside IL-17A and has previously demonstrated efficacy sustained from the 16 through 52-week marks in those with PsA. The chronic condition of PsA, during which treatments may lose therapeutic efficacy over time, required an evaluation of the long-term maintenance of treatment response for bimekizumab in those achieving earlier therapeutic milestones.

Consequently, an evaluation of two phase 3 studies was conducted, assessing subcutaneous bimekizumab 160 mg which was administered every 4 weeks. The analyses had been titled BE OPTIMAL, with a focus on biologic DMARD-naïve patients, and BE COMPLETE, focused on individuals with TNFi-IR.

In each of the 2 trials, a placebo-controlled phase was used up until the 16-week mark. Those included in BE OPTIMAL at 52 weeks and BE COMPLETE at 16 weeks were eligible to take part in the BE VITALn open-label extension study. The investigators assessed efficacy outcomes for those initially randomized to bimekizumab, with safety data including all treated individuals.

Assessment of long-term response sustainability occurred through evaluation of the proportion who maintained their 16-week results through to the 104-week mark for BE OPTIMAL or the 100-week mark for BE COMPLETE. In their efficacy assessments, the team looked at data such as Psoriasis Area and Severity Index (PASI)75/90/100, ACR20/50/70, Minimal or Very Low Disease Activity (MDA/VLDA), and Disease Activity Index for PsA (DAPSA) remission or low disease activity (REM ≤4; REM+LDA ≤14).

Safety findings were presented by the investigative team as exposure-adjusted incidence rates per 100 patient-years (EAIR/100 PY) up to the 104-week mark for both biologic DMARD-naïve and TNFi-IR participants.

Among bimekizumab-randomized individuals, the investigators found that 83.3% of biologic DMARD-naïve subjects and 80.5% of TNFi-IR subjects completed their respective time points. It was concluded that high proportions successfully achieving ACR50, PASI100, and MDA responses at the 16-week marks sustained such outcomes through Weeks 104 and 100.

The research team found that 43.9% of biologic DMARD-naïve and 43.1% of TNFi-IR subjects at the 16-week mark achieved ACR50. Among these, the team noted that 79.4% and 75.7%, respectively, maintained such responses. In a similar vein, among those with baseline psoriasis involving at least 3% of their body surface area, it was found that 47.5% of biologic DMARD-naïve and 58.5% of TNFi-IR subjects had a PASI100 response at the 16-week mark.

It was also reported that 70.9% and 80.6% of these participants, respectively, sustained their responses at the 104 and 100-week marks. MDA was achieved by 45.0% of biologic DMARD-naïve and 43.8% of TNFi-IR individuals at the 16-week mark, with 75.8% and 74.4%, respectively, maintaining such responses. Comparable trends were observed across other skin, joint, and composite efficacy measures at Week 104 and 100.

In November 2024, the US Food and Drug Administration (FDA) approved bimekizumab for adults with moderate-to-severe hidradenitis suppurativa (HS). This approval by the FDA added to bimekizumab’s growing list of indications, including for PsA.²

References

1. ^{Walsh J, Merola J, Tillett W, et al. Bimekizumab Maintained Efficacy Responses in Patients with Active Psoriatic Arthritis: Up to 2-Year Results from Two Phase 3 Studies. Presented at the 2024 ACR Convergence. Washington, DC. 14-19 November.}
2. ^{Smith T. FDA Approves Bimekizumab for Adults with Hidradenitis Suppurativa. HCPLive. November 20, 2024. https://www.hcplive.com/view/fda-approves-bimekizumab-adults-with-hidradenitis-suppurativa. Date accessed: November 25, 2024.}