The U.S. Food and Drug Administration (FDA) has approved bimekizumab-bkzx (Bimzelx, UCB Pharma) for the treatment of moderate-to-severe hidradenitis suppurativa (HS) in adult patients. This approval marks a significant advancement in the treatment landscape for HS, a chronic inflammatory skin disease characterized by recurring abscesses, nodules, and draining tunnels, particularly in areas like the armpits, groin, and buttocks.
The approval is based on data from two Phase 3 clinical trials, BE HEARD I (NCT04242446) and BE HEARD II (NCT04242498), which evaluated the efficacy and safety of bimekizumab in over 1,000 adults with moderate-to-severe HS. These double-blind, placebo-controlled studies used the Hidradenitis Suppurativa Clinical Response (HiSCR50) as the primary endpoint, defined as at least a 50% reduction in total abscess and inflammatory nodule count with no increase in draining tunnels. Key secondary endpoints included HiSCR75 and pain reduction.
Clinical Trial Results
Both trials demonstrated that a significantly greater percentage of patients treated with bimekizumab achieved at least a 50% reduction in disease signs and symptoms (HiSCR50) at week 16 compared to those in the placebo arms. Furthermore, significant improvements were observed in HiSCR75, with these results sustained through 48 weeks. According to Chris Sayed, MD, an investigator in the BE HEARD trials, the studies also used a higher benchmark of 75% reduction in inflammatory lesions, and bimekizumab clearly differentiated itself from placebo.
Bimekizumab is a humanized IgG1 monoclonal antibody that uniquely targets and inhibits both interleukin (IL)-17A and IL-17F cytokines. This dual inhibition is believed to provide a more complete blockade of inflammation compared to agents that only target IL-17A. Dr. Sayed noted that by blocking both IL-17A and IL-17F, a more complete blockade of the type of inflammation that drives these kinds of conditions is achieved, potentially leading to improved symptoms overall.
Long-Term Efficacy and Safety
Data from an open-label extension study, evaluating bimekizumab in patients previously enrolled in BE HEARD I and II, showed that the drug's response was maintained over time. Week 96 data indicated that patients who were on bimekizumab for nearly two years continued to improve, with a subset achieving even deeper responses. Approximately 40% of patients who stayed in the trial over a two-year period had a HiSCR100, meaning they had no abscesses and no inflammatory nodules.
The safety profile of bimekizumab in these trials was consistent with previous studies across various indications, with no new safety concerns identified.
Addressing Unmet Needs in HS Treatment
"The approval of (bimekizumab) in moderate-to-severe hidradenitis suppurativa is welcome given the substantial unmet clinical needs and limited number of treatment options available today," said Alexa B. Kimball, MD, MPH, investigator and professor of dermatology at Harvard Medical School. The addition of bimekizumab to the treatment armamentarium offers a valuable new option for patients struggling with this debilitating condition.
This approval expands bimekizumab's indications, which already include psoriatic arthritis, non-radiographic axial spondyloarthritis, ankylosing spondylitis, and moderate-to-severe plaque psoriasis.
