The FDA has granted approval to bimekizumab-bkzx (Bimzelx; UCB) for the treatment of moderate-to-severe hidradenitis suppurativa (HS) in adults. This marks a significant advancement as bimekizumab-bkzx is the first and only approved therapy that selectively inhibits both interleukin-17F (IL-17F) and interleukin-17A (IL-17A). The approval addresses a critical unmet need in managing this chronic inflammatory skin condition.
Clinical Efficacy
The approval is supported by data from two pivotal Phase 3 trials, BE HEARD I (NCT04242446; n=505) and BE HEARD II (NCT04242496; n=509). These were identical 48-week, double-blinded studies involving patients aged 18 years and older with moderate-to-severe HS. Participants were randomized to receive subcutaneous bimekizumab-bkzx 320 mg every two weeks, bimekizumab-bkzx 320 mg every two weeks until week 16 followed by every four weeks until week 48, bimekizumab-bkzx 320 mg every four weeks until week 48, or placebo until week 16 followed by bimekizumab-bkzx 320 mg every two weeks. The primary endpoint was achieving at least a 50% clinical response at week 16.
Results from the studies indicated that a significantly higher proportion of patients treated with bimekizumab-bkzx achieved a 50% or greater improvement in HS signs and symptoms at week 16 compared to those receiving placebo. Specifically, in BE HEARD I, approximately 48% of patients on bimekizumab-bkzx achieved the primary outcome versus 29% on placebo. In BE HEARD II, the corresponding figures were 52% and 32%, respectively. Furthermore, a Hidradenitis Suppurativa Clinical Response 50 (HiSCR50) was observed in 54% of patients in the every-4-week bimekizumab-bkzx group, compared to 32% in the placebo group. These improvements were sustained through week 48.
Safety Profile
In terms of safety, serious treatment-emergent adverse events were reported in 8% of patients in BE HEARD I and 5% in BE HEARD II. The most commonly reported adverse events included COVID-19, diarrhea, oral candidiasis, and headache. One death occurred due to congestive heart failure in a patient with a significant cardiovascular history; however, investigators deemed it unrelated to the bimekizumab-bkzx treatment.
Context of Hidradenitis Suppurativa
HS is a chronic inflammatory skin condition characterized by painful lesions, often leading to physical discomfort, pain, drainage, malodor, and scarring. These symptoms can significantly impact patients' psychosocial well-being. Current treatments include lifestyle modifications, antibiotics, anti-inflammatory medications, laser therapy, and surgical excision with skin grafting.
Expert Commentary
According to Alexa B. Kimball, MD, MPH, professor of dermatology at Harvard Medical School, "The approval of [bimekizumab-bkzx] in moderate-to-severe hidradenitis suppurativa is welcome given the substantial unmet clinical needs and limited number of treatment options available today. In the phase 3 clinical studies, patients treated with bimekizumab-bkzx achieved deep and sustained clinical responses up to 48 weeks."
Prior Approvals
Bimekizumab-bkzx has previously been approved for the treatment of active psoriatic arthritis, active non-radiographic axial spondyloarthritis with objective signs of inflammation, and active ankylosing spondylitis. It initially received FDA approval in October 2023 for adults with moderate-to-severe plaque psoriasis who are candidates for systemic therapy or phototherapy.
