NEW ORLEANS – In two phase 3 trials, bimekizumab, a monoclonal antibody targeting two types of interleukin-17 — IL-17A and IL-17F — reduced the abscess and inflammatory nodule count better than placebo in the chronic inflammatory skin condition hidradenitis suppurativa (HS), according to results presented together during a late-breaker session at the annual meeting of the American Academy of Dermatology.
“We are very excited to add this data to what we already have around IL-17 inhibition. This clearly validates this target for the control of HS,” reported lead investigator Alexa B. Kimball, MD, MPH, professor of dermatology at Harvard Medical School and Beth Israel Deaconess Medical Center, both in Boston.
Ted Bosworth
Dr. Alexa B. Kimbal
The trials, called BE HEARD I and BE HEARD II, enrolled 505 and 509 patients with HS, respectively. About 50% of patients in BE HEARD I and 60% of patients in BE HEARD II had Hurley stage 3 disease, which is the most severe of the three stratifications. The remainder were in Hurley stage 2. The mean duration of HS was 8.3 and 7.1 years, respectively.
Patients in both studies were randomized to one of four groups – either to a dosing regimen of 320 mg of bimekizumab administered by subcutaneous injection or to a placebo group. Both trials comprised double-blind 16-week initial and 32-week maintenance treatment periods.
In one experimental group, bimekizumab was given once every 2 weeks for the full course of the 48-week study (Q2W/Q2W). In another, patients started on the every-2-week schedule for 16 weeks and then were switched to every-4-week dosing (Q2W/Q4W). In the third group, patients started and remained on the every-4-week schedule (Q4W/Q4W). Patients in a fourth group started on placebo and switched at 16 weeks to the every-2-week bimekizumab schedule (placebo/Q2W).
Results at primary endpoint
The primary endpoint was HiSCR50, signifying a 50% reduction from baseline in abscess and inflammatory nodule count on the Hidradenitis Suppurativa Clinical Response (HiSCR) assessment tool. At 16 weeks, the initial Q2W dose in two of the groups outperformed the placebo in both BE HEARD I (47.8% vs. 28.7%) and BE HEARD II (52.0% vs. 32.2%). The response rates in the Q4W arm in BE HEARD I (45.3%) and BE HEARD II (53.8%) were also higher than the placebo, but the difference was only significant in BE HEARD II.
At 48 weeks, the proportion of patients with an HiSCR50 response climbed in all groups in both trials. The patterns were generally the same with slightly higher numerical responses among the groups that received the every-2-week dosing schedule relative to the every-4-week schedule.
In BE HEARD I at 48 weeks, the HiSCR50 response rate was about 60% for those who started and remained on every-2-week bimekizumab (Q2W/Q2W) or were switched at 16 weeks to every-4-week bimekizumab (Q2W/Q4W). For those who started and remained on every-4-week bimekizumab and the group started on placebo and switched to every-2-week bimekizumab, the response rates were 52.7% and 45.3%, respectively.
In BE HEARD II, the HiSCR50 response rates were higher in all groups, including the placebo, and the patterns of response were similar at 48 weeks. Most patients reached the HiSCR50 response – 79.8% (Q2W/Q2W), 78.4% (Q2W/Q4W), 76.7% (Q4W/Q4W), and 65.9 % (placebo/Q2W) of patients.
It is notable that, although there was rapid increase in the proportion of placebo patients reaching HiSCR50 after the switch at 16 weeks, there appeared to be an advantage at 48 weeks for starting on full-dose bimekizumab over starting on placebo.
In this trial, patients were listed as nonresponders if they received antibiotics at any time and for any reason after randomization. This might have concealed an even greater benefit of bimekizumab, Dr. Kimball said, but the study design element was considered necessary to isolate the activity of the study drug.
“In future HS trials, it will be helpful to address the difficulty of handling the impact of antibiotics and pain medications [in assessing results],” Dr. Kimball said.