A Study to Test the Efficacy, Safety and Pharmacokinetics of Bimekizumab in Subjects With Moderate to Severe Hidradenitis Suppurativa.

Inclusion Criteria:

- Adult subjects (18 to 70 years of age, inclusive) must have a diagnosis of HS for at
least

1 year prior to Baseline

- Stable HS for at least 2 months prior to Screening and also at the Baseline Visit

- Inadequate response to at least a 3-month study of an oral antibiotic for treatment of
HS

- Total abscess and inflammatory nodule count >=3 at the Baseline Visit

- Subject must agree to daily use (and throughout the entirety of the study) of 1
pre-specified over-the-counter topical antiseptics on their HS lesions

- Female subjects must be postmenopausal, permanently sterilized or, if of childbearing
potential, must be willing to use a highly effective method of contraception up till
20 weeks after last administration of study drug and have a negative pregnancy test at
Visit 1 (Screening) and immediately prior to first dose

- Male subjects must be willing to use a method of contraception when sexually active,
up till 20 weeks after the last administration of study medication

Exclusion Criteria:

- Prior treatment with anti-IL17s or participation in an anti-IL17 study

- Previously received anti-TNFs

- Subject requires, or is expected to require, opioid analgesics for any reason
(excluding tramadol)

- Subject received prescription topical therapies for the treatment of HS within 14 days
prior to the Baseline Visit

- Subject received systemic non-biologic therapies for HS with potential therapeutic
impact for HS less than 28 days prior to Baseline Visit

- Draining fistula count >20 at the Baseline Visit

- Diagnosis of inflammatory conditions other than HS