Study CSL324_1002 will investigate the safety and pharmacokinetics of repeat doses of CSL324 in subjects with hidradenitis suppurativa and palmoplantar pustulosis. CSL324 is a novel, recombinant therapy that may treat diseases caused by increased numbers of neutrophils at sites of inflammation.

Inclusion Criteria:

• Male or female subjects between 18 and 75 years of age, inclusive
• Confirmed clinical diagnosis of moderate to severe HS as per International Hidradenitis Suppurativa Severity Score System (IHS4) guidelines (ie, IHS4 ≥ 4)
• PPP differentiated from other forms of pustulosis
• Psoriasis with a Palmoplantar Pustulosis Psoriasis Area and Severity Index (ppPASI) score of ≥ 12.
• Subjects with HS only: inadequate response to at least a 3-month (90 days) trial of oral antibiotics for treatment of HS
• Subjects with PPP only: confirmed clinical diagnosis of PPP at least 6 months before Screening and inadequate response to topical therapy, phototherapy, and / or previous systemic therapy for the treatment of PPP

Exclusion Criteria:

• Treatment with any medications and therapies not permitted during the study.
• History of myeloproliferative disease.
• Malignancy within 5 years at Screening with the exception of nonmelanoma skin cancer, carcinoma in situ, or prostate cancer not requiring treatment.
• Current, or a recent clinically significant history of, uncontrolled renal, hepatic(including currently active hepatitis B virus and / or hepatitis C virus), hematologic, endocrine, pulmonary, psychiatric, or cardiac disease, assessed as potentially having an effect on study outcomes as determined by the Investigator and / or Sponsor.
• Congenital or acquired immunosuppressive condition(s), including human immunodeficiency virus infection.
• Clinical signs of active infection and / or fever > 38°C during the 7 days before Day 1.
• Clinically significant abnormalities on physical examination, ECG, or laboratory assessments, or neutropenia (defined as absolute neutrophil count < 2.0 × 109/L) at Screening.
• Subjects with PPP only: concurrent psoriasis vulgaris (not including scaly scalp and / or ears).
• Subjects with HS only: > 20 draining fistulas."

CSL will consider requests to share Individual Patient Data (IPD) from systematic review groups or bona-fide researchers. For information on the process and requirements for submitting a voluntary data sharing request for IPD, please contact CSL at clinicaltrials@cslbehring.com.

Applicable country specific privacy and other laws and regulations will be considered and may prevent sharing of IPD.

If the request is approved and the researcher has executed an appropriate data sharing agreement, IPD that has been appropriately anonymized will be available.

IPD requests may be submitted to CSL no earlier than 12 months after publication of the results of this study via an article made available on a public website.

Requests may only be made by systematic review groups or bona-fide researchers whose proposed use of the IPD is non-commercial in nature and has been approved by an internal review committee.

An IPD request will not be considered by CSL unless the proposed research question seeks to answer a significant and unknown medical science or patient care question as determined by CSL's internal review committee.

The requesting party must execute an appropriate data sharing agreement before IPD will be made available.