Sponsor business decision, not related to safety concerns.

A Phase 2, double-blind, randomized, placebo-controlled parallel-group study to evaluate the efficacy and safety of daxdilimab in participants with moderate-to-severe active primary Discoid Lupus Erythematosus (DLE) refractory to standard of care.

Approximately 72 participants will be enrolled to receive daxdilimab or placebo administered subcutaneously once every four weeks (Q4W) from Day 1 to Week 20. The maximum trial duration per participant is approximately 36 weeks including screening, the 24 weeks for the treatment period where participants will receive daxdilimab or placebo, and approximately 8 weeks for the follow-up period. Safety evaluations will be performed regularly throughout the course of the study.

Acquired from Horizon in 2024.

Key Inclusion Criteria:

• Willing and able to understand and provide written informed consent.

• Willing and able to comply with the prescribed treatment protocol and evaluations for the duration of the trial.

• A diagnosis of DLE for ≥ 6 months prior to screening supported by a history of:

  1. A biopsy or
  2. a clinical feature score of ≥ 7 on the DLE Classification Criteria (DLECC) scale.

• Currently active discoid lupus with all the following:

  1. Digital photography adjudicated with central reading to confirm a currently active discoid disease lesion.
  2. CLASI-A score ≥ 8 related to discoid lesions at Baseline.

• Treatment refractory DLE defined as active disease despite current or historical treatment with a systemic treatment.

• Females are eligible to participate if they are not pregnant or breastfeeding, and meet the contraceptive/barrier requirement(s).

• Males are eligible to participate if they agree to the contraceptive/barrier requirement(s).

• Vaccination status should be up to date per local standards.

Key Exclusion Criteria:

• Participation in another clinical study with an investigational drug within 4 weeks prior to Randomization or within 5 published half-lives, whichever is longer.

• Any condition that, in the opinion of the Investigator, would interfere with evaluation of the investigational product (IP) or interpretation of participant safety or trial results.

• Weight > 160 kg (352 pounds) at Screening.

• History of allergy, hypersensitivity reaction, or anaphylaxis to any component of the IP or to a previous monoclonal antibody (mAb) or human immunoglobin (Ig) therapy.

• Breastfeeding or pregnant women or women who intend to become pregnant anytime from signing the informed consent form (ICF) through 6 months after receiving the last dose of IP.

• Splenectomy.

• Spontaneous or induced abortion, still or live birth, or pregnancy ≤ 4 weeks prior to screening through randomization.

• History of clinically significant cardiac disease including unstable angina, myocardial infarction, congestive heart failure within 6 months prior to Randomization; arrhythmia requiring active therapy, except for clinically insignificant extra systoles, or minor conduction abnormalities.

• History of cancer within the past 5 years, except as follows:

  • Cutaneous basal cell or squamous cell carcinoma treated with curative therapy.

• Any underlying condition that in the opinion of the Investigator significantly predisposes the participant to infection.

• Known history of a primary immunodeficiency or an underlying condition, such as known human immunodeficiency virus (HIV) infection, or a positive result for HIV infection per central laboratory.

• Participants with positive hepatitis B serologic test results.

• All participants will undergo testing for hepatitis C antibody (HCVAb) during Screening.

• Participants who are HCVAb positive will be reflex tested for hepatitis C virus (HCV) RNA and if HCV RNA is positive, the participant is not eligible for the study.

• Active tuberculosis (TB), or a positive interferon-gamma release assay (IGRA) test at screening, unless documented history of appropriate treatment for active or latent TB.

Participants with an indeterminate IGRA test result can repeat the test, but if the repeat test is also indeterminate, they will be excluded.

• Any severe herpes virus family infection (including Epstein-Barr virus, cytomegalovirus (CMV)) at any time prior to Randomization, including, but not limited to, disseminated herpes, herpes encephalitis, recent recurrent herpes zoster (defined as 2 episodes within the last 2 years), or ophthalmic herpes.
• Any herpes zoster, CMV, or Epstein-Barr virus infection that was not completely resolved 12 weeks prior to Randomization.
• Opportunistic infection requiring hospitalization or parenteral antimicrobial treatment within 2 years prior to Randomization.
• Any acute illness or evidence of clinically significant active infection on Day 1.
• Participants who have COVID-19 or other significant infection, or in the judgment of the Investigator, may be at a high risk of COVID-19 or its complications should not be randomized.
• Systemic lupus erythematosus defined by fulfilling 2020 American College of Rheumatology/European Alliance of Associations for Rheumatology criteria for systemic lupus erythematosus (SLE).
• Current diagnosis of a systemic connective tissue disease.
• Current inflammatory skin disease other than DLE, that, in the opinion of the Investigator, could interfere with the inflammatory skin assessments and confound the disease activity assessments.
• Exposure to an experimental drug either 30 days, 5 half-lives of the agent, or twice the duration of the biological effect of the agent, whichever is longer, prior to Randomization and through the final trial visit.
• Receipt of a live-attenuated vaccine within 4 weeks prior to Randomization.

De-identified individual patient data for variables necessary to address the specific research question in an approved data sharing request.

Data sharing requests relating to this study will be considered beginning 18 months after the study has ended and either 1) the product and indication have been granted marketing authorization in both the US and Europe or 2) clinical development for the product and/or indication discontinues and the data will not be submitted to regulatory authorities. There is no end date for eligibility to submit a data sharing request for this study.

Qualified researchers may submit a request containing the research objectives, the Amgen product(s) and Amgen study/studies in scope, endpoints/outcomes of interest, statistical analysis plan, data requirements, publication plan, and qualifications of the researcher(s). In general, Amgen does not grant external requests for individual patient data for the purpose of re-evaluating safety and efficacy issues already addressed in the product labelling. Requests are reviewed by a committee of internal advisors. If not approved, a Data Sharing Independent Review Panel will arbitrate and make the final decision. Upon approval, information necessary to address the research question will be provided under the terms of a data sharing agreement. This may include anonymized individual patient data and/or available supporting documents, containing fragments of analysis code where provided in analysis specifications. Further details are available at the URL below.