Phase I Study of DS-2741a in Healthy Volunteers and Participants With Atopic Dermatitis

DS-2741a Phase I Study- A Three-part First-in-human Study: Single Ascending Dose and Multiple Dose Study to Assess the Safety, Pharmacokinetics and Pharmacodynamics of DS-2741a After Subcutaneous Injection in Healthy Japanese Male Subjects, and Single Dose Study to Assess the Pharmacokinetics, Safety, Pharmacodynamics and Efficacy of DS-2741a After Subcutaneous Injection in Japanese Subjects With Moderate to Severe Atopic Dermatitis.

This is a phase 1, single-center, first-in-human study to assess the safety, pharmacokinetics and pharmacodynamics of DS-2741a after subcutaneous injection in healthy Japanese male volunteers and Japanese participants with moderate to severe atopic dermatitis.

This study consists of three parts. Part 1 and Part 3 are a single ascending and multiple dose study to assess the safety, pharmacokinetics and pharmacodynamics of DS-2741a after subcutaneous injection in healthy Japanese male participants. Part 2 is a single-dose study to assess the pharmacokinetics, safety, pharmacodynamics and efficacy of DS-2741a after subcutaneous injection in Japanese participants with moderate to severe atopic dermatitis.

Inclusion Criteria:

• For Part 1 and Part 3:

  • Japanese healthy male subjects.
  • Age ≥20 and ≤45 years upon providing informed consent.
  • Body mass index (BMI) ≥18.5 and <25.0 kg/m^2 at screening.

• For Part 2:

  • Japanese Male or female, Age ≥20 upon providing informed consent.
  • Diagnosed with chronic atopic dermatitis (AD) at least 3 years before screening and by the criteria of Hannifin and Rajka at screening.

Exclusion Criteria:

• For Part 1 and Part 3:

  • Having a history of atopic dermatitis
  • Having a history of hypersensitivity to drugs or other substances or being idiosyncratic
  • Having alcohol or drug dependence, etc.

• For Part 2:

  • Having an active dermatological disease other than AD, which, in the investigator's opinion, would affect study assessments.
  • Having a history of serious disease in the study potentially endangering the participant, as judged by the investigator or sub-investigator.
  • Having a chronic or acute infection requiring treatment within 28 days before screening.
  • Having superficial skin infections within 7 days before screening.
  • Having a history of recurrent oral herpes and recurrent genital herpes.
  • Having a history of parasitic infection or invasive, opportunistic infection such as histoplasmosis despite infection resolution, etc.