Inclusion Criteria:
- Participant must be aged greater than or equal (≥)18 years at the time of signing the informed consent
- Participant has chronic atopic dermatitis (AtD) (according to American Academy of Dermatology Consensus Criteria) that has been present for at least ≥1 year prior to initiating the study (ie, signing of the informed consent form \[ICF\]) and with:
1. validated Investigator Global Assessment (vIGA) score ≥3 at Screening and Baseline
2. Eczema Area and Severity Index (EASI) score ≥16 at both Screening and Baseline
3. Peak Pruritus Numerical Rating Scale (PP-NRS) score of ≥4 at both Screening and Baseline
4. ≥10% body surface area (BSA) of AtD involvement at both Screening and Baseline
5. Documented recent history (within 6 months prior to Screening) of inadequate response to treatment with topical medications, or study participants for whom topical treatments are otherwise medically inadvisable (eg, due to important side effects or safety risks) and who are candidates for systemic therapy
Exclusion Criteria:
- Participant has any history or presence of any medical or psychiatric condition, physical examination finding, laboratory test result, or electrocardiogram (ECG) signal that, in the opinion of the investigator, could constitute a risk when taking the study intervention; or interfere with the interpretation of data and could jeopardize or would compromise the study participant's ability to participate in this study
- Active dermatologic conditions that may confound the diagnosis of AtD or would interfere with assessment of treatment, such as but not limited to scabies, seborrheic dermatitis, cutaneous lymphoma, ichthyosis, psoriasis, active allergic or irritant contact dermatitis
- Presence or family history (first degree) of inflammatory bowel disease (includes Crohn's disease and ulcerative colitis)
- History of chronic or recurrent infections, or a serious or life-threatening infection within the 6 months prior to the Baseline (including herpes zoster) as judged by the investigator
- Participants are not permitted to enroll into the study if they meet tuberculosis (TB) exclusion criteria
- Previous treatment with galvokimig
- Participant has relevant safety events to one or more interleukin (IL)-13 biologic response modifiers (ie, dupilumab, tralokinumab and lebrikizumab) that resulted in discontinuation and change of treatment
- All systemic therapies (other than biologics), topical therapies and other treatments for AtD must be discontinued at least 4 weeks prior to Baseline
- Treatment with biologic agents must discontinued at least 3 months prior to baseline