Efficacy and Safety Evaluation of RO7790121 in Moderate to Severe Atopic Dermatitis: A Phase II Multicenter, Double-Blind, Placebo-Controlled Study

The primary objective of this study is to evaluate the efficacy of **RO7790121** compared with placebo in achieving an Eczema Area and Severity Index (EASI)-75 response, defined as a ≥ 75% improvement from baseline, at Week 16 in patients with moderate to severe atopic dermatitis. This objective is clinically relevant as achieving an EASI-75 response is a significant indicator of treatment success in reducing the severity and extent of atopic dermatitis, thereby improving patient quality of life.

Secondary objectives include:

• Evaluating the efficacy of RO7790121 compared with placebo in achieving an Investigator Global Assessment (IGA) score of clear (0) or almost clear (1) with ≥ 2-grade improvement at Week 16 and Week 32, EASI-75 response at Week 32, EASI-90 response at Week 16 and Week 32, and percent change from baseline in EASI by visit.
• Assessing improvement in participant-reported outcomes (PROs).
• Characterizing the dose response efficacy of RO7790121.
• Evaluating the safety of RO7790121 compared with placebo.
• Characterizing the pharmacokinetics (PK) of RO7790121.

The clinical trial involved a total of **89 participants** diagnosed with **Moderate to Severe Atopic Dermatitis (AD)**. The study population included both male and female subjects, with an age range encompassing children and adults. Participants were selected based on specific criteria, including a confirmed diagnosis of atopic dermatitis according to the Hanifin/Rajka criteria at least one year prior to screening. The trial population was required to have moderate to severe AD, as indicated by an Eczema Area and Severity Index (EASI) score of 16 or higher and an Investigator's Global Assessment (IGA) score of 3 or higher at screening and baseline visits, with at least 10% body surface area involvement. Additionally, participants were required to use an additive-free, bland emollient at least once daily for a minimum of seven days prior to the baseline visit and throughout the study. The trial included a vulnerable population, ensuring a comprehensive evaluation of the treatment's efficacy across diverse demographic groups.

The clinical trial is designed as a **randomized**, **double-blind**, **placebo-controlled** study to evaluate the efficacy and safety of **RO7790121** in patients with moderate to severe **atopic dermatitis**. The primary objective is to assess the proportion of participants achieving an Eczema Area and Severity Index (EASI)-75 response, defined as a ≥ 75% improvement from baseline, at Week 16. Secondary endpoints include the proportion of participants achieving an Investigator Global Assessment (IGA) score of clear or almost clear with a ≥ 2-grade improvement at Week 16 and Week 32, as well as other measures of clinical response and safety.

The trial is expected to commence recruitment on February 3, 2025, and conclude by February 20, 2027. Participants will be involved in the study for a maximum treatment period of 1 year. The study will include an initial screening visit to confirm eligibility based on criteria such as a confirmed diagnosis of atopic dermatitis according to the Hanifin/Rajka criteria, an EASI score ≥ 16, and an IGA score ≥ 3. Participants must also have at least 10% body surface area involvement and have used an additive-free emollient daily for at least 7 days prior to the baseline visit.

Following the screening, eligible participants will be randomized to receive either RO7790121 or placebo via subcutaneous injection. Study visits will occur at regular intervals to monitor efficacy and safety, with assessments including EASI scores, IGA scores, and adverse event monitoring. The end-of-study visit will occur at Week 32, where final assessments will be conducted. Participants may be withdrawn from the study early due to adverse events, non-compliance with study procedures, or withdrawal of consent.

The clinical trial involves the administration of **RO7790121**, an experimental medication formulated as a **solution for injection/infusion**. The active substance, RO7790121, is a protein of other origin, developed by F. Hoffmann-La Roche Ltd. The medication is administered via **subcutaneous injection**. The dosing schedule is determined by the study protocol, with a maximum treatment period of one unit of time, as specified in the trial documentation. The dosage is measured in milligrams, although specific dosing amounts are not provided. Participant compliance with the dosing regimen is monitored throughout the study to ensure adherence to the protocol.

In addition to the experimental treatment, a **placebo** is used as a comparator in this double-blind, placebo-controlled study. The placebo is referred to as RO7790121 Placebo and is utilized to assess the efficacy and safety of the experimental medication. The placebo does not contain any active substance and serves as a control to evaluate the treatment's effect on patients with moderate to severe **atopic dermatitis**. The administration route and form of the placebo are not specified, aligning with the study's design to maintain blinding and ensure unbiased results.

The efficacy of RO7790121 in patients with moderate to severe **Atopic Dermatitis** will be assessed through a Phase II, multicenter, double-blind, placebo-controlled clinical trial. The primary endpoint for evaluating efficacy is the proportion of participants achieving an Eczema Area and Severity Index (EASI)-75 response, defined as a ≥ 75% improvement from baseline, at Week 16. Secondary endpoints include the proportion of participants achieving an Investigator Global Assessment (IGA) score of clear (0) or almost clear (1) with a ≥ 2-grade improvement at Week 16 and Week 32, the proportion achieving EASI-75 and EASI-90 responses at various timepoints, and percent changes from baseline in EASI and peak pruritus Numerical Rating Scale (NRS) scores by visit.

Additional secondary endpoints involve changes from baseline in the Dermatology Quality of Life Index at Week 16, Week 32, and by visit, as well as the incidence and severity of adverse events, including serious adverse events and those leading to study treatment discontinuation. Changes from baseline in selected vital signs and clinical laboratory test results will also be monitored. Serum concentration of RO7790121 will be measured at specified timepoints to further assess the drug's efficacy. These efficacy parameters will be collected and analyzed at designated intervals throughout the study to ensure a comprehensive evaluation of the treatment's impact on the condition.