PF-07264660

The purpose of this study is to learn about the safety and effects of 2 study medicines (PF-07275315 and PF-07264660) for the treatment of atopic dermatitis (AD). AD is a long- lasting itchy red rash, caused by a skin reaction.
This study is seeking participants who:
* are 18 years of age or more.
* Were confirmed to have AD at least 6 months ago.
* Are not having an effective treatment result from medicines that are applied on skin for AD.
* Are considered by their doctors to have moderate to severe AD.
All participants in the study will receive either PF-07275315 or PF-07264660 or placebo. A placebo does not have any medicine in it but looks just like the medicines being studied.
PF-07275315 or PF-07264660 or placebo will be given as multiple shots in the clinic over the course of 12 weeks.
Stage 1 participants will receive shots at the study clinic on Day 1, Week 1, Week 2, Week 4, Week 6, Week 8, Week 10 and Week 12.
Stage 2 participants will receive shots at the study clinic on Day 1, Week 4, Week 8 and Week 12.
The experiences of people receiving PF-07275315 or PF-07264660 will be compared to people who do not. This will help determine if PF-07275315 and PF-07264660 are safe and effective.
Participants will be involved in this study for up to 40 weeks (20 months). During this time, Stage 1 participants will have 16 visits at the study clinic, and Stage 2 participants will have 12 visits at the study clinic.

The purpose of this clinical trial is to learn about the safety and effects of study medicine PF-07264660 compared to a placebo. This is the first study of PF-07264660 in humans. All participants in this study will received PF-07264660 or a placebo and it will be assigned by chance. People may be able to participate if they are healthy. The study medicine may be given by shots under the skin or through a vein depending on which group you are assigned to. If you are assigned into Part A, you will receive the study medicine once, stay overnight at the research unit from 3 to 5 overnight stays and you will need to visit the clinic about 11 follow-up visits. Participants will be in this study for up to about 541 days. If you are assigned into Part B, you will receive the study medicine three times, stay overnight at the clinic from 3 to 5 overnight stays and you will need to visit the research unit about 12 follow-up visits. Participants willbe in this study for up to about 561 days.