The purpose of this study is to learn about the safety and tolerability of a study medicine called PF-07940369 when it is taken by mouth in different amounts and/or at multiples times a day by healthy adult participants. The study will also look at the pharmacokinetics of PF-07940369 (how the medicine is changed and eliminated from the body).

The study is seeking participants that are:

• male or female aged between 18 to 65 years
• have a body mass index (BMI) of 16 to 32 kilogram per meter squared, and
• are considered to be generally healthy by the study doctor.

In each dose group, 10 participants will be randomly assigned to take PF-07940369 (8 participants) or placebo (2 participants). A placebo does not have any medicine in it but looks just like the medicine being studied. Participants will receive the study medication by mouth 1 to 2 times a day for 14 days while admitted to the study clinic.

The study team will look for the experiences of people receiving the study medicine. This will help the team see if the study medicine is safe and if the study can go to the next dose group. An optional Japanese group may be conducted later.

Participants will take part in this study for 10 weeks. During this time, the participants will stay in the study clinic for 16 days to receive the study medication. The participants will have multiple blood samples drawn during dosing for safety laboratory assessments and up to 48 hours after receiving the last dose of PF-07940369 to look at how the body processes the study medicine. After being discharged from the study clinic, the participants will have a study visit 7 to 10 days after the last dose. The study team will also call participants one time over the phone 28 to 35 days after receiving their last dose on Day 14.

Inclusion Criteria:

• Male participants and female participants who are not of childbearing potential who are overtly healthy as determine by medical evaluation including medical history, physical examination, laboratory tests, and standard 12 lead electrocardiogram (ECG).
• Body mass index (BMI) of 16 to 32 kg/m2; and a total body weight >50 kg (110 lb).

Exclusion Criteria:

• Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurological, or allergic disease.
• Any of the following conditions: History of iron storage diseases, History of iron utilization disorder, Diagnosis of hemolytic anemia or hemoglobinopathy, Diagnosis of iron deficiency anemia, Recent blood donation.
• History of intravenous iron therapy, erythropoiesis stimulating agent therapy and/or oral iron containing concomitant medications or nutritional supplements exceeding recommended dietary allowances for iron in adults.

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.

Participants will be assigned to receive study intervention according to the assigned treatment group from the randomization scheme. Investigators will remain blinded to each participant's assigned study intervention through the course of the study.

In order to maintain this blind, an otherwise uninvolved third party will be responsible for the preparation and dispensing of all study intervention.