The purpose of this study is to learn if a medicine called itraconazole changes how the body processes the study medicine (PF-08642534) in healthy adults.

This study is seeking healthy participants (men or women) who:

• are aged 18 to 65 years of age
• are confirmed to be healthy by their medical history and medical tests
• have body mass index (BMI) of 16 to 30 kilograms per meter squared
• have a total body weight of more than 50 kilograms.

Participants will receive single doses of the study medicine (PF-08642534) with and without itraconazole.

The total planned time of participation is about 12 weeks. The study consists of:

• a screening period of up to 28 days before taking study drug
• about 4 weeks of staying in the study clinic
• a follow-up contact that will occur 28 to 35 days after taking itraconazole the last time.

Inclusion criteria:

• Generally healthy as determined by medical evaluation including medical history, physical examination, laboratory tests, blood pressure, pulse rate and standard 12-lead electrocardiogram (ECG).
• Body Mass Index (BMI) of 16-30 kilograms per meter squared, inclusive, and a total body weight greater than 50 kilograms (110 pounds).

Exclusion criteria:

• Evidence or history of clinically significant disease
• Specified abnormalities in safety assessments at Screening

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.