This clinical study is being conducted to evaluate the safety and efficacy of an investigational medicine, lenacapavir, to reduce the chance of getting HIV—also known as pre-exposure prophylaxis (PrEP).

Your answers to the questions in the online prescreening form will determine if you meet certain key criteria that are required to participate in the PURPOSE 4 study. If you meet these criteria, you may then contact a participating doctor’s office of your choice using their contact details on our website. Their staff will answer any questions you may have and will discuss the next steps to further determine whether you meet all of the criteria for participation. Not all people who complete the online prescreening form will be able to participate in this study.

If you meet the criteria in the prescreening form and then contact a participating doctor’s office, you will have a single visit where the staff at the doctor’s office will ask you to review and sign an informed consent form that explains more about the study. During that visit you will get an HIV test and other lab tests. Then the staff at the doctor’s office will ask more questions and run some medical tests to see if you meet all eligibility criteria to participate in the clinical research study. If you do not have HIV and meet the other eligibility criteria, you can choose to participate in the second part of the study. If you are confirmed to have HIV, we will link you to HIV care in your community.

Feel free to discuss your study-related medical care with the study doctor or staff at any time during the course of the research study. It is important to take the investigational medicine as prescribed. You will answer questions regarding how you feel during your participation and whether the investigational study medicine has been taken at the appropriate times. Participants are encouraged to discuss study participation with their primary care doctor.

The study will last for at least 1 year and up to 2.5 years. The visits are 4-13 weeks apart, with 4-8 visits per year.

Approximately 250 people across the United States will be enrolled in PURPOSE 4. This study is looking for people who use injection drugs and are at least 18 years old.

Reimbursement for study-related travel may be available depending on local practice.

If you participate, study-related doctors' visits, monitoring of your health, and the study medicine will be provided to you at no cost. You do not need health insurance to participate. The study staff at the participating site will be able to answer any questions you may have.

The choice to participate in this study is entirely yours. Your primary care doctor does not have to give his or her permission or a referral for you to participate in this study. However, you should tell your primary care physician about your participation and keep him or her informed about the study. You should also keep the study doctor informed if your primary care physician changes or if there are other changes to your health during the study.

You could experience side effects associated with the study medicine. The study staff will discuss the known risks in detail with you before you decide whether to participate.

After a clinical study is complete, all of the information is collected and analyzed to help determine the study medicine’s safety and efficacy. Please consult with your study doctor or primary healthcare provider to determine your HIV prevention options after completing the study.

The PURPOSE 4 study is being conducted by trained, qualified, and licensed medical doctors across the United States.

PURPOSE 4 is a collaboration between Gilead Sciences, Inc, the HIV Prevention Trials Network, the National Institute of Allergy and Infectious Diseases (NIAID) and the National Institute on Drug Abuse (NIDA) at the National Institutes of Health. Gilead Sciences, Inc. is developing the study medicine and sponsoring the clinical trial. GILEAD is a trademark of Gilead Sciences, Inc. All other trademarks referenced in this document are the property of their respective owners.