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PURPOSE 2: Study of Lenacapavir for HIV Prevention

About this study

PURPOSE 2 (GS9023) is a research study to test a drug that may be able to prevent Human Immunodeficiency Virus (HIV) infection before it occurs. This type of medicine is called PrEP, or pre-exposure prophylaxis. Lenacapavir is a drug that is effective at preventing HIV among adults. It is long acting, injectable, and may need to be given only 2 times a year.

PURPOSE 2 is a study to find out if long-acting, injectable (given as a shot) lenacapavir for PrEP is safe and acceptable for adolescents.

St. Jude is one of about 100 sites taking part in the study worldwide. The study will enroll a total of around 3,000 participants at all locations.

Who is eligible for the PURPOSE 2 study?

You may be eligible for this study if you:

  • Are at least 16 years old
  • Are a cisgender man, transgender or gender nonbinary individual who has receptive anal sex
  • Have had or are interested in sexual experiences with male or transgender partners
  • Have not taken oral PrEP in the past 12 weeks or any prior use of long-acting systemic PrEP

Take the quiz to see if you qualify.

Why is the study important?

More than 20% of new HIV infections occur among people ages 13 to 24. PrEP medicine is an effective way to prevent HIV infection in adolescents and adults. PrEP does not prevent other kinds of sexually transmitted diseases.

There are daily oral tablet options for PrEP. But, according to the Centers for Disease Control and Prevention, not everyone who could benefit from these medicines takes them. There are many reasons they are not being used as widely as they could be. Reasons include:

  • Lack of health-system access
  • Medical mistrust due to homophobia, transphobia, and stigma
  • Unwilling to take daily oral PrEP
  • Concerns about side effects, especially while taking gender-affirming hormones

A long-acting, injectable form of PrEP, such as lenacapavir, could give at-risk individuals a more flexible, less-stigmatized option to prevent HIV.

Learn more

If you have questions about the PURPOSE 2 study or want to talk with someone about it, call or text us at 901-216-1166 or email

Review Frequently Asked Questions about the PURPOSE 2 study.

Read about the St. Jude HIV program and learn how we and our community partners are working to end the HIV epidemic in Shelby County.

Call the St. Jude Hughes Infectious Disease Clinic/HIV Clinic: 901-595-5027.

Call our HIV Linkage to Care Program Coordinator: 901-857-7783 or 901-595-7405.

The above information is intended to provide only a basic description about a research protocol that may be currently active at St. Jude. The details made available here may not be the most up-to-date information on protocols used by St. Jude. To receive full details about a protocol and its status and or use at St. Jude, a physician must contact St. Jude directly.


Full title:

A Phase 3, Double-Blind, Multicenter, Randomized Study to Evaluate the Efficacy and Safety of Subcutaneous Twice Yearly Long-Acting Lenacapavir for HIV Pre-Exposure Prophylaxis in Cisgender Men, Transgender Women, Transgender Men, and Gender Nonbinary People ≥ 16 Years of Age Who Have Sex With Male Partners and Are at Risk for HIV Infection

Study goal:

To find out if long-acting, injectable (given as a shot) lenacapavir for PrEP is safe and acceptable for adolescents. 




At least 16 years old

For physicians and researchers

Patients accepted to St. Jude must be referred by a physician or other qualified medical professional. Learn how St. Jude can partner with you to care for your patient.


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