Two friends laughing together.
Actor portrayal.

Welcome to PURPOSE 1

Prevention should include women.

Globally, women and adolescent girls bear the highest burden of HIV, highlighting the critical need for effective HIV prevention options. In Sub-Saharan Africa, women and adolescent girls make up almost 60% of all new HIV infections. Stigma, marginalization, poverty, gender-based violence, and social inequities are some of the factors that have made women and adolescent girls especially vulnerable to HIV. PURPOSE 1, which enrolled cisgender women, will evaluate an investigational drug, lenacapavir, and an FDA-approved PrEP drug for people assigned male at birth, emtricitabine/​tenofovir alafenamide, also known as F/TAF or DESCOVY®, for PrEP. This trial is taking place in South Africa and Uganda and has completed enrollment.

The PURPOSE 1 study is currently in progress with interim results now available.

More information about the PURPOSE 1 study can also be found at clinicaltrials.gov.

What Is PrEP?

PrEP, or pre-exposure prophylaxis, helps prevent people from getting HIV. It is for people who do not have HIV (are HIV-negative), but could get HIV. It means taking prescription medicine routinely before exposure to HIV to help reduce the risk of getting HIV.

  • The PURPOSE studies are being done to see whether an investigational PrEP medicine, lenacapavir, helps reduce the chance of getting HIV through sex
  • PURPOSE 1 is also being done to see whether DESCOVY for PrEP helps reduce the chance of getting HIV through sex in people assigned female at birth

Some factors that may increase the chance of getting HIV include:

  • Having sex with partners of unknown HIV status
  • Having sex with people who are living with HIV but not on HIV treatment and with an undetectable viral load
  • Having sex in a geographic area where HIV is common
  • Having sex while under the influence of substances or alcohol (which can increase risk indirectly by lowering people’s inhibitions and reducing use of safer sex practices)
  • Not using condoms consistently with partners of unknown status

Know the limits of PrEP

PrEP is the routine use of prescription medicine before exposure to HIV to prevent getting it. The most common way to get HIV is through sex or injection drug use.

According to Centers for Disease Control and Prevention (CDC), PrEP is very effective when taken as prescribed. It can reduce the chance of getting HIV through sex by 99%. It also reduces getting HIV from injection drug use by at least 74%.

PrEP medication does not protect against other sexually transmitted infections (STIs), so consistent condom use is important.

What is a sexual network?

“Sexual network” is a term that describes how you and your sexual partner or partners are connected.

Your sexual network includes:

  • You
  • Any current partners
  • All past partners
  • All of your partner’s partners (and so on)

What Does the Study Involve?

The first part of the study is a single visit where you will get an HIV test and other lab tests.

  • Participants who do not have HIV and met the other eligibility criteria may choose to participate in the second part of the study
  • Those confirmed to be living with HIV will be linked to nearby HIV care facilities

Everyone who enrolls in the second part of the study will receive a daily pill and an injection given every 6 months.

  • Of the injection and the pill, one is the active drug and one is a placebo

The second part of the study will last for at least 1 year and up to 3 years.

  • The visits are 4-13 weeks apart, with 4-8 visits per year

Which drug participants receive is determined by chance.

  • The active drug may be lenacapavir (2 out of 5 chance) or F/TAF (2 out of 5 chance) or F/TDF (1 out of 5 chance)
  • Neither the study participant nor the study doctor know which medication is active and which is placebo
  • When the second part of the study is over, participants will find out which active drug they were taking and have the option to enroll in an extension phase where everyone receives lenacapavir

Our Commitment to Inclusion

From day 1, Gilead designed the PURPOSE 1 study with all people who would benefit from PrEP in mind.

Explore a video from Moupali Das, MD, MPH, the Executive Director of HIV Clinical Development at Gilead, as she describes why it was important that PURPOSE add study sites in new locations.