The goal of this clinical study is to learn more about the study drug lenacapavir (LEN), safety, tolerability, and pharmacokinetics (how LEN is absorbed, modified, distributed, and removed from the body of the participants) of once-yearly intramuscular for HIV pre-exposure prophylaxis (PrEP) in people with an indication for PrEP.

The primary objective of this study is to evaluate the pharmacokinetics (PK) and the safety and tolerability of intramuscular (IM) every 12 months (Q12M) LEN for PrEP among people with an indication for PrEP.

Key Inclusion Criteria:

• At least 16 years of age at screening.

• Receptive anal or vaginal sex in the past 6 months and at least 1 of the following:

  1. Condomless receptive sex (vaginal or anal) with 1 or more sex partners of unknown HIV status during the past 6 months
  2. For a person who has engaged in anal sex in the past 6 months: diagnosis of syphilis, gonorrhea, or chlamydia in the past 6 months
  3. For a person who has engaged in vaginal sex in the past 6 months: diagnosis of syphilis or gonorrhea in the past 6 months
  4. Sex with partner known to be living with HIV with an unknown or detectable viral load in the past 6 months

• Negative local rapid fourth generation HIV-1/2 antibody (Ab)/antigen (Ag) test, central fourth generation HIV-1/2 Ab/Ag, and HIV-1 RNA quantitative nucleic acid amplification testing (NAAT) at screening.

Key Exclusion Criteria:

• Current signs or symptoms suggesting HIV infection
• Acute viral hepatitis A, B, or C or evidence of chronic hepatitis B or C infection
• Severe hepatic impairment or a history of or current clinical decompensated liver cirrhosis (eg, ascites, encephalopathy, variceal bleeding)
• Past or current participation in HIV vaccine or HIV broadly neutralizing antibody study unless participant provides documentation of receipt of placebo (ie, not active product)
• Prior use of oral LEN in the past 90 days or subcutaneous LEN in the past 18 months

Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Cisgender men, Transgender women, Transgender men, Cisgender women, and Gender non-binary