Sexual Risk Compensation and Retention in PrEP Care in Korea: An HIV PrEP Demonstration Study

Area of Science:

• Public Health
• Infectious Diseases
• Clinical Pharmacology

Background:

• Pre-exposure prophylaxis (PrEP) using tenofovir disoproxil fumarate and emtricitabine (TDF-FTC) is a proven HIV prevention strategy.
• Feasibility and effectiveness of PrEP in the Republic of Korea, particularly among men who have sex with men (MSM), remained unevaluated.
• This study represents the first demonstration of PrEP in Korea, offering medication, lab tests, and clinic visits free of charge.

Purpose of the Study:

• To assess the feasibility and safety of daily oral PrEP (TDF-FTC) in HIV-negative MSM in Korea.
• To evaluate HIV and sexually transmitted infection (STI) incidence rates within this population.
• To analyze adherence, adverse events, and potential risk compensation behaviors associated with PrEP use.

Main Methods:

• HIV-negative MSM received daily TDF-FTC and attended regular outpatient clinic visits.
• Assessments included questionnaires on adverse reactions, adherence, and sexual behavior.
• Residual pill counts, plasma, and urine samples were collected to measure tenofovir diphosphate (TFV) concentrations.

Main Results:

• A total of 100 participants were followed for a median of 392 days, with a 77% retention-in-care rate.
• HIV incidence was 0.98 per 100 person-years; STI incidence was 13.67 per 100 person-years. No serious adverse events were observed.
• Adequate TFV concentrations (>40 ng/mL) were achieved by 55.3% at week 28 and 41.7% at week 52. Positive STI results correlated with higher TFV levels (aOR, 3.67; P=0.034).

Conclusions:

• Daily oral PrEP (TDF-FTC) demonstrated safety and effectiveness in Korean MSM.
• PrEP use was not associated with increased sexual risk behaviors, suggesting no significant risk compensation.
• This study provides the first analysis of risk compensation among PrEP users in East Asia.