Abstract
INTRODUCTION: The CAPRISA 018 Phase I trial evaluated the safety, tolerability and pharmacokinetics of a 110 mg tenofovir alafenamide (TAF) implant for HIV prevention in South African women. This follow-up cohort study, CAPRISA 097, assessed the long-term resolution of implant site reactions (ISRs) after implant removal and explored user acceptability and implant attribute preferences to inform the development of next-generation pre-exposure prophylaxis (PrEP) implants. METHODS: Women previously enrolled in CAPRISA 018 were recruited and followed quarterly for 12 months between 13 October 2022 and 27 October 2023. ISR prevalence, severity and resolution were evaluated at each visit. Implant acceptability, implant attribute preferences and PrEP preferences were assessed at enrolment and at month 12. RESULTS: Of 36 eligible participants, 35 were enrolled a median of 299 days after implant removal (IQR: 243-490). At enrolment, all 35 participants (100%) had ongoing mild (Grade 1) scarring, with additional findings of hyperpigmentation (14%), induration (6%) and hypopigmentation (3%). By study exit, scarring persisted in all participants (median duration: 623 days; IQR: 579-819), while hyperpigmentation and induration remained in two and one participant, respectively. Acceptability ratings for implant visibility were similar at enrolment and month 12 (77.1% vs. 75.0%), as were ratings for pain (68.6% vs. 78.1%). Side effects due to ISRs received the highest "very unacceptable" ratings, in 37.1% of participants at enrolment and 21.9% at study exit. Scarring was considered acceptable by 65.7% of participants at enrolment, increasing to 78.1% at exit. Perceived partner interest in the various PrEP products aligned with participant interest. A palpable 12-month implant was acceptable to most participants, whereas increased length, width or stiffness reduced the likelihood of use. Preferred PrEP options were a 12-monthly implant (38.2% at enrolment vs. 50.0% at month 12), a 6-monthly injection (29.0% vs. 37.5%) and daily oral PrEP tablets (12.0% vs. 3.0%). CONCLUSIONS: Mild but persistent scarring was observed following TAF implant removal, with limited cases of hyperpigmentation and induration. Despite these local side effects, a 12-monthly implant remained the most preferred PrEP option among women previously enrolled in the TAF implant trial.