From Acceptability to Affordability: A Decision Cascade Analysis of Long-Acting Injectable HIV Pre-Exposure Prophylaxis (Lenacapavir) Among HIV-Negative Men Who Have Sex with Men in Bali, Indonesia

Background Long-acting injectable HIV pre-exposure prophylaxis (PrEP) using lenacapavir (LEN) may reduce adherence challenges associated with daily oral PrEP. However, evidence remains limited on how populations at risk progress from acceptability to preference and affordability of LEN. We examined a sequential decision cascade for LEN among HIV-negative men who have sex with men (MSM) in Bali, Indonesia. Methods We conducted a cross-sectional survey among 116 HIV-negative MSM in Bali. Data included awareness of LEN, willingness to use LEN, preferred PrEP modality under hypothetical availability (LEN versus oral PrEP), and willingness to pay (WTP). Descriptive analyses characterised each cascade stage, and multivariable logistic regression identified factors associated with preference for LEN. Results Participants had a median age of 32 years (IQR 26.8–37.3), and 52.6% had ever used oral PrEP. Awareness of LEN was low, with only 28.4% having heard of LEN. Despite this, acceptability was high: 50.8% reported being willing or very willing to use LEN. Only 45.7% of respondents preferred LEN compared with oral PrEP, indicating attrition at the modality choice stage.. In multivariable analyses, perceived convenience of the six-monthly injection schedule was the only factor independently associated with preference for LEN (unadjusted OR 5.68, 95% CI 1.97–16.39; adjusted OR 4.91, 95% CI 1.65–14.59). No significant associations were observed for age, education level, prior oral PrEP use, perceived effectiveness, stigma-related concern, or concern about side effects. Willingness to pay further declined at > IDR 500.000 higher price thresholds, highlighting affordability as an additional barrier despite high acceptability. Conclusion Among HIV-negative MSM in Bali, acceptability of LEN was high, but preference and affordability were more selective. Considering the full decision cascade, from acceptability to affordability, is essential when planning the introduction of long-acting injectable PrEP.