Partially self-financed pre-exposure prophylaxis of HIV feasible for HK MSM
A pilot study found that partially self-financed pre-exposure prophylaxis (PrEP) is a feasible strategy for preventing HIV transmission among men who have sex with men (MSM) in Hong Kong.
The study recruited 71 PrEP-naïve HIV-negative adult MSM (median age, 32 years) with high behavioural risk of HIV transmission. Study participants received daily PrEP with tenofovir disoproxil fumarate (TDF) 300 mg/emtricitabine (FTC) 200 mg for 30 weeks at 13.3 percent of the drug cost. [Hong Kong Med J 2019;25:382-391]
None of the participants contracted HIV during the study period. At the end of the prescription period, the majority of participants (89 percent) indicated interest in continuing with PrEP.
Adverse events (AEs) related to the use of TDF/FTC were reported by 52 percent of participants who attended the clinic at least twice. The main AEs were dyspepsia (18 percent), loose stool or increased bowel motions (16 percent), fatigue (15 percent), headache (12 percent), and nausea with or without decreased appetite (12 percent). Two participants withdrew from the study because of grade 2 AEs that lasted over 2 weeks.
“The AEs were generally mild (grade 1), self-limiting, and did not bother the participants, and the majority resolved within the first week,” wrote the researchers.
At the last visit during the prescription period, the participants (n=65) were asked about their future intentions regarding PrEP. Fifty-eight participants (89 percent) responded that they would like to continue with PrEP after the study. At the end of the study period, 57 participants (80 percent) remained in the programme. Price (83 percent) was the main factor affecting their PrEP-using decision, followed by efficacy (46 percent) and potential AEs (42 percent).
“The results highlight the cost of PrEP as the major obstacle to its implementation, as patented TDF/FTC is too expensive for out-of-pocket acquisition. In our study, requiring participants to pay an amount closer to the cost of generic products (HKD 750 or <USD 100 per month) appealed to only a fraction of the MSM approached. About half of the eligible MSM did not join this project because of the high cost incurred,” wrote the researchers. [PLoS One 2018;13:e0191671; Lancet 2018;392(Suppl 1):S77]
Risk compensation, defined as the increased practice of condomless sex, is a concern in PrEP users. [AIDS 2018;32:523-530; Sex Transm Infect 2018;94:457-462] Condomless sex was reported by 99 percent of the participants. Out of the 59 MSM followed up through week 20 or beyond, compared with baseline, condom use decreased in 49 percent, increased in 20 percent, and was unchanged in 31 percent for sexual intercourse with known partners, and the corresponding rates for newly met partners were 40 percent, 15 percent, and 45 percent, respectively. “Risk compensation was observed, with a sexually transmitted infection incidence of 3.17 per 100 person-years,” commented the researchers.
“Our results showed that the operation of a PrEP clinic in Hong Kong is feasible and acceptable to the MSM community, as evidenced by our high retention rate of 80 percent among users of a daily regimen over the 7-month observation period. Making PrEP free or affordable should be an effective strategy for preventing HIV transmission through high-risk behaviours,” concluded the researchers.