Update on baseline STIs in UK oral PrEP study (PROUD)

Simon Collins, HIV i-Base

The cost-effectiveness of pre-exposure prophylaxis (PrEP) can only be considered in association with the background risk of HIV in the people who use it. Baseline data from the UK PROUD are important for showing that this study has accurately enrolled a suitably high-risk group.

PROUD is an ongoing randomised two-year pilot study of oral PrEP (using daily Truvada) that compares immediate PrEP to a standard-of-care control group that gets PrEP after 12 months. It has been fully enrolled since April 2014.

Baseline data including HIV risk and recent STI history for 511 of the 545 participants were presented in a poster at AIDS 2014. [1]

The study recruited largely white, educated, employed gay men in their thirties. Baseline demographics include median age 36 (IQR 30-43), ethnicity: white (79%), other (5%), mixed (4%), Asian (4%), black (3%), Chinese (2% and Irish (2%); education level: 60% at university degree level or above, 17% to A-level. Most men were in full-time (72%) or part-time (9%) employment and 8% were unemployed (11% other or no answer). Almost half (46%) were in an ongoing relationship and 30% were living with a partner.

The median number of partners (for anal sex) in the previous three months was 10 (IQR 4-20) with median of 2 (IQR 1-5) and 3 (IQR 1-7) times for receptive and insertive anal sex respectively.

Participants already highly aware of HIV: they had a median of three HIV tests in the previous year and 36% had used post exposure prophylaxis (PEP). Of 446/511 answering the questions on STI history during the previous year, this included rectal gonorrhoea (27%), rectal chlamydia (22%) and syphilis (11%). Of 279 participants tested at baseline, 12 (5%) had rectal gonorrhoea, 10 (4%) had chlamydia and 12 (5%) had syphilis.

An earlier analysis of this data was previously presented at the BHIVA 2014 spring conference. [2]

Early data on STI rates during the study included five cases of sexually transmitted HCV, also presented at BHIVA. [3]


The PROUD study is due to announce results within a year after the last enrolled participant reaches the end of the two-year follow-up. Gilead has agreed to provide TDF/FTC to all participants until the end of this study.

The HIV Clinical Reference Group (CRG) have set up a group to look at drawing up a policy for PrEP on behalf of NHS England that includes broad membership including clinicians, PHE, NHS England, patient reps, BHIVA, BASHH, as well as modellers and economists. This group is currently finalising search criteria for an evidence review that will cover predicted uptake, number of infections averted, cost effectiveness, cost and affordability.

These draft guidelines are likely to be available for stakeholder and public comment in 2015.

It is currently unclear whether the bottleneck for an EU review of Truvada for PrEP use is due to lack of a clear regulatory pathway from the European Medicines Agency (EMA), given phase III randomised data was sufficient for the FDA approval and subsequent data is now available, or due to the Gilead not submitting an application regardless.

The lack of an indication should not be used to further block access given the wide use of ARVs as PEP for which no indication has been granted.


  1. Antonucci S et al. The UK PROUD PrEP Pilot Study: a baseline analysis. 20th International AIDS Conference (AIDS 2014), 20-25 July 2014, Melbourne. Poster abstract THPE197.
  2. Dolling D et al. Who accesses PrEP? An analysis of baseline data in the PROUD pilot study. 3rd joint BHIVA/BASHH Conference, 3-6 April 2014, Liverpool. Oral abstract abstract 043. (PDF)
  3. Tiraboschi J et al. Acute Hepatitis C in the PROUD pilot study. 3rd Joint BHIVA/BASHH Conference, 3-6 April 2014, Liverpool. Oral abstract O45. (PDF)

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