1. Is on-demand PrEP a suitable tool for MSM who practice chemsex
Is on-demand PrEP a suitable tool for MSM who practice chemsex? Results from a sub-study of the ANRS-IPERGAY trial
Roux P1, Fressard L1, Suzan-Monti M1, Chas J2, Capitant C3, Meyer L3, Tremblay C4, Molina JM5, Pialoux G2, Spire B1
1INSERM UMR912 – SESSTIM, Marseille; 2Hôpital Tenon, Paris; 3INSERM SC10, Le Kremlin-Bicêtre; 4Université de Montréal; 5Hôpital Saint-Louis, Paris

2. No conflicts of interest to declare.
Conflict of Interest
No conflicts of interest to declare.

3. Context
Chemsex - the use of psychoactive substances during sexual encounters : a growing concern among MSM Stuart, HIV Nursing, 2013; McCall, 2015, BMJ
Main reasons for practicing chemsex reported by MSM Weatherburn, 2017, STI
to increase confidence, disinhibition and stamina
to enhance sexual arousal and eroticism
Main drugs involved : crystal meth, GHB/GBL, cathinones
Psychostimulants, empathogens, hallucinogens
High potential of addiction

4. Context
One very risky element in chemsex is “slamming” = drug injection before sex Foureur, 2015, AIDES
Many negative consequences of chemsex : related to drug use but also to sexual risk behaviors Bourne, 2015, IJDP
Including HIV transmission
ANRS-Ipergay trial : efficacy of on-demand PrEP in preventing HIV transmission among MSM Molina, 2015, NEJM; Molina, 2017, Lancet HIV
Question: Is PreP a suitable tool to prevent HIV transmission in MSM who practice chemsex ?

5. Methods (1)
ANRS IPERGAY : a double-blind RCT conducted in France and Canada providing sexual activity-based antiretroviral prophylaxis (PrEP)
Inclusion criteria:
HIV- males or transgender women who have sex with men
aged 18 years or older
at high risk of HIV
Data collection: online questionnaire every 2 months
sociodemographic characteristics
alcohol and recreational drug use
sexual behaviors
PrEP adherence
during the most recent sexual encounter

6. Methods (2) Present sub-study : open-label extension
N=331 participants, 1,657 visits
Median[IQR] follow-up=10 [9-11] months
Objectives
To characterize chemsexers (being under the effect of a psychoactive drug during most recent sexual encounter)
To study the association between chemsex and PrEP use (having used PrEP during most recent sexual encounter)
Statistical analyses: logistic regression using a GEE model

7. least once during follow-up
Results (1) Characteristics of participants : chemsex versus no chemsex during follow-up
Participants (N=331)
Practiced chemsex at
least once during follow-up p† No
N=236 (71%)
Yes
N=95 (29%)
% or mean (SD)
Age
36 (10)
36 (9)
Educational level > high school
74.2
81.1
Active employment
86.9
85.2
Anxiolytic consumption
19.5
40.0
***
Antidepressant consumptiona
14.8
14.7
Recent depressiona
20.8
22.1
Sensation Seeking Score (BSSS-4)b
11 (4)
13 (4)
Participation in prevention activitiesa
37.7
39.0
Practiced slamming at least once during follow-upc
1.9
23.5
Number of sexual encounters (previous 4 weeks)d
11 (11)
20 (24)
† Chi² tests for categorical variables, t-test for continuous variables. *** p≤0.001
a during the previous 12 months b 10 missing values c 39 missing values d Reported at most recent assessment; 2 missing values
Abbreviations: BSSS-4 = Brief Sensation Seeking Scale, as per Stephenson et al., 2003.

8. Results (2) Factors associated with chemsex at most recent sexual encounter
 Visits (N=1657)
Practiced chemsex during most
recent sexual encounter p† No
N=1400 (84%)
Yes
N=257 (16%)
% or mean (SD)
Chemsex with one partner (vs. multiple partners)a -
75.9
Psychoactive substances involved a
GHB/GBL
51.4
Mephedrone/cathinone/PDPV/NRJ3/4MEC
45.9
Amphetamine-like substances (ecstasy/methamphetamines)
24.5
Cocaine
22.2
Type of partner
***
Main partner
33.6
12.1
Casual partner
59.4
63.8
Multiple partners
6.9
24.1
High-risk HIV exposure : condomless anal sexb
68.4
79.6
Hardcore sexual practices (fisting, sadomasochistic practices)c
7.1
33.5
HIV transmission risk perception [0;10]
3 (3)
4 (3)
PrEP used
80.1
94.1
† Chi² test for categorical variables, t-test for continuous variables. *** p≤0.001 
a Among 257 visits reporting chemsex (195 with one, 62 with multiple partners) b 29 missing values c 16 missing values d 19 missing values

9. Results (3) Factors associated with PrEP use at most recent sexual encounter
Results from GEE multiple logistic regression,
n=331 participants, 1619 visits 
aOR [95% CI] p†
Age (ref. 19-29)
30-42
2.3 [1.3;4.1] **
43-61
4.3 [2.2;8.6]
***
Educational level > high school (ref. No)
0.6 [0.3;0.96] *
Active employment (ref. No)
1.5 [0.9;2.7]
Recent depression (ref. No)
0.6 [0.3;0.95]
At most recent sexual encounter:
Type of partner (ref. Main partner)
Casual partner
7.8 [5.3;11.6]
Multiple partners
29.2 [8.6;98.4]
Sexual practices (ref. Oral sex)
Insertive anal sex and/or oral sex
1.4 [0.8;2.4]
Receptive anal sex and/or insertive anal sex and/or oral sex
1.2 [0.7;2.0]
High-risk HIV exposure: condomless anal sex (ref. No)
1.5 [0.9;2.4]
HIV transmission risk perception [0;10]
1.1 [1.0;1.2]
Chemsex practice (ref. No)
2.2 [1.1;4.6]
† p-values for the parameters estimates. * p≤0.05 ** p≤0.01 *** p≤0.001.
Abbreviations: aOR [95%CI] = adjusted odds-ratio [95% confidence interval]

10. Discussion (1) Chemsex practice is associated with PrEP use
No significant difference between chemsexers and non-chemsexers regarding sociodemographic characteristics
However, chemsexers have a more vulnerable psychological profile: anxiolytic consumption and higher scores on sensation-seeking scale

11. Discussion (2)
Chemsex associated with: sex parties/casual partners, high-risk/hardcore practices but higher HIV transmission risk perception
PrEP is a suitable tool to reduce HIV transmission in chemsexers
Access to PrEP is an opportunity to provide other prevention interventions and comprehensive care for chemsexers

12. Acknowledgments
Participants
Study and Peer Counselors
Trial Scientific committee
DSMB
ANRS Staff
INSERM SC10-US19