Preferences regarding emerging HIV prevention technologies among Toronto men who have sex with men Darrell H.S. Tan1, Jayoti Rana1, Shawn Fowler2, Trevor A. Hart3, James Wilton4, Ahmed M. Bayoumi1 1. St. Michael’s Hospital; 2. Hassle Free Clinic; 3. Ryerson University; 4. Ontario HIV Treatment Network Abstract WEAC0102. July 26, 2017

Disclosure I have received investigator-initiated research grants from Gilead and Viiv I am a Site Principal Investigator for industry-sponsored clinical trials by GSK

Background New HIV prevention technologies (NPTs) are currently in development, each with unique attributes that may appeal differently to different users Long-acting injectable agents (eg. cabotegravir) Rectal microbicides (eg. tenofovir reduced glycerin 1% gel) Understanding patient preferences can inform: How providers discuss, present and frame NPTs with patients How policy-makers project uptake and population-level impact

Background A Discrete Choice Experiment (DCE) is a health economics method for quantifying such preferences, involving: 1. Identifying attributes of interest (eg. route of administration) 2. Assigning levels to each attribute (eg. pill, injection, etc.) 3. Creating scenarios combining these attributes/levels 4. Having participants choose between scenarios 5. Mixed logistic regression to assess trade-offs between attributes We used a DCE to characterize preferences for NPTs among Toronto MSM

Methods Design: Administered within an anonymous survey Participants: Adult MSM undergoing anonymous point-of-care HIV testing Setting: Hassle Free Clinic + 3 satellite sites Downtown sexual health clinic serving large MSM population Highest HIV+ rate of all anonymous testing sites in Ontario

Discrete Choice Experiment 12 “choice sets”, each presenting 3 options: Two hypothetical NPT options “Usual methods to prevent HIV infection” (excluding PrEP) NPT options differed according to 4 attributes: Route/frequency: daily pill, on-demand pill, monthly injection, on-demand rectal gel HIV prevention efficacy: 50%, 65%, 80%, 99% risk reduction Side effects: none, mild (nausea, injection site reaction, or rectal discomfort) Risk of resistance: no, low, moderate chance of decreasing future treatment options

Example question

Analyses Pilot phase (first 62 respondents) to ensure: Questions understandable Trade-offs being made Mixed logistic regression to infer relative preferences for attributes and to estimate heterogeneity Beta coefficients then linearly transformed so that utility 0 = least preferred combination of NPT attributes 100 = most preferred combination of NPT attributes Latent class analysis to identify response patterns

Results 306 respondents of which 53 excluded from DCE analyses due to invariant responses (n=38), on PrEP (n=12), all missing responses (n=2), transgender (n=1) Characteristic Value Age 31 (25-38) Race White Asian Latino/Hispanic South Asian Middle Eastern Black Other 169 (55.2) 56 (18.3) 24 (7.8) 19 (6.2) 14 (4.6) 12 (3.9) Characteristic Value Education High school College/Undergrad Grad/Professional 40 (13.2) 161 (53.0) 103 (33.9) # partners, past 6 mo. 6 (3, 10) # times condomless receptive anal sex, past 6 mo. 0 (0, 2) Aware of PrEP 278 (90.9)

Utility scores by attribute & level Variable Coefficient 95% Conf. Int. No PrEP 47.3 (38.6 to 56.0) Formulation and side effects Daily pill 9.8 (0.7 to 18.9) Daily pill with mild nausea -31.8 (-110.7 to 47.1) On-demand pill 16.5 (4.6 to 28.3) On-demand pill with mild nausea 14.6 (1.6 to 27.7) Monthly injection 4.9 (-6.7 to 16.6) Monthly injection, mild site reaction -3.5 (-16.9 to 10.0) On-demand rectal gel -4.5 (-16.4 to 7.3) On-demand rectal gel, mild discomfort -11.8 (-26.9 to 3.4) Efficacy 50% risk reduction 40.2 (35.8 to 44.5) 65% risk reduction 52.4 (46.7 to 58.1) 80% risk reduction 64.7 (57.7 to 71.7) 99% risk reduction 80.2 (71.6 to 88.9) Risk of resistance No Risk 3.3 (1.5 to 5.1) Low Risk 2.9 (1.3 to 4.4) Moderate Risk -8.3 (-10.5 to -6.2)

Illustrative examples Variable Coefficient No PrEP 47.3 Formulation and side effects Daily pill 9.8 Daily pill with mild nausea -31.8 On-demand pill 16.5 On-demand pill with mild nausea 14.6 Monthly injection 4.9 Monthly injection, mild site reaction -3.5 On-demand rectal gel -4.5 On-demand rectal gel, mild discomfort -11.8 Efficacy 50% risk reduction 40.2 65% risk reduction 52.4 80% risk reduction 64.7 99% risk reduction 80.2 Risk of resistance No Risk 3.3 Low Risk 2.9 Moderate Risk -8.3 Best combination: On-demand pill No side effects 99% efficacy No risk of resistance Utility score = 100

Illustrative examples Variable Coefficient No PrEP 47.3 Formulation and side effects Daily pill 9.8 Daily pill with mild nausea -31.8 On-demand pill 16.5 On-demand pill with mild nausea 14.6 Monthly injection 4.9 Monthly injection, mild site reaction -3.5 On-demand rectal gel -4.5 On-demand rectal gel, mild discomfort -11.8 Efficacy 50% risk reduction 40.2 65% risk reduction 52.4 80% risk reduction 64.7 99% risk reduction 80.2 Risk of resistance No Risk 3.3 Low Risk 2.9 Moderate Risk -8.3 Best combination: On-demand pill No side effects 99% efficacy No risk of resistance Utility score = 100 Worst combination: Daily pill Mild side effects 50% efficacy Moderate risk of resistance Utility score = 0

Illustrative examples Variable Coefficient No PrEP 47.3 Formulation and side effects Daily pill 9.8 Daily pill with mild nausea -31.8 On-demand pill 16.5 On-demand pill with mild nausea 14.6 Monthly injection 4.9 Monthly injection, mild site reaction -3.5 On-demand rectal gel -4.5 On-demand rectal gel, mild discomfort -11.8 Efficacy 50% risk reduction 40.2 65% risk reduction 52.4 80% risk reduction 64.7 99% risk reduction 80.2 Risk of resistance No Risk 3.3 Low Risk 2.9 Moderate Risk -8.3 Injection Mild side effects 80% efficacy Low risk of resistance Utility score = 64.1

Illustrative examples Variable Coefficient No PrEP 47.3 Formulation and side effects Daily pill 9.8 Daily pill with mild nausea -31.8 On-demand pill 16.5 On-demand pill with mild nausea 14.6 Monthly injection 4.9 Monthly injection, mild site reaction -3.5 On-demand rectal gel -4.5 On-demand rectal gel, mild discomfort -11.8 Efficacy 50% risk reduction 40.2 65% risk reduction 52.4 80% risk reduction 64.7 99% risk reduction 80.2 Risk of resistance No Risk 3.3 Low Risk 2.9 Moderate Risk -8.3 Injection Mild side effects 80% efficacy Low risk of resistance Utility score = 64.1 Rectal gel Utility score = 55.8

Utility scores by attribute & level

Trade-offs: What is the minimum efficacy a strategy must have in order to be preferred over no PrEP? (95% CI) On-demand pill 50.5 (43.9 to 57.2) Daily pill 58.7 (50.6 to 66.8) Monthly injection 64.7 (58.0 to 71.4) On-demand rectal gel 76.2 (68.2 to 84.2)

Heterogeneity in utility scores Average score=47.3

Minimum efficacy required for strategy to be preferred over no PrEP Latent class analysis identified four subsets of participants Minimum efficacy required for strategy to be preferred over no PrEP   Class 1 (40.5%) 2 (20.7%) 3 (21.9%) 4 (16.9%) Daily pill 15.6% >100% 66.4% 88.0% Daily pill with mild nausea <0% 86.5% 94.7% On-demand pill 64.3% 77.7% On-demand pill with mild nausea 82.8% 83.3% Monthly injection 22.6% 69.7% 84.2% Monthly injection, mild site reactions 14.7% 64.5% 85.8% On-demand rectal gel 31.1% 91.7% 71.0% On-demand rectal gel, mild discomfort 3.8% 71.7% Favours pill Averse to all Averse to gel Ambivalent

Limitations Context: Toronto, Summer 2016 Simplifying assumptions Social acceptability of PrEP modest, rising slowly Simplifying assumptions eg. severity of side effects always mild Only considered 4 attributes Hypothetical bias

Conclusions Attitudes towards emerging PrEP formulations among MSM are heterogeneous Most favoured: On-demand pill with no side effects, 99% efficacy, no risk of resistance Least favoured: Daily pill causing nausea, 50% efficacy, moderate risk of resistance HIV prevention efficacy was primary driver of utility Preferences or aversions towards specific routes of administration may affect uptake of and adherence to emerging HIV prevention strategies

Acknowledgements All participants in the pilot and final phases DHST is supported by a New Investigator Award from