1. #AIDS2016 | @AIDS_conference Changes in Bone Mass after Discontinuation of PrEP with Tenofovir Disoproxil Fumarate/Emtricitabine (TDF/FTC) in Young Men Who Have Sex with Men (YMSM): Extension Phase Results of Adolescent Trials Network (ATN) Study 110 Mulligan K, Hosek S, Kapogiannis BG, Landovitz RJ, Liu N, Cofield SS, Perumean-Chaney SE, Rutledge B, Havens PL, Wilson CM, for the ATN 110 Study Team ATNonline.org

2. #AIDS2016 | @AIDS_conference Conflicts of Interest No Conflicts among authors Gilead Sciences provided drug for the study as well as partial support for drug levels

3. #AIDS2016 | @AIDS_conference Background on ATN 110/113 Blinded and open label studies among MSM support the efficacy of TDF/FTC for HIV prevention In the US, gay/bisexual/MSM ages 13-24 are hardest hit by HIV epidemic – 18-24 year old MSM not well-represented in PrEP safety or efficacy studies in US – No PrEP data available on adolescent MSM to date Additional safety and behavioural data, as well as implementation data, in youth are needed to support a PrEP indication Paired PrEP studies: – ATN 110 (ages 18-22); data presented 2015 – ATN 113 (ages 15-17); data presented AIDS 2016

4. #AIDS2016 | @AIDS_conference ATN 110 Study Flow Pre-Screening Survey (venue-based or online) Ineligible or refuse survey In-person screening visit (IC and screening labs) In-person screening visit (IC and screening labs) Ineligible based on labs Baseline Visit (review labs & VL) Baseline Visit (review labs & VL) Behavioral Intervention (3MV or PCC) Behavioral Intervention (3MV or PCC) Week 0 – Dispense PrEP Follow-up Visits (weeks 4,8,12,24,36,48) Follow-up Visits (weeks 4,8,12,24,36,48) HIV Seropositive Visits Week 48: Evaluate for EPH Week 48: Evaluate for EPH Extension Phase Visits

5. #AIDS2016 | @AIDS_conference Baseline Demographics for ATN 110 Mean age20.18 Sexual IdentityGay – 77.8% Bisexual – 13.7% Highest grade completed High School – 33.8% Some college – 45.5% Not currently working30.1% Ever kicked out17.2% Ever paid for sex28.6% Partners in past mo5 Condomless sex81% CRAI w/last partner58% Any positive STI test22%

6. #AIDS2016 | @AIDS_conference ATN 110 Extension Phase (EPH) Background: – Prior studies with TDF/FTC PrEP in older populations showed modest bone loss by DXA scan – Prior studies showed resolution of bone density loss once TDF/FTC PrEP was discontinued EPH design: – Follow any subjects meeting minimal renal or bone criteria for an additional 48 weeks off of TDF/FTC – F/U visits at 24 (EPH1) and 48 (EPH2) weeks that included DXA assessment

7. #AIDS2016 | @AIDS_conference Extension Phase Criteria Bone Criteria – Participants < 20 years old, no increase in whole-body BMC or in BMD in lumbar spine from Baseline to Week 48 – Participants ≥ 20 years old, a decrease of 1% or greater in whole-body BMC or in BMD in total hip, femoral neck, or lumbar spine from Baseline to Week 48 – Decrease in BMD z-score ≥ 0.5 in total hip, femoral neck, or lumbar spine Renal Criteria – Confirmed ≥ Grade 1 sCr; increase in sCr of 50% or more from baseline (i.e., value at Screening visit); Confirmed CrCl < 60 ml/min – Confirmed > Grade 2 hypophosphatemia – Confirmed proteinuria as indicated by urine dipstick result > 1+ – Confirmed normoglycemic glucosuria

8. #AIDS2016 | @AIDS_conference Consort Diagram for ATN 110 EPH 200 Enrolled Completed Week 48 Visit w/ DXA N = 135 Completed Week 48 Visit w/ DXA N = 135 Met Criteria for EPH N = 102 (76%) (1 Renal and 101 Bone Criteria) Met Criteria for EPH N = 102 (76%) (1 Renal and 101 Bone Criteria) DXA Data Through EPH Week 48 N = 72 DXA Data Through EPH Week 48 N = 72 58 Discontinued Study -Lost to F/U (35) -Withdrew Consent (10) -Moved from area (8) -HIV+ at baseline (2) 58 Discontinued Study -Lost to F/U (35) -Withdrew Consent (10) -Moved from area (8) -HIV+ at baseline (2) 4 seroconversions = 3.3 per 100 person years 5 seroconversions = 7.2 per 100 person years Electively Remained on PrEP N = 16 1 Seroconversion = 7.0 per 100 person years Electively Remained on PrEP N = 16 1 Seroconversion = 7.0 per 100 person years 9 Discontinued Study -Lost to F/U (4) -Withdrew Consent (3) -Moved from area (2) 9 Discontinued Study -Lost to F/U (4) -Withdrew Consent (3) -Moved from area (2)

9. #AIDS2016 | @AIDS_conference ATN 110 EPH DXA Data Discontinued PrEP (N=72) Baseline VariableMean Hip BMD1.1 Hip % Change (Δ) Hip Z 1 -0.323 Whole Body BMD1.192 WB BMD % Δ WB BMD Z-0.489 L1 L4 BMD1.09 L1 L4 BMD % Δ L1L4 Z-0.475 p < 0.05 Z 1 (Z score): Normalized for age, sex, race

10. #AIDS2016 | @AIDS_conference ATN 110 EPH DXA Data Discontinued PrEP (N=72) Change BaselineWeek 48-0 VariableMean Hip BMD1.1-0.015 Hip % Change (Δ)-1.43 Hip Z 1 -0.323-0.097 Whole Body BMD1.192-0.008 WB BMD % Δ-0.63 WB BMD Z-0.489-0.108 L1 L4 BMD1.09-0.003 L1 L4 BMD % Δ-0.25 L1L4 Z-0.475-0.151 p < 0.05 Z 1 (Z score): Normalized for age, sex, race

11. #AIDS2016 | @AIDS_conference ATN 110 EPH DXA Data Discontinued PrEP (N=72) Change BaselineWeek 48-0EPH2 – Wk 48 VariableMean Hip BMD1.1-0.015+0.01 Hip % Change (Δ)-1.43+1.02 Hip Z 1 -0.323-0.097+0.059 Whole Body BMD1.192-0.008+0.007 WB BMD % Δ-0.63+0.64 WB BMD Z-0.489-0.108+0.048 L1 L4 BMD1.09-0.003+0.012 L1 L4 BMD % Δ-0.25+1.15 L1L4 Z-0.475-0.1510 p < 0.05 Z 1 (Z score): Normalized for age, sex, race

12. #AIDS2016 | @AIDS_conference ATN 110 EPH DXA Data Discontinued PrEP (N=72) Change BaselineWeek 48-0EPH2 – Wk 48EPH2-Wk 0 VariableMean Hip BMD1.1-0.015+0.01-0.004 Hip % Change (Δ)-1.43+1.02-0.35 Hip Z 1 -0.323-0.097+0.059-0.038 Whole Body BMD1.192-0.008+0.007-0.001 WB BMD % Δ-0.63+0.64-0.11 WB BMD Z-0.489-0.108+0.048-0.071 L1 L4 BMD1.09-0.003+0.012+0.009 L1 L4 BMD % Δ-0.25+1.15+0.87 L1L4 Z-0.475-0.1510-0.164 p < 0.05 Z 1 (Z score): Normalized for age, sex, race

13. #AIDS2016 | @AIDS_conference ATN 110 EPH DXA Data Continued PrEP (N = 15) Baseline VariableMean Hip BMD1.005 Hip % Change (Δ) Hip Z 1 -0.667 Whole Body BMD1.154 WB BMD % Δ WB BMD Z-0.6 L1 L4 BMD0.989 L1 L4 BMD % Δ L1L4 Z-1.2-1.2 p < 0.05 Z 1 (Z score): Normalized for age, sex, race

14. #AIDS2016 | @AIDS_conference ATN 110 EPH DXA Data Continued PrEP (N = 15) Change BaselineWeek 48-0 VariableMean Hip BMD1.005-0.025 Hip % Change (Δ)-2.55 Hip Z 1 -0.667-0.133 Whole Body BMD1.154-0.004 WB BMD % Δ-0.29 WB BMD Z-0.6-0.053 L1 L4 BMD0.989-0.016 L1 L4 BMD % Δ-1.63 L1L4 Z-1.2-1.2-0.227 p < 0.05 Z 1 (Z score): Normalized for age, sex, race

15. #AIDS2016 | @AIDS_conference ATN 110 EPH DXA Data Continued PrEP (N = 15) Change BaselineWeek 48-0EPH2 – Wk 48 VariableMean Hip BMD1.005-0.025-0.006 Hip % Change (Δ)-2.55-0.51 Hip Z 1 -0.667-0.133-0.05 Whole Body BMD1.154-0.004-0.007 WB BMD % Δ-0.29-0.61 WB BMD Z-0.6-0.053-0.1 L1 L4 BMD0.989-0.016+0.01 L1 L4 BMD % Δ-1.63+1.02 L1L4 Z-1.2-1.2-0.2270 p < 0.05 Z 1 (Z score): Normalized for age, sex, race

16. #AIDS2016 | @AIDS_conference ATN 110 EPH DXA Data Continued PrEP (N = 15) Change BaselineWeek 48-0EPH2 – Wk 48EPH2-Wk 0 VariableMean Hip BMD1.005-0.025-0.006-0.032 Hip % Change (Δ)-2.55-0.51-3.19 Hip Z 1 -0.667-0.133-0.05-0.186 Whole Body BMD1.154-0.004-0.007-0.011 WB BMD % Δ-0.29-0.61-0.93 WB BMD Z-0.6-0.053-0.1-0.15 L1 L4 BMD0.989-0.016+0.01-0.008 L1 L4 BMD % Δ-1.63+1.02-0.81` L1L4 Z-1.2-1.2-0.2270-0.236 p < 0.05 Z 1 (Z score): Normalized for age, sex, race

17. #AIDS2016 | @AIDS_conference Conclusions There is evidence of impact on bone density caused by exposure to TDF/FTC used as PrEP over 48 weeks in 18-22 yo males

18. #AIDS2016 | @AIDS_conference Conclusions There is evidence of impact on bone density caused by exposure to TDF/FTC used as PrEP over 48 weeks in 18-22 yo males Discontinuation of exposure to TDF/FTC leads to a trend to recovery of bone density changes over a 48 week follow-up period

19. #AIDS2016 | @AIDS_conference Conclusions There is evidence of impact on bone density caused by exposure to TDF/FTC used as PrEP over 48 weeks in 18-22 yo males Discontinuation of exposure to TDF/FTC leads to a trend to recovery of bone density changes over a 48 week follow-up period In a small group of subjects who voluntarily continued TDF/FTC PrEP beyond 48 weeks, there is evidence of lessening of rate of impact on bone density over the subsequent 48 weeks of exposure

20. #AIDS2016 | @AIDS_conference Conclusions 2 More data are needed on the impact of longer exposure to TDF/FTC PrEP on bone development in males in this age range

21. #AIDS2016 | @AIDS_conference Conclusions 2 More data are needed on the impact of longer exposure to TDF/FTC PrEP on bone development in males in this age range Possible study of impact of Vit D supplemental therapy

22. #AIDS2016 | @AIDS_conference Conclusions 2 More data are needed on the impact of longer exposure to TDF/FTC PrEP on bone development in males in this age range Possible study of impact of Vit D supplemental therapy Ongoing analyses may identify biomarkers that could be used as a surrogate for DXA changes

23. #AIDS2016 | @AIDS_conference Conclusions 2 More data are needed on the impact of longer exposure to TDF/FTC PrEP on bone development in males in this age range Possible study of impact of Vit D supplemental therapy Ongoing analyses may identify biomarkers that could be used as a surrogate for DXA changes Further work is needed to identify more optimal support for youth using daily oral PrEP

24. #AIDS2016 | @AIDS_conference Acknowledgements Most importantly, I would like to thank the young men who participated in this study for their willingness to share their lives and their time with us. My Protocol Co-Chair, Sybil Hosek, MD The 110/113 Medical Monitors - Bret Rudy, MD, & Raphy Landovitz, MD The 110/113 protocol team –Michelle Lally, MD, Kathleen Mulligan, PhD, Jaime Martinez, MD, Ken Mayer, MD, Greg Zimet, PhD, Kelly Bojan, DNP, Liz Salomon, MEd Protocol Statisticians – Brandy Rutledge, PhD & James Bethel, PhD NICHD Program Scientist and Medical Monitors – Bill Kapogiannis, MD, George Siberry, MD, & Sonia Lee, PhD The best Protocol Specialist in the world – Nancy Liu, MPH Gilead Sciences for their donation of study drug and financial assistance with costs of drug level assessments Project Director – Jennifer Brothers; Recruitment Coordinator – Pedro A. Serrano; and Counseling Coordinator – Christopher Balthazar The Adolescent Medicine Trials Network for HIV/AIDS Interventions (ATN) and its coordinating center (ACC)