Poster #0629 HEPATITIS B VIRUS DNA LEVEL CHANGES IN HBeAg+ PREGNANT WOMEN RECEIVING TDF

FOR PREVENTION OF MOTHER-TO-CHILD TRANSMISSION IRD-CMU PHPT CROIConference on Retroviruses Nicole Ngo-Giang-Huong1, Nicolas Salvadori2, Woottichai Khamduang2, Tim R. Cressey2, Linda J. Harrison3, Luc Decker1, Camlin Tierney3, Jullapong Achalapong4, and Opportunistic Infections Trudy V. Murphy5, Noele Nelson5, George K. Siberry6, Raymond T. Chung7, Stanislas Pol8, Gonzague Jourdain1, for the iTAP study group

1IRD, Chiang Mai, , 2Chiang Mai University, Chiang Mai, Thailand, 3Harvard University, Boston, MA, USA, 4Chiangrai Prachanukroh Hospital, Chiang Rai, Thailand, 5CDC, Atlanta, GA, USA, 6USAID, Arlington, VA, USA, 7Massachusetts General Hospital, Boston, MA, USA, 8Cochin Hospital, Paris, France

Background HBV DNA load measurements • 12% (19 of 161) did not achieve 5.3 log10 IU/ml at delivery; References • Population: all women assigned to the TDF arm + a randomly the median (range) HBV DNA for these women was 8.3 • High hepatitis B virus (HBV) DNA levels and positive hepatitis (7.1 to 9.1) log IU/mL at baseline, 7.4 (4.7 to 8.6) at • Sarin SK, Kumar M, Lau GK, et al. Asian-Pacific clinical practice guidelines on selected subset of 50 women assigned to the placebo arm 10 B e antigen (HBeAg-an indicator of rapid viral replication and 32-weeks, 7.0 (3.9 to 8.5) at 36 weeks and 7.8 (5.3 to 8.9) the management of hepatitis B: a 2015 update. Hepatol Int 2016;10:1-98. • European Association for the Study of the Liver. Electronic address eee, high level of HBV DNA) are the main markers of risk for • Timing: at baseline (28 weeks gestation), at Weeks 32 and at delivery. mother-to-child transmission (MTCT) of HBV. 36 gestation, delivery, Month 1 and 2 postpartum, and after European Association for the Study of the L. EASL 2017 Clinical Practice discontinuation of the study treatment at 3, 4, 6 and 12 HBV DNA load measurements in the Placebo arm Guidelines on the management of hepatitis B virus infection. Journal of • Decreasing HBV DNA levels with antivirals administered during hepatology 2017;67:370-98. months postpartum the last trimester of pregnancy may help reduce HBV MTCT. • The median HBV DNA levels were unchanged during • Terrault NA, Lok ASF, McMahon BJ, et al. Update on prevention, diagnosis, • Current guidelines recommend initiating antiviral prophylaxis • All laboratory staff were blind to the randomized assignment pregnancy and the postpartum period (see Figure 2). and treatment of chronic hepatitis B: AASLD 2018 hepatitis B guidance. to prevent MTCT during pregnancy when maternal HBV DNA of the women Hepatology (Baltimore, Md) 2018;67:1560-99. • Jourdain G, Ngo-Giang-Huong N, Harrison L, et al. Tenofovir versus Placebo level is above 200,000 IU/mL (5.3 log IU/mL) (Sarin et al. 10 • Technique: Abbott RealTime HBV assay (Abbott Molecular Inc., to Prevent Perinatal Transmission of Hepatitis B. The New England journal of 2016; EASL 2017; Terrault et al. 2018); the optimal duration IL, USA) medicine 2018;378:911-23. of antiviral prophylaxis is unknown. Statistical considerations Acknowledgements Objective • Assuming an observed mean (standard deviation) HBV DNA of 7.0 (1.6) log IU/mL at each time point in the placebo arm, • We would like to thank all the subjects who participated in the iTAP trial, the • Within a randomized trial, we assessed the changes in HBV 10 a sample size of 50 women would ensure that the width of PHPT laboratory and the coordination center study team, and the study teams DNA levels among HBeAg+ pregnant women who received the 95% confidence interval (CI) at each time point is as low of the 17 participating clinical sites: Health Promotion Center Region 10 either tenofovir disoproxil fumarate (TDF) or placebo during Figure 2: HBV DNA levels during pregnancy and postpartum period in (12) Suraphan Sangsawang, Kanokwan Jittayanun; Lamphun Hospital (9) as 0.91 log10 IU/mL (see Table). pregnancy and in the early postpartum period. women randomized to TDF arm (blue) and women randomized to Wanmanee Matanasarawut, Rosalin Somsamai; Phayao Provincial Hospital Table: Estimates of sample size and 95% confidence interval placebo arm (red) (14) Pornnapa Suriyachai, Pannarai Nasomchai; Chiangrai Prachanukroh N 95%CI (log IU/mL) Width (log IU/mL) Hospital (55) Jullapong Achalapong, Chulapong Chanta; Chiang Kham Methods 10 10 Conclusion - Discussion Hospital (14) Chaiwat Putiyanun, Ratthakhet Ek-isariyaphorn; Mae Chan 30 6.60,7.60 1.19 Hospital (4) Sudanee Buranabanjasatean; Prapokklao Hospital (31) • HBV DNA was retrospectively quantified in HBeAg-positive 40 6.49, 7.51 1.02 • 88% of pregnant women receiving TDF from 28 weeks gestation Prapap Yuthavisuthi, Chaiwat Ngampiyaskul; Banglamung Hospital (29) and HIV-negative pregnant women enrolled in a phase III, 50 6.55, 7.46 0.91 achieved HBV DNA levels below 200,000 IU/mL at delivery. Prateep Kanjanavikai, Siriluk Phanomcheong; (16) placebo-controlled, double-blind, randomized clinical trial 57 6.58, 7.43 0.85 • In the iTAP clinical trial, there were no HBV transmissions in Nantasak Chotivanich, Suchat Hongsiriwon; (18) (iTAP study) assessing the efficacy and safety of TDF 300 mg the TDF arm though some women had not decreased their Aram Limtrakul, Arunrat Suwannarat; Nopparat Rajathanee Hospital (28) once daily versus placebo from 28 weeks' gestation through plasma HBV DNA levels below 200,000 IU/mL . Anita Luvira, Orada Patamasingh Na Ayudhaya; Bhumibol Adulyadej 2 months post-partum (NCT01745822) (Jourdain et al. 2018) Results • These results suggest a threshold of >200,000 IU/mL HBV Hospital (28) Sinart Prommas , Prapaisri Layangool; DNA might be too low to predict a substantial risk of HBV (19) Thitiporn Siriwachirachai, Ussanee Srirompotong; Samutsakhon Mothers HBV DNA load measurements in the TDF arm MTCT for antiviral prophylaxis. Hospital (14) Supang Varadisai, Sawitree Krikajornkitti; Samutprakarn GA Antepartum Postpartum 28 Wks Hospital (19) Prapan Sabsanong, Parichart Wongngam; Hospital 3rd Trimester 2 Months 12 Months • The median HBV DNA levels decreased from 8.1 log10 IU/mL (11) Prateung Liampongsabuddhi, Kultida Pongdetudom; Maharat Nakhon

Delivery Prophylaxis at baseline to 4.9 log10 IU/mL at 32 weeks, 4.2 at 36 weeks, Limitations Ratchasima Hospital (10) Pichit Puernngooluerm, Anucha Saereejittima. Placebo (Reference Arm) Follow-up 3.9 at delivery and then to 3.4 at 1 month and 3.3 at 2 • The study was supported by a grant from the Eunice Kennedy Shriver National until • Maternal HBV DNA level at delivery may not be an appropriate 12 months months post-partum. After discontinuation of TDF, the Institute of Child Health & Human Development (NICHD) (U01HD071889) postpartum marker of risk for mother-to-child of transmission since it Tenofovir DF (300 mg, OD) median HBV DNA level returned to baseline level within under a cooperative agreement between NICHD, the Centers for Disease

andomization does not provide an accurate reflection of adherence to TDF

R Control and Prevention, United States of America, and Institut de recherche one month (see Figure 2) during pregnancy. pour le développement, France. Birth to 12 Months • The percentage of women who achieved HBV DNA <200,000 • Maternal HBV DNA levels were reported according to scheduled HBV vaccine at (< 5.3 log IU/mL) was: • Study drugs (tenofovir disoproxil fumarate and matching placebo) were 10 visits and not according to the duration of TDF prophylaxis birth, 1, 2, 4 and Follow- Infants • 61% (99 of 162 women), (exact 95% CI 53% to 69%) at donated by Gilead Sciences Inc., CA, United States of America. 6 months* plus up which may have differed by a few days • HBV DNA kits for the measurement of HBV DNA at delivery were donated by HBIg at birth 32 weeks, • There were only 3 perinatal transmissions of HBV in the *according to the Thai national guidelines Abbott Molecular (Singapore). • 84% (133 of 158) (95%CI 78% to 89%) at 36 weeks, placebo arm which did not permit reassessing a threshold of Figure 1: iTAP study design • 88% (142 of 161) (95% CI 82% to 93%) at delivery. risk for mother-to-child transmission of HBV