LB749. High HBsAb Seroprotection Achieved 4 Weeks after 3 doses of HepB-CpG Vaccine in People Living with HIV (PLWH) without Prior HBV Vaccination (ACTG A5379 Group B Preliminary Results)

Abstract

Background Three-dose series of conventional alum-adjuvanted Hepatitis B surface antigen (HBsAg)-based vaccines achieve seroprotection rates (SPRs) of 35-70% in PLWH. HepB-CpG, a HBsAg vaccine adjuvanted with a TLR-9 agonist, achieves high SPR in immunocompetent adults with a 2-dose regimen, but limited data exist in PLWH. Methods A5379 is an ongoing prospective, open-label study to evaluate immunogenicity of the HBV vaccine HepB-CpG in PLWH. The HBV vaccine-naïve group consisted of PLWH without past HBV infection on antiretroviral therapy with CD4 ≥100 cells/mm3 and HIV-1 RNA < 1000 copies/mL. Participants received 0.5 mL of HepB-CpG intramuscularly (20 mcg recombinant HBsAg and 3000 mcg of CpG 1018® adjuvant) at Wks 0, 4, and 24. Primary objectives were to determine the proportion of participants who achieve seroprotection (HBsAb≥10 mIU/mL) at Wk 28 and to assess safety. This study was designed to conclude SPR >55%, with up to 10% loss to follow-up prior to 28 wks. Results Of the 74 eligible participants enrolled at 13 global sites: 46% were male, 66% Asian, 16% Black,15% White and median age was 47 years (range 23-68). 27% were enrolled in the US, 65% in Thailand. Median CD4 was 625 cells/mm3, 96% had HIV-1 RNA < 60 copies/mL, and 9% had diabetes. Primary analysis set per analysis plan consisted of 68 participants (excluded: 3 missed visit, 3 out of visit window). All 68 completed 3 doses and achieved seroprotection (100% [95% CI: 94.7%, 100%]). 88% had HBsAb >1000 mIU/mL (assay upper limit). The SPR was also 100% [CI: 94.2%,100%] in the per protocol analysis set of 62 participants. At 8 wks after the 2nd dose, the SPR was 94.4% followed by 98.5% at Wk 24, prior to the 3rd dose. The proportion of participants with HBsAb >1000 mIU/mL increased from 27.9% at Wk 24 to 83.8% at Wk 28. One or more AEs related to study treatment were experienced by 61% of participants (39% Grade 1, 20% Grade 2, Grade 3 malaise in one participant). Vaccination site pain (40%), malaise (26%), fatigue (23%), myalgia (22%) and headache (22%) were the most frequent AEs. Seroprotection achieved by study week. Percentage of participants achieving seroprotection over the first 28 study weeks. HepB-CpG vaccine was administered at Entry, Week 4, and Week 24. Conclusion In this study of PLWH with no history of HBV vaccination or evidence of prior HBV exposure, 100% seroprotection was achieved at 4 weeks after 3 doses of the HepB-CpG. No unexpected safety issues were observed. Disclosures Kristen Marks, MD, MS, Gilead Sciences: Grant/Research Support Andrea L. Cox, M.D. Ph.D., Janssen: Advisor/Consultant Jennifer C. Price, MD, PhD, AbbVie: Grant/Research Support|Gilead Sciences: Grant/Research Support|Gilead Sciences: Honoraria|Merck: Grant/Research Support|Theratechnologies: Advisor/Consultant Kelvin McKoy, M.D., M.B.A., Dynavax Technologies: Employee|Dynavax Technologies: Ownership Interest|Dynavax Technologies: Stocks/Bonds Kenneth E. Sherman, MD, PhD, AbbVie: Grant/Research Support|Gilead: Advisor/Consultant|Gilead: Grant/Research Support|Helio: Grant/Research Support|Inovio: DSMB|Intercept: Grant/Research Support|MedPace: DSMB|Theratechnologies: Advisor/Consultant|Zydus: Grant/Research Support.

Observational Study Evaluating the Seroprotection of HepB-alum Vaccine and HepB-CpG Vaccine in People With HIV

“…Regardless of study differences, all 3 studies, ours, the Schnittman et al [ 8 ] study, and A5379 [ 12 ], all suggest high incidence of seroconversion with HepB-CpG in PWH. Further, pending the full results from A5379, our study is thus far the only study to directly compare HepB-CpG with HepB-alum, which aligns with the findings in immunocompetent hosts that HepB-CpG provides better protection against HBV in PWH.…”

“…While an A1C of <9% was required for study inclusion in A5379, little information otherwise is available in the preliminary results on incidence of comorbidities within the cohort [ 12 ]. Additionally, preliminary data comparing 2-dose HepB-CpG vs 3-dose HepB-CpG vs HepB alum have not yet been released; therefore, our study provides the only data directly comparing HepB-CpG with HepB-alum in PWH at this time.…”

“…Larger prospective studies are warranted to assess waning of HepB-CpG immunity in both the general population and PWH. A5379 is designed to follow patients for 72 weeks, and thus should be able to provide information on durability of vaccine response in PWH once final results are available [ 12 ].…”