Developing Safer TB Vaccines for Children with HIV
Transcription
Developing Safer TB Vaccines for Children with HIV
Developing Safer TB Vaccines for Children with HIV Jerald C. Sadoff, MD Aeras Global TB Vaccine Foundation Catalysing HIV/TB Research: innovation, funding and networking Desmond Tutu HIV Center Cape Town July 18th -19th 2009 AERAS GLOBAL TB VACCINE FOUNDATION Invention of BCG – The World’s Most Widely Used Childhood Vaccine (> 100 million doses/year) By Calmette & Guérin 1906-1921 No new TB Vaccine in 88 years AERAS GLOBAL TB VACCINE FOUNDATION Variable Efficacy of BCG vs. Pulmonary TB Vaccine Efficacy (%) -900 -500 -300 -100 0 20 40 60 70 80 90 Population British School Children BritishSchool SchoolChildren Children British N. American Indians USA (Chicago Infants) Puerto Rico (Gen. Pop.) S. India (Madanapalle) USA (Georgia & Alabama) S. India (Chingleput) USA (Georgia Children) Brazil (Sao Paulo) Argentina (Buenos Aires) Brazil (Belo Horizonte) Cameroon (Yaounde) Canada (Manitoba Indians) Indonesia (Jakarta) Surinam (Rangoon) Sri Lanka (Colombo) Colombia (Cali) Argentina (Santa Fe) Togo (Lome) Thailand AERAS GLOBAL TB VACCINE FOUNDATION Results of SATVI/Aeras trial in over 10,000 infants in Worcester S.A. of BCG given at birth 18 month TB incidence = 4.5% AERAS GLOBAL TB VACCINE FOUNDATION Efficacy of BCG vs. Disseminated TB Summary Efficacy Miliary Tuberculosis 77% (58 to 87) Summary Efficacy Tuberculous Meningitis 73% (67 to 79) Trunz, Fine, Dye. The Lancet 2006; 367:1173-1180 AERAS GLOBAL TB VACCINE FOUNDATION Tuberculosis: TB Vaccine Too Dangerous for Babies With AIDS Virus, Study Says July 2, 2009 – The vaccine against tuberculosis that is routinely given to 75 percent of the world’s infants is too risky to give to those born infected with the AIDS virus, says a new study published by the World Health Organization. It recommended that vaccination be delayed until babies can be tested. AERAS GLOBAL TB VACCINE FOUNDATION WHO 2007 Recommendations on BCG • Children with HIV infection regardless of symptoms should not be BCG vaccinated – BCG immunized asymptomatic HIV infected children at later risk of disseminated BCG 1 • All high risk infants need HIV screening – Maternal antibody masks antibody tests – Detection of virus required – Very difficult to implement in many places • Disseminated BCG in HIV infected infants recently (2009) estimated by Hesseling et al to be 992 per 100 000 (95% CI: 567–1495)2. 1Anneke C et al. Vaccine, 2007, 25:14–18. Fallo A et. Al. Presented at the International AIDS Society Meeting, 2005 2 Hesseling et al Bulletin of the World Health Organization; Type: Research Article DOI: 10.2471/BLT.08.055657 2009 AERAS GLOBAL TB VACCINE FOUNDATION A new, safer and more effective TB vaccine regimen is required for infants AERAS GLOBAL TB VACCINE FOUNDATION Prime –Boost Regimen for Infants Recombinant BCG IM or as an aerosol Capsids in bacteria orally or as an aerosol 14- 24 Weeks 10 -14 Weeks AERAS GLOBAL TB VACCINE FOUNDATION Safer, More Effective Infant TB Vaccines • Develop a safer BCG that is more potent – Endosomal membrane perforation increases safety through greater access to organism • Lysteriolysin or Perfringolysin expression – Over-expression of key proteins increases potency and ability to prime for booster • Safe booster vaccines – Proteins with adjuvants safe for use in children – Non-replicating viral vectors AERAS GLOBAL TB VACCINE FOUNDATION Current TB Vaccine Pipeline Pre-clinical Other rBCG rMtb AERAS Other Virus AERAS rBCG AERAS 405 Capsid Phase I VPM 1002 Phase II HyVac4/ AERAS 404 AERAS PSS Hybrid 1 SSI Phase III Recombinant BCGs for priming infants AERAS 402/ Crucell AdAg85A Other Protein PSS Phase IIB GSK M72 Replicationdeficient viral vectored (2009) vaccines for MVA85A/ boosting AERAS infants, young 485 adults & HIV positive Recombinant fusion proteins for boosting infants, adolescents, young adults, HIV positive April 2009 is more immunogenic thanT its TICE BCG parent % rBCG30 Ag85-specific IFN-γ γ Producing CD8+ cells (Hanekom Assay) AERAS GLOBAL TB VACCINE FOUNDATION Point:of Mediantigen an; Box: 25%-specific 75%; Whisker: Non- Outlier Range in humans for induction CD8+ T cells 0.45 0.40 % CD8 cells 0.35 Day Day Day Day 0 56 112 252 0.30 0.25 0.20 * 0.15 0.10 0.05 0.00 Tice (n=10) rBCG30 (n=10) Group *p=0.05 by Wilcoxon matched pairs test AERAS GLOBAL TB VACCINE FOUNDATION SSI Danish BCG AERAS-401 (Perfringolysin) AFRO-1 Parent BCG Strain Endosome Perturbation: Increased Safety Increased Immunogenicity Research Vaccine strain Endosome Perturbation: Increased Safety Increased Immunogenicity Over-expression Ag85A, Ag85B, Ag10.4 from Kanamycin containing Plasmid AERAS GLOBAL TB VACCINE FOUNDATION Enhanced Expression of Ag85A and Ag85B in Culture Supernatant of AFRO-1 AERAS GLOBAL TB VACCINE FOUNDATION Increased Safety of rBCG with endosome pertubation in Immunocompromised SCID Mice Experiment #225: SCID data (wk 65) AFRO-1 (5x106) Percent survival 100 90 80 70 60 50 40 30 20 10 0 5 Buffer BCG (5x106) 0 5 10 15 20 25 30 35 40 45 50 55 60 65 Weeks post-inoculation AERAS GLOBAL TB VACCINE FOUNDATION AERAS-402 boosts immune responses in Nonhuman primates better after initial priming with rBCG AFRO-1 compared to priming with BCG Ag85B Stimulation of whole blood IFN-γγ (pg/ml) 500 400 300 200 100 0 Week 15 Week 16 BCG-primed AFRO-1 rBCG-primed AERAS GLOBAL TB VACCINE FOUNDATION Survival of rhesus macaques vaccinated with indicated regimens and then challenged intratracheally with 500 CFU virulent M. tuberculosis, Erdman strain. 100 Percent surviving AFRO-1 rBCG/AERAS402/AERAS402 75 Unvaccinated controls 50 BCG/AERAS402/AERAS402 25 0 0 25 50 75 100 Days post challenge 125 AERAS GLOBAL TB VACCINE FOUNDATION Aeras rBCG strains in preparation for human testing that should be safe in HIV positive infants • AERAS-422 – Similar to AFRO-1 shown safe in SCID mice – Over-expresses Ag85A, Ag85B and 3407 from multicopy plasmid complementing panCD • AERAS-418 – Endosome perturbation similar to AFRO-1 – Chromosomal expression of Ag85A, Ag85B Rv3407, Rpf A, C, D and the DosR regulon (>45 proteins) • AERAS-430 – Severely growth restricted panCD mutant + endosomal perturbation (designed for HIV+) – Chromosomal expression identical to AERAS-418 R R v3 v2 33 R 62 4 v 4 R 05 c R v2 70 v 6 R 26 29 v 2 R 18 6c v 1 R 05 2c v 7 R 31 2c v0 30 R 57 c v 3 R 31 c R v1 29 v3 73 R 13 8 v 2 R 19 c v 9 R 20 6 v 3 R 26 2 R v3 23 v 1 R 16 31 v 2 R 05 5c v3 74 R 13 c v 4 R 05 c v 6 R 26 9 R v0 28 v 0 R 20 81 v 2 R 18 9c v 1 R 26 3c v 2 R 17 5c v2 37 R 03 c R v1 1c v 9 R 17 97 v2 35 R 00 c R v0 7c v 5 R 17 67 v 3 R 20 3c v 3 R 17 0c v 3 R 20 6c v 0 R 26 5c v2 94 62 c 7c Fold Upregulation AERAS GLOBAL TB VACCINE FOUNDATION DosR Regulon Expression AERAS-418 v BCG 1331 25 20 15 10 5 0 AERAS GLOBAL TB VACCINE FOUNDATION Scoring of Antigens Over-expressed/Upregulated in AERAS-418 – From List of Top 45 Rv1738 Rv2450c Rv2623 Rv1009 Rv0867c Rv2031c Rv1886c Rv0288 Rv2032 Rv2626c Rv3873 Rv2005c Rv3127 Rv1733c Rv1996 Rv2389c Rv0685 Rv2628 Rv1980c Rv3804c Rv0079 Rv3130c Rv3131 Rv0824c Rv1908c Rv1174c Rv1349 Rv1813c Rv2006 Rv2029c Rv2029c Rv2627c Rv2780 Rv1884c Rv2620c Rv2744c Rv3875 Rv1926c Rv2030c Rv3132c Rv3347c Rv0467 Rv1130 Rv1169c Rv1793 Rv2629 32/45 top scoring antigens by bioinformatics analysis directly over-expressed or up-regulated in AERAS-418 AERAS GLOBAL TB VACCINE FOUNDATION Boost Regimen for Infants that will be safe in HIV + infants Recombinant BCG IM or as an aerosol Capsids in bacteria orally or as an aerosol 14- 24 Weeks 10 -14 Weeks AERAS GLOBAL TB VACCINE FOUNDATION GSK Mtb72F in ASO-1E Adjuvant 192 323 195 1 ~14KD ~39KD ~20KD Mtb32 C-term Mtb39 Mtb32 N-term 1 391 4 2 Mtb39 3 Mtb32N 1 Skeiky et al (2004); J. Immunol Mtb32C Corixa/ GSK/Aeras AERAS GLOBAL TB VACCINE FOUNDATION Frequency of dcyt CD4/million CD4+ T Cells GSK M72 fusion protein induces CD4+ T cells in naïve and BCG vaccinated humans MTB-004/002: H9-specific ad CD4 T Cells (ATP Cohort) CD4 only 4000 Q1 Median Q3 3000 2000 1000 0 D0 PII PIII BCG-VAC (004 ATP) D0 PII INF-VAC (004 ATP) PIII D0 PII PIII Naive-VAC (002) timepoint/group AERAS GLOBAL TB VACCINE FOUNDATION Safety of M72/AS01E in 37 HIV positive adults with CD4>200 on ARV 1 • Well tolerated and no vaccine-related serious AEs were reported. • Causally related AEs were mainly local, transient and lasted usually between 1-3 days and resolved without sequelae in all groups • Mild and moderate injection site pain, fatigue and headache were the most frequently reported solicited AEs. • The M72/AS01E vaccine had no clinically relevant adverse effect on biological safety tests, HIV viral load and CD4 count and on individual HAART regimens 1Gambillara, E. 5th IAS Conference on HIV Pathogenesis Treatment and Prevention. Cape Town, SA, 2009 AERAS GLOBAL TB VACCINE FOUNDATION Frequency of M72-specific CD4+ T-cells expressing at least two markers among CD40-L, IL-2, IFN-γγ and TNF-α α (ICS) - Robust induction of M72-specific CD4+ T cells after vaccination. - No immune response with AS01E or saline - Increase of response from dose 1 to dose 2 10000 Q3 Median Q1 8000 6000 4000 Day 0 Day 30 Day 60 Saline AS01E M72/AS01E Saline AS01E M72/AS01E AS01E 0 Saline 2000 M72/AS01E Frequency of CD4+ T cells per 106 CD4+ cells 12000 AERAS GLOBAL TB VACCINE FOUNDATION Functional characterisation of M72-specific CD4+ T cells expressing at least two immunological markers on Day 60 Profile: CD40-L = IL-2 > TNF-α α > IFN-γγ Q3 Median Q1 10000 8000 6000 4000 All doubles CD40-L IL-2 TNFα IFNγ Saline AS01E M72/AS01E Saline AS01E M72/AS01E Saline AS01E M72/AS01E Saline AS01E M72/AS01E Saline 0 AS01E 2000 M72/AS01E Frequency of CD4+ T cells per 106 CD4+ cells 12000 AERAS GLOBAL TB VACCINE FOUNDATION Targets CD46 on Human Dentritic Cells Low African seroprevalence Ad35 Viral Vector E1 & Part of E3 deleted • Makes room for TB antigens (85A, 85B, 10.4) • Can’t replicate in humans Grows to high titer in PerC6 cells • Ad5 E1 in PerC6 chromosome • Ad5 E4 Orf6, 6/7 put in Ad35 • Ad35 pIX put back ψ ITR E1 L1-L3 E2B L4 E2A Genomic Structure E3 L5 E4 ITR Longitudinal Ag85-specific CD4 T cell subset analysis (Group 3) AERAS GLOBAL TB VACCINE FOUNDATION AERAS GLOBAL TB VACCINE FOUNDATION Aeras Study C-003-402 DMSO subtracted Ag85A/b CD8 Response Planned Treatment: AERAS-402 3x10^10 vp 2 doses (N=8) BCG Experienced S. African Adults 2.0 1.5 1.0 0.5 %CD8 Response 0.45 0.35 0.25 0.15 0.05 -0.0 -0.1 DOSE 1 DOSE 2 -0.2 -0.3 Day 0 Day 7 Day 14 Day 28 Day 56 Day 63 Day 70 Day 84 Longitudinal Ag85-specific CD8 T cell subset analysis (Group 3) AERAS GLOBAL TB VACCINE FOUNDATION AERAS GLOBAL TB VACCINE FOUNDATION Studies with NIH VRC – Bob Seder, Mario Roederer AERAS GLOBAL TB VACCINE FOUNDATION BCG priming enhances immune responses [ CD4] to Oxford MVA85A/ AERAS-485 TB vaccine (McShane, Hill) CD4 AERAS GLOBAL TB VACCINE FOUNDATION MVA85A/AERAS-485 induced antigen specific CD4+ T cells are highly polyfunctional Pre-MVA85A Pre-MVA85A Wk 1 Wk 2 Wk 1 Wk 2 Wk 8 Wk 8 Wk 24 Wk 24 Number of functions: 4+ 2+ 3+ 1+ Beveridge N et al, EJI 2007 AERAS GLOBAL TB VACCINE FOUNDATION Studies with MVA85A in 61 HIV+ subjects • CD4 > 350, no anti-retrovirals – UK: – S. Africa: – Senegal 18 12 7 12 +/-TB infection + TB infection - TB infection +/- TB infection • CD4 > 350 on ARV – S. Africa 12 • Safety profile excellent – No effect on viral load or CD4 count AERAS GLOBAL TB VACCINE FOUNDATION Immunogenicity of MVA85A in HIV infected subjects UK (n = 8) S u m m e d 8 5 A p o o ls 8500 7500 6500 5500 4500 3500 SFCs/million PBMC 2500 1500 500 500 450 400 350 300 250 200 150 100 50 0 0 1 2 4 Weeks 8 12 24 AERAS GLOBAL TB VACCINE FOUNDATION SATVI Research Site Tulbagh And Wolseley Ceres De Doorns Rawsonville Cape Town 110 km Worcester Breede River AERAS GLOBAL TB VACCINE FOUNDATION Vaccine Efficacy Trials • MVA85A/AERAS-485 – First efficacy trial of a new TB vaccine in infants in more than 80 years (proof of principle) – 2,800 infants – 90% power for 60% efficacy compared to BCG – In collaboration with SATVI, Oxford-Emergent Tuberculosis Consortium (OETC) and Wellcome Trust • AERAS-402/Crucell Ad35 – Planned multicenter study including SATVI (South Africa), Makerere University (Uganda), KEMRI/CDC (Kenya), Manhiça Health Research Centre (Mozambique) – In collaboration with EDCTP and Crucell • GSK M72 to be tested late 2010 • AERAS-rBCG to be tested in infant Phase III noninferiority trial vs BCG in 2011 AERAS GLOBAL TB VACCINE FOUNDATION MVA85A/AERAS-485 Phase IIb Proof of Concept Efficacy Trial First infant vaccinated 15 July, 2009, at the South African Tuberculosis Vaccine Initiative (SATVI) AERAS GLOBAL TB VACCINE FOUNDATION MVA85A/AERAS-485 Phase IIb Proof of Concept Efficacy Trial AERAS GLOBAL TB VACCINE FOUNDATION Safety & Proof of Principle in HIV+ Individuals • AERAS-402/Crucell Ad35 to be tested this year in S. Africa and possibly other sites for safety & efficacy • MVA85A/AERAS-485 in HIV + subjects in 2010 (Aeras & EDCTP sponsorship) • Establish safety and efficacy in HIV infected prior to testing in HIV positive infants AERAS GLOBAL TB VACCINE FOUNDATION Summary • Three Aeras rBCG vaccines in preparation for the clinic and intended to be safe and immunogenic in HIV + infants • Recombinant protein + adjuvant and nonreplicating viral vectored TB vaccines thus far appear safe and immunogenic as boosters in HIV + individuals • Proof of concept studies underway in infants and about to start in HIV+ adults • New TB vaccines for HIV + infants 2014-16 AERAS GLOBAL TB VACCINE FOUNDATION Aeras gratefully acknowledges the support of the following major donors Netherlands Ministry of Foreign Affairs Ministry of Foreign Affairs of Denmark