23 July RV144: Clinical Development Plans IAS 2012, Washington, DC USA The views expressed are those of the presenter and should not be construed to represent the positions of the U.S. Army or DoD Nelson L. Michael, M.D., Ph.D Colonel, Medical Corps, U.S. Army Director US Military HIV Research Program (MHRP) Walter Reed Army Institute of Research
23 July Past HIV Vaccine Concepts : AIDSVAX VaxGen Env gp120 Humoral Immunity Phase III studies in high- risk subjects in the US/Thailand Elicited type-specific Abs but not broadly reactive NAbs No efficacy 2007: STEP-PHAMBILI STUDIES Merck Ad5-Gag/Pol/Nef Cellular Immunity Phase IIb study in high-risk subjects in North/South America Elicited cellular immunity by IFN- γ ELISPOT assays No efficacy, possible increased HIV-1 acquisition 2009: RV144 Sanofi ALVAC prime, AIDSVAX gp120 boost Humoral and Cellular Immunity Phase III study in low-risk subjects in Thailand 31% reduction in HIV-1 acquisition with no viral load effect Advancing HIV vaccine candidates to efficacy trials will accelerate progress in the field, bringing us closer to an effective global vaccine. Although only three concepts have undergone clinical efficacy testing to date, each HIV vaccine efficacy trial has yielded unexpected outcomes that have transformed the HIV landscape.
23 July NEJM 361:2209 (03 Dec 09)
23 July RV 144 demonstrated efficacy for HIV acquisition N=16, vaccine, 74 placebo HIV infected Est. VE = 31% 95% CI 1-51% (p=0.04) Rerks-Ngarm et al. (2009, NEJM) Years Probability of HIV Infection (%) Placebo Vaccine C. Modified Intention-to-Treat Analysis*
23 July What we have learned—RV 144 Protection among low incidence heterosexual Thais, VE 31.2% at 42 months No effect on post-infection viremia or CD4 count Relatively monophyletic circulating variants CRF01_AE Efficacy appears to be early and non-durable Evoked binding Ab but not measurable, primary isolate Nab— BAb appeared early and decreased by > 10 fold over 6 months CD4+ Env responses, but not CD8 responses Correlate/surrogate studies limited by samples and endpoints
23 July What we would want next Extend the observation of early 60% efficacy by increasing the durability of immune responses Additional vaccine boosts Improved adjuvants Improved vaccines Elucidate correlates of risk of infection. Adequately powered studies Adequate sample collections Public health implementation--establish protection in higher incidence populations (additional boosts/improved adjuvants) Heterosexuals in sub-Saharan Africa MSM in Africa and Asia
23 July RV 144 correlates of risk—a teaser
23 July RV 144 Correlates Discovery Effort RV144 Steering Committee Scientific Steering Committee Product Development Advisory Group Humoral & Innate Immunity Cellular Immunity Host Genetics Animal Models Scientific Advisory Groups MHRP - DAIDS Steering Committee PA H Steering Committee ADVISORY GROUPS Clinical Development Correlates
23 July NEJM 366:1275 (05 Apr 2012)
23 July Multivariate Logistic Regression: Quantitative Variables VariableRelative riskP-valueQ-value IgA Binding to Envelope Panel IgG Avidity A244 gp ADCC AE.HIV-1 Infected CD4 Cells Tier 1 Neutralizing Antibodies IgG Binding to gp70-V1V CD4+ T Cell Intracellular Cytokines All 6 variables together in multivariate analysis, P=0.08 Only -Env IgA and IgG gp70:V1V2 binding, p = (log reg), (Cox) 2 individual variables were significant: gp70 V1V2 inversely correlates with infection [q = 0.08] Estimated 43% reduction in infection rate (per SD) Plasma IgA directly correlates with infection [q = 0.08] Estimated 54% increase in infection rate (per SD)
23 July Is it V1V2 or both?
23 July Case control analysis of microarray shows trend to inverse correlation at tip of V2 and in CD4 binding site
23 July Sieve Analysis of RV144 Breakthrough Viruses supports importance of V2 loop
23 July Sieve Analysis of V2 Comparison of viruses from HIV-1 infected vaccine versus HIV-1 infected placebo recipients These are not transmitted/founder viruses—the mean time to last negative visit was ~ 3 months. V2 was a major focus of analysis. Analysis—collaboration between Dr. Morgane Rolland (MHRP), Dr. Jim Mullins (UW), SCHARP
23 July Sequence variation in position 169 Edlefsen, SCHARP
23 July Sequence variation in position 181 Edlefsen, SCHARP
23 July Results: Sites 169 and 181 Separately For each site, VE significantly differs against match vs. mismatched infection vaccine reduced infection rate 3.77 times more for 181-mm than 181-m Positive VE for 169-matched infection and181-mismatched infection The sieve analysis suggests that the vaccine selectively blocked acquisition with 169-matched and with 181-mismatched virus; but conferred no protection against 169-mismatched or 181-matched virus GenotypeNo. InfectionsEst. VE95% CIP-value 169m8748%18% to 66% mm23-45%-258% to 33% m88-20%-26% to 45% mm2278%35% to 93% GenotypesNo. InfectionsEst. HR / HR95% CIP-value 169mm/169 m 87/ to m/181m m 22/ to
23 July Correlates of Risk of Infection WARNING—it is textbook (Stan Plotkin’s) knowledge that different vaccines for the same pathogen can have different correlates of risk/protection. Will correlate of risk for ALVAC-AIDSVAX B/E in RV 144 generalize to…. These products in Thai MSM? ALVAC-gp120 engineered for heterosexuals in Africa? Other HIV vaccines such as DNA/Ad5 (HVTN 505 phase IIb), Ad26- MVA, etc? We want all subsequent efficacy trials to seek correlates—now more than ever. This impacts clinical design.
23 July Collaborators Duke Bart Haynes Larry Liao Georgia Tomaras Nathan Vandergrift Garnett Kelsoe David Montefiori Thomas Kepler Marcella Sarzotti-Kelsoe Munir Alam Bill and Melinda Gates Foundation Nina Russell Francine McCutchan HVTN Peter Gilbert Nicole Frahm Julie McElrath UMDNJ Abe Pinter NYU/VA Susan Zolla-Pazner Harvard Joseph Sodroski Steve Harrison Norm Letvin IHV George Lewis Tony DeVico NIH VRC Gary Nabel Peter Kwong John Mascola Marie Pancera Jason McLellan Thai Ministry of Public Health
23 July Towards a Globally Effective HIV Vaccine
23 July MHRP’s Product Development Plan 21 REGIONAL VACCINE STRATEGY Building on the RV144 outcome and lessons learned, conduct efficacy trials of the prime-boost concept in: a)Thai MSM populations b)High-risk populations in Southern Africa BUILDING ON RV144 1 GLOBAL VACCINE STRATEGY Pursuing diverse platforms (e.g. vectors, multi- valent constructs or mosaic inserts) that build on the prime-boost concept and readily translate to multi-clade testing and a globally effective vaccine. DIVERSIFYING AND REFINING THE PORTFOLIO 2 MHRP’s vaccine development strategy emphasizes regional and global approaches.
23 July Pox-Protein Public Private Partnership (NIAID-Gates led)
23 July Planned studies are mutually reinforcing and will amplify public health impact and regional relevance. 23 May 2011 Precedent for vaccine efficacy Focus on regional public health impact Strategy for achieving potential licensure in target markets and having the broadest public health impact. Future amplification of global reach Mutually reinforcing studies strengthen and support public health benefit in target populations and the translation of the platform globally. THAILAND High Risk MSM THAILAND High Risk MSM US/EUROPE SOUTHEAST ASIA Republic of South Africa (RSA) High Risk Heterosexual Republic of South Africa (RSA) High Risk Heterosexual RV144 SOUTHERN AFRICA
23 July Timeline RV305 RV328 RV Vax (?) RV348 Bridge Study RV349 Go/No-Go
23 July Short-term Development Objectives Characterize vaccine immune responses using samples collected In sufficient amounts At the right times From systemic as well as mucosal sites Improve magnitude and durability of vaccine- induced responses
23 July Research Strategy Three Exploratory Phase II immunogenicity trials in Thailand Collections: serum, plasma, cells, genital fluids Special collections: leukapheresis, gut biopsy, cervical biopsy, bone marrow aspiration (except RV305) Broad array of humoral and cellular assays
23 July RV305 (RV144 extended boost study) =162
23 July RV306 (Intensive Immunogenicity) =460
23 July Bridging Study—from AIDSVAX/alum to delta 11/MF59 ALVAC-HIV prime as before gp120 boost comparison: One B and one E, both gD negative, C1 delta 11 Novartis process and MF59 adjuvant Part A Open Label safety assessment in the U.S. for Novartis product: Wk GpN A110AAA/N A=ALVAC-HIV, N=Novartis rgp120B/E
23 July Bridging Study Part B Thailand— compare AIDSVAX/alum vs Novartis gp120/MF59 BWk GpN B1*90AAA/AVX 10PPP/P B290AAA/N 10PPP/P B390AAA/N 10PPP/P A=ALVAC-HIV, AVX=AIDSVAX B/E, N=Novartis rgp120B/E *Possibly use RV306 samples
23 July Studies: RV144i immune correlates studies RV305 protein boosting study RV306 expanded immunogenicity study Objective: Determine correlate of protection for use in future trials; optimize the regimen Partners/Funders: US Army, Thai Gov’t, NIH, sanofi pasteur, BMGF Ongoing RV144 Follow- up in Thailand Population: MSM, high-risk Products: ALVAC (sanofi) + gp120/MF59 (NVD) Objective: Confirm result & demonstrate efficacy in target population with potential for licensure Partners/Funders: US Army, Thai Gov’t, NIH, sanofi, BMGF? Thailand ph2b Population: Heterosexual, high-risk Products: ALVAC (sanofi) + gp120/MF59 (NVD) Objective: Extend result & translate vaccine to Africa, other high-risk groups Partners/Funders: NIH, HVTN, sanofi, Novartis, BMGF, RSA? Africa ph2b Population: Heterosexual, high-risk Products: DNA + NYVAC (sanofi) + gp140 (Polymun)/MF59 (NVD) vs. NYVAC (sanofi) + gp140 (Polymun)/MF59 (NVD) Objective: Extend results & accelerate evaluation of other products using adaptive trial design and first available protein Partners/Funders: NIH, HVTN, sanofi pasteur, Novartis, BMGF S. Africa ph2b Licensure Research Candidate selection ALVAC is default vector prime Proteins boosts TBD RV144 immune correlates Immune grid Cost, product availability Pox-Protein Development Plan
23 July Ad26-MVA +/- protein Barouch et al Nature 482: Feb 2012
23 July Nature 482, 89–93 (02 February 2012) % Uninfected Number of IR Challenges DNA/MVA MVA/MVA Ad26/MVA MVA/Ad26 Sham
23 July MVA/Ad26 and Ad26/MVA Regimens Lower Early Setpoint Viral Loads Following SIVmac251 Infection Log SIV RNA Days Following Infection Log SIV RNA Sham MVA/MVADNA/MVA MVA/Ad Days Following Infection Ad26/MVA x resistance to infection 4/8 : viremia blunted 1 log 3/8 : rapid virologic control 1/8 : persistently uninfected
23 July Protection Against Acquisition of IR SIVmac251 by Ad35/Ad26-SIVsmE543GagPolEnv Vaccine
23 July Ad26-MVA correlates analysis Acquisition endpoint. envelope binding antibody r=.79 p< neutralization antibody r=.50 p=.0034 ADCC r=.38 p=.034 (trend) set point viral load endpoint, Many correlates (N=27); prechallenge gag elispot count and gag elispot breadth were both correlated (r=-.50 p=.006 and r=-.64 p=.0002, respectively) with the endpoint. peak envelope binding antibody r=-.70 followed by prechallenge neutralizing antibody r=.67.
23 July Summary RV 144 demonstrated that vaccines can provide HIV acquisition protection. Correlates of risk of infection were discovered in RV 144. Correlates of risk of infection in Ad26-MVA (and other) vaccines have been discovered in NHP models. We must educate (and remind) ourselves that correlates of risk may or may not generalize. There is great value (but at a cost) to seek correlates of infection risk in future HIV vaccine trials. Product development and scientific rationale must communicate with each other.
23 July Acknowledgements Supported by: Collaboration for AIDS Vaccine Discovery Grant From the Bill and Melinda Gates Foundation HVTN, DAIDS, NIAID With Collaborations with the MHRP and Thai Ministry of Public Health National Institute of Allergy and Infectious Diseases (NIAID) National Institutes of Health (NIH) Division of AIDS (DAIDS) U.S. Department of Health and Human Services (HHS) Center for HIV/AIDS Vaccine Immunology (CHAVI) # U19 AI HVTN