HIV Cure Update. Christine Durand, MD 14 de abril de 2016, XIII Conferência Brasil Johns Hopkins University em HIV/AIDS

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1 HIV Cure Update Christine Durand, MD 14 de abril de 2016, XIII Conferência Brasil Johns Hopkins University em HIV/AIDS

2 Financial Disclosures Research grants paid to my institution: Gilead Sciences, Bristol Meyers Squibb Advisory boards: Gilead Sciences, Merck Pharmaceuticals, Bristol Meyers Squibb

3 Outline Why do we need a cure? Barriers to HIV cure Strategies for HIV cure and examples Bone marrow transplant/gene therapy Early antiretroviral therapy (ART) Shock and Kill

4 Antiretroviral therapy restores life

5 Modern ART less toxic, one pill/day But access and cost are still a major issue.

6

7 Persistent disease despite ART Deeks, S. G. et al. (2015) HIV infection Nat. Rev. Dis. Primers doi: /nrdp

8 Even in 2016, stigma remains

9 Outline Why do we need a cure? Barriers to HIV cure Strategies for HIV cure and examples Bone marrow transplant/gene therapy Early antiretroviral therapy Shock and Kill

10 Natural history of HIV infection ART

11 Viral rebound with treatment interruption (Davey et al, 1999 Davey et al, PNAS, Davey et al, PNAS, 1999

12 Resting memory CD4 + T cells

13 HIV targets activated CD4 + T cells Activated CD4+ T cell

14 Virus integrates within cell genome Activated CD4+ T cell HIV genome

15 Infected cells die within 1-2 days Activated CD4+ T cell HIV genome

16 Immunologic memory Resting memory CD4+ T cell Subset of activated cells revert to resting memory state Designed to live for decades Activated CD4+ T cell

17 Immunologic memory Resting memory CD4+ T cell Subset of activated cells revert to resting state Designed to live for decades + Ag Activated CD4+ T cell Upon re-encountering antigen, cell is reactivated

18 Most of the time infected cells die Activated CD4+ T cell

19 But rarely, infected cell reverts to resting state before cell death HIV-infected resting memory CD4+ T cell Activated CD4+ T cell

20 Latent reservoir: an unlucky consequence of immune memory Latent state HIV transcriptionally silent Invisible to immune system Unaffected by ART

21 Latent reservoir: an unlucky consequence of immune memory + Ag Activated CD4+ T cell Latent state HIV transcriptionally silent Invisible to immune system Unaffected by ART Reversible state ART interruption high levels of virus and clinical disease will return

22 Outline Why do we need a cure? Barriers to HIV cure Strategies for HIV cure and examples Bone marrow transplant/gene therapy Early antiretroviral therapy Shock and Kill

23 HIV cure.or remission Sterilizing cure complete eradication of the virus HIV remission ability to control the virus off antiretroviral medication

24 Viral load Examples of remission (and perhaps cure) 2-4 weeks Boston A 3 months ART Boston B 8 months Mississippi child 28 months Visconti, French Teenager Limit of detection Timothy Brown years Hütter et al. N Engl J Med 2009; Persaud et al. N Engl J Med 2013; Luzuriaga et al. N Engl J Med 2015; Henrich et al. Ann Intern Med 2014; Saez-Cirion et al. Plos Path 2013; Saez-Crion et al., IAS 2015, Vancouver 2015;.

25 HIV cure Berlin patient

26 Boston patients bone marrow transplant without gene therapy

27 Analytical treatment interruptions Patient A rebound 12 weeks Patient B rebound 30 weeks

28 Gene therapy CCR5Δ32 Cannon et al, Curr Opin HIV/AIDS, 2011.

29 Outline Why do we need a cure? Barriers to HIV cure Strategies for HIV cure and examples Bone marrow transplant/gene therapy Early antiretroviral therapy Shock and Kill

30 Mississippi baby ART at 30 hours Rebound at 46 months

31 20 adults (and one child) who started therapy early (but not in hyperacute stage), remained on therapy for years, and had no rebound after stopping therapy Low reservoir size, low T cell activation and strong immune responses HIV remission?

32 Lessons learned Limiting the size of the reservoir through early ART or bone marrow transplant reduces reservoirs and delays rebound Gene therapy holds promise These approaches are limited Toxicity, cost, scalability, feasibility of identifying those very early infection

33 Outline Why do we need a cure? Barriers to HIV cure Strategies for HIV cure and examples Bone marrow transplant/gene therapy Early ART Shock and Kill

34 Shock and kill Latency reversing agent 1. Reactivate latent HIV to induce active replication

35 Shock and kill Latency reversing agent ART 1. Reactivate latent HIV to induce active replication 2. Continue ART to prevent new cells from infection ART = antiretroviral therapy

36 Shock and kill Latency reversing agent ART Death CTL Death 1. Reactivate latent HIV to induce active replication 2. Continue ART to prevent new cells from infection 3. Infected cells will die from virus or immune response ART = antiretroviral therapy CTL = cytolytic T cell response

37 Mechanisms of HIV latency Global insufficiency of cellular transcription factors Epigenetic silencing at the LTR promoter Repression of transcription elongation factors Transcriptional interference from proximal host genes Defective nuclear export Siliciano RF and Greene WC. Cold Spring Harb Perspect Med

38 Global T cell activation reverses HIV latency Unacceptable toxicity seen in clinical trials using T cell activation

39 Targeted latency reversing agents Cytoplasm Nucleus IκB p50 p65 HDAC inhibitors HDACs CTIP-2 Suv39h1 P NFAT HMT inhibitors Me Nuc-0 CpG Island 1 p50 p50 SP1 SP1 SP1 TSS Nuc-1 CpG Island 2 Me Me DNMTs 7SK RNA CDK9 Cyclin T1 Hexim-1 DNMTs DNMT inhibitors Induce permissive chromatin state HDAC inhibitors (vorinostat, panobinostat, romidepsin) Histone methyltransferase inhibitors DNA methyltransferase inhibitors

40 Targeted latency reversing agents PKC activators Cytoplasm IκB p50 p65 P NFAT Ca 2+ influx Nucleus HDACs CTIP-2 Suv39h1 Me CpG Island 1 p50 p50 SP1 SP1 SP1 TSS Nuc-0 CpG Island 2 Nuc-1 Me DNMTs 7SK RNA CDK9 Cyclin T1 Hexim-1 ptefb activators Activate necessary transcription factors Me DNMTs PKC agonists (prostratin, bryostatin, ingenols, DPP) P-TEFb activators (JQ-1, HMBA) Xing S and Siliciano RF. Drug Discovery Today

41 Forms of HIV present in vivo 1. HIV RNA in plasma 2. Cell associated HIV DNA integrated in CD4+ cells: a. defective and b. infectious virus 3. Cell associated HIV RNA in cells

42 Assays to measure persistent HIV Viral outgrowth assay Cell associated HIV DNA Cell associated HIV RNA Plasma HIV RNA

43 Viral outgrowth assay Resting CD4 + T cells from patients on ART 1 x x x x x10 2 Finzi D et al, 1997; Siliciano JD et al, 2005

44 Viral outgrowth assay Resting CD4 + T cells from patients on ART 1 x x x x x10 2 p24 positive Activation Finzi D et al, 1997; Siliciano JD et al, 2005

45 Viral outgrowth assay Resting CD4 + T cells from patients on ART 1 x x x x x10 2 p24 p24 positive positive p24 negative Activation Day supernatant p24 antigen Finzi D et al, 1997; Siliciano JD et al, 2005

46 PCR for cell-associated HIV DNA or RNA Advantages Lower blood volume Less time intensive Lower cost Frozen cells

47 HIV RNA in plasma in patients on ART Start ART Residual viremia Time on ART (days)

48 Infected cell frequency (per 10 6 ) Viral outgrowth vs PCR assays Assay Cell/tissue 10,000 1, Viral outgrowth Total HIV DNA Resting CD4 PBMC Resting CD4 r = 0.38 p = 0.28 Integrated HIV DNA Total HIV DNA 2 LTR circles Residual viremia PBMC 30 Resting patients CD4 Rectal on CD4 ART PBMC Plasma Compared 11 different assays of HIV persistence r = 0.70 p < 0.01 r = 0.41 p = 0.13 r = 0.05 p = 0.86 rho = 0.19 p = 0.31 rho = 0.07 p = ,000 1, Plasmas HIV RNA (copies/ml) Cohort Chronic Acute Chronic Acute Chronic Acute Chronic Acute Chronic Acute Chronic Acute Chronic Acute Chronic Acute Eriksson S/ JD Siliciano PLOS Pathogens, 2013

49 Infected cell frequency (per 10 6 ) Viral outgrowth vs PCR assays Assay Cell/tissue 10,000 1, Viral outgrowth Total HIV DNA Resting CD4 PBMC Resting CD4 300x r = 0.38 p = 0.28 Integrated HIV DNA Total HIV DNA 2 LTR circles Residual viremia PBMC 30 Resting patients CD4 Rectal on CD4 ART PBMC Plasma Compared 11 different assays of HIV persistence r = 0.70 p < 0.01 rho = 0.19 p = 0.31 rho = 0.07 p = 0.71 PCR based assays measured at least 2 logs higher No r significant = 0.41 r = 0.05 correlations between p = 0.13 measurements p = ,000 1, Plasmas HIV RNA (copies/ml) Cohort Chronic Acute Chronic Acute Chronic Acute Chronic Acute Chronic Acute Chronic Acute Chronic Acute Chronic Acute Eriksson S/ JD Siliciano PLOS Pathogens, 2013

50 Only 4% of viruses are infectious Hypermutated 9% Hypermutated and Deleted 7% Intact 4% Packaging Signal Deletions 4% Large Internal Deletions 19% 3' Deletions 34% 5' Deletions 23% Ho Y et al, Cell, 2013

51 Assays to monitor HIV eradication Viral outgrowth infectious reservoir Cell associated HIV DNA all virus Cell associated HIV RNA shock Plasma HIV RNA - shock

52 8 patients Single dose of VOR No detectable plasma HIV RNA 4.8 fold increase in cell associated HIV RNA Archin N, Margolis D. Nature 2012

53 Some shock. 18/20 patients had increase Median increase: 7 fold

54 No change in HIV plasma RNA or cell associated DNA Not enough to detect in plasma. And no kill.

55 Disulfiram (2000 mg/day) induces modest increase cell-associated RNA and a delayed increase in plasma HIV RNA

56 Romidepsin HDAC inhibitor Søgaard, PLoS Pathogens 2015

57 Single drugs have limited efficacy Bullen C, Laird G et al. Nat Med 2014

58 Some combinations have BIG effect Laird G, Bullen C et al. JCI 2015

59 Lessons learned What you measure matters (cells, plasma, dead virus vs infectious) Getting a little better at the shock Combinations, new classes on the horizon Need to get better at the kill

60 Shock and kill : No good kill strategies HDAC inhibitor Death CTL Death ART 1. Reactivate latent HIV to induce active replication 2. Continue ART to prevent new cells from infection 3. Infected cells will die from virus or immune response ART = antiretroviral therapy CTL = cytolytic T cell response

61 Chronic HIV constant immune activation, inflammation Exhausted immune system Increased expression of exhaustion markers: PD1, CTLA4

62 Cancer immunotherapy unleash the immune system

63 Immune checkpoint (IC) receptors Cells expressing IC (esp PD1) have higher levels of HIV 1,2 Combination IC blockade: IC blockade (esp CTLA-4) activates HIV Both shock and kill? In vitro 3 and in vivo 4 IC blockade enhances the function of HIV or SIV-specific T cells 3,5 Combination ICB is highly effective for cancer treatment 6 1 Chomont et al. Nat Med : Porichis et al. Blood : Fromentin R et al. Towards an HIV Cure Symposia Australia. 5 Wightman F et al. AIDS : Hryniewicz A et al. Blood : Postow MA, et al. NEJM :

64 Blocking PD1 (and CTLA-4) to boost immune function Drug Target Registration HIV Nivolumab PD-1 FDA approved: melanoma Case report FDA approved: Pembrolizumab PD-1 melanoma and lung no cancer BMS PD-L1 Phase III: solid organ malignancy On hold Ipilimumab CTLA-4 FDA approved: melanoma Case report Wightman et al., AIDS 2015;29(4):504-6

65 Anti CTLA-4 (ipilimumab) perturbs the reservoir Wightman et al., AIDS 2015;29(4):504-6 Metastatic melanoma HIV RNA < 20 CD4= 620 cells/ul On ART for 8 years cart ipilimumab

66 U S H IV R N A c o p ie s (p e r m illio n 1 8 S ) P la s m a H IV R N A (S C A, c o p ie s p e r m L ) Anti CTLA-4 (ipilimumab) perturbs the reservoir Wightman et al., AIDS 2015;29(4):504-6 Metastatic melanoma HIV RNA < 20 CD4= 620 cells/ul On ART for 8 years cart ipilimumab Cell Associated US-HIV RNA Plasma Single copy HIV RNA Ipilimumab treatment cycle Ipilimumab treatment cycle Up to 19 fold increases Larger than seen in vorinostat trials 0 Decreases in plasma HIV RNA: 60 to 5 copies

67 Single infusion of anti PD-1 (nivolumab) cart Ipilimumab Nivolumab

68 U S H IV R N A / H IV D N A P la s m a H IV R N A (c o p ie s p e r m L ) U S H IV R N A (c o p ie s p e r m illio n 1 8 s ) H IV D N A c o p ie s p e r m illio n c e lls Single infusion of anti PD-1 (nivolumab) Cell Associated US-HIV RNA Cell Associated HIV DNA D a y - 1 D a y + 1 D a y + 7 Ratio US-HIV RNA : HIV DNA 5 0 D a y - 1 D a y + 1 Plasma HV RNA D a y + 7 S C A R o c h e Plasma HIV RNA Roche: <20 at both day-1 and day7; SCA on day -1 = 3.35 and +1 = 3.05 copies/ml D a y - 1 D a y + 1 D a y D a y - 1 D a y + 1 D a y + 7

69 Toll-like receptor 7 agonist Whitney, CROI 2015

70 Lower viral set point Shock and kill? Whitney, CROI 2015

71 Broadly neutralizing antibodies VRC01 already in human studies

72 Conclusions HIV cure remains a goal due to chronic inflammation, cost, access, stigma Several examples of remission that provide insight into effective strategies Limiting reservoir size Reactivating latent HIV Boosting the immune response Clinical trials underway

73 Acknowledgements Slides Steve Deeks Sharon Lewin Korin Bullen Greg Laird Bob Siliciano Mentors Rich Ambinder Robert Siliciano Siliciano Lab Korin Bullen Greg Laird Janet Siliciano Jun Lai Adam Longwich Daniel Xu Ya Chi Ho K23CA177321