Immunotherapy for HCC: What’s next

Immunotherapy for HCC:What’s next Anthony El-Khoueiry, MD Associate Professor of Medicine Director of Hepatobiliary Cancers Research Program Section of Gastrointestinal Cancers Phase I Program Director Medical Director of Clinical Investigations Support Office USC Norris Comprehensive Cancer Center

Disclosures • Consultancy/advisory roles: BMS, Bayer, Eisai, Merck, Cytomx, EMD-Serono, Roche-Genentech, Agenus, Pieris • Research Funding: Astex, Astra-Zeneca, Merck

Tumors Use Complex, Overlapping Mechanisms to Evade and Suppress the Immune System A. Ineffective presentation of tumor antigens (eg, downregulation of MHC I) B. Recruitment of immunosuppressive cells (eg, Tregs, MDSCs) DC Active T cell Inactive T cell Tumor-associated antigens Tumor cells Treg C. T-cell checkpoint dysregulation (eg, CD27, 4-1BB, CTLA-4, LAG-3, OX-40, PD-1) D. Tumor release of immunosuppressive factors (eg, TGF-β, IDO, IL-10) Immunosuppressive factors CD, cluster of differentiation; CTLA-4, cytotoxic T-lymphocyte antigen-4; DC, dendritic cell; IDO, indoleamine 2,3-dioxygenase; IL, interleukin; LAG-3, lymphocyte activation gene-3; MDSC, myeloid-derived suppressor cell; MHC, major histocompatibility complex; PD-1, programmed death receptor-1; TGF-β, transforming growth factor beta; TIM-3, T cell immunoglobulin and mucin domain-3; Treg, regulatory T cell. Vesely MD et al. Ann Rev Immunol. 2011;29:235-271. Mellman I et al. Nature. 2011;480(7378):480-489.

Targeting PD-1 and PD-L-1 in cancer PD-1 therapy works on differentiated T cells Only affects CD8 T cells Does not expand clonal diversity Does not move T cells into tumors J Immunother Cancer. 2018; 6: 8.

Nivolumab in HCC: checkmate 040 ORR by RECIST 1.1 in expansion cohorts 20% ORR by RECIST 1.1 In post sorafenib Patients 14.3% El-Khoueiry A et al, Lancet2017

Keynote 224: Pembrolizumab in advanced HCC Slide 6 Zhu AX, et al. Lancet Oncol. 2018 Jul;19(7):940-952.

Camrelizumab (SHR-1210) in HCC - 84% of patients had hepatitis B - All had failed ≥ 1 prior line of systemic therapy Qin S et al, ESMO 2018

KEYNOTE-240 Study Design Pembrolizumab 200 mg Q3W + BSC Key Eligibility Criteria • Pathologically/radiographically confirmed HCC • Progression on/intolerance to sorafenib • Child Pugh class A • BCLC stage B/C • ECOG PS 0-1 • Measurable disease per RECIST v1.1 • Main portal vein invasion was excluded Randomized 2:1 N = 413 Saline-placebo Q3W + BSC Stratification Factors • Geographic region (Asia w/o Japan vs non-Asia w/Japan) • Macrovascular invasion (Y vs N) • AFP level (≥200 vs <200 ng/mL) • Enrollment May 31, 2016 – November 23, 2017

Overall Survival Pre-specified p=0.0174 required for statistical significance Data Cutoff: Jan 2, 2019. Finn R et al, ESMO GI 2019

Objective Response Rate at Final Analysis(RECIST 1.1, BICR) Duration of response, median (range)b,c: • Pembrolizumab: 13.8 mo (1.5+ mo − 23.6+ mo) • Placebo: not reached (2.8 mo−20.4+ mo) Finn R et al, ESMO GI 2019

Trial: NCT02576509 CHECKMATE-459: Phase III trial of nivolumab vs sorafenib in first-line advanced HCC patients1 Key Eligibility Criteria N=726 • Advanced HCC not eligible for or progressive after surgical and/or locoregional therapies • Child-Pugh A CheckMate -459, a randomized Phase 3 study evaluating Opdivo (nivolumab) versus sorafenib as a first-line treatment in patients with unresectable hepatocellular carcinoma (HCC). The trial did not achieve statistical significance for its primary endpoint of overall survival (OS) per the pre-specified analysis (HR=0.85 [95% CI: 0.72-1.02]; p=0.0752). PD-L1 PD-1 R Adapted from Mellman I et al 2011.2 Start Date: November 2015 Primary Endpoints: OS Other Endpoints: ORR, PFS, biomarkers Nivolumab Sorafenib 1. Clinicaltrials.gov. NCT02576509. Accessed July 28, 2016. 2. Mellman I et al. Nature. 2011;480(7378):480-489. HCC, hepatocellular carcinoma; ORR, objective response rate; OS, overall survival; PD-1, programmed death-1; PD-L1, programmed death-ligand 1; PFS, progression-free survival; PK, pharmacokinetics; TTP, time to progression.

My preliminary thoughts on the negative phase 3 trials • Is it a statistics and design issue? • Co-primary endpoints (Keynote 240) • Split α • Adequate power • Is it a problem of the “median” versus “tail of the curve”? • Is OS a challenge in the age of multiple therapeutic options and cross-over? • Is single agent activity not sufficient?

Moving forward: review of select strategies • Using biomarkers to predict benefit and guide patient selection • Target checkpoints beyond PD-1 and PD-L-1 • Smart combinations to address various mechanisms of immune resistance (primary and secondary) • Improve and leverage our understanding of biologic subgroups to guide future therapeutic development • Immune therapy strategies other than checkpoint inhibition (cellular therapy approaches)

Biomarkers for patient selection and enrichment strategies • Hypothesis: increasing the number of responders and frequency of prolonged stable disease will result in improved survival (A) 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 Median OS (95% CI), mo = NR (NE–NE) Probability ofsurvival Complete or partial response (n =22) Stable disease (n =65) Progressive disease (n =59) 0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 Median OS (95% CI), mo = 16.7(13.8–20.2) Median OS (95% CI), mo = 8.9(7.3–13.4) n =146a Months El-Khoueiry A et al, GI Cancers Symposium, 2018

Checkmate 040: Best Overall Response by Tumor Cell PD-L1 Status • Clinically meaningful responses were observed in all patients, including those with PD-L1 <1% (6 patients had a complete response) • In the overall population, numerically higher ORRs were observed in patients with PD-L1 ≥1% versus PD-L1 <1% with overlapping 95% CI • The SOR-experienced population had ORRs comparable to the overall population Melero I et al, AACR 2019 El-Khoueiry et al, JSMO 2019

Keynote 224: Association of CPS score with outcome Zhu AX, et al. Lancet Oncol. 2018 Jul;19(7):940-952.

Best Overall Response by T-Cell Markers CD4 CD3 • In the tumor microenvironment, CD3-positive cell frequency was higher versus the other T-cell markers assessed (data not shown) • CD3-positive cell frequency was associated with response (CR/PR vs SD; P = 0.03) FOXP3 CD8 Melero I et al, AACR 2019 El-Khoueiry et al, JSMO 2019

Checkmate 040:Gene Expression Signatures and Response • For the subset of patients in CheckMate 040 for whom RNA sequencing data were available (n = 37): • Several inflammatory signatures, such as the BMS 4-gene, Gajewski, Merck 6-gene interferon gamma, NanoString interferon gammabiology, and NanoString T-cell exhaustion signatures correlated significantly with improved response and OS Melero I et al, AACR 2019 El-Khoueiry et al, JSMO 2019

Potential use of immune therapy biomarkers in HCC • Enrich populations for clinical trials • Will the same biomarkers apply or be useful for combination therapy? • Can biomarker enrichment strategies inform patient selection for single agent versus combination therapy • Minimize toxicity exposure when not needed

Targeting Checkpoints other than PD-1 and PD-L-1 Select Agents Targeting NK Cells (Innate Immunity) Select Agents Targeting T Cells (Adaptive Immunity) MOXR0916 Tremelimumab Ipilimumab Lirilumab CD28 PD-1 TRX518 KIR OX40 Nivolumab Pembrolizumab Durvalumab* Atezolizumab* B7-1 CTLA-4 GITR Urelumab T cell TIM-3 CD137 BTLA Varlilumab BMS-986016 CD27 VISTA HVEM LAG-3 Adapted from Pardoll et al.1 Adapted from Mellman et al and Pardoll et al.1,2 Blocking agents Stimulating agents * These agents target PD-L1. CTLA-4=cytotoxic T-lymphocyte antigen-4; GITR=glucocorticoid-induced TNFR family related gene; KIR=killer-cell immunoglobulin-like receptor; LAG-3=lymphocyte-activation gene-3; NK=natural killer; PD-1=programmed death-1; PD-L1=programmed death ligand-1. 1. Pardoll DM. Nat Rev Cancer. 2012;12(4):252-264. 2. Mellman I et al. Nature. 2011;480(7378):480-489. 3. Clinicaltrials.gov.

Tremelimumab: Overview of Trial NCT01008358: Phase II trial of tremelimumab in advanced HCC patients with chronic HCV2 • Primary Endpoint: Tumor response • Secondary Endpoint: Changes in HCV viral load Activatingreceptors Inhibitoryreceptors CTLA-4 Key Eligibility Criteria • Chronic HCV infection • Inoperable, not amenable to ablation/transarterial therapy • CP A or B • ECOG PS 0 or 1 • Previous treatment allowed with ≥4 week washout T cell CD28 PD-1 OX40 B7-1 GITR T cell TIM-3 Adapted from Mellman et al.1 CD137 BTLA anti-CTLA-4monoclonal antibodyinhibitsB7-CTLA-4–mediated downregulation of T-cell activation Works during priming and expands clonal diversity Primarily affects CD4 cells Can move T cells into cold tumors CD27 VISTA Tremelimumab HVEM LAG-3 T-cell stimulation 1. Mellman I et al. Nature. 2011;480(7378):480-489. 2. Sangro B et al. J Hepatol. 2013;59(1):81-88.

Tremelimumab: Key Efficacy Data • Significant ↓ HCV viral load: • d0: 3.78105 IU/mL • d120: 3.02104 IU/mL (n=11; P=0.011) • d210: 1.69103 IU/mL(n=6; P=0.017) • AFP >50% ↓ in 36% pts with baseline AFP >100 ng/mL • ORR: 17.6% • DCR:76.4% • TTP:6.5 mo (95% CI: 4–9) • mOS:8.2 mo (95% CI: 4.6–21.3) AFP=alpha-fetoprotein; CI=confidence interval; d=day; DCR=disease control rate; HCC=hepatocellular carcinoma; HCV=hepatitis C virus; IFN=interferon; mOS=median overall survival; ORR=objective response rate; TTP=time to progression. Sangro B et al. J Hepatol. 2013;59(1):81-88.

Targeting OX-40 (P-8600) in solid tumors including HCC Diab A, ….El-Khoueiry A, AACR 2018

How do we expand the benefit of immunotherapy to more patients with hepatocellular carcinoma? . - Enhance tumor associated antigen exposure (SBRT, locoregionaltx,Intra-tumoraltx) • Beyond PD-1: OX40, LAG-3 • IO/IO combinations • Anti VEGF combinations (TKI, Bevacizumab) • Other ongoing preclinical and early clinical research • Chen Y et al. Hepatology. 2015;61(5):1591-1602. • Greten et al. Rev Recent Clin Trial. 2008 • Hedge PS, Semin Cancer Biol2017 • Tim F Greten et al. Gut 2015;64:842-848

Rationale Behind Combination Approaches Targeted Therapy (anti-angiogenic) Localized Therapy (TACE/RFA/PEI) Targeted therapy induces: • ↓ Treg population • ↓ MDSC • ↑PD-L1 expression • Enhanced T cell tumor infiltration and activation Localized therapy induces: • High antigen load • Damage to liver cells • Tumor-specific T-cell response Tumor Microenvironment • Chen Y et al. Hepatology. 2015;61(5):1591-1602. • Greten et al. Rev Recent Clin Trial. 2008 3. Hedge PS, Semin Cancer Biol 2017

Example of IO and liver directed therapy

Tremelimumab in combination with ablation in patientswith advanced hepatocellular carcinoma Partial response rate 26% (95% CI: 9.1–51.2%) Median TTP 7.4 months (95% CI 4.7 to 9.4 months) Median OS 12.3 months (95% CI 9.3–15.4 months) Duffy A et al, Journal of Hepatology 2017 (vol. 66 j 545–551

Tremelimumab in combination with ablation in patientswith advanced hepatocellular carcinoma Duffy A et al, Journal of Hepatology 2017 (vol. 66 j 545–551

Examples of IO and TKI or anti VEGF therapy

A phase Ib trial of Lenvatinib and Pembrolizumab in patients with HCC Ikeda M et al, AACR 2019

A phase Ib of Atezolizumab and Bevacizumab in advanced HCC Lee KH, ILCA 2019

Safety Summary: Atezolizumab + Bevacizumab a Grade 5 treatment-related adverse events: abnormal hepatic function, hepatic cirrhosis and pneumonitis. Data cutoff: 14 June 2019. Lee KH, ILCA 2019

Examples of IO/IO combinations

Combination of PDL-1 and CTLA4 antibodies • Phase I/II of durvalumab and tremelimumab • 40 pts enrolled (11 HBV+, 9 HCV+, 20 uninfected) • 30% had no prior systemic therapy • 93% Child Pugh Class A • Most common (≥15%) treatment-related AEs: fatigue (20%), increased ALT (18%), pruritus (18%), and increased AST (15%). Kelley RK et al, J ClinOncol 35, 2017 (suppl; abstr 4073)

CheckMate 040 Nivolumab Plus Ipilimumab Combination Cohort Study Design Study endpoints Primary Arm A: • Safety and tolerability NIVO1 + IPI3 Key eligibility criteria • Advanced HCC, sorafenib treated, intolerant, or progressors • Uninfected, HCV infected, or HBV infected • CP score A5–A6 • ECOG PS 0–1 using NCI CTCAE v4.0 Q3W × 4 Nivolumab • ORR and DOR based on 240 mg IV Unacceptable investigator assessmenta Q2W toxicity flat dose Arm B: Secondary or R NIVO3 + IPI1 disease 1:1:1 • DCR • TTP Q3W × 4 progression • PFS • TTR • OS Other Arm C: NIVO3 Q2W + • BOR and ORR based on IPI1 Q6W BICR-assessed tumor responsea BICR, blinded independent central review; BOR, best overall response; CP, Child-Pugh; DCR, disease control rate; DOR, duration of response; ECOG PS, Eastern Cooperative Oncology Group performance status; HBV, hepatitis B virus; HCC, hepatocellular carcinoma; HCV, hepatitis C virus; IPI1, ipilimumab 1 mg/kg; IPI3, ipilimumab 3 mg/kg; IV, intravenous; NCI CTCAE, National Cancer Institute Common Terminology Criteria for Adverse Events; NIVO1, nivolumab 1 mg/kg; NIVO3, nivolumab 3 mg/kg; ORR, objective response rate; OS, overall survival; PFS, progression-free survival; Q2W, every 2 weeks; Q3W, every 3 weeks; Q6W, every 6 weeks; R, randomization; RECIST, Response Evaluation Criteria in Solid Tumors; TTP, time to progression; TTR, time to response. aUsing RECIST v1.1. Minimum follow-up at time of data cutoff: 28 months.

Efficacy Results 100 Arm A mOS (95% CI) = 22.8 mo (9.4–NE) 90 Arm B mOS (95% CI) = 12.5 mo (7.6–16.4) • Similar ORR, DCR, and DOR were observed across treatment arms, with consistently high ORR (> 30%) achieved in all treatment arms • The greatest survival benefit was observed in arm A, with a median OS of 22.8 months and the highest OS rate of 44% through 30 months Arm C mOS (95% CI) = 12.7 mo (7.4–33.0) 80 70 60 Overall survival (%) 50 40 30 20 10 0 0 3 6 9 12 15 18 21 24 27 30 33 36 39 Time (months) CR, complete response; NE, not estimable; PD, progressive disease; PR, partial response; SD, stable disease. Yau T, et al. Presented at the American Society of Clinical Oncology Annual Meeting 2019; May 31–June 4, 2019; Chicago, IL. Poster 4012.

Summary of TRAEs by Category • Although rates of any-grade TRAEs were higher in arm A, the types of TRAEs observed were similar across treatment arms • No new safety signals were observed, and most TRAEs were manageable and reversible • Serious TRAEs were reported in 11 patients (22%) in arm A, 9 patients (18%) in arm B, and 7 patients (15%) in arm C • One serious hepatobiliary disorder was reported in arm A (drug-induced liver injury); 3 serious hepatic investigations were reported (elevated AST in arm A; elevated AST and elevated ALT in arm B) TRAE, treatment-related adverse event. Listed in the table are any-grade TRAEs that occurred in ≥10% of patients in any arm and grade 3/4 TRAEs that occurred in ≥5% of patients in any arm. Includes events reported between first dose and 30 days after last dose of study therapy.

Examples of IO combinations with novelagents to potentiate immune response

Viral mimicry state induced by epigenetic therapy Jones P et al, Nature Reviews 2019

Leveraging Epigenetics and Checkpoint Inhibition in HCC Guadecitabine (SGI110) induces expression of ERVs and viral defense genes in HCC A Phase Ib Study of Guadecitabine (SGI-110) and Durvalumab (MEDI 4736) in Patients with Advanced Hepatocellular Carcinoma Blood Tissue biopsy Blood Tissue biopsy Guadecitabine SubQ D1-5 Durvalumab D8 Guadecitabine SubQ D1-5 Durvalumab D8 CYCLE 2 screening CYCLE 1 Genome wide methylation Immune cell subsets Whole exome seq ERV proteins Genome wide methylation Immune cell subsets Whole exome seq ERV proteins Liu M, et al, Hepatology 2018

sEphB4-HSA single agent recruits CTLs into tumors and shows activity in an expansion cohort in HCC H&E CD4 CD8 Pre-Treatment Post-Treatment Thomas J et al, ASCO GI 2018

Thoughts regarding combination therapies • Is combination therapy needed for all patients up-front? • Therapeutic index of the combinations: toxicity versus efficacy • What magnitude of benefit would justify the additional toxicity • Could we achieve the same benefit by sequencing the therapies • In what patients • If multiple combinations show efficacy, how will we chose the best combination for a specific patient? • Biomarkers? • Toxicity differences?

IgA+ plasmocytes in NAFLD HCC IgA+ accumulate in the setting of inflammation and fibrosis in humans and mice with NAFLD IgA+ cells express PD-L1 and interleukin 10 IgA+ cells suppress liver cytotoxic CD8+ T cells Pharmacologic interference with IgA+ cells induces cytotoxic T-lymphocyte-mediated regression of established hepatocellular carcinoma. Anti PD-L-1 treatment resulted in decreased liver IgA+IL-10+ cell abundance Anti PD-L-1 resistant tumors lacked immune cells infiltration AND were encapsulated by fibrotic tissue A pilot study of losartan and pembrolizumab with evaluation of IgA+ cells and markers of peri-tumoral fibrosis launching soon Shalapour S et al, Nature 2017

Identifying subgroups of interest for immunotherapyβ-catenin/Wnt pathway Acting CTNNB1 mutations or inactivating AXIN1 mutations Associated with poorer outcome in HCC patients treated with anti-PD-1 therapy Inverse correlation between b-catenin protein level and T-cell-inflamed gene expression. Harding J et al, CCR 2019 LukeJ et al, CCR 2019

Adjuvant Immunotherapy With Autologous Cytokine-Induced Killer Cells for HCC 1.00 Randomized Phase III open-label trial 0.80 Immunotherapy 0.60 230 patients with HCC after resection, RFA, or ethanol injection RFS (Probability) 0.40 Control 0.20 Injection of activated cytokine-induced killer cells • CD3+/CD56+ T cells • CD3+/CD56– T cells • CD3–/CD56+ natural killer cells 0.00 0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 Time (months) No. at risk Immunotherapy 114 106 98 93 89 87 85 82 79 76 59 52 47 40 29 18 8 2 Control 112 98 87 76 67 60 54 52 51 46 40 32 27 23 18 12 10 1 Immunotherapy 1.00 • Primary Endpoint: Recurrence-free survival 0.80 Control OS (Probability) 0.60 0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 Time (months) No. at risk Immunotherapy 114 109 109 109 109 109 108 108 107 100 84 74 70 64 47 35 21 6 Control 112 102 100 99 97 96 93 92 90 80 70 59 56 53 42 30 21 4 . Lee JH et al. Gastroenterology. 2015;148(7):1383-1391.

Phase 1 study (NCT03132792) to evaluate safety and anti-tumor activity in patients with HCC being treated with genetically engineered affinity-enhanced autologous SPEAR T-cells (ADP-A2AFP) directed toward the HLA-A*02-restricted AFP peptide FMNKFIYEI

Immunotherapy for HCC: What’s next