Enhancing Anti-Tumor Activity of Checkpoint Inhibition Jeffrey Schlom, Ph.D. Laboratory of Tumor Immunology and Biology (LTIB) Center for Cancer Research National Cancer Institute, NIH
Laboratory of Tumor Immunology and Biology (LTIB) Center for Cancer Research, NCI LTIB Senior Staff J. Hodge C. Palena K.Y. Tsang J. Greiner R. Donahue S. Gameiro D. Hamilton C. Jochems C. Heery NCI Collaborators J. Gulley R. Madan R. Hassan A. Rajan 2
Avelumab Fully human IgG1 anti-pd-l1 monoclonal antibody Engineered to mediate Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC) Cooperative Research and Development Agreement (CRADA) Laboratory of Tumor Immunology and Biology, National Cancer Institute, NIH EMD Serono, Pfizer 3
mab Mechanisms of Action Direct Effect on Receptor Function Ribas, New Engl J Med. 2012; 366(26):2517-9. 4
Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC) 5
Pros and Cons of ADCC Activity of an anti-pd-l1 MAb Con: toxicity of subpopulations of immune cells expressing PD-L1 - not observed to date Pro: 2 different methods of anti-tumor activity (a) interfering with PD-L1/PD-1 axis (T cells) (b) direct lysis of tumor cells (ADCC/NK) can enhance ADCC activity by enhancing NK activity - IL2 (low dose) - IL12 (immunocytokine) - IL15 (multiple forms) - other immune modulators - some small molecule targeted therapies alter tumor cell phenotype enhancing NK anti-tumor activity 6
Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC) and anti-tumor Activity ADCC has been implicated as a mode of action in highly effective anti-tumor MAbs Target Trastuzumab (Herceptin)* Her 2/neu Rituximab (Rituxin)* CD20 Cetuximab (Erbitux)* EGF-R targets all expressed on some normal tissues some degree of toxicity highly effective *Multiple prior studies: Specific polymorphisms in the FcγR2A and 3A of NK cells correlates with enhanced clinical outcomes 7
PD-L1 MFI is a Stronger Predictor of Sensitivity to ADCC Mediated by Avelumab as Compared to % Positive Cells AA. % PD-L1 + vs ADCC AB. MFI vs ADCC AC. PD-L1 score vs ADCC Each dot represents lysis of a different human tumor cell line. A, Correlation between % PD-L1 positive tumor cells and % ADCC lysis (p<0.0001, r=0.799). B, Correlation between PD-L1 tumor cell MFI and % ADCC lysis (p<0.0001, r=0.811). C, Correlation between the PD-L1 score and % lysis (p<0.0001, r=0.826). The PD-L1 score was derived by scoring each cell line for % positive cells and normalized MFI on a quartile scale ranging from 1 4. All correlations show the p value and Spearman s rank correlation coefficient.
Purified NK Cells from Cancer Patients Mediate ADCC Induced by Avelumab as Effectively as Those Isolated from Healthy Donors Isolated NK cells from 5 healthy donors and 5 lung cancer patients were used in in vitro ADCC assays against the H441 human lung cancer cell line. 9
ADCC Mediated by Avelumab Can Be Inhibited by anti-cd16 Antibody ** Human lung cancer cell line as target and purified NK cells as effectors. 10
Phase I Trial of a Novel anti-pdl1 Checkpoint Inhibitor Rare diseases (NCI): Thymoma Adrenal Cortical Cancer Mesothelioma Tumor shrinkage seen to date: Common diseases (NCI and in multi-center study): Lung adenocarcinoma Melanoma Breast cancer Ovarian cancer Cessation of tumor growth seen to date: Rare diseases (NCI): Chordoma Adrenal Cortical Cancer Common diseases (NCI): Colorectal cancer Pancreatic cancer HPV+ anal cancer Cholangiocarcinoma Clear cell renal cancer 11
Flow Cytometry Analysis of PBMC Immune Subsets Subsets analyzed: 9 standard immune cell subsets, PD-L1 and PD-1 in standard subsets, and 100 additional subsets relating to maturation/function 1. CD4: Helper T lymphocytes (32 subsets) 2. CD8: Cytotoxic T lymphocytes (29 subsets) Markers of PD-1 pathway and T cell activation (in CD4 and CD8): EOMES: activation TCR-αβ: activation Tbet: activation BATF: activation/exhaustion Maturation status of T lymphocytes (in CD4 and CD8): Naïve: CD45RA + CCR7 + Central Memory: CD45RA - CCR7 + Effector Memory: CD45RA - CCR7 - Terminal (EMRA): CD45RA + CCR7 - T lymphocyte markers (in CD4 and CD8): CTLA-4: inhibition PD-1: activation/inhibition PD-L1: activation/cross-inhibition TIM-3: inhibition ICOS: activation (only on CD4) 3. Tregs: Regulatory T lymphocytes (CD4 + CD25 + FoxP3 + CD127 - ) (7 subsets) CD45RA: Tregs highly expandable in vitro CTLA-4: Treg suppression CD49d: contaminating effector lymphocytes (non-tregs) ICOS: Treg suppression PD-1: activation/inhibition PD-L1: cross-inhibition 4. B lymphocytes: CD19 + (5 subsets) CTLA-4: inhibition TIM-3: inhibition PD-1: activation/inhibition 30 markers, 127 subsets PD-L1: cross-inhibition 5. NK: Natural killer cells (CD56 + CD3 - ) (20 subsets) CD16 + CD56 br : Functional intermediate, lytic and cytokine production CD16 + CD56 dim : Mature NK, cytokine production CD16 - CD56 br : Immature, abundant in human placenta CD16 - CD56 dim : non-lytic, non-cytokine production TIM-3: activation PD-1: activation/inhibition PD-L1: cross-inhibition 6. NK-T: CD56 + CD3 + (4 subsets) TIM-3: activation PD-1: activation/inhibition PD-L1: cross-inhibition 7. cdcs (Conventional DCs): CD3 - CD56 - CD1c + CD303 - (5 subsets) 8. pdcs (plasmacytoid DCs ): CD3 - CD56 - CD1c - CD303 + (5 subsets) Markers of DC activation CD83: activation TIM-3: inhibition PD-1: activation/inhibition PD-L1: cross-inhibition 9. MDSCs: Myeloid-derived suppressor cells (CD11b + HLA-DR low/- CD33 + ) (20 subsets) CD14: Common Myeloid Marker (high in monocytes, dim in granulocytes) CD15: Granulocyte marker CD16: most immature monocytic MDSCs PD-1: activation/inhibition PD-L1: cross-inhibition 12
Analyses of PBMCs During anti-pdl1 Therapy First-in-human Phase I Study of Fully Human IgG 1 anti-pdl1 in Patients with Metastatic Cancer Absolute Lymphocyte Count = Normal ALC range Subsets Immune Cell Subsets Expressing PD-L1 Normal individuals (n=6) Pre (n=22) Day 15 (n=19) Day 43 (n=14) CD8 0.2 (0.1-0.4) 0.3 (0.3-0.4) 0.3 (0.2-0.4) 0.3 (0.2-0.4) CD4 0.2 (0.1-0.3) 0.3 (0.2-0.4) 0.3 (0.2-0.5) 0.3 (0.2-0.3) Count x10 3 /µl Treg 0.3 (0.2-0.4) 0.4 (0.3-0.6) 0.4 (0.3-0.6) 0.4 (0.3-0.5) NK 0.7 (0.5-1.1) 1.2 (1.0-1.7) 1.2 (0.9-1.8) 1.1 (1.0-1.4) NK-T 4.5 (1.8-7.6) 1.8 (1.4-3.2) 1.6 (1.3-3.7) 1.5 (1.3-2.9) B cells 11.7 (8.1-13.4) 9.9 (7.0-11.4) 11.3 (7.4-12.6) 11.0 (7.7-12.4) cdcs 14.0 (11.5-17.0) 23.4 (17.7-40.1) 26.4 (16.2-45.9) 19.4 (15.1-26.4) pdcs 3.9 (2.7-8.3) 33.8 (18.0-48.2) 26.6 (12.2-42.2) 27.9 (19.1-56.7) Changes vs. pre = = 1 and 3 mg/kg anti-pdl1 10 mg/kg anti-pdl1 20 mg/kg anti-pdl1 MDSCs 4.0 (3.0-5.6) 8.6 (6.5-9.8) 8.8 (5.0-15.0) 10.7 (4.6-13.7) Values indicate % median (25-75 percentile) There were no statistically significant changes at day 15 and day 43 compared to pre-therapy in the above listed subsets. 13
Pros and Cons of ADCC Activity of an anti-pd-l1 MAb Con: toxicity of subpopulations of immune cells expressing PD-L1 - not observed to date Pro: 2 different methods of anti-tumor activity (a) interfering with PD-L1/PD-1 axis (T cells) (b) direct lysis of tumor cells (ADCC/NK) can enhance ADCC activity by enhancing NK activity - IL2 (low dose) - IL12 - IL15 (multiple forms) - other immune modulators - some small molecule targeted therapies alter tumor cell phenotype enhancing NK anti-tumor activity 14
NK Cell Dynamics During and After Daily Interleukin-15 (IL-15) Infusions B All data are shown as mean ± SEM for administration of IL-15 3 μg/kg (n = 4; all panels) or (A, B) 0.3 μg (n = 9). All fold-change values were computed by individual relative to baseline (Pre). Light blue bars indicate IL-15 infusion times. (A) Absolute count for total natural killer (NK) cells. (B) Representation within NK cells. P values are from two-tailed Student's t test for peak time point. Conlon, J Clin Oncol. 2015; 33(1):74-82. 15
H460 Cells Express MUC1, Are Resistant to MUC1-Specific CTL, but Are Sensitive to ADCC MUC1 CTL Muc1 + HLA-A24 NK ADCC ** **** 16
T Cell vs. NK Tumor Cell Lysis Expression of MHC Class I on tumor cells: enhances CTL activity reduces NK activity Lack of, or minimal, MHC Class I on tumor cells: reduces or eliminates CTL activity enhances NK activity 17
Pros and Cons of ADCC Activity of an anti-pd-l1 MAb Con: toxicity of subpopulations of immune cells expressing PD-L1 - not observed to date Pro: 2 different methods of anti-tumor activity (a) interfering with PD-L1/PD-1 axis (T cells) (b) direct lysis of tumor cells (ADCC/NK) can enhance ADCC activity by enhancing NK activity - IL2 (low dose) - IL12 (immunocytokine) - IL15 (multiple forms) - other immune modulators - some small molecule targeted therapies alter tumor cell phenotype enhancing NK anti-tumor activity 18
Spectrum of Cancer Immunotherapeutics Recombinant Vaccines Cytokines/Immunocytokines Immune Checkpoint Inhibitors Immuno-Oncology Platform: Combination Therapies Chemotherapy Radiation Therapy Small Molecule Targeted Therapies - Hormonal Therapy