poster imprimepgg (imprime) plus pembrolizumab(pem): a ...€¦ · 4. innate effector activation...

1
Abstract Imprime PGG (Imprime) plus pembrolizumab (PEM): a phase 2 immunotherapeutic combination in patients selected for an Imprime-specific biomarker. Steven O’Day 1 , Nandita Bose 2 , Mark Uhlik 2 , Radha Prathikanti 2 , Ben Harrison 2 , Steven Leonardo 2 , Richard Huhn 2 , Nadine Ottoson 2 , Xiaohong Qiu 2 , Richard Walsh 3 , Paulette Mattson 2 , Mable Ma 2 , Katie Ertelt 2 , Jamie Lowe 2 , Michele Gargano 2 , Michael Chisamore 5 , Bruno Osterwalder 4 , Jeremy R Graff 2 1 John Wayne Cancer Institute, Santa Monica, CA 90404, 2 Biothera Pharmaceuticals, Inc. Eagan, MN 55121, 3 Immuno Research, Eagan, MN 55121, 4 B.O. Consulting GmbH, Riehen, Switzerland CH-4125 5 Merck & Co., Inc., Kenilworth, NJ, USA Poster #733 LB-A31 AACR-NCI-EORTC Molecular Targets and Cancer Therapeutics, Biothera Pharmaceuticals, Inc. , Philadelphia, PA, Oct 26-30, 2017 Imprime PGG (Imprime) is a novel immunotherapeutic that acts as a non-self danger signal to activate the innate immune system and coordinate an adaptive immune system response. In multiple preclinical tumor models, Imprime significantly enhances anti-tumor efficacy of multiple immune checkpoint inhibitors (CPI). Mechanistically, Imprime directly binds to innate immune effector cells via the formation of an immune complex with naturally-occurring anti-b glucan antibodies (ABA). This immune complex is required for Imprime to activate innate effector functions- monocyte and dendritic cell activation, and enhanced cytokine production. In a recently completed healthy volunteer study, activation of innate immune cell functions was demonstrated after intravenous (IV) infusion of Imprime in subjects with pre-treatment [Tx] ABA levels > 20 μg/ml. In ex vivo human donor blood studies, whole blood from subjects with low (i.e. insufficient) ABA failed to show innate immune activation unless rescued by the addition of purified ABA (ABA from the serum of high ABA donors) or commercial immunoglobulin (IVIg). Retrospective analyses of data from previous clinical trials showed that higher pre-Tx ABA levels correlated with enhanced overall survival in patients (pts) treated with Imprime. Collectively, these data support the hypothesis that ABA are essential to the therapeutic benefit of Imprime. A phase 2 clinical trial combining Imprime (4 mg/kg weekly IV) with Pembro (200 mg, q3w) has begun in metastatic melanoma pts who have failed a CPI and in CPI naïve, triple-negative breast cancer (TNBC) pts who have failed chemotherapy. Pts are screened for sufficient ABA (> 20 μg/ml) by ELISA. Pre- and early-on Tx biopsies (6 wks) and at time of response/progression or end of Tx are requested to assess immune cells at the tumor site by multispectral immunofluorescence. Blood samples are collected pre- and post- Imprime infusion on Day 1 of each treatment cycle for the first 6 cycles and q4 cycle thereafter. The first TNBC pt had a pre-Tx ABA of 31 μg/ml. Following 6 wks of Tx, the pt’s total target lesion mass was reduced >40%. Partial response continued at 12, 18 and 24 wks (>50% reduction vs baseline). A biopsy of a remaining pelvic lesion after 18 wks Tx revealed primarily fibrotic tissue. Blood samples showed evidence of innate immune activation including increased expression of MCP-1, IL-8, chemokines targeting CCR5 and CXCR3 that are associated with enhanced T cell infiltration and effector function. The first melanoma pt (pre-Tx ABA 42 μg/ml) showed a modest increase in lesion size at 12 wks (+12% versus baseline). Pre- and on-Tx (6 wk) biopsy material (from two different lesion locations) was obtained for multichannel immunofluorescence. The pre-Tx biopsy tumor sample was primarily devoid of immune cells. In contrast, the on-Tx biopsy tumor sample indicates extensive infiltration of the tumor bed by CD8 and CD4 T cells, and innate immune cells. Previous Imprime clinical and ex vivo data suggest that sufficient ABA may be important for Imprime-mediated innate immune activation. Early clinical observations in ABA pre-selected patients support the notion that Imprime may provide benefit in combination with Pembro in these two populations. Imprime Mechanism of Action Cytokine Chemokine Production IFNs Monocyte Macrophage Dendritic Cell Neutrophil Proposed mechanism of action ignites a fully functional immune response against cancer 1. Imprime forms an immune complex Anti-β glucan antibodies (ABA) (IgG2a) Complement fragment (iC3b) Imprime-β glucan 2. Binds to and co-ligates 3 surface receptors ABAs bind Fcγ receptor IIa (CD32a) iC3b binds complement receptor 3 (CR3) Imprime binds dectin-1 receptor 3. Receptor co-ligation provides activation signal Type 1 interferon gene expression Chemokines/cytokines 4. Innate effector activation Promotes tumor killing Macrophages, neutrophils Alleviates immunosuppression M2èM1 repolarization MDSC maturation/differentiation Activates antigen presentation Dendritic cell maturation M1 APCs Imprime PGG: An Immunological “Ignition Switch” IgG ABA Complement opsonin iC3b iC3b 4 Imprime and CPI: Preclinical Efficacy Imprime ABA (RAU/mL): 0 350 700 0 500 1000 1500 2000 15000 20000 25000 IL-8 MCP-1 Chemokine (pg/mL) 0 10 20 30 40 50 60 70 0 20 40 60 80 100 Citrate + Raji Imprime + Raji Imprime + 175 RAU/mL ABA Imprime + 250 RAU/mL ABA Imprime + 350 RAU/mL ABA Time (min) Reactive Oxygen Species (ROS) in RLU PD Effects ROS Generation Left Panel- Imprime induced pharmacodynamic effects (MCP-1, IL-8) are enhanced in whole blood from a “low binder” by purified ABA supplementation. Right Panel- The generation of Reactive Oxygen Species (ROS) is enhanced in neutrophils isolated from a “low binder” when exposed to rituximab-opsonized Raji B cell lymphomas. Note: Dose dependent ROS generation with ABA supplementation. RAU = relative antibody units. ABA Supplementation in a Non-Responsive Donor Rescues ImmunoPD Effects and Functional Tumor Cell Killing Activities Neutrophils Monocytes Vehicle Imprime PGG Imprime PGG + ABA Imprime Binding Can Be Rescued by ABA Supplementation in “Low Binding” Individuals Whole blood was isolated from a low-binding healthy human donor. Imprime was detected on the surface of Neutrophils and Monocytes using an anti-β glucan imaging antibody BfDIV followed by flow cytometry. Binding was substantially enhanced by the addition of purified human IgG ABA as indicated by the shift up (right panels). Imprime and ABA: Ex Vivo Studies Imprime and ABA: Retrospective Studies Human Healthy Volunteer Study CONFIDENTIAL Imprime PGG Enhances the Response to Checkpoint Inhibitor Therapy 0 10 20 30 40 50 60 70 80 90 100 % of Injected mice without tumor (day 29) 5.6% 11% 33% 83%* Control Imprime PGG αPD-L1 Imprime + αPD-L1 MC-38 colon cancers were subcutaneously injected into C57BL/6 mice. 3 days later, treatment was initiated. N = 18 per group except Imprime PGG + PD-L1, n =17. Tumor-free mice were re-injected in the opposite flank with MC-38 and remained tumor-free for another month, without any additional therapy. Tumors grew in all age-matched, tumor naïve control mice injected with MC-38. * ANOVA analysis, Tukey adjustment, p = 0.001 vs. aPD-L1, p < 0.0001 vs vehicle control. Differences between all other groups were not significant ( p 0.05). Tumor-free mice were re-challenged with MC-38 cells on the opposite flank and remained tumor-free. This suggests the establishment of immunological memory. 1.0 0.8 0.2 0.0 0.6 0.4 0 10 20 30 40 50 ABA 35 ABA < 35 HR=0.40 (0.22-0.73) p=0.0018 Survival Probability 85 36 8 1 0 0 27 17 6 2 1 1 Significant (p<0.05) tests: 36 out of 86 (41.9%) Imprime + Cetuximab 2 1 0.5 10 20 30 40 50 Imprime + Cetuximab 1.0 0.8 0.2 0.0 0.6 0.4 Survival Probability HR=0.24 (0.1-0.55) p=0.00031 ABA > 45 ABA < 45 0 10 20 30 40 50 0 10 ABA < 20 ABA 20 1.0 0.8 0.2 0.0 0.6 0.4 HR=0.77 (0.49-1.22) p=0.27 Survival Probability % Subjects- ABA levels: 49% 20 24% 35 16% 45 57 25 5 1 0 55 28 9 2 1 1 94 40 10 1 0 18 13 4 2 1 1 ABA IgG (μg/ml) CRC Primus Trial: Higher Pre-Treatment ABA Levels Correspond with Improved Overall Survival 0.25 0.13 HR with 95% CI Retrospective analyses: Primus trial, 3 rd line CRC cetuximab ± Imprime. Pre-treatment ABA levels were measured by ELISA. Sample “cutpoints” for ABA are noted at 20, 35 and 45 !g/ml. 0 20 40 60 80 100 120 140 160 180 200 220 ABA IgG (ug/ml) Donors Distribution of ABA IgG in Lung Cancer Samples 53.5% 0 20 40 60 80 100 120 140 160 180 200 220 ABA IgG (ug/ml) Donors Distribution of ABA IgG in Breast Cancer Samples 45.8% 0 20 40 60 80 100 120 ABA IgG (ug/ml) Donors Distribution of ABA IgG in Ovarian Cancer Samples 58.6% IgG ABA Distribution in Patients with Different Cancers Biothera Trials Indication n median IgG ABA Colon (Primus) 169 18.7 μg/ml NSCLC (0821) 58 20.4 μg/ml NSCLC (0822) 59 23.0 μg/ml Tumor (EphA2 + Ki67 + ) CD8 T-cells (CD3 + CD8 + ) Activated CD8 T-cells (CD3 + CD8 + Ki67 + GrzB High ) Vehicle Imprime Increased Activation of T-Cells in the MC-38 Tumor Bed after Imprime Treatment MC-38- Imprime dosed IV 1.2mg/mouse twice weekly. 10 days treatment. Tumor Tissues imaged using the Perkin Elmer Vectra Multi-spectral Imaging System. Phase 2 Imprime + Pembro Studies Imprime and Pembro: CPI Experienced Metastatic Melanoma Pre Treatment Sample Post Treatment Sample 2mm 800 μm Pre Treatment Sample Post Treatment Sample Patient 103103 Hematoxylin and Eosin Stains for Pre- and On-Tx Melanoma Biopsies Pharmacodynamic Effects of Imprime are Restricted to Biomarker Positive Human Subjects Blue = ABA IgG+ Red = ABA IgG-/ IgM- Black = ABA IgG-/IgM+ 0.10 1.00 10.00 100.00 1000.00 IL-6 IL-8 IP-10 MCP-1 MIG MIP-1 ALPHA MIP-1 BETA TNF-ALPHA Cytokine/chemokine expression. At the end of infusion, serum was taken to assess cytokine and chemokine expression changes versus pre-dose values in each subject (fold increase shown) using the Luminex XMAP technology. NSCLC Metastatic Melanoma Triple-Negative Breast Cancer Head and Neck Cancer Phase Phase 1b/2 Phase 2 Phase 2 Phase 2 Combination Therapy Pembrolizumab Pembrolizumab Pembrolizumab Pembrolizumab Patients 2 nd line patients 2 nd line patients - Pembro failure 2 nd- 3 rd line patients - Pembro Naive Stable disease >3 mos Pembro Pembro Failure Number of Subjects 36 29 42 87 Randomization Single arm Single arm Single arm Single arm Primary Endpoint PFS ORR ORR ORR Secondary Endpoints Safety, PFS, OS Safety, PFS, OS Safety, PFS, OS Safety, PFS, OS Initiation 3Q 2016 4Q 2016 4Q 2016 1Q 2017 Phase 2 Clinical Studies: Imprime + Pembrolizumab 24 Patients selected for Imprime-specific biomarker (Anti-Beta glucan Antibodies, ABA > than 20 μg/ml) Pre Treatment Sample Post Treatment Sample DAPI Tumor CD4 CD8 GrzB Fold Increase vs Pre-Tx Cytotoxic T cells (CD8) Total number = 28X Proliferating = 33X Activated = 50X Helper T Cells (CD4) Total Number= 58X Proliferating = 73X Activated = 24X Lymphocyte Infiltration: Pre and On Tx Biopsy Pre Treatment Sample Post Treatment Sample Nuclei Tumor Mac/Mono CD80 PD-L1 Myeloid Character Post vs Pre Tx Myeloid Infiltration 56X increase CD80+ 100X increase PD-L1+ Myeloid 13X increase Increased Myeloid Infiltration and Activation Post Treatment Pre-Treatment Post-Treatment % of Myeloid Cells CD80+: 6.34% % of Myeloid Cells PD-L1+: 0.90% % of Myeloid Cells CD206+: 18.45% % CD80+/CD206+ (M1:M2 ratio): 0.34 Tumor CD163 CD206 CD80 % of Myeloid Cells CD80+: 13.79% % of Myeloid Cells PD-L1+: 14.88% % of Myeloid Cells CD206+: 3.11% % CD80+/CD206+ (M1:M2 ratio): 4.44 Evidence for increased M1:M2 Character Post Treatment Translational Research: Schedule of Assessments Cycle Screening 1 2 3 4 5 6 10, Q4C End of Trtmnt Week Tube type Up to -4 1 4 7 10 13 16 28 CBC/Diff: Pre and 4 hr Post SOI ETDA X X X X X PBMC: Pre and Post Heparin X X X X PAXGene (RNA): Pre-Imprime and Post Pembro PAXGene X X X X X ABA: Pre and Post Imprime Serum X X X X X X X X X Cytokines: Pre and Post Imprime Serum X X X X X X X X Imprime PK: Pre, 1.5 hr post EOI Imprime Serum X X Pembo PK: Pre Pembro and 3 hr post EOI Pembro Serum X X Biopsies (archival, pre-C1, pre- C3 and upon time of response/progression Tissue X X X SOI: Start of Infusion Imprime- Induced PD Effects Are Restricted to ABA + Subjects 0 20 40 60 80 100 Circulating Immune Complexes (Eq ug/ml) 25 39 67 10 34 55 70 Imprime Dose Week #1 Subjects 0 250 500 750 1000 1250 1500 Monocytes (cell/ul) 25 67 10 34 55 70 Imprime Dose Week #1 39 0 2500 5000 7500 10000 12500 15000 17500 20000 Neutrophils (cell/ul) 25 67 10 34 55 70 Imprime Dose Week #1 39 0 2500 5000 7500 10000 12500 15000 SC5b-9 (ng/ml) 25 67 10 34 55 Imprime Dose Week #1 Subjects 39 70 0 5000 10000 15000 20000 25000 30000 MCP-1 (pg/ml) 25 67 10 34 55 Imprime Dose Week #1 Subjects 39 70 Biomarker + (ABA ≥ 20μg/ml) Biomarker – (ABA < 20μg/ml) Immune Complex Monocyte Mobilization Neutrophil Mobilization Complement Cytokines Whole blood or serum was drawn from healthy volunteers at various time points before and after a single dose of Imprime infusion. ABA were measured in serum by ELISA. Circulating Immune complex formation was measured using the MicroVue Complement CIC-Raji Cell Replacement Kit. Cell mobilization was measured by complete blood cell counts, plus differentials. Monocyte and Neutrophil numbers are shown. Complement activity was measured by ELISA using the SC5b- 9 Plus kits (Quidel). Cytokines and chemokines were measured in serum using Luminex XMAP technology. Fold over pre- dose values are plotted. Data from subjects who were treated with Imprime (4 mg/kg) and no pre-medications. CONFIDENTIAL Cycle 1 Wk 1-pre Cycle 1 Wk 1-EOI Cycle 2 Wk 4-pre Cycle 2 Wk 4-EOI Cycle 3 Wk 7-pre Cycle 3 Wk 7-EOI Cycle 4 Wk 10-pre Cycle 4 Wk 10-EOI Cycle 5 Wk 13-pre Cycle 5 Wk 13-EOI 0 1 2 3 4 5 10 20 30 40 fold over pre-C1 SC5b9 Fold changes 103102 Cycle 1 Pre-Infusion Cycle 1 EOI Cycle 2 Pre-Infusion Cycle 2 EOI Cycle 3 Pre-Infusion Cycle 3 EOI Cycle 4 Pre-Infusion Cycle 4 EOI Cycle 5 Pre-Infusion Cycle 5 EOI 0 20 40 60 80 0 100 200 300 Patient 103102 CIC vs ABA CIC ABA IgG (μg/ml) CIC ABA fold over Pre-C1 Circulating Immune complex formation was measured using a commercial immuno assay system (MicroVue Complement CIC-Raji Cell Replacement Kit). Complement activity was measured by ELISA using the SC5b-9 Plus kits (Quidel). TNBC 103102: ABA, Immune Complex Formation and Complement Activation TNBC Pt 103102: Induction of Imprime-Responsive Cytokines Cycle 1 Week 1 PRE Cycle 1 Week 1 EOI Cycle 2 Week 4 PRE Cycle 2 Week 4 EOI Cycle 3 Week 7 PRE Cycle 3 Week 7 EOI Cycle 4 Week 10 PRE Cycle 4 Week 10 EOI Cycle 5 Week 13 PRE Cycle 5 Week 13 EOI 0 5 10 15 500 600 700 800 900 1000 pg/ml IL-8 IL-8 Cycle 1 Week 1 PRE Cycle 1 Week 1 EOI Cycle 2 Week 4 PRE Cycle 2 Week 4 EOI Cycle 3 Week 7 PRE Cycle 3 Week 7 EOI Cycle 4 Week 10 PRE Cycle 4 Week 10 EOI Cycle 5 Week 13 PRE Cycle 5 Week 13 EOI 0 20 40 60 80 100 1000 2000 3000 4000 pg/ml MIP-1 beta MIP-1 beta Cycle 1 Week 1 PRE Cycle 1 Week 1 EOI Cycle 2 Week 4 PRE Cycle 2 Week 4 EOI Cycle 3 Week 7 PRE Cycle 3 Week 7 EOI Cycle 4 Week 10 PRE Cycle 4 Week 10 EOI Cycle 5 Week 13 PRE Cycle 5 Week 13 EOI 0 10 20 30 40 100 200 300 1000 1500 2000 pg/ml RANTES RANTES LOD1: 0.78 LOD2: 0.99 Cycle 1 Week 1 PRE Cycle 1 Week 1 EOI Cycle 2 Week 4 PRE Cycle 2 Week 4 EOI Cycle 3 Week 7 PRE Cycle 3 Week 7 EOI Cycle 4 Week 10 PRE Cycle 4 Week 10 EOI Cycle 5 Week 13 PRE Cycle 5 Week 13 EOI 0 50 100 150 pg/ml Eotaxin Eotaxin Cycle 1 Week 1 PRE Cycle 1 Week 1 EOI Cycle 2 Week 4 PRE Cycle 2 Week 4 EOI Cycle 3 Week 7 PRE Cycle 3 Week 7 EOI Cycle 4 Week 10 PRE Cycle 4 Week 10 EOI Cycle 5 Week 13 PRE Cycle 5 Week 13 EOI 0 20 40 60 80 2000 4000 6000 pg/ml MCP-1 MCP-1 LOD1: 1.23 LOD2: 2.43 Cycle 1 Week 1 PRE Cycle 1 Week 1 EOI Cycle 2 Week 4 PRE Cycle 2 Week 4 EOI Cycle 3 Week 7 PRE Cycle 3 Week 7 EOI Cycle 4 Week 10 PRE Cycle 4 Week 10 EOI Cycle 5 Week 13 PRE Cycle 5 Week 13 EOI 0 20 40 50 100 150 pg/ml MIP-1 alpha MIP-1 alpha LOD1: 0.49 LOD2: 1.32 Cytokines and chemokines were measured in serum using Luminex XMAP technology. TNBC Pt 103102: Induction of Imprime-Responsive Cytokines Cycle 1 Week 1 PRE Cycle 1 Week 1 EOI Cycle 2 Week 4 PRE Cycle 2 Week 4 EOI Cycle 3 Week 7 PRE Cycle 3 Week 7 EOI Cycle 4 Week 10 PRE Cycle 4 Week 10 EOI Cycle 5 Week 13 PRE Cycle 5 Week 13 EOI 0 5 10 15 pg/ml GM-CSF GM-CSF Cycle 1 Week 1 PRE Cycle 1 Week 1 EOI Cycle 2 Week 4 PRE Cycle 2 Week 4 EOI Cycle 3 Week 7 PRE Cycle 3 Week 7 EOI Cycle 4 Week 10 PRE Cycle 4 Week 10 EOI Cycle 5 Week 13 PRE Cycle 5 Week 13 EOI 0 5 10 50 100 150 200 250 pg/ml GRO-alpha GRO-alpha Cycle 1 Week 1 PRE Cycle 1 Week 1 EOI Cycle 2 Week 4 PRE Cycle 2 Week 4 EOI Cycle 3 Week 7 PRE Cycle 3 Week 7 EOI Cycle 4 Week 10 PRE Cycle 4 Week 10 EOI Cycle 5 Week 13 PRE Cycle 5 Week 13 EOI 0 5 10 15 20 2000 4000 6000 pg/ml IL-6 IL-6 Cycle 1 Week 1 PRE Cycle 1 Week 1 EOI Cycle 2 Week 4 PRE Cycle 2 Week 4 EOI Cycle 3 Week 7 PRE Cycle 3 Week 7 EOI Cycle 4 Week 10 PRE Cycle 4 Week 10 EOI Cycle 5 Week 13 PRE Cycle 5 Week 13 EOI 0 1 2 3 4 5 pg/ml IL-7 IL-7 Cycle 1 Week 1 PRE Cycle 1 Week 1 EOI Cycle 2 Week 4 PRE Cycle 2 Week 4 EOI Cycle 3 Week 7 PRE Cycle 3 Week 7 EOI Cycle 4 Week 10 PRE Cycle 4 Week 10 EOI Cycle 5 Week 13 PRE Cycle 5 Week 13 EOI 0 50 100 150 200 50000 100000 150000 pg/ml IL-1RA IL-1RA Cycle 1 Week 1 PRE Cycle 1 Week 1 EOI Cycle 2 Week 4 PRE Cycle 2 Week 4 EOI Cycle 3 Week 7 PRE Cycle 3 Week 7 EOI Cycle 4 Week 10 PRE Cycle 4 Week 10 EOI Cycle 5 Week 13 PRE Cycle 5 Week 13 EOI 0 50 100 150 200 500 1000 1500 pg/ml IP-10 (CXCL10) IP-10 (CXCL10) LOD1: 0.51 LOD2: 1.78 Cytokines and chemokines were measured in serum using Luminex XMAP technology. Cycle 1 Week 1 PRE Cycle 1 Week 1 EOI Cycle 2 Week 4 PRE Cycle 2 Week 4 EOI Cycle 3 Week 7 PRE Cycle 3 Week 7 EOI Cycle 4 Week 10 PRE Cycle 4 Week 10 EOI Cycle 5 Week 13 PRE Cycle 5 Week 13 EOI 0 10 20 30 pg/ml IL-18 IL-18 Cycle 1 Week 1 PRE Cycle 1 Week 1 EOI Cycle 2 Week 4 PRE Cycle 2 Week 4 EOI Cycle 3 Week 7 PRE Cycle 3 Week 7 EOI Cycle 4 Week 10 PRE Cycle 4 Week 10 EOI Cycle 5 Week 13 PRE Cycle 5 Week 13 EOI 0 1 2 3 4 pg/ml IL-15 IL-15 Cycle 1 Week 1 PRE Cycle 1 Week 1 EOI Cycle 2 Week 4 PRE Cycle 2 Week 4 EOI Cycle 3 Week 7 PRE Cycle 3 Week 7 EOI Cycle 4 Week 10 PRE Cycle 4 Week 10 EOI Cycle 5 Week 13 PRE Cycle 5 Week 13 EOI 0 50 100 150 200 pg/ml ITAC (CXCL11) ITAC (CXCL11) LOD1: 4.13 LOD2: 6.4 Cycle 1 Week 1 PRE Cycle 1 Week 1 EOI Cycle 2 Week 4 PRE Cycle 2 Week 4 EOI Cycle 3 Week 7 PRE Cycle 3 Week 7 EOI Cycle 4 Week 10 PRE Cycle 4 Week 10 EOI Cycle 5 Week 13 PRE Cycle 5 Week 13 EOI 0 500 1000 1500 2000 pg/ml SDF-1 alpha SDF-1 alpha LOD1: 2.6 LOD2: 18.11 Cycle 1 Week 1 PRE Cycle 1 Week 1 EOI Cycle 2 Week 4 PRE Cycle 2 Week 4 EOI Cycle 3 Week 7 PRE Cycle 3 Week 7 EOI Cycle 4 Week 10 PRE Cycle 4 Week 10 EOI Cycle 5 Week 13 PRE Cycle 5 Week 13 EOI 0 5 10 15 20 pg/ml IL-2 IL-2 Cycle 1 Week 1 PRE Cycle 1 Week 1 EOI Cycle 2 Week 4 PRE Cycle 2 Week 4 EOI Cycle 3 Week 7 PRE Cycle 3 Week 7 EOI Cycle 4 Week 10 PRE Cycle 4 Week 10 EOI Cycle 5 Week 13 PRE Cycle 5 Week 13 EOI 0 50 100 200 250 300 350 400 pg/ml IL-22 IL-22 TNBC Pt 103102: Cytokine Induction Cytokines and chemokines were measured in serum using Luminex XMAP technology. TNBC Patient Melanoma Patient 0.1 1 10 100 1000 GM-CSF IL-7 Eotaxin GRO-alpha IL-8 IP-10 (CXCL10) ITAC (CXCL11) MCP-1 MIP-1 alpha MIP-1 beta RANTES SDF-1 alpha IFN-alpha IFN-gamma IL-1 alpha IL-1 beta IL-2 IL-6 TNF-alpha IL-12 p70 IL-1RA IL-10 IL-27 TNF-beta IL-15 IL-18 IL-21 IL-17A IL-22 IL-23 IL-4 IL-5 IL-9 IL-13 IL-31 Chemokines 0.1 1 10 100 1000 GM-CSF IL-7 Eotaxin GRO-alpha IL-8 IP-10 (CXCL10) ITAC (CXCL11) MCP-1 MIP-1 alpha MIP-1 beta RANTES SDF-1 alpha IFN-alpha IFN-gamma IL-1 alpha IL-1 beta IL-2 IL-6 TNF-alpha IL-12 p70 IL-1RA IL-10 IL-27 TNF-beta IL-15 IL-18 IL-21 IL-17A IL-22 IL-23 IL-4 IL-5 IL-9 IL-13 IL-31 C1 C2 C3 Inflammatory Cytokines Th2 Th17 Cytokine Profiles: TNBC Patient and Melanoma Patient Cytokines and chemokines were measured in serum using Luminex XMAP technology. Each ring radiating from the center represents an order of magnitude increase in expression. Imprime and Pembro: CPI Naïve TNBC Imprime + Pembro: Early Experience CONFIDENTIAL Phase 2 Imprime + Pembrolizumab: Early Clinical Experience Triple Negative Breast Cancer Patient 103102 Objective Responder Tumor Shrinkage- 44% evident at week 6 Tumor Shrinkage > 50% for > 28 weeks Tumor Biopsy at ~ week 18- no tumor, fibrotic tissue Increased ABA after Imprime dosing Evidence for Imprime-induced cytokines/ chemokines Metastatic Melanoma Patient 103103 Tumor Biopsy at week 6 suggests activated T cell Infiltration Tumor Biopsy at week 6 shows myeloid infiltration and activation Evidence for Imprime- induced cytokines/ chemokines Patient off therapy at week 18 Early clinical experience provides evidence of clinical response (TNBC) and 1st proof of mechanism- i.e. that Imprime may drive immune activation at the tumor bed

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Page 1: Poster ImprimePGG (Imprime) plus pembrolizumab(PEM): a ...€¦ · 4. Innate effector activation • Promotes tumor killing – Macrophages, neutrophils • Alleviates immunosuppression

Abstract

Imprime PGG(Imprime)pluspembrolizumab (PEM):aphase2immunotherapeuticcombinationinpatientsselectedforanImprime-specificbiomarker.

StevenO’Day1, Nandita Bose2,MarkUhlik2,Radha Prathikanti2,BenHarrison2,StevenLeonardo2,RichardHuhn2, NadineOttoson2,Xiaohong Qiu2,RichardWalsh3,PauletteMattson2,MableMa2,KatieErtelt2,JamieLowe2,MicheleGargano2,MichaelChisamore5,BrunoOsterwalder4,JeremyRGraff21JohnWayneCancerInstitute,SantaMonica,CA90404,2BiotheraPharmaceuticals,Inc.Eagan,MN55121,3ImmunoResearch,Eagan,MN55121,4B.O.ConsultingGmbH,Riehen,SwitzerlandCH-41255Merck&Co.,Inc.,Kenilworth,NJ,USA

Poster#733LB-A31

AACR-NCI-EORTCMolecularTargetsandCancerTherapeutics,BiotheraPharmaceuticals,Inc.,Philadelphia,PA,Oct26-30,2017

Imprime PGG (Imprime) is a novel immunotherapeutic that acts as a non-self danger signal to activatethe innate immune system and coordinate an adaptive immune system response. In multiple preclinicaltumor models, Imprime significantly enhances anti-tumor efficacy of multiple immune checkpointinhibitors (CPI). Mechanistically, Imprime directly binds to innate immune effector cells via theformation of an immune complex with naturally-occurring anti-b glucan antibodies (ABA). This immunecomplex is required for Imprime to activate innate effector functions- monocyte and dendritic cellactivation, and enhanced cytokine production. In a recently completed healthy volunteer study,activation of innate immune cell functions was demonstrated after intravenous (IV) infusion of Imprimein subjects with pre-treatment [Tx] ABA levels > 20 µg/ml. In ex vivo human donor blood studies, wholeblood from subjects with low (i.e. insufficient) ABA failed to show innate immune activation unlessrescued by the addition of purified ABA (ABA from the serum of high ABA donors) or commercialimmunoglobulin (IVIg). Retrospective analyses of data from previous clinical trials showed that higherpre-Tx ABA levels correlated with enhanced overall survival in patients (pts) treated with Imprime.Collectively, these data support the hypothesis that ABA are essential to the therapeutic benefit ofImprime. A phase 2 clinical trial combining Imprime (4 mg/kg weekly IV) with Pembro (200 mg, q3w)has begun in metastatic melanoma pts who have failed a CPI and in CPI naïve, triple-negative breastcancer (TNBC) pts who have failed chemotherapy. Pts are screened for sufficient ABA (> 20 µg/ml) byELISA. Pre- and early-on Tx biopsies (6 wks) and at time of response/progression or end of Tx arerequested to assess immune cells at the tumor site by multispectral immunofluorescence. Bloodsamples are collected pre- and post- Imprime infusion on Day 1 of each treatment cycle for the first 6cycles and q4 cycle thereafter. The first TNBC pt had a pre-Tx ABA of 31 µg/ml. Following 6 wks of Tx,the pt’s total target lesion mass was reduced >40%. Partial response continued at 12, 18 and 24 wks(>50% reduction vs baseline). A biopsy of a remaining pelvic lesion after 18 wks Tx revealed primarilyfibrotic tissue. Blood samples showed evidence of innate immune activation including increasedexpression of MCP-1, IL-8, chemokines targeting CCR5 and CXCR3 that are associated with enhanced Tcell infiltration and effector function. The first melanoma pt (pre-Tx ABA 42 µg/ml) showed a modestincrease in lesion size at 12 wks (+12% versus baseline). Pre- and on-Tx (6 wk) biopsy material (from twodifferent lesion locations) was obtained for multichannel immunofluorescence. The pre-Tx biopsy tumorsample was primarily devoid of immune cells. In contrast, the on-Tx biopsy tumor sample indicatesextensive infiltration of the tumor bed by CD8 and CD4 T cells, and innate immune cells. PreviousImprime clinical and ex vivo data suggest that sufficient ABA may be important for Imprime-mediatedinnate immune activation. Early clinical observations in ABA pre-selected patients support the notionthat Imprime may provide benefit in combination with Pembro in these two populations.

Imprime MechanismofAction

Cytokine Chemokine Production

IFNs

MonocyteMacrophageDendritic CellNeutrophil

Proposed mechanism of action ignites a fully functional immune response against cancer

1. Imprime forms an immune complex• Anti-β glucan antibodies (ABA) (IgG2a)• Complement fragment (iC3b)• Imprime-β glucan

2. Binds to and co-ligates 3 surface receptors• ABAs bind Fcγ receptor IIa (CD32a)• iC3b binds complement receptor 3 (CR3)• Imprime binds dectin-1 receptor

3. Receptor co-ligation provides activation signal• Type 1 interferon gene expression• Chemokines/cytokines

4. Innate effector activation• Promotes tumor killing– Macrophages, neutrophils

• Alleviates immunosuppression– M2èM1 repolarization– MDSC maturation/differentiation

• Activates antigen presentation– Dendritic cell maturation– M1 APCs

Imprime PGG: An Immunological “Ignition Switch”

IgG ABA Complement opsoniniC3b

iC3b

4

Imprime andCPI:PreclinicalEfficacy

Imprime

ABA (RAU/mL): 0 350 700

0500

100015002000

15000

20000

25000

IL-8MCP-1

Che

mok

ine

(pg/

mL)

0 10 20 30 40 50 60 700

20

40

60

80

100

Citrate + RajiImprime + RajiImprime + 175 RAU/mL ABAImprime + 250 RAU/mL ABAImprime + 350 RAU/mL ABA

Time (min)

Reac

tive

Oxyg

en S

pecie

s (R

OS) i

n RL

U

PD Effects ROS Generation

Left Panel- Imprime induced pharmacodynamic effects (MCP-1, IL-8) are enhanced in whole blood from a “low binder” by purified ABA supplementation. Right Panel- The generation of Reactive Oxygen Species (ROS) is enhanced in neutrophils isolated from a “low binder” when exposed to rituximab-opsonized Raji B cell lymphomas. Note: Dose dependent ROS generation with ABA supplementation. RAU = relative antibody units.

ABA Supplementation in a Non-Responsive Donor Rescues ImmunoPD Effects and Functional Tumor Cell Killing Activities

Neutrophils

Monocytes

Vehicle Imprime PGG Imprime PGG + ABA

Imprime BindingCanBeRescuedbyABASupplementationin“LowBinding”Individuals

Wholebloodwasisolatedfromalow-bindinghealthyhumandonor.Imprime wasdetectedonthesurfaceofNeutrophilsandMonocytesusingananti-βglucan imagingantibodyBfDIV followedbyflowcytometry.BindingwassubstantiallyenhancedbytheadditionofpurifiedhumanIgG ABAasindicatedbytheshiftup(rightpanels).

Imprime andABA:ExVivoStudies

Imprime andABA:RetrospectiveStudies

HumanHealthyVolunteerStudy

CONFIDENTIAL

Imprime PGG Enhances the Response to Checkpoint Inhibitor Therapy

0

10

20

30

40

50

60

70

80

90

100

Control Imprime PGG only

PDL-1 only Imprime PGG + PDL-1

% of

Inje

cted

mice

with

out t

umor

(d

ay 29

)

5.6% 11%

33%

83%*

Control Imprime PGG αPD-L1 Imprime + αPD-L1MC-38 colon cancers were subcutaneously injected into C57BL/6 mice. 3 days later, treatment was initiated. N = 18 per group except Imprime PGG + PD-L1, n =17. Tumor-free mice were re-injected in the opposite flank with MC-38 and remained tumor-free for another month, without any additional therapy. Tumors grew in all age-matched, tumor naïve control mice injected with MC-38. * ANOVA analysis, Tukey adjustment, p = 0.001 vs. aPD-L1, p < 0.0001 vs vehicle control. Differences between all other groups were not significant ( p ≤ 0.05).

Tumor-free mice were re-challenged with MC-38 cells on the opposite flank and remained tumor-free. This suggests the

establishment of immunological memory.

1.0

0.8

0.2

0.0

0.6

0.4

0 10 20 30 40 50

ABA ≥ 35

ABA < 35

HR=0.40 (0.22-0.73)p=0.0018

Surv

ival P

roba

bilit

y

85 36 8 1 0 027 17 6 2 1 1

Significant (p<0.05) tests: 36 out of 86 (41.9%)

Imprime + Cetuximab

2

1

0.5

10 20 30 40 50

Imprime + Cetuximab

1.0

0.8

0.2

0.0

0.6

0.4

Surv

ival P

roba

bilit

y

HR=0.24 (0.1-0.55)p=0.00031

ABA > 45

ABA < 45

0 10 20 30 40 50

0 10 20 30 40 50

ABA < 20

ABA ≥ 20

1.0

0.8

0.2

0.0

0.6

0.4

HR=0.77 (0.49-1.22)p=0.27

Surv

ival P

roba

bilit

y

% Subjects- ABA levels:49% ≥2024% ≥35 16% ≥45

57 25 5 1 0 55 28 9 2 1 1

94 40 10 1 0 18 13 4 2 1 1

ABA IgG (μg/ml)

CRC Primus Trial: Higher Pre-Treatment ABA Levels Correspond with Improved Overall Survival

0.25

0.13HR w

ith 9

5% C

I

Retrospective analyses: Primus trial, 3rd line CRC cetuximab ± Imprime. Pre-treatment ABA levels were measured by ELISA. Sample “cutpoints” for ABA are noted at 20, 35 and 45 !g/ml.

0 20 40 60 80 100 120 140 160 180 200 220

ABA IgG (ug/ml)

Don

ors

Distribution of ABA IgG in Lung Cancer Samples

53.5%

0 20 40 60 80 100 120 140 160 180 200 220

ABA IgG (ug/ml)

Dono

rs

Distribution of ABA IgG in Breast Cancer Samples

45.8%

0 20 40 60 80 100 120

ABA IgG (ug/ml)

Dono

rs

Distribution of ABA IgG in Ovarian Cancer Samples

58.6%

IgG ABA Distribution in Patients with Different Cancers

Biothera Trials

Indication n median IgG ABAColon (Primus) 169 18.7 μg/mlNSCLC (0821) 58 20.4 μg/mlNSCLC (0822) 59 23.0 μg/ml

Tumor(EphA2+Ki67+)

CD8 T-cells(CD3+CD8+)

Activated CD8 T-cells(CD3+CD8+Ki67+GrzBHigh)

Vehic

leIm

prim

e

Increased Activation of T-Cells in the MC-38 Tumor Bed after Imprime Treatment

MC-38- Imprime dosed IV 1.2mg/mouse twice weekly. 10 days treatment. Tumor Tissues imaged using the Perkin Elmer Vectra Multi-spectral Imaging System.

Phase2Imprime +Pembro Studies Imprime andPembro:CPIExperiencedMetastaticMelanoma

Pre Treatment Sample Post Treatment Sample

2mm 800 µm

Pre Treatment Sample Post Treatment Sample

Patient 103103

Hematoxylin and Eosin Stains for Pre- and On-Tx Melanoma Biopsies

Pharmacodynamic Effects of Imprime are Restricted to Biomarker Positive Human Subjects

Blue=ABAIgG+Red =ABAIgG-/IgM-Black=ABA IgG-/IgM+

0.10

1.00

10.00

100.00

1000.00IL-6

IL-8

IP-10

MCP-1

MIG

MIP-1 ALPHA

MIP-1 BETA

TNF-ALPHA

Cytokine/chemokine expression. At the end of infusion, serum was taken to assesscytokine and chemokine expression changes versus pre-dose values in each subject (foldincrease shown) using the Luminex XMAP technology.

NSCLCMetastatic Melanoma

Triple-Negative Breast Cancer

Head and Neck Cancer

Phase Phase 1b/2 Phase 2 Phase 2 Phase 2

Combination Therapy Pembrolizumab Pembrolizumab Pembrolizumab Pembrolizumab

Patients 2nd line patients 2nd line patients- Pembro failure

2nd- 3rd line patients

- Pembro Naive

• Stable disease >3 mosPembro

• Pembro Failure

Number of Subjects 36 29 42 87

Randomization Single arm Single arm Single arm Single arm

Primary Endpoint PFS ORR ORR ORR

Secondary Endpoints Safety, PFS, OS Safety, PFS, OS Safety, PFS, OS Safety, PFS, OS

Initiation 3Q 2016 4Q 2016 4Q 2016 1Q 2017

Phase 2 Clinical Studies: Imprime + Pembrolizumab

24

Patients selected for Imprime-specific biomarker (Anti-Beta glucan Antibodies, ABA > than 20 μg/ml)

Pre Treatment Sample Post Treatment Sample

DAPITumorCD4CD8GrzB

Fold Increase vs Pre-TxCytotoxic T cells (CD8)

Total number = 28XProliferating = 33XActivated = 50X

Helper T Cells (CD4)

Total Number= 58XProliferating = 73XActivated = 24X

Lymphocyte Infiltration: Pre and On Tx Biopsy

Pre Treatment Sample Post Treatment Sample

NucleiTumor

Mac/MonoCD80PD-L1

Myeloid Character Post vs Pre TxMyeloid Infiltration 56X increaseCD80+ 100X increasePD-L1+ Myeloid 13X increase

Increased Myeloid Infiltration and Activation Post Treatment

Pre-Treatment Post-Treatment

% of Myeloid Cells CD80+: 6.34%% of Myeloid Cells PD-L1+: 0.90%% of Myeloid Cells CD206+: 18.45%% CD80+/CD206+ (M1:M2 ratio): 0.34

TumorCD163CD206CD80

% of Myeloid Cells CD80+: 13.79%% of Myeloid Cells PD-L1+: 14.88%% of Myeloid Cells CD206+: 3.11%% CD80+/CD206+ (M1:M2 ratio): 4.44

Evidence for increased M1:M2 Character Post TreatmentTranslational Research: Schedule of Assessments

Cycle Screening 1 2 3 4 5 6 10,Q4C EndofTrtmnt

Week Tubetype Upto-4 1 4 7 10 13 16 28

CBC/Diff:Preand4hrPostSOI ETDA X X X X X

PBMC:PreandPost Heparin X X X X

PAXGene (RNA):Pre-ImprimeandPostPembro PAXGene X X X X X

ABA:PreandPostImprime Serum X X X X X X X X X

Cytokines:PreandPostImprime Serum X X X X X X X X

ImprimePK:Pre,1.5hr postEOIImprime Serum X X

Pembo PK:PrePembro and3hrpostEOIPembro Serum X X

Biopsies(archival,pre-C1,pre-C3andupontimeofresponse/progression Tissue X X X

SOI:StartofInfusion

Imprime- Induced PD Effects Are Restricted to ABA + Subjects

0

20

40

60

80

100

Circu

lating

Immu

ne Co

mplex

es (E

q ug/m

l)

Longitudinal CIC

253967

10345570

Imprime Dose Week #1

Subjects

0

250

500

750

1000

1250

1500

Mono

cytes

(cell

/ul)

Monocyte Mobilization

25

67

10345570

Imprime Dose Week #1

Subjects

39

0

2500

5000

7500

10000

12500

15000

17500

20000

Neutr

ophil

s (ce

ll/ul)

Neutrophil Mobilization

25

67

10345570

Imprime Dose Week #1

Subjects

39

0

2500

5000

7500

10000

12500

15000

SC5b

-9 (ng

/ml)

Complement

25

67

103455

Imprime Dose Week #1

Subjects

39

70

0

5000

10000

15000

20000

25000

30000

MCP-1

(pg/m

l)

Cytokines

25

67

103455

Imprime Dose Week #1

Subjects

39

70

Biomarker + (ABA ≥ 20μg/ml)Biomarker – (ABA < 20μg/ml)

Immune Complex Monocyte Mobilization Neutrophil Mobilization

Complement Cytokines

Whole blood or serum was drawn from healthy volunteers at various time points before and after a single dose of Imprimeinfusion. ABA were measured in serum by ELISA. Circulating Immune complex formation was measured using theMicroVue Complement CIC-Raji Cell Replacement Kit. Cell mobilization was measured by complete blood cell counts, plusdifferentials. Monocyte and Neutrophil numbers are shown. Complement activity was measured by ELISA using the SC5b-9 Plus kits (Quidel). Cytokines and chemokines were measured in serum using Luminex XMAP technology. Fold over pre-dose values are plotted. Data from subjects who were treated with Imprime (4 mg/kg) and no pre-medications.

CONFIDENTIAL

Cycle 1 Wk 1-pre

Cycle 1 Wk 1-EOI

Cycle 2 Wk 4-pre

Cycle 2 Wk 4-EOI

Cycle 3 Wk 7-pre

Cycle 3 Wk 7-EOI

Cycle 4 Wk 10-pre

Cycle 4 Wk 10-EOI

Cycle 5 Wk 13-pre

Cycle 5 Wk 13-EOI

012345

10

20

30

40

fold

ove

r pre

-C1

SC5b9 Fold changes 103102

fold over Pre-C1

Cycle

1 Pre-

Infusion

Cycle

1 EOI

Cycle

2 Pre-

Infusion

Cycle

2 EOI

Cycle

3 Pre-

Infusion

Cycle

3 EOI

Cycle

4 Pre-

Infusion

Cycle

4 EOI

Cycle

5 Pre-

Infusion

Cycle

5 EOI

0

20

40

60

80

0

100

200

300

Patient 103102CIC vs ABA

CIC

CIC

ABAABA IgG (µg/m

l)

Cycle 1 Pre-Infusion

Cycle 1 EOI

Cycle 2 Pre-Infusion

Cycle 2 EOI

Cycle 3 Pre-Infusion

Cycle 3 EOI

Cycle 4 Pre-Infusion

Cycle 4 EOI

Cycle 5 Pre-Infusion

Cycle 5 EOI0

20

40

60

80

0

100

200

300

Patient 103102CIC vs ABA

CIC

CIC

ABAABA IgG (µg/ml)

Cycle

1 Wk 1

-pre

Cycle

1 Wk 1

-EOI

Cycle

2 Wk 4

-pre

Cycle

2 Wk 4

-EOI

Cycle

3 Wk 7

-pre

Cycle

3 Wk 7

-EOI

Cycle

4 Wk 1

0-pre

Cycle

4 Wk 1

0-EOI

Cycle

5 Wk 1

3-pre

Cycle

5 Wk 1

3-EOI

012345

10

20

30

40

fold

ove

r pre

-C1

SC5b9 Fold changes 103102

fold over Pre-C1

Circulating Immune complex formation was measured using a commercial immuno assay system (MicroVue Complement CIC-Raji Cell Replacement Kit). Complement activity wasmeasured by ELISA using the SC5b-9 Plus kits (Quidel).

TNBC 103102: ABA, Immune Complex Formation and Complement Activation TNBC Pt 103102: Induction of Imprime-Responsive Cytokines

Cycle 1 Week 1 PRE

Cycle 1 Week 1 EOI

Cycle 2 Week 4 PRE

Cycle 2 Week 4 EOI

Cycle 3 Week 7 PRE

Cycle 3 Week 7 EOI

Cycle 4 Week 10 PRE

Cycle 4 Week 10 E

OI

Cycle 5 Week 13 PRE

Cycle 5 Week 13 EOI

0

5

10

15500600700800900

1000

pg/m

l

IL-8

IL-8

Cycle 1 Week 1 PRE

Cycle 1 Week 1 EOI

Cycle 2 Week 4 PRE

Cycle 2 Week 4 EOI

Cycle 3 Week 7 PRE

Cycle 3 Week 7 EOI

Cycle 4 Week 10 PRE

Cycle 4 Week 10 E

OI

Cycle 5 Week 13 PRE

Cycle 5 Week 13 EOI

020406080

100

1000200030004000

pg/m

l

MIP-1 beta

MIP-1 beta

Cycle 1 Week 1 PRE

Cycle 1 Week 1 EOI

Cycle 2 Week 4 PRE

Cycle 2 Week 4 EOI

Cycle 3 Week 7 PRE

Cycle 3 Week 7 EOI

Cycle 4 Week 10 PRE

Cycle 4 Week 10 E

OI

Cycle 5 Week 13 PRE

Cycle 5 Week 13 EOI

010203040

100200300

100015002000

pg/m

l

RANTES

RANTES

LOD1: 0.78LOD2: 0.99

Cycle 1 Week 1 PRE

Cycle 1 Week 1 EOI

Cycle 2 Week 4 PRE

Cycle 2 Week 4 EOI

Cycle 3 Week 7 PRE

Cycle 3 Week 7 EOI

Cycle 4 Week 10 PRE

Cycle 4 Week 10 E

OI

Cycle 5 Week 13 PRE

Cycle 5 Week 13 EOI

0

50

100

150

pg/m

l

Eotaxin

Eotaxin

Cycle 1 Week 1 PRE

Cycle 1 Week 1 EOI

Cycle 2 Week 4 PRE

Cycle 2 Week 4 EOI

Cycle 3 Week 7 PRE

Cycle 3 Week 7 EOI

Cycle 4 Week 10 PRE

Cycle 4 Week 10 E

OI

Cycle 5 Week 13 PRE

Cycle 5 Week 13 EOI

020406080

2000

4000

6000

pg/m

l

MCP-1

MCP-1

LOD1: 1.23LOD2: 2.43

Cycle 1 Week 1 PRE

Cycle 1 Week 1 EOI

Cycle 2 Week 4 PRE

Cycle 2 Week 4 EOI

Cycle 3 Week 7 PRE

Cycle 3 Week 7 EOI

Cycle 4 Week 10 PRE

Cycle 4 Week 10 E

OI

Cycle 5 Week 13 PRE

Cycle 5 Week 13 EOI

0

20

40

50

100

150

pg/m

l

MIP-1 alpha

MIP-1 alpha

LOD1: 0.49LOD2: 1.32

Cytokines and chemokines were measured in serum using Luminex XMAP technology.

TNBC Pt 103102: Induction of Imprime-Responsive Cytokines

Cycle 1 Week 1 PRE

Cycle 1 Week 1 EOI

Cycle 2 Week 4 PRE

Cycle 2 Week 4 EOI

Cycle 3 Week 7 PRE

Cycle 3 Week 7 EOI

Cycle 4 Week 10 PRE

Cycle 4 Week 10 E

OI

Cycle 5 Week 13 PRE

Cycle 5 Week 13 EOI

0

5

10

15

pg/m

l

GM-CSF

GM-CSF

Cycle 1 Week 1 PRE

Cycle 1 Week 1 EOI

Cycle 2 Week 4 PRE

Cycle 2 Week 4 EOI

Cycle 3 Week 7 PRE

Cycle 3 Week 7 EOI

Cycle 4 Week 10 PRE

Cycle 4 Week 10 E

OI

Cycle 5 Week 13 PRE

Cycle 5 Week 13 EOI

0

5

10

50100150200250

pg/m

l

GRO-alpha

GRO-alpha

Cycle 1 Week 1 PRE

Cycle 1 Week 1 EOI

Cycle 2 Week 4 PRE

Cycle 2 Week 4 EOI

Cycle 3 Week 7 PRE

Cycle 3 Week 7 EOI

Cycle 4 Week 10 PRE

Cycle 4 Week 10 E

OI

Cycle 5 Week 13 PRE

Cycle 5 Week 13 EOI

05

101520

2000

4000

6000

pg/m

l

IL-6

IL-6

Cycle 1 Week 1 PRE

Cycle 1 Week 1 EOI

Cycle 2 Week 4 PRE

Cycle 2 Week 4 EOI

Cycle 3 Week 7 PRE

Cycle 3 Week 7 EOI

Cycle 4 Week 10 PRE

Cycle 4 Week 10 E

OI

Cycle 5 Week 13 PRE

Cycle 5 Week 13 EOI

0

1

2

3

4

5

pg/m

l

IL-7

IL-7

Cycle 1 Week 1 PRE

Cycle 1 Week 1 EOI

Cycle 2 Week 4 PRE

Cycle 2 Week 4 EOI

Cycle 3 Week 7 PRE

Cycle 3 Week 7 EOI

Cycle 4 Week 10 PRE

Cycle 4 Week 10 E

OI

Cycle 5 Week 13 PRE

Cycle 5 Week 13 EOI

050

100150200

50000

100000

150000

pg/m

l

IL-1RA

IL-1RA

Cycle 1 Week 1 PRE

Cycle 1 Week 1 EOI

Cycle 2 Week 4 PRE

Cycle 2 Week 4 EOI

Cycle 3 Week 7 PRE

Cycle 3 Week 7 EOI

Cycle 4 Week 10 PRE

Cycle 4 Week 10 E

OI

Cycle 5 Week 13 PRE

Cycle 5 Week 13 EOI

050

100150200

500

1000

1500

pg/m

l

IP-10 (CXCL10)

IP-10 (CXCL10)

LOD1: 0.51LOD2: 1.78

Cytokines and chemokines were measured in serum using Luminex XMAP technology.

Cycle 1 Week 1 PRE

Cycle 1 Week 1 EOI

Cycle 2 Week 4 PRE

Cycle 2 Week 4 EOI

Cycle 3 Week 7 PRE

Cycle 3 Week 7 EOI

Cycle 4 Week 10 PRE

Cycle 4 Week 10 E

OI

Cycle 5 Week 13 PRE

Cycle 5 Week 13 EOI

0

10

20

30

pg/m

l

IL-18

IL-18

Cycle 1 Week 1 PRE

Cycle 1 Week 1 EOI

Cycle 2 Week 4 PRE

Cycle 2 Week 4 EOI

Cycle 3 Week 7 PRE

Cycle 3 Week 7 EOI

Cycle 4 Week 10 PRE

Cycle 4 Week 10 E

OI

Cycle 5 Week 13 PRE

Cycle 5 Week 13 EOI

0

1

2

3

4

pg/m

l

IL-15

IL-15

Cycle 1 Week 1 PRE

Cycle 1 Week 1 EOI

Cycle 2 Week 4 PRE

Cycle 2 Week 4 EOI

Cycle 3 Week 7 PRE

Cycle 3 Week 7 EOI

Cycle 4 Week 10 PRE

Cycle 4 Week 10 E

OI

Cycle 5 Week 13 PRE

Cycle 5 Week 13 EOI

0

50

100

150

200

pg/m

l

ITAC (CXCL11)

ITAC (CXCL11)

LOD1: 4.13LOD2: 6.4

Cycle 1 Week 1 PRE

Cycle 1 Week 1 EOI

Cycle 2 Week 4 PRE

Cycle 2 Week 4 EOI

Cycle 3 Week 7 PRE

Cycle 3 Week 7 EOI

Cycle 4 Week 10 PRE

Cycle 4 Week 10 E

OI

Cycle 5 Week 13 PRE

Cycle 5 Week 13 EOI

0

500

1000

1500

2000

pg/m

l

SDF-1 alpha

SDF-1 alpha

LOD1: 2.6LOD2: 18.11

Cycle 1 Week 1 PRE

Cycle 1 Week 1 EOI

Cycle 2 Week 4 PRE

Cycle 2 Week 4 EOI

Cycle 3 Week 7 PRE

Cycle 3 Week 7 EOI

Cycle 4 Week 10 PRE

Cycle 4 Week 10 E

OI

Cycle 5 Week 13 PRE

Cycle 5 Week 13 EOI

0

5

10

15

20

pg/m

l

IL-2

IL-2

Cycle 1 Week 1 PRE

Cycle 1 Week 1 EOI

Cycle 2 Week 4 PRE

Cycle 2 Week 4 EOI

Cycle 3 Week 7 PRE

Cycle 3 Week 7 EOI

Cycle 4 Week 10 PRE

Cycle 4 Week 10 E

OI

Cycle 5 Week 13 PRE

Cycle 5 Week 13 EOI

0

50

100200250300350400

pg/m

l

IL-22

IL-22

TNBC Pt 103102: Cytokine Induction

Cytokines and chemokines were measured in serum using Luminex XMAP technology.

TNBC Patient Melanoma Patient

0.1

1

10

100

1000GM-CSF

IL-7Eotaxin

GRO-alpha

IL-8

IP-10(CXCL10)

ITAC (CXCL11)

MCP-1

MIP-1alpha

MIP-1beta

RANTES

SDF-1alpha

IFN-alpha

IFN-gamma

IL-1alpha

IL-1betaIL-2IL-6TNF-alphaIL-12p70

IL-1RA

IL-10

IL-27

TNF-beta

IL-15

IL-18

IL-21

IL-17A

IL-22

IL-23

IL-4

IL-5

IL-9IL-13

IL-31

Chemokines

0.1

1

10

100

1000GM-CSF

IL-7Eotaxin

GRO-alpha

IL-8

IP-10(CXCL10)

ITAC (CXCL11)

MCP-1

MIP-1alpha

MIP-1beta

RANTES

SDF-1alpha

IFN-alpha

IFN-gamma

IL-1alphaIL-1beta

IL-2IL-6TNF-alphaIL-12p70IL-1RA

IL-10

IL-27

TNF-beta

IL-15

IL-18

IL-21

IL-17A

IL-22

IL-23

IL-4

IL-5

IL-9IL-13

IL-31

C1 C2 C3InflammatoryCytokines

Th2

Th17

Cytokine Profiles: TNBC Patient and Melanoma Patient

Cytokines and chemokines were measured in serum using Luminex XMAP technology. Eachring radiating from the center represents an order of magnitude increase in expression.

Imprime andPembro:CPINaïveTNBC Imprime +Pembro:EarlyExperience

CONFIDENTIAL

Phase 2 Imprime + Pembrolizumab: Early Clinical Experience

Triple Negative Breast Cancer Patient 103102Objective ResponderTumor Shrinkage- 44% evident at week 6Tumor Shrinkage > 50% for > 28 weeksTumor Biopsy at ~ week 18- no tumor, fibrotic tissueIncreased ABA after Imprime dosingEvidence for Imprime-induced cytokines/ chemokines

Metastatic Melanoma Patient 103103Tumor Biopsy at week 6 suggests activated T cell InfiltrationTumor Biopsy at week 6 shows myeloid infiltration and activationEvidence for Imprime- induced cytokines/ chemokinesPatient off therapy at week 18

Early clinical experience provides evidence of clinical response (TNBC) and 1st proof of mechanism- i.e. that Imprime may drive immune activation at the tumor bed