Dual-targeting anti- CD47 bispecific antibodies: Safely provoking macrophages to feast NALM-6 tumor cells (B-ALL) Human macrophages

Transcription

1 Dual-targeting anti- CD47 bispecific antibodies: Safely provoking macrophages to feast Krzysztof Masternak, PhD, Head of Biology 1 2 nd Biologics & BOARD Biosimilars MEETING Congress MARCH 2012 NALM-6 tumor cells (B-ALL) Human macrophages α-cd47 bispecifc antibodies B-ALL: Acute B lymphoblastic leukemia 2 1

2 Unleash powerful serial killing with CD47 blockade Nalm-6 tumor cells Human macrophages Anti-CD47 κλ body 3 CD47 is an immune checkpoint receptor Cancer cell Macrophage Activating eat me signal CD47 Inhibitory don t eat me signal CD47 is over expressed in various cancers Helping tumors escape immune surveillance and killing Poor clinical prognosis correlates with levels of CD47 expression 4 2

3 However, CD47 is ubiquitously expressed Universal marker of self CD47 interacts with SIRPα on phagocytes preserving healthy cells, for example, RBCs, platelets 5 Targeting CD47 in cancer Rationale for targeting with bispecific antibodies CD47 CD47 CD47 Tumor Associated Antigen Anti-CD47 mab Binding to all cells - incl. RBC & platelets Anticipated: - poor PK - toxicity Poor pharmacological half-life, anemia, thrombocytopenia and neutropenia observed in animals 6 CD47/TAA BiAb Selective for malignant cells Prolonged half-life Lower toxicity 3

4 dual-targeting bispecific κλ body Tethering the CD47 blocking to CD19 positive cells Tethering arm Selective for CD19 High affinity κ λ Effector arm Disrupts CD47-SIRPα don t eat me signal Right affinity Fischer et al., Nature Commun Fc Fc-mediated effector functions IgG pharmacokinetic half-life 7 binds selectively to CD19 + B cells Whole blood flow cytometry RBC IgG1 control B cells anti-cd47 monovalent anti-cd19 monovalent anti-cd47 mab B6H12 Binding (MFI) Binding (MFI) Platelets IgG1 control anti-cd47 monovalent anti-cd19 monovalent anti-cd47 mab B6H12 8 B6H12: mouse anti-human CD47 mab 4

5 : Single dose PK in NHP Linear kinetics observed at both doses 2 dose groups: - : 0.5 mg/kg - : 10 mg/kg Single i.v. Suggesting no target mediated-clearance 9 : Dose finding toxicology study in NHP No hematological toxicity after 4 doses up to 100mg/kg 4 doses i.v. - 30, 30, 100, 100 mg/kg Red blood cells 1/week Platelets Vehicle Hemoglobin Hematocrit 10 DOSING DAYS 5

6 efficacy in B cell tumor model Raji cells s.c. xenograft IgG1 control α-cd19 mab α-cd47 monovalent ab α-cd19 monovalent ab Anti-CD47/CD19 biab () Synergistic effect when targeting CD19 combined with CD47 11 Assessing phagocytosis in vivo GFP + Raji cells Tumour volume mm Day 13 Isotype control Tumor harvest Days post start of treatment Tumor harvest Day Isotype control Days post start of treatment ** ** D13 Control tumor growth yet similar levels of infiltrating: Mouse cells (CD45 + ) D23 % of CD45+ cells Mouse Mφs (F4/80 + ) D13 D23 6

7 Phagocytosis significantly increased With IgG1 control (D13) GFP + Raji cells F4/80 F4/80 13 (D13) GFP With : - More TAMs engulf GFP+ tumor cells - More GFP+ tumor cells per TAM TAM tumor associated macrophage controls tumor growth in bone marrow Disseminated B-ALL xenograft model (NALM-6) Bone marrow Weight loss % of starting weight B-ALL: Acute B lymphoblastic leukemia 14 7

8 Engulfment and elimination of tumor cells + Isotype control + B-ALL tumor cells Human macrophages 15 mediates effective phagocytosis by MØ Cells from B-CLL patient Method: Patient cells + human MØ + antibodies B-CLL cells from patient samples Antibody concentration (ng/ml) Rituximab (anti-cd20) Control higg1 no antibody % of Mφ with > 1 fluorescent event ng/ml 10 10,000 IgG1 control Rituximab Phagocytosis index red = macrophages green = B-CLL cells B-CLL: B-cell chronic lymphocytic leukemia 16 8

9 The anti-tumor power of targeting CD47 Phagocytosis ADCC Syngeneic Tumor Rechallenge model Durable Immunity 17 Adapted from Chao et al., 2012 Necrosis Apoptosis Necrosis Syngeneic tumor rechallenge model Testing for durable immune responses Part 1: Tumor ENGRAFTMENT Part 2: Tumor RECHALLENGE hcd19 A20 Lymphoma A20 Lymphoma hcd19 Engraftment Treatment Evaluation Rechallenge Evaluation s.c. A20-hCD19 In Balb/c mice s.c. A20-hCD19 engraftment CTX: 1 dose i.p. - cyclophosphamide (opposite side) κλ body: 3 doses i.t. α-human CD19/mouse CD47 PBS: 3 doses i.t. 18 9

10 A20-hCD19 tumor model challenge phase Synergistic effect of κλ body and CTX combination PBS α-mcd47/hcd19 κλ body CTX CTX + κλ body 100% tumor-free 19 Syngeneic tumor rechallenge model Testing for durable immune responses Part 1: Tumor ENGRAFTMENT Part 2: Tumor RECHALLENGE hcd19 A20 Lymphoma A20 Lymphoma hcd19 Engraftment Treatment Evaluation Rechallenge Evaluation s.c. A20-hCD19 In Balb/c CTX: 1 dose i.p. + κλ body: 3 doses i.t. s.c. A20-hCD19 engraftment (opposite side) 20 10

11 A20-hCD19 tumor model tumor rechallenge phase Animals developed protective antitumor immunity tumor volume (mm3) Part 1 Priming CTX + κλ body 100% tumor-free tumor volume (mm3) Part 2 Rechallenge 100% protected Day post engraftment α-mcd47/hcd19 κλ body produces a synergistic effect with CTX to cure the animals and induce durable immune responses 21 In Summary Targeting CD47, an immune checkpoint, with biabs Exploits the don t eat me signal hijacked by cancer cells Unleashing cells of the innate and adaptive immune system Avoiding toxicity and rapid drug elimination Human macrophage (red) eating patient tumor cells (green) when incubated with Has the potential to induce durable responses in cancer patients Mechanism complements other IO therapeutic strategies 22 11

12 Novimmune s pipeline Product Target Indication Status Milestone Timing Orphan Products NI-0501 IFNγ Bispecific Antibody Platform; Κλ-body NI-1801 NIBX-2101 Partner: Baxalta Programs for Partnering NI-0101 NI-0401 Partner: Tiziana NI-1401 Partner: Genentech CD47/ CD19 CD47/ Mesothelin Hemophagocytic lymphohistiocytosis (HLH); Other interferonopathies Phase 2 ongoing Approval 2017 B cell cancers Preclinical FTIM 2017 Various cancer indications Discovery Drug candidates 2016 Undisclosed Undisclosed Discovery Drug candidates 2016 TLR4 CD3 Ɛ IL-17 Autoimmune and inflammatory diseases Autoimmune diseases and transplant Autoimmune and inflammatory diseases Phase 1 Completed Phase 1/2a Completed Phase 1 Completed (Genentech) Start Proof-of-Concept Phase 2 (RA) Start Proof-of-Concept Phase 2 Not disclosed Acknowledgements Novimmune A Papaioannou E Hatterer L Broyer V Moine X Chauchet B Daubeuf S Limin Z Johnson S Salgado-Pires V Buatois N Fischer K Masternak W Ferlin A Michie, MD E Cosimo, MD Pr A Fielding A Dey K Bailey Pr S Hughes J Dubrot Armendariz 24 12