Development of Next-generation Therapeutic

Transcription

1 2015 World Biologics Korea Development of Next-generation Therapeutic Antibodies for Treating Ovarian Cancer (Therapeutic Targeting of Tetraspanin8 in Epithelial Ovarian Cancer Invasion and Metastasis) Scripps Korea Antibody Institute Lab. of Molecular Cancer Therapeutics Lee, Sukmook

2 Contents 1. Unmet medical needs of existing ovarian cancer therapeutics 2. Generation and characterization of a potential therapeutic antibody inhibiting ovarian cancer invasion and metastasis 3. The mode of action (MOA) and nonclinical efficacy and toxicity evaluation of the developing antibody 4 S h i th t th d ibl li ti f th 4. Summary showing the strength and possible application of the developing antibody

3 Epithelial Ovarian Cancer Epithelial ovarian cancer (EOC) is the most common type of ovarian cancer and is the fifth leading cause of cancer-related deaths among women worldwide This cancer arises from epithelial cells of the ovary, which are important for hormonal regulation and female reproduction Because of a lack of characteristic symptoms and early detection strategies, most ovarian cancer patients are diagnosed at stages III and IV, after the cancer has already metastasized to other organs The high mortality rate associated with this cancer is largely explained by the fact that the majority (~75%) of patients present at advanced stages with widely metastatic disease within the peritoneal cavity. These cancers grow rapidly, metastasize early, and have a very aggressive disease course Thus, ovarian cancer invasion and metastasis still represent a major hurdle that must be overcome to improve patient outcomes.

4 Current status of EOC therapeutics Over the course of several decades, a number of chemotherapeutic agents that target DNA and microtubule structures have been developed for treating ovarian cancer. Despite their clinical efficacy, these agents are not targeted therapies and result in widespread cytotoxicity and side effects, including vomiting, diarrhea, hair loss, bleeding, and bone marrow suppression However, so far, the 5-year survival rates for stages III and IV ovarian cancer patients are extremely low, at t219% 21.9% and d56% 5.6%, respectively 1 st line standard chemotherapy

5 Anti-angiogenic therapeutic antibody; Avastin Bevacizumab Humanized antibody specific to VEGF-A Blockade to inhibit a complex formation between VEGF and VEGFR2 Angiogenesis inhibitor, a drug that stop or delay the growth of new blood vessel In 2004, FDA approval for treating metastatic colorectal cancer (For combination use with standard chemotherapy) Currently, used in various cancer therapy including lung, brain, and renal cancer Recently, received EMA approval as a first-line therapy for advanced ovarian cancer and recurrent, platinum-resistant it tovarian cancer, in combination with chemotherapy.

6 Unmet medical needs of anti-vegf therapy in EOC 1 Lack of therapeutic efficacy of Avastin According to clinical result for advanced ovarian cancer, bevacizumab extends progression-free survival up to ~4 months in combination with standard chemotherapy (carboplatin, paclitaxel) Based on clinical result for recurrent, platinum-resistant ovarian cancer, bevacizumab extends progressionfree survival up to ~3 months in combination with chemotherapy (carboplatin, gemcitabine) 2 Side effects of Avastin Bevacizumab interrupts VEGF signaling on normal endothelial cells so that it cause various side effects including bleeding, proteinuria, hypertension, gastrointestinal perforation, stroke, and heart attack 3 Avastin resistance Long-term treatment of bevacizumab results in a drug resistance that is occurred by redundancy of tumorsecreted angiogenic factors, including placental growth factor, angiopoietin-2, bfgf, insulin-like growth factor, and epidermal growth factor

7 Tetraspanin 8 (TSPAN8) TSPAN8 A member of tetraspanin superfamily that forms tetraspain-enriched microdomains i (TEMs) complexing with various membrane proteins A tumor associated antigen highly overexpressed during the progression of colorectal, liver, pancreatic, and gastric cancers Its increased expression promotes liver and lung metastasis TSPAN8 may also act as an adaptor molecule, forming a complex with various membrane proteins, including CD151, EpCAM, claudin-7, E-cadherin, and CD44v6, that has been shown to promote cancer progression and metastasis However, the relevance and role of TSPAN8 are yet to be investigated t in EOC. Tetra spain-enriched Micro odomains (TEM M)

8 Analysis of TSPAN8 Expression in EOC Patient Samples A High expression ~ 52% (14/27) of EOC tissues P = 0.034

9 Identification of TSPAN8-LEL as a Key Target in EOC Invasion ***P < SEL: small LEL: large extracellular loop extracellular loop ***P < 0.001

10 Generation of human antibodies specific to TSPAN8-LEL Sequential pre-clearing steps of Fc binders Ab source: human synthetic antibody library Bio-panning: phage display tech. Isolation of anti-tspan8-lel abs using phage display technology

11 In vitro characterization of TSPAN8-blocking antibody

12 Effect of TSPAN8-blocking antibody on Inhibition of EOC Invasion **P < 0.01, ***P < 0.001

13 Effect of TSPAN8-blocking antibody on angiogenesis- or metastasisrelated gene changes Using qpcr array, evaluated the effect of TSPAN8-blocking antibody on angiogenesis- or metastasis-related gene changes in SK-OV3 Metastasis-related gene: tumor suppressor gene (CCL7, TSHR) was up-regulated tumor promoting gene (KISS1R) was down-regulated anti-metastatic effect Angiogenesis-related gene: pro-angiogenic factors (EGF, endoglin, TGFα, TGFβ1, letin, HGF), VEGF receptor 1 (FLT1), and angiopoietin 1 receptor (TEK) were down-regulated anti-angiogenic effect

14 Effect of TSPAN8-blocking antibody on Inhibition of EOC Metastasis *P < 0.05 n=31 n=30

15 In vitro and in vivo toxicity of TSPAN8-blocking antibody

16 Internalization and concomitant down-regulation of membrane surface TSPAN8

17 Mode of action (MOA) of TSPAN8-blocking antibody TSPAN8-blocking antibody induced internalization and concomitant down-regulation of cell surface TSPAN8 TSPAN8 Suppression of TSPAN8-mediated signaling implicated in EOC invasion and metastasis

18 Summary Scope Contents Summary Characteristics Type Human antibody Ag TSPAN8 Epitope Specific to TSPAN8-LEL (a.a 31-96) Efficacy MOA Application Affinity Stability & productivity In vitro (Invasion inhibition) In vitro (Gene changes) In vivo ~ nM Visible aggregate is not observed; 250~300 mg/l Metastatic Ovarian Cancer OK (SK-OV3, SNU-8, SNU-251) Metastatic Colorectal Cancer OK (HCT-116, LoVo) Metastatic Brain Glioblastoma Multiforme OK (U87) Metastatic Pancreatic Cancer OK (PANC-1) Angiogenesis- or metastasis-related gene changes OK (peritoneal ovarian cancer metastasis model) Internalization and concomitant down-regulation of membrane surface TSPAN8 Cancer therapy in a variety of cancers including EOC, mcrc, GBM, and pancreatic cancers in combination with existing chemotherpy Antibody-drug conjugate (ADC) Radioimmunotherapy

19 Acknowledgement Dr. Chang Sik Park Dr. Taek-keun Kim Mee Hyun Jeoung Research Grant Woo Ran Lee Nam Kyung Go Dr. Kyun Heo Dr. Youn-Jae Kim Han Gyul Kim Prof. Shim, Hyunbo