Towards Well-Defined ADCs (Antibody Drug Conjugates) Next generation approach June 10, 2015 Dr. Yong Zu Kim, CEO and President LegoChem Biosciences, Inc.
Antibody Drug Conjugates ADC binds to Antigen Endocytosis Proteolysis Drug release ADC is an ideal drug for its high potency and specificity to the target antigen 2
Heterogeneous Mixture Lys-ADC Drug Distribution 0 1 2 3 4 5 6 7 8 9 Highly Heterogeneous 80-90 Lysine residues/mab ~50% of Lysine is available for drug conjugation >2000 isomers when 2 drugs are attached Loss of Lys charges mab integrity is disturbed Drug Distribution Less heterogeneous than Lys-ADC Cys-ADC 0 1 2 3 4 5 6 7 8 9 4 inter-chain Cysteine pairs/mab 3 isomers generated when 2 drugs are attached Structural integrity of the antibody is disturbed Higher drug-loaded species antibody character, ADC stability, T 1/2, aggregation therapeutic index 3
Thiol-Maleimide Conjugation O O mab SH N Drug N Drug O mab S O blood stream (ph ~ 7.4) R-SH O N Drug Thiol-maleimide conjugate Recently, it was shown that a slow transfer of the drug from the ADC to albumin cysteines in the plasma occurs with alkyl-maleimide ADCs R S O Bioconjugate Chem, 2010, 21, 5 RSH : albumin cystein, GSH Resulting in off-target toxicity Therapeutic Index 4
LCB s Approach Primary objective Site-specific & Homogeneous (exact DAR, DAR=2 or DAR=4) Plasma-stable linker (no unstable thiol-maleimide conjugation) Strategy Antibody expression with extra sequence @ C-term (Heavy chain or Light chain) Specific functionalization via prenylation Linker-Drug conjugation LCB s ADC has site specific, homogeneous, and non-reversible conjugation 5
HIC Analysis: LCB14-0110(Herceptin-LC-LBG*-MMAF, DAR2) mab-caax Herceptin-LC-CAAX 20ug loaded Enzymatic Rxn. mab-caax-fpp farnesyl pyrophosphate analog (FPP) Herceptin-LC-CAAX after prenylation 30ug loaded Chemical Rxn. LCB s Linker-Drug mab-caax- FPP-linker-drug LCB14-0110(ADC) 30ug loaded LCB s ADC preparation is highly efficient and homogeneous * LBG : LCB s proprietary BG linker 6
DAR PK Profile : LCB14-0110(Herceptin-LC-LBG*-MMAF, DAR2) * Data generated by Prof. Young Keun Shin Drug-Antibody Ratio (DAR) in Rat 2.5 2.0 1.5 1.0 DAR 0.5 0.0 0 10 20 30 Time (day) Drug-Antibody Ratio (DAR) in Monkey Superb DAR stability * LBG : LCB s proprietary BG linker 7
PK Profile in Rats & Monkeys: LCB14-0110(Herceptin-LC-LBG*--MMAF, DAR2) Terminal half-life (day) Herceptin Kadcyla ADC14-0110 * Data generated by Prof. Young Keun Shin Rat 13.4 (3 mpk) * 4.9~5.4 (0.3~20 mpk) 12.8 (3 mpk) * Monkey 6 (0.5 mpk) 10.1 (3 mpk) * 1 (0.3 mpk) 5.3 (30 mpk) 8.6 (3 mpk) * Human 28.5(4 2 mpk) 4 (3.6 mpk) TBD AUC (µg*day/ml) Herceptin Kadcyla ADC14-0110 Rat 689.3±21.9 (3 mpk)* 189±26.5 (3 mpk) 965.5±33.5 (3 mpk) * Monkey 622.9±26.5 (3 mpk) * 180 ±15.0 (3mpk) 684.8±20.4(3 mpk) * Human 578 (4 2 mpk) 300(3.6 mpk) TBD Much better PK profile than Kadcyla * LBG : LCB s proprietary BG linker 8
Plasma-stable Linker Antibody-Linker-Drug Kadcyla ADC-110 (LBG-MMAF, DAR 2) ADC-113 (LBG-MMAE, DAR 2) ADC-127 (LBG-MMAF, DAR 4) ADC-128 (LBG-MMAE, DAR 4) LCB s ADCs are highly stable in mouse and rat plasma * LBG : LCB s proprietary BG linker 9
Binding & Aggregation Analysis No Change in Binding Affinity (ELISA) Minimized Aggregate Formation (SEC-HPLC) Kd(M)=1.5x10-11, R 2 =0.99 Herceptin-LC-CAAX 20ug Herceptin Kd(M)=1.6x10-11, R 2 =0.99 LCB s ADC ADC aggregates 97.6 % LCB14-0110(ADC) 30ug 2.4 % LCB s ADC does not perturb the binding affinity of Herceptin and shows minimal aggregation 10
Combinations of Payloads and Linkers Payload Linker DAR Antibody MMAF LBG 1 2 or 4 MMAE Tubulysin Maytansine LBG VC NC 2 2 or 4 2 2 Herceptin CD19 Mesothelin + 4 other antibodies Amanitin LBG 2 or 4 MMAF/Amanitin LBG 4 LCB s ADC technology can be applied to various payloads 1. LBG : LCB s proprietary BG linker 2. NC : non-cleavable linker 11
Summary of Tests against Various Targets Target Antibody Prenylation Drug conjugation Reactivity (%) Yield (%) Reactivity (%) Yield (%) Her2 Herceptin ~98 ~81 ~97 ~95 EGFR Erbitux ~96 ~69 ~96 ~81 Partner A s Non-Ab scaffold ~98 ~79 ~91 ~70 CDXX ~95 ~92 ~93 ~69 Partner B s CDXX ~96 ~86 ~90 ~57 Target C Partner C s ~98 ~78 ~96 ~92 additional 6< targets are ongoing with partners LCB s ADC technology can be applied to various targets and antibodies 1. N/A : not available yet 2. TBD : To be determined 12
In vitro Anti-proliferation Results Sample CC 50 (nm) of ADC or free MMAF Code Linker-toxin MCF-7 SK-BR3 SK-OV3 JIMT-1 NCI-N87 ADC14-110 (DAR2) LBG-MMAF >6.66 0.16 2.8 0.92 0.45 ADC14-127 (DAR4) LBG-MMAF >6.66 0.03 0.38 0.08 0.08 ADC14-113 (DAR2) LBG-MMAE >6.66 0.30 - - 0.37 ADC14-128 (DAR4) LBG-MMAE >6.66 0.10 0.46 0.25 0.10 ADC20-0110 (DAR2) LBG-amanitin >33.3 0.22 0.43 >33.3 3.23 ADC20-0113(DAR4) LBG-amanitin >33.3 0.02 1.49 0.96 2.35 T-DM1 (DAR =3.5 avg.) >6.66 0.45 0.61 6.50 0.60 Herceptin(LC)-CaaX >6.66 >6.66 >6.66 >6.66 >6.66 Free MMAF 221 149 217 110 247 13
In vitro Anti-proliferation Results Binding affinity * Data generated by a third-party company Cytotoxic activity IC 50 (nm) JIMT-1 SK-BR-3 Raji Herceptin-MMAF (LCB) 0.091 0.010 NA Herceptin NA 0.345 NA NA : Not Active LCB14-110 s activities were verified externally 14
In vivo anti-tumor efficacy (BT474) - LCB14-109 (Herceptin-LC-triazole-LBG-MMAF) * Data generated at GREEN CROSS Vehicle ADC109 0.1 mpk ADC109 1 mpk Herceptin 5 mpk AKT p-akt S473 p-akt T389 ERK p-erk Actin PARP Protein/phospho-protein expression analysis by Western Cleaved PARP: marker for apoptosis LCB s ADC dramatically reduce tumor volume to baseline via apoptosis, BT474 orthotopic Xenograft 15
In vivo anti-tumor efficacy (BT474) - LCB14-109(Herceptin-LC-triazole-LBG-MMAF) & LCB14-110(Herceptin-LC-oxime-LBG-MMAF) * Data generated at GREEN CROSS LCB14-110(oxime linker) shows similar efficacy as LCB14-109(triazole linker), BT474 orthotopic Xenograft 16
Mean tumor volume (mm 3 ± SEM) In vivo Anti-tumor Efficacy (BT474) - LCB14-110(Herceptin-LC-oxime-LBG-MMAF) & LCB14-410(Herceptin-HC-oxime-LBG-MMAF) 1,000 900 800 700 600 500 400 300 200 100 0 BT474 Orthotopic model (n=12) 1 3 5 7 9 11 13 15 17 19 21 23 25 2729 31 33 35 37 39 41 434547 Time (d) iv. dosing * Data generated at GREEN CROSS Vehicle Herceptin (5mg/kg) ADC110 (5mg/kg) ADC410 (5mg/kg) LCB14-110(LC-oxime linker) shows similar efficacy as LCB14-410(HC-oxime linker), BT474 orthotopic Xenograft 17
In vivo Anti-tumor Efficacy (NCI-N87) - LCB14-110 (Herceptin-LC-oxime-LBG-MMAF) * Data generated at Asan Medical Center LCB14-110(LC-oxime-LBG-MMAF) shows excellent efficacy against Herceptin-resistant gastric cancer cell line(nci-n87) 18
In vivo Anti-tumor Efficacy (NCI-N87) * Data generated at Asan Medical Center Tumor growth inhibition Herceptin 0133 PBS T-DM1 0110 0113 0127 0128 LCB s anti- HER2-ADCs LCB14-110 LCB14-113 LCB14-127 LCB14-128 LCB14-133 Linker-toxin /DAR LBG-MMAF/DAR2 LBG-MMAE/DAR2 LBG-MMAF/DAR4 LBG-MMAE/DAR4 VC-MMAF/DAR2 single iv. dosing Herceptin has no efficacy at 5 mpk ADC14-0133 (VC-MMAF/DAR2) has no efficacy at 2 mpk Herceptin(5 mpk) << T-DM1(2mpk) < ADC110, ADC113 << ADC127, ADC128 DAR4 > DAR2 at 2 mpk in terms of efficacy MMAF MMAE at 2 mpk in terms of efficacy 19
Key Comparisons Summary ADC structure Conventional Approaches Heterogeneous Mixture - difficulty in regulatory affairs (reproducibility, impurity profiles ) LCB s Approach With defined mab-drug ratio w/o stereo isomers DAR Heterogeneous, ~4 (average) 2, 4 (higher, if necessary) Conjugation method Conjugate stability Linker chemistry Mostly thiol-maleimide method With disruption of mab structure (@cys or lys) Unstable (retro Michael reaction of thiolmaleimide) lowers therapeutic index Cleavable & non-cleavable Excess drug part non-recyclable No thiol-maleimide route employed Minimum perturbation of original structure Highly stable Cleavable & non-cleavable Excess drug part recyclable 20
Summary New Platform with better safety and efficacy Therapeutic Window 25
ADC Collaborations Ongoing collaboration International Collaboration / Potential Licensee Partners * Pharmaceuticals, biotechs, and non-profit institutes M (US) A (US) A (China) H (Germany) C (UK) B (France) 22
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