Towards Well-Defined ADCs (Antibody Drug Conjugates)

Transcription

1 Towards Well-Defined ADCs (Antibody Drug Conjugates) Next generation approach June 10, 2015 Dr. Yong Zu Kim, CEO and President LegoChem Biosciences, Inc.

2 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

3 Heterogeneous Mixture Lys-ADC Drug Distribution Highly Heterogeneous 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 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

4 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

5 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 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

6 HIC Analysis: LCB (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 LCB (ADC) 30ug loaded LCB s ADC preparation is highly efficient and homogeneous * LBG : LCB s proprietary BG linker 6

7 DAR PK Profile : LCB (Herceptin-LC-LBG*-MMAF, DAR2) * Data generated by Prof. Young Keun Shin Drug-Antibody Ratio (DAR) in Rat DAR Time (day) Drug-Antibody Ratio (DAR) in Monkey Superb DAR stability * LBG : LCB s proprietary BG linker 7

8 PK Profile in Rats & Monkeys: LCB (Herceptin-LC-LBG*--MMAF, DAR2) Terminal half-life (day) Herceptin Kadcyla ADC * 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 ADC 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

9 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

10 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 % LCB (ADC) 30ug 2.4 % LCB s ADC does not perturb the binding affinity of Herceptin and shows minimal aggregation 10

11 Combinations of Payloads and Linkers Payload Linker DAR Antibody MMAF LBG 1 2 or 4 MMAE Tubulysin Maytansine LBG VC NC 2 2 or 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

12 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

13 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 ADC (DAR2) LBG-MMAF > ADC (DAR4) LBG-MMAF > ADC (DAR2) LBG-MMAE > ADC (DAR4) LBG-MMAE > ADC (DAR2) LBG-amanitin > > ADC (DAR4) LBG-amanitin > T-DM1 (DAR =3.5 avg.) > Herceptin(LC)-CaaX >6.66 >6.66 >6.66 >6.66 >6.66 Free MMAF

14 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) NA Herceptin NA NA NA : Not Active LCB s activities were verified externally 14

15 In vivo anti-tumor efficacy (BT474) - LCB (Herceptin-LC-triazole-LBG-MMAF) * Data generated at GREEN CROSS Vehicle ADC 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

16 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

17 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, BT474 Orthotopic model (n=12) 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

18 In vivo Anti-tumor Efficacy (NCI-N87) - LCB (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

19 In vivo Anti-tumor Efficacy (NCI-N87) * Data generated at Asan Medical Center Tumor growth inhibition Herceptin 0133 PBS T-DM LCB s anti- HER2-ADCs LCB LCB LCB LCB LCB 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 ADC (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

20 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

21 Summary New Platform with better safety and efficacy Therapeutic Window 25

22 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

23 Thank you!! Contact info Phone +82 (0)70 / Fax +82 (0)42 / bd@legochembio.com