Drug Discovery Michael Palazzolo and William Boyle December 12, 2014

Reminders

• Questions

– Webinar participants: chat box

– In house: microphone

• Survey questions

• Course evaluation

Overview – High Level Objectives

3

Case Study of Therapeutic Antibody Generation and Development:

• Drug concept, competitive landscape and strategy for success

• Use of technology for optimal activity

• Preclinical testing

• Generation of new intellectual property (IP)

• Manufacturing and IND enabling studies

• Business development and partnering for clinical development

CASE STUDY

Best-in-class anti CD22 antibody drug conjugate(ADC) for the treatment of

B-cell cancers

4

CD22 Superfamily of Sialoadhesions

CD22 Biology

6

CD22 B-cell specific surface receptor that plays a key role in humoral immune response

Expressed at high levels during B-cell differentiation and in a majority of lymphomas and leukemias

B-cells implicated in the molecular pathology of a variety of autoimmune diseases, e.g. RA, Lupus, MS

CD22 is an extracellular signaling receptor and is internalized, therefore making it an attractive therapeutic target for both naked antibodies and ADCs

Mab LL2 / Epratuzumab binding to CD22 and internalization negatively regulates B-cell tumor cell growth

Established pattern of CD22 expression

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Frequency of NHL subtypes

CD22 is expressed in most non Hodgkin’s lymphomas and lymphocytic leukemias, including the major categories

WHO classification of tumours, 2001

CD22 is expressed in most non Hodgkin’s lymphomas and lymphocytic leukemias

CD22 is known to be expressed only in developing B cells and in B-cell lymphomas and leukemias. CD22 expression has not be reported in other tissues (Stein, R., Belisle, E., Hansen, H. J., and Goldenberg, D. M. Epitope specificity of the anti-B-cell lymphoma monoclonal antibody, LL2. Cancer Immunol. Immunother., 37:293-219989,3).

CD22 is a 135-kDa B-cell-restricted sialoglycoprotein expressed on the B-cell surface only at the mature stages of differentiation (Dorken B, Moldenhauer G, Pezzutto A, et al. 39 (B3), a B lineage restricted antigen whose cell surface expression is limited to resting and activated human B lymphocytes. J Immunol 1986;136:4470–9.).

CD22 is expressed in almost all lymphomas and B-cell leukemias. In B-cell NHL, CD22 expression ranges from 91% to 99% in the aggressive and indolent populations, respectively (Cesano A, Gayko U, Brannan C, et al. Differential expression of CD22 by indolent and aggressive NHLs: implications for targeted immunotherapy. Blood 2002;100:350a.).

Using immunohistochemistry staining of formalin-fixed paraffin-embedded samples, CD22 positivity has shown to be highly variable between samples and within the same samples in terms of the percentage of positive cells, intensity of staining, and localization (i.e., membrane versus cytoplasm).

Anti-CD22 Antibodies in Development

Pre-clinical Phase I Phase II Phase III IND

VivaMab Naked mAb

RA

Genentech CD22-MMAE

Onc

UCB Emab

Autoimmunity

Pfizer Ino-ozo

Onc

VivaMab CD22-ADC

Onc

Humanized IgG4 with calicheamicin ADC

Deprioritized in Ph 2

Humanized IgG1 (LL2)

Difficult indication for approval (SLE)

Onc indications with ADC in early stages

Humanized IgG1 with Aurestatin E ADC POC achieved in Ph 1

Humanized IgG1 (LL2 derivative) with superior affinity and internalization

Ready for cell line development and IND enabling studies

ADC antibody w/ chemotherapy is appropriate for leukemia and lymphoma

Early Stage programs with enhanced antibodies represent next generation

biobetter opportunities

Epratuzumab (UCB-Immunomimedics) Currently in late stage clinical trials for

Lupus (Phase III) Development of naked antibody for

lymphoma and CLL stopped due to lack of efficacy

UCB and Immunomedics, Inc. announced epratuzumab, has provided a significant reduction in disease activity with moderate to severe active systemic lupus erythematosus (SLE) in Phase IIb study

EMBLEM study in the combined index responder rates were numerically higher in all groups given epratuzumab at 600 mg per week (p = 0.0265 *) o Emblem was a 12-week, multicenter, phase

IIb, randomized, double-blind, controlled versus placebo to evaluate the efficacy and safety of epratuzumab and define a dose and diet in patients with moderate to severe SLE. The primary efficacy endpoint in the emblem was a test of combined response index, including several indices of SLE activity

Two phase III studies, EMBODY™ 1 and 2, underway for pipeline drug epratuzumab in December 2010. Results due in 1Q2015

Inotuzumab Ozagamicin (Pfizer)

Currently in clinical development for hematological malignancies

Summary of Phase I results (JCO, 2010) o Seventy-nine patients enrolled o MTD was determined to be 1.8 mg/m2 o Common AEs at MTD were thrombocytopenia

(90%), asthenia (67%), and nausea and neutropenia (51% each)

o Objective response rate at the end of treatment was 39% for the 79 enrolled patients, 68% for all patients with follicular NHL treated at the MTD, and 15% for all patients with diffuse large B-cell lymphoma treated at the MTD

o Median PFS was 317 days (approximately 10.4 months) and 49 days for patients with follicular NHL and diffuse large B-cell lymphoma, respectively

Although high response rate, hematological tox profile may be limiting

CD22-MMAE Genentech/Roche

Genentech (gRED) has developed an IgG to CD22 that is conjugated to MMAE (Seattle Genetics)

Phase I trial completed

Good effects in lymphoma patients – may have issues with potency

Review of the competition indicates that a best-in-class anti-CD22 antibody combined with the best linker-toxin ADC represents a bio-

superior drug for the oncology market

CD22 Targeted Therapeutics in Development

Emab UCB

Inotuzumab Pfizer

CD22-MMAE Genentech

VM101 VivaMab

X X

X X

X X

X Microtubulin inhibitor

Nucleic acid inhibitor

CIAOTM

VivaMab has used Comprehensive Integrated Antibody Optimization (CIAOTM) to evolve Epratuzumab (Emab) into an improved, target-specific antibody therapeutic; enabled generation of an anti-CD22 ADC for use with a tumor appropriate chemotherapy

X

X DNA Binder

X X

X X

X X

Differentiation in CD22 Targeted Therapeutics

Best-in-class antibody with tumor appropriate drug conjugation for a highly differentiated CD22- targeted bio-chemotherapy

Properties Emab UCB

Inotuzumab Pfizer

CD22-MMAE Genentech

VM101 VivaMab

Affinity + +++ + +++++

Internalization + + ++ +++++

MOA Neg growth regulator

Delivers calicheamicin

Delivers auristatin

Neg growth regulator by delivering nucleic acid inhibitor

Isotype IgG1 IgG4 IgG1 IgG1

Linker Stability

NA Unstable Stable Stable

Stage of Development

Phase III Phase II Phase I Preclinical

Anti-CD22 Target Product Profile

Profile VivaMab 101 CD22 affinity ~200 pM

Isotype Human IgG1

Projected half-life ~21 days

Route of delivery IV (initially); SQ subsequently

Dosing schedule Q 4 wk

Safety Predictable & manageable

Proof of mechanism (POM) Healthy volunteers or Psoriasis

IND ~9 months from funding

First patient In ~10-12 months from funding

Biomarkers CD22 receptor occupancy; B cell depletion

Proof of Concept (POC) Severe to moderate Psoriasis; RA; Hem-Onc

Expanded indications with partner

RA, CD, MS, SLE, ALL, NHL

CD22 Selection of VM101

VM101 Selection - Summary

Lead selection based on key design goals; high affinity, surface binding, internalization and expression levels and

good manufacturing characteristics

Twenty top humanized VM101 candidates obtained from murine LL2 monoclonal using CIAO!TM

o Selected based on FTO, affinity, surface binding and internalization (FACS)

Ten variants analyzed by confocal immunofluorescent microscopy

o Rapid surface binding and internalization

Three candidates with a clear lead selected

o Lead shows greatest internalization, superior expression levels, lack of oxidizable residues in V-gene regions (Asn, Cys, Met)

o High level expression in CHO cells

o Other two candidates retained as backups and for ADC conjugation assessment

Humanization Process

Murine Antibody

Mouse Immunization

Published Mouse Ab Sequence

and immediate

grafting and affinity

maturation

CDR-Grafted Antibody CDR Grafting

(Winter method. MRC)

Random Mutagenesis and/or

PDL Technology (Queen

method)

“wet” approach

• Murine Mabs still to be the largest source of new antibody medicines in the future

• Traditional methods use both Winter and Queen patents to humanize murine monoclonal antibodies for therapeutic uses

• Winter IP is close to expiration • Queen Patent still in force and an issue for humanization

• Alternative methods for humanization and affinity improvement – Framework grafting

“Dry” approach

VivaMab Antibodies for Life

Humanization of Murine Mab to Therapeutic Target

Framework grafting used to produce humanized clone Analysis of humanized clones: 33 hits with specific activity >75% of wild type 12 hits with specific activity equal to or better than wild type

Frame works fully human No back mutations needed to restore binding activity

Several Hits with improved activity by Elisa

Summary of VM101 Engineering Strategy

Anti-human CD22 mouse mAb LL2

Clone BA006-12E11-RVG

Clone VM101

Affinity maturation CDR sequence diversification

Humanization Characterization (ELISA, SPR, Internalization, Sequence, Expression) Lead Selection

KD ≈ 20 nM

KD ≈ 1 nM

KD ≈ 0.22 nM

Epratuxumab KD ≈ 5 nM

Internalization – Top Lead Analysis

Relative Mean Fluorescence

Emab Vm 101

10 208

0 min 90 min 0 min 90 min

Quantitative confocal immunofluorescent microscopy demonstrates dramatic improvements in surface binding and internalization

Internalization (minutes incubated at 37oC)

Emab Vm 101 Vm 101 Emab

VivaMab Antibodies for Life

Induction of Tyrosine Phosphorylation

Humanized anti-CD22 mAbs induce Tyrosine-Phosphorylation of CD22

Immunoprecipitation from Daudi cells

Anti-Phospho-Tyrosine blot

Anti-CD22 blot

Unt

reat

ed

Ant

i-hu

man

IgG

Fc

Ant

i-hu

man

IgM

Fab

BA00

6 (E

-mAb)

H

um18

H

um

43

H

um01

H

um02

2 % 3% 177% 100% 100% 142% 26% 20% Tyrosine Phosphorylation relative to BA006

VM101 Lead Candidate

Clone Vm 43 consistently expresses at highest levels and lacks Asn, Cys and Met residues in the variable domain – good manufacturing characteristics;

Vm 02 and 04 selected as backups

Clone KD (nM) Daudi Internalization by Confocal (RMF)

LL2 (mouse Mab) 20.00 ND

Epratuzumab 5.00 ~10

Vm 01 0.50 ~100

Vm 02 0.22 ~100

Vm 04 0.33 ~150

Vm 05 0.34 ~150

Vm 07 0.80 ~100

Vm 018 2.70 ~200

Vm 20 1.00 ~200

Vm 43 0.26 ~200

Production of recombinant VM101-ADC

PBD payload conjugate Characterization In vitro bioactivity

Payload -Pyrrolobenzodiazepines (PBDs)

Original natural products isolated from streptomyces species Bind sequence selectively (purine-guanine-purine motifs) in the

minor groove of DNA Synthetic PBD dimers crosslink DNA without distortion.

• Selective activity in tumor cells vs. normal cells • “10,000 times more active that potent microtubulin inhibitors...”

No cross resistance with cisplatins and mustards

SG2000 in Phase II clinical trials for cisplatin refractory ovarian carcinoma

HP-SEC Analysis Before Conjugation

HP-SEC Analysis of VM101 ADC

VM101-ADC Superior to Emab-ADC in vitro

CD22 Preclinical

Development

Purpose: Determine Tumor Growth Delay of the Daudi human Burkitt's lymphoma with treatment of a novel ADC

Established tumors ~120 mm

Dosed once week 3X (Day 1, 7, 14) CX1 = VM101 in PBS CX2 = VM101-ADC in PBS Rituximab = Rituximab in Saline vehicle = vehicle

Daudi-e219 experiment

Day 60 data complete; study extended to 60 days to monitor durability of complete responses in the VM101 ADC and Rituxan treatment arms

10/10 complete responses in VM101 ADC 0.5 and 2.5 mg/kg groups; 8/10 complete responses in 0.1 mg group

Body weights are within the safety range

Summary of Results

Mouse Tumor Xenograft Model – Day 60 Group Mean Summary

• 10/10 complete remission of existing tumor in VM101 ADC 0.5 and 2.5 mg/kg. 8/10 CR’s at 0.1 mg/kg – Body weight remains normal

• Some dosage effect, but MED not determined (>0.1 mg/kg)

• Approximately 2 log superiority to Rituximab

• One animal in the positive control arm (Rituxan) reached the study endpoint and was sacrificed

• No animals in any of the VM101 ADC dose groups reached an endpoint

Summary

Pilot study to test the effects of VM101 in a tumor xenograft model. VM101 ADC was not fully optimized with respect to conjugation chemistry and comparison of in vitro activity – Potent activity in vitro and in vivo

VM101 lead clone and back-up clone have been assessed for manufacturability – Test expression levels comparable to Herceptin (trastuzumab)

PK analysis in rodents – T1/2 equivalent to expectations for a human IgG1

Optimization of VM101-ADC chemistry and production underway – cell line development are the next steps

CD22 recently found to be expressed on lung cancer cell lines and primary tumors – potential new use as an important drug to lung cancer treatments

Mab Discovery Timeline and Costs

Manufacturing

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• Expensive process - ~US$ 5.0 MM

• ~18 months from lead antibody to cGMP material needed for IND enabling studies

• Contract cell line development, process development and clinical manufacturing available from various CMO’s (e.g. BI, Lonza)

• Expression yields are in the 5g/l range

Timing is Critical to Remain on Track

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Timing, Contd.

Mab Discovery Timeline and Costs

IND Exit

Clincal POC Exit

Preclinical Exit

Therapeutic Antibodies – Early Stage Exits

Company Target Partner Stage Year Upfront Milestones (Royalty Net Sales)

Aveo RON JNJ/Centocor Preclinical 2011 $15 MM $555 MM

Alder BioPharma

IL-6 BMS Ph II 2009 $85 MM $765 MM

Merrimack HER3 Sanofi Aventis Ph I 2009 $60 MM $410 MM

Agensys PsCA Merck Preclinical 2005 $17.5 MM $200 MM

NovImmune IFN/CD3 Serono Preclinical 2005 $15 MM $105 MM

Micromet EpcAM Serono Ph 2 2004 $147 MM ND

BioStratum Laminin-5 Novo Nordisk Preclinical 2004 $80 MM ND

Seattle Genetics 5T4 Pfizer Ph 1 2011 $8 MM $200 MM

Seattle Genetics EGFR Abbive Preclinical 2 014 $25 MM $225 MM CytomX EGFR and

Platform Pfizer Preclinical 2014 $25 MM $610 MM (tiered double digit)

Ablynx IL-6 Abbvie Ph 2a 2013 $175 MM $675 MM (tiered double digit)

Partnering

• VM101 licensed to ADC Therapeutics Sarl

• At preclinical stage prior to cell line development

• Financial terms not discussed

– Upfront cash

– Milestones

– Joint ownership

• Preclinical data indicates it is the most potent molecule in its class

– Eradicates Rituximab resistant tumors

• Ongoing development – Tox studies in non-human

primates

….

Key Areas for IP Consideration and Generation

FTO Assessment on Mabs to

Target

Antibody Claims to Target

Target IP and generic claims to antibodies

Method of Treatment

Claims

Composition on Clinical

Candidate

Monocloncal antibody development plan Time Frame (in Months)1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

Target selection and Mab generationSelect target based on key criteriaFTO ScrubAntigen production and mab generationScreening and in vitro characterizationIn vivo testingHumanization & Clinical candidate selection *Manufacturing of clinical material

IND enabling Preclinical Studies

IND *POC Clinical Studies

Take Away Points

• Therapeutic Mabs are the largest growing area of human therapeutics

• Diverse targets with preference to specific classes – some classes are relatively intractable

• Multiple modality opinions; naked and ADC’s

• PK/PD is critical for design goals

• Other properties are manufacturability, IP and Integration of Target Biology and Drug Concept, strategy for clinical development

Acknowledgements

• UCLA Pharmacology

• UCLA CTSI

• UC BRAID CAI

• NCAI (UC, Harvard, Ohio)

• NHLBI

Upcoming Webinar: UC CAI I-Corps Stephanie Marrus Friday, January 23, 2015 @ 11 AM PST Archived Webinars: http://uccai.ctsi.ucla.edu/pages/education