CH
TE
O
BI

D
IM
A

Risk-free Lead Antibody
Discovery

Over 5000 Pre-validated Monoclonal Antibodies for 300+ Drug Targets

Dedicate on Drug Targets，Specialize in recombinant mAb development

01

Risk-free Lead Antibody Discovery

Challenges and opportunities for antibody
drug discovery

CH

Monoclonal antibodies (mAbs) are the fastest growing class of drugs over the past decade. With recent
scientific discovery on new mechanisms of immune-oncology and progress of new technologies in
mAbs development, more and more antibody drug candidates are on the horizon. Antibody drug

occupied almost 20% of all FDA approved medicines during the past few years. Most of them are fortreatment of cancer patients. The characteristics of antibody drugs, e.g., high specificities and low levelTEside effects, make them the most popular drug category in medical market. In 2022, two antibody
drugs, Humira and Keytruda are within the top 3 sales of drugs, only after mRNA vaccine (Comirnaty).

Until now, FDA has approved more than 100 antibody drugs with the size of market share over 1500
billion dollars.

O

Antibody drugs normally target the membrane proteins on the cell surface that are related to humandiseases. The drug formats evolved from original simple monoclonal antibody to various innovative
formats, e.g., bi-specific antibody, antibody drug conjugates (ADC) and Nanobodies. The market forBItherapeutic antibody drugs has experienced explosive growth as new drugs have been approved for
different human diseases, including cancers, autoimmune, metabolic and infectious diseases.

D
IM
A

Formats of Antibody Drugs:

l Fully human or humanized mAbs: Fully human or humanized antibodies greatly reduce immuneside effects caused by heterologous antibodies to human body, thereby improving the therapeutic
effect. They are the most common format of antibody drugs.

l Antibody–drug conjugate (ADC) is typically composed of a monoclonal antibody covalently attached

to a cytotoxic drug via a chemical linker. It combines both the advantages of highly specifictargeting ability and highly potent killing effect to achieve accurate and efficient elimination ofcancer cells, which has become one of the hotspots for research and development of anticancer
drugs.

l Bispecific or multi-specific antibody drug is a rising star in antibody drugs. Two or multiple antibody
fragments against different antigens are fused through antibody engineering, which improves thekilling effect of cancer cells through multi-target, multi-pathway inhibitions. So far, FDA has
approved 2 bispecific antibodies.

Risk-free Lead Antibody Discoveryl02

Nanobodies have many unique properties such as small size, good solubilities and stabilities, quick
clearance and strong tissue penetration abilities, which make them promising tools for diagnosis andtherapy of diseases. They can improve the efficacy of antibody drug therapy through the lesionCAR-T cell therapy is a new direction for antibody drug research and development. The variable

regions of antibody heavy and light chains are constructed into a CAR structure and transduced intoCHlspecific delivery of drugs and effector domains.

the patient's T cells as a single-chain fragment (scFv). The engineered CAR-T cells can be used to killtumor cells in vivo.

Antibody drug development is like a marathon, from initial target research to the development of leadTE

antibody molecules, preclinical functional and toxicity research, to the later clinical I/II/III experimental
stage, and finally NDA declaration, which requires a lot of money and time, with a high degree of

D
IM
A

BI

O

uncertainty and risk (Figure 1).

Figure 1: This schematic shows investment and time required for the preclinical and clinical stages ofantibody drug development. The process of antibody drug development is very costly and lengthy. A
good lead mAb molecule can be the entry key to the process.
Antibody drug development has been focused on a few popular targets, e.g., PD-1/PD-L1, HER2 for a longtime. However, the studies of other targets have never stopped. Out of all FDA approved antibody drugs
in 2021, most of them are First in Class (FIC) antibody drugs except Dostarlimab for PD-1. This highlights a

new trend of antibody drug development, e.g., new targets and new formats. Currently there areapproximately 400~500 targets identified as tumor targets. As more and more innovative targets are
discovered, it is difficult to rely solely on company's own preclinical R&D capabilities or its CRO partners

to make early antibody molecule discovery. Both have their own pros and cons, as summarized in table 1.
Due to the complexity and unpredictability of therapeutic lead mAb discovery process, there will be no
guarantees of success at this stage, which impose a bottleneck for the current antibody drug
development.

03

Risk-free Lead Antibody Discovery

Table 1: Pros and Cons of different strategies for lead antibody discovery
CRO companies

easy communications

small or no equipment investment

Manage internally

Flexibility

CH

Pros

Internal R&D team

Limitations on internal R&D capacity and efficacy
Cons

Hard to control development timeline

Initial big investment on equipment and reagents

Hard to control development timeline
Extensive management cost

High risk on project, No guarantees

TE

High risk on project, No guarantees

Upfront payment with little guarantees

O

DIMA's Solutions for Lead Antibody DiscoveryBI

All Druggable Targets (ADT) Program

To help Biopharma accelerate its pace on pre-clinical antibody drug lead selection and optimization,
DIMA, equipped with its proprietary single B cell discovery platform, launched an “All Druggable

Targets (ADT)” lead discovery program. The goal is to provide on-shelf pre-stocked and pre-validated

hit-to-lead stage antibody molecules for all druggable targets. Compared to traditional in-house R&D

DIMAor CRO models, DIMA lead antibody molecules provide an on-shelf solution for pharmaceuticalcompanies. Our zero-waiting, zero-risk business model allows pharmaceutical companies toeffectively avoid unnecessary risks and financial investments during early drug discovery stage. The

complete list of our available targets can be found on our website (www.dimabio.com/lead-antibodymolecule).

Figure 2: DIMA Biotech ADT Lead Discovery Program

04

CH

Risk-free Lead Antibody Discovery

Figure 3: Comparison of DimAb lead discovery program and traditional lead discovery strategies

TE

After in-vitro and in-vivo screenings of pre-selected mAbs, one or several druggable mAbs can bepicked up for the downstream clinical studies. Both antibody sequences and plasmid DNA are ready to

be transferred. If none of the preselected candidate antibodies works for you, our DimAb® B cell library

D
IM
A

BI

O

can easily obtain more than 10,000 positive hits in as short as a month's time.

Figure 4: Development of DimAb® B cell seed libraries and lead mAbs molecules

05

Risk-free Lead Antibody Discovery

DimAb® B cell seed libraries >>DimAb® lead mAb molecules >>defined functional evaluation datal Next day delivery of lead mAb moleculesl Guaranteed performance without big
upfront costl Flexible terms to meet different businessexpectations

l Save customer at least 8 months inl From cultivation to lgG sequences in 3045 daysl High diversity and large number of
unexplored bindersl No binder no payment, zero riskl Save customer at least 6 months indevelopment timeOdevelopment timefunctional screeningTEl No binder no payment, zero risk

l Live B cells stored and pre-validated withCH

l Pre-developed lead mAb molecules withBI

DimAb® lead mAb molecules

Using our proprietary single B cell antibody development platform, we have completed hit-to-leaddiscovery for around 300 druggable targets and obtained over 5000 antibody molecules with IgGDIMAsequence information and antibody validation data. The complete list of our available targets can befound on our website (www.dimabio.com/lead-antibody-molecule).

We choose rabbits as our host animals because rabbits have a high success rate with challenging

antigens like small peptides or post-translational modification (PTM) sites, which are often nonimmunogenic in mice. The antibodies produced in rabbits also recognize more epitopes per antigen
than mouse antibodies. Rabbit antibodies have better affinities and specificities than mouse

antibodies. They can bind to target proteins in the picomolar range, while mouse antibodies generally
recognize proteins to the nanomolar range. The druggability of rabbit antibodies has also beenverified in 2019. As of today, there are 2 FDA approved drugs based on rabbit antibodies.

Three Advantages of Rabbit Monoclonal Antibodies

Rabbit monoclonal antibody has three advantages in antibody drug discovery.

06

D
IM
A

BI

O

TE

CH

Risk-free Lead Antibody Discovery

Risk-free Lead Antibody Discovery

O

TE

CH

07

BI

DimAb® B cell seed libraries

DimAb® B cell seed libraries are a pool of frozen B cells prepared from immunized rabbits, and prevalidated by FACS as positive binders to antigen proteins. Most of the libraries have been used for thescreening of lead mAbs by our internal R&D team and customers. The antibodies prepared fromD
IM
A

DimAb® B cell seed libraries have shown diverse CDR sequences and good druggability in downstream
testing results. Each library contains lots of potential binders for antibody drug discovery.

Key Features:l Pre-made B cell libraries containing diverse FACS binders for target proteinl Quick freezing in liquid nitrogen after PBMC isolation to prevent injury to cells and keep thediversity of original B cells.

l Risk free, no binder no paymentl Save your time for lead molecule discovery, skip immunization and early screening steps (3~4months).

l Two steps validation:l Validation of immunized rabbit serum as specific binders to the target proteins.

l Validation of capabilities for FACS binder screening during lead mAbs discovery.

Risk-free Lead Antibody Discovery

08

Advantages of DimAb® Lead Antibody Program
Quality

Sequence

CH

Quality
All antibodies are FC validated
We ensure unique sequence of CDR region, and customers can buy out
all B cells produced from their immunized animal.

TE

Worry-freeService
Provide professional technical support and high-quality
antibody production services

O

More Choices

We have an average of more than 5 prestocked and pre-validated monoclonal

D
IM
A

BI

antibody molecules for each target, which
are free for testing. If you need more

molecules, our DimAb® B cell library canhelp you easily obtain more than 10,000
positive hits in as short as a month's time.

09

Risk-free Lead Antibody Discovery

Antibody Engineering

In addition to on-shelf pre-stocked and pre-validated hit-to-lead stage antibody molecules, DIMA

BI

O

TE

their antibody drug discovery.

CH

offers multiple antibody engineering platforms to provide researchers with more powerful bullet forD
IMA

Antibody Humanization & Affinity Maturation Platform

Bi-specific Antibody Platform

10

CH

Risk-free Lead Antibody Discovery

TE

CAR-T in-vitro and in-vivo testings

Antibody Humanization & Affinity Maturation

O

Antibody humanization is important for therapeutic antibody development, especially for the

candidate antibodies derived from animal sources. DIMA Biotech has developed a proprietary

mammalian display platform for antibody humanization and affinity maturation, DiLibraryTM antibody

BIengineering platform. With this platform, we can deliver a panel of humanized variants with improved

affinity than its parental antibody. In addition to improved affinity, the engineered clones also exhibit
improved developability for downstream development, such as high expression level and low
aggregation tendency. Therefore, DiLibraryTM system is a superior antibody engineering platform toDIMA

help us optimize antibody molecules with better developability.

1

Mammalian cell display

2

Experiment oriented
screening

3

Antibody yieldassessment

4

At least 3x increase inaffinity

5

Finish in 48 days

Advantages:

PowerfulFlexible

Fasthumanization, optimization

mAb library formAb sequences andOne-step process for& developability assessment

Custom designed
your needs

Complete

Risk Free

discovery , optimization tohumanization

One stop shop from antibodyfunctional evaluation.

Guarantee affinity after

Deliver humanizeddata in 48 days.

11

Risk-free Lead Antibody Discovery

Platform Workflow

D
IM
A

BI

O

TE

CH

Human IgG germline FR libraryServices & Deliverables
Service

Deliverable

Time

Antibody affinity screening
and ranking

Progress Report- Affinity ranking result

2~3 weeks

QC report for selected humanized antibodies- antibody sequences- FACS binding- SPR examination

2 weeks

Construct humanizedantibody expression library

Antibody cloning andsequencing

Antibody production andaffinity testing
PTM removal

Progress Report- Validation of antibody expression on cell membrane- Validation of antibody-antigen Flow cytometry analysis

1~2 weeks

Progress Report- DNA cloning status

2~3 weeks

Antibody sequence after PTM removal PTM removal report

VariesRisk-free Lead Antibody Discovery

12

CAR-T Lead Antibody Molecules
A good lead antibody molecule is crucial to ensure the efficacy and safety of CAR-T cells in clinicalapplications. DIMA Biotech has established a complete screening platform for CAR-T lead antibody
molecules. We have a range of advanced technologies, in vitro and in vivo assays to identify and optimize

the best candidate antibody molecules for CAR-T therapy. Our approach has been successful inCHdeveloping good CAR-T lead molecules for various cancer targets. We are constantly working to expand
our capabilities and bring more innovative solutions to the field of cancer immunotherapy. As of today,
we have developed 5000+ pre-stocked and pre-validated mAb molecules against 300+ drug targets. SomeTEof them have already entered clinical trial phase.

D
IM
A

BI

O

Workflow

Platform Advantages

On-shelf
Availability

Fast
Turnaround

5000+ mAb molecules for

A complete platform for

Verified CAR molecules withvalidation data andready-to-use CAR-T and

antibody sequences.

300+ druggable targets with
antibody sequences

CAR T cell preparation, andreporter cells to save theassay preparation time.

High Quality
In-Vitro and In-Vivo data and13

Risk-free Lead Antibody Discovery

CAR Targets Under Development

GPRC5D&BCMA
CD138
GPC3

FcRL5

Claudin18.2
CD38

Mesothelin
5T4

CD70
AXL

CD123
EGFR

CEACAM5
CS1

In Vitro
TestingBI

MUC1

Lentivirus
packaging

D
IM
A

FAP

B7H3

EpCAM
ROR1

GUCY2C
FOLR1
CD5
CD7

CDH17
CD79A

CD79B
CD30
CD33

In Vivo Testing

IIT

CH

BCMA

CAR
ConstructionTE

GPRC5D

Lead mAb
discoveryO

TargetRisk-free Lead Antibody Discovery

14

Case Studies

The red arrow indicates the reference antibody which isin clinical trial

Characterization of CAR T cell expansion andcancer cell killing efficacy during In Vitro assay

D
IM
A

BI

O

TE

Flow analysis for CAR molecule affinity

CH

Anti-GPRC5D flow cytometry assay with RPMI8226 cells

In Vivo efficacy experiment in mouse

Case Study: Development of anti-BCMA
therapeutic mAbs for CAR-T application
Multiple myeloma (MM) is the second most common hematologic malignancy after non-Hodgkin
lymphoma with a very high probability of recurrence. It is considered as an incurable disease, and thedevelopment of new treatment options is urgent. BCMA is an ideal target for the treatment of multiple
myeloma (MM) because it is highly expressed in MM cells but not other normal cells except for mature
B lymphocytes and plasma cells.

Risk-free Lead Antibody Discovery

CH

15

TE

Workflow for BCMA DimAb® lead antibody molecules project

Equipped with our recombinant protein production and single B cell antibody development platforms,

we developed 5 lead mAbs molecules for human BCMA targets with verified functional data andantibody sequences. We also created a DimAb B cell seed library for theOhuman BCMA target which presumably contains 10 thousands Flow positive BCMA binders andBIprovides a good resource for additional screening of anti-BCMA therapeutic lead mAb molecules.

Antigen Preparation: Bioactive BCMA Recombinant Protein Preparation

To ensure good functional property and native structure of immunogen, the purities and activities ofDIMA

purified proteins were validated by SDS-PAGE and different binding assays before immunization.

BCMA Antigen Validation Data： A. Human BCMA, Fc-tagged on SDS-PAGE under reducing condition.

B. ELISA plate pre-coated by 2 μg/ml (100 μl/well) Human BAFF, hFc tagged protein can bind Human

BCMA, Fc- tagged protein in a linear range of 0.03-15.625 ng/ml. C. ELISA plate pre-coated by 2 μg/ml(100 μl/well) Human BCMA, Fc-tagged protein can bind Anti-BCMA (huC11D5.3) (Its variable region wasused to construct scFv portion of CAR-T Idecabtagene vicleucel (bb2121).) in a linear range of 3.7122.29 ng/ml

Risk-free Lead Antibody Discovery

16

Lead mAbs Development against BCMA proteins

After immunization, around 3~5 X10^8 B cell pools were isolated from the immunized rabbit andquickly frozen in liquid nitrogen as our B-cell seed library for human BCMA target. From 4ml of rabbit
whole blood, we identified 70 ELISA positive B cell clones, out of which 13 worked for the flow
application and were picked up for the downstream mAb cloning and sequencing. After epitopeCH

comparison, 5 new clones were identified with unique CDR sequences comparing to the Bluebird antiBCMA huC11D5.3 clone. All of them have shown comparable tumor cell killing efficacy with the

Bluebird anti-BCMA huC11D5.3 clone in the CAR-T application after humanization. One has been

D
IM
A

BI

O

TE

picked up for an Investigator Initiated trial (IIT). The preliminary data is encouraging at this moment.

Phylogenetic analysis of 13 different Anti-BCMA DimAb clones A) heavy chain and B) Light chain. All
these clones work for flow application. The boxed regions indicate heavy and light chains of the sameclone come from the same lineage group.

Epitope comparison between different anti-BCMA
DimAb clones and anti-BCMA huC11D5.3 clone(Bluebir d bb2 1 2 1 ) . ELISA plate was coated withrecombinant BCMA-hFc fusion protein, followed by preblocking with huC11D5.3 antibody (Grey bar) or rabbit

control IgG (Black bar) and then different rabbit DimAbs
antibodies were added to check the competitive

inhibition of huC11D5.3. One clone e x hi bi t s t hestrongest inhibition (Red bar). This data indicated that
one clone binds to the same epitope as bb2121.

17

Risk-free Lead Antibody Discovery

Antibody Engineering

Based on the Anti-BCMA antibody gene sequence

provided by the DimAb® recombinant monoclonalCH

antibody platform, we humanized five validated
high-affinity clones and constructed bispecific BITE

molecules, CAR molecules for the in vitro functionalTE

verification.

Development of anti-BCMA therapeutic mAbs for CAR-T application

O

Perform in vitro and in vivo efficacy
verification analysis of 5 humanized
modified CAR targeting BCMA . The testBIresults show that our molecules are

not inferior to Bluebird's antibody
under different target ratio conditions,D
IMA

whether in vitro or in vivo tests.

Flexible Business Models

We provide flexible business models for the lead antibody molecule development. Customers canselect the ideal molecules from our pre-stocked and pre-validated antibodies and test them for free in

their own assays. If the results meet customers requirement, they can sign an agreement to directly
obtain the sequence of the required antibody and corresponding intellectual property. If there is no

ideal molecules in the existing antibody list, we can screen more molecules from our DimAb® B cell
seed libraries and it only takes 1~2 month for us to get more positive candidates for further testing.

For targets without B-cell libraries, we provide customized development services using our wellestablished antigen preparation platform and single B-cell antibody development platform. The timerequired for each models is shown in next page, compared with the traditional hybridoma platform,
DIMA Bio can save at least 6~8 months of antibody development time.

18

D
IM
A

BI

O

TE

CH

Risk-free Lead Antibody Discovery

DIMA Biotechnology LTD

D
IM
A

BI

O

TE

CH

Dedicate on immuno-oncology，Perfect with recombinant mAb development

DIMA Biotechnology LTD

Fuchunjiang Rd No. 188, Gaoxin District, Suzhou+001-86-15307149771

Wuhan institute of Biotechnology B7, No.666 Gaoxin Road, Wuhan

info@dimabio.com

www.dimabio.com