One-Stop Antibody Drug Discovery Services from GenScript ProBio

1. Inspire,Accelerate&Co-create BiomedicalInnovation

2. GenScriptProBio GenScript ProBio is the bio-pharmaceutical CDMO segment of the world's leading biotech company GenScript Biotech Corporation (Stock Code: 1548.HK). Founded in 2002 in New Jersey, GenScript started business from gene synthesis. Now, GenScipt’sbusinessesencompassfourmajorcategoriesbasedonitsleadinggenesynthesistechnology,includingoperation as a Life Science CRO, enzyme and synthetic biology products, biologics development and manufacturing, as well as cell therapy. In Jan 2019, GenScript established the Biologics Development Business Unit (BDBU) which is the predecessor of GenScript ProBio. The nameof "ProBio" indicates 3 core philosophies - being PROACTIVE, PROFESSIONAL and PROCESS-oriented. GenScript ProBio shows our dedication to proactively provide end to end service (discovery to commercialization) with professionalsolutions, and efficientprocess to accelerate drugdevelopment for customers. GenScriptProBioprovidesanintegratedbiologicsdiscovery&developmentsolutionfromtargettoIND.Withourcutting-edge technology platforms in therapeutic antibody discovery & development, GenScript is able to deliver functional antibody lead withgooddevelopabilityandsafetyindiscoveryphase,aswellasreliable,productiveandregulatory-compliantprocess&drug productfor IND filing indevelopment phase, which significantly saveclient's time and cost. • LeadGeneration • Hybridomageneration • Humannaïve library &Synthetic library • Fullyhumantransgenicmice • SingleBcellcloning • SMABbispecificantibodydiscovery LeadOptimization • BiologicsDevelopment • Celllinedevelopment • Process development • Analyticaldevelopment • Clinicalbatchsupply • Antibodyhumanization • Affinitymaturation • Developabilityassessment • Bioassay&Bioanalytics 1 www.GenScriptProBio.com

3. GMP Plant #1 Nanjing, China GMP Plant #2 Nanjing, China GMP Plant #3 Zhenjiang, China LeadingTherapeuticAntibodyCDMO FromTargettoMarketSolutions 500+Employees,40+Expertswithextensive experiencesin industry cGMPcompliantMammalian CellCultureFacility ComprehensiveAnalyticsPlatform www.GenScriptProBio.com2

4. HybridomaAntibodyDrug Discovery GenScript's13yearsofcustomantibodygenerationexperiencecandeliverapanelofhybridomas under 4monthswithourstandardprotocol. WeProvide Afullspectrumofimmunizationapproaches: Protein, peptide, whole cells and DNA. OptimumAntigen™ Design Tool guarantee results. Optimized immunization:Transgenic mice* generate human antibodies. Proprietary adjuvant and immunogen modification breaks immunological tolerance for superior immune response. Complete service: From antigen production to hybridomadevelopmentandcharacterization. High throughput: High efficiency screening. Proprietary NativeSelect™ELISAfor soluble targets. iQue HT Screener, and BD FACS CaliburwithHTloaderformembranetargets. Comprehensive functional assays: Validated functional assay platforms provide reliable in vitroscreening. Readilyintegratedwithotherdrugdiscovery services: Antibody sequencing, antibody humanization, recombinant antibody production andanti-idiotypeantibodygeneration. Target Animal immunization Test bleedreport Cellfusion 40000clones Highthroughput ELISA& FACS screening 100clones SuperdomaTM assay&lsotyping Customerfunction assay 50-100clones Binder clones subcloning & production 1-5 mg mAb/clones Customerfunction assay Topclones for antibody engineering Note: Wecancustomizeyourprojectbasedonyourspecificrequirement. We providefreecell linestorageservicefor6monthsfromthe dateofcellfreezing. WerecommendGenScript providesimmunogenfor highestquality. * 3 www.GenScriptProBio.com

5. PhageDisplay andAntibodyLibrary Humanantibodysequencein2months Fully human antibodies are the mainstream of therapeutic antibody development because of the increasing concern on immunogenicity and safety issues. Among the techniques that develop fully human antibodies, Human Naïve Library and Phage Display have been proved* to be an effectiveplatformto pave the way to the fully human candidates. GenScript has successfully developed in-house Human Naïve and Llama Naïve Library, which have been internally validated for multiple targets. Besides, our experienced scientists will develop multiple panning strategies, which are just right for you to getthe best antibody candidate. GenScript’sNaïveLibraryandPhageDisplayService: • Panning: • Diversified panning methods to increasethesuccessfulrate. • Panningstrategiestailoredtodifferent targets: soluble and transmembrane targets. • No more than 3-round panning to retainthesequencediversity. Llama Naïve LibraryforsdAb (Available Now) Human Naïve Library Technical Indicator 100healthyalpaca donors 2400healthydonors Source Fab-HK Fab-HL Libraryformat sdAb 2*1010 (InExpanding) 1.04*1011 (InExpanding) Librarysize • Screening: • Acombination ofFASEBAhigh throughput platform, ELISA/FACS screening,andSPRaffinityscreening. / >90% Insert rate >95% >85% Inframerate/ORFrate Normal Distribution Normal distribution CDR3 diversity NatureFrequency Naturefrequency Germline analysis Advantages Betteratpresentingall possibleepitopes,highdiversity Liquid panning Simpleformat,suitableformosttarget Solid panning Cellpanning Generating antibodiesableto recognizenaturalepitope presentedbycells Generating antibodies able to recognize more diversified epitopes and naturalepitope presentedby cells Ag.biotin-cell panning Ag-cellpanning Generating antibodiesableto recognizenaturalepitopes presentedbycells Competitive panning Eliminate antibodies targeting irrelevant epitopes, acquiring antibodies specificto desiredepitope *Adalimumab, Belimumab, Raxibacumab, Ramucirumab, Necitumumab, Avelumab, Ranibizumab and Durvalumab are known to be developed by phage displayantibody library technology. www.GenScriptProBio.com 4

6. SingleBCellScreening forAntibodyDrugDiscovery FinishAntibodyScreeningwithin24hours Single B cell screening platform, also known as single B cell cloning technology, is a microsystem based screening method. This platform conducts isolation, screening and evaluation on the B cells, avoiding the cell fusion and the library construction step. Also, single B cell screening platforms usually integrate high throughput platforms, therefore assays could be carried out ina highly efficientmanner. GenScript has built our own single B cell platform by using Beacon™, a micro-chamber based platform. With dozens years of experience on antibody discovery and cell manipulation, GenScript now provides a one-stop solution on antibody discovery usingsingle B cell screening technology. GenScriptProSpeedTMServiceFeatures EXPEDITEDTIMELINE Screeningcompletedin1day Asfastas1monthtogetfunctional sequences MAXIMIZEDDIVERSITY Minimaldiversityloss,forward functionalscreening HUMANSAMPLECOMPATIBLE Full human antibody screened directly from humanPBMC Suitableforinfectiousdiseaseresearch INTRINSICADVANTAGEforCHALENGING TARGET Highhitrate:multiplescreening/assaymethodto selectfunctional leadsat earlierstage Low hit rate: limited B cell repertoire due to fusion loss Antibody Secreting Antibody Expression Single B Cell B Cell Harvest Immunization Cell And Sequencing Enrichment Purification Beacon MULTIPLEXASSAY IMPORT EXPORT 1 day GenScript ProSpeedTMService: suitable for soluble targets, single transmembrane targets and also multiple transmembranetargets. Human PBMC samples could alsobe used as startingmaterial. Phase Item TAT MaterialsPreparation Antigenpreparation Antigen ligand (positive control antibody) binding/blocking with ELISA and/or FACS, EC50 measurement, optimize antigen concentration and/or secondary antibody concentration Pilot Experiment Option1:Immunizationwithprotein(regularanimals) 8-14Weeks(Standard) 2Weeks(Express) Option2:Immunization withprotein(Transgenicanimals*) Protein-basedIgG Protein-basedantigenspecificbinding Cellbasedassays(epitope mapping,antigenbinding, ligandblocking,etc) AssayonSingleBSystem: Beacon 1 Day Desirable single B cells (given the selection criteria) will be exported for totalcDNArecovery and single cell VH/VLsequencing Sequencing 1Week RecombinantAntibody Production Abexpression&purification 1-2Weeks * www.GenScriptProBio.com 5

7. Antibody Sequencing OurExperiencedHands,YourUniqueSequence GenScript takes the greatest care to ensure a 100% accurate sequence. Each chain is cross verified amongst 5 independent clones. No mutation is introduced with both 5’ and 3’-RACE Full Length sequencing of the variable regionfrom FR1. StartingMaterialfromClients:>1×106cells Sequencingof Variable Domain/FullLengthIgG CloneintoStandardSequencing Vector Optional:CloneintoExpression Vector Optional: RecombinantAntibody Expression Optional:Antibody Binding Confirmation ValueandSpeed Within duration as short as 6 days, GenScript delivers the data needed with your intellectual property being protected. Sequencing of antibody binding regions also sheds light upon further development such as humanization and recombinant antibody production. www.GenScriptProBio.com6

8. Antibody Humanization • ReducetheImmunogenicity, KeeptheAccuracy • Replacing everything but the complementarity determining region (CDR) reduces the degree to which an antibody drug itself acts as an immunogen. Immunization against an antibody drug lowers efficacy through reduction in circulating half-life and/or neutralization. • OurStrategy • CDR-grafting • Patentedlibrarybased“frameworkassembly” • FASEBA:FAst Screening forExpression level, Biophysical properties, andAffinities • CaseStudy Mouse IgG HumanizedIgG K =4.92×10 M -10 K =7.22×10 M -10 D D 30 30 nM nM 4nM 8nM 16nM 2nMRepetition nM nM 4nM 8nM 16nM 2nMRepetition Response(RU) Response(RU) 20 10 20 10 0 0 0 200 400 Time (s) Tm =66.3℃ 600 0 200 400 600 Time (s) Tm = 70.6℃ 8 8 217nm 208nm 202nm 4 0 4 217nm 208nm 202nm CD (mdeg) CD (mdeg) 0 -4 -8 -12 -16 -4 -8 -12 42526272 Temperature(℃) 8292 42526272 Temperature(℃) 8292 The engineering and screening procedures are integrated, allowing for simultaneous antibody humanization and stabilization. Weevenguaranteetheaffinityofthehumanizedantibody,whichwillbeequaltoorhigherthantheaffinityofyourparental antibody. Service Milestone Deliverables Chimeric antibody production andbindingconfirmation Turnaround PTManalysis（optional） • Sequence, DNAandchimericAb & top 3humanizedAbs(0.5mg) • Guaranteeatleast1Abwithaffinity comparable with parentalAbs Express Humanization Expresshumanizationbyrational designandsequencesynthesis Humanizedantibodyproduction 8Weeks andaffinityranking Humanized antibody production andaffinitydetermination Chimeric antibody production and Bindingconfirmation • Sequence, DNAandchimericAbs • & top 3 humanizedAbs (0.5 mg) • Guarantee at least1Abs with affinity comparablewithparentalAbs SequencePTManalysis,Backmutation librarydesignandlibraryconstruction 11Weeks Deluxe Humanization Humanizedantibodyselection Humanized antibody production andcharacterization 7 www.GenScriptProBio.com

9. Affinity Maturation 5-100foldofAffinityMaturation Affinity is one of the key parameters of an antibody drug, which will affect the function and efficacy of the antibody. Generally, antibody candidates from hybridoma platform has already acquired high affinity, but it may not exactly fit in the practical needs inresearch. GenScript providesAffinity Maturation Service, which will help to improve the antibodyaffinityas you desired. LibraryDesign and HTPScreening AffinityMaturedIgG Production and Characterization Paratope Mapping SinglePoint Mutation • CoreAdvantages • Guaranteethe5-10foldincrease • Application of FASEBA High Throughput platform, in which affinity, expression level and thermal stability are screened simultaneously. • Service Details Deliverables Timeline • Antibodyandsequenceandreportanalysis • Top5clones • Guarantee5-10foldaffinityimprovement Antibodysequencingandsequence analysis Paratope mapping, library design and HTP screening 20-24 weeks CaseStudy Affinity maturation was performed for the Wild Type IgG and 3 positive clones were found, with Clone 1 showing highest fold increase(751fold increase). www.GenScriptProBio.com8

10. PreliminaryDevelopability Assessment SeamlessConnectionfromAntibodyDiscoverytoPreclinicalCMCDevelopment Some antibody candidates discovered in early stage will involve issues such as post translational modification (PTM) hotspots orpoorphysiochemicalstability,whichwillleadtopotentialriskduringpreclinicalCMCdevelopment,resultinginhugetimeand financial loss to researchers. Taking advantage of bioinformatics tools and a series of quality study instruments, GenScript introduces Developability Assessment Service to identify the inherent risk in antibody discovery stage, which seamlessly connects antibody discovery withpreclinical CMC development. PTMAnalysis Fragmentation Deamidation Developability Isomerization N-Glycosylation Physical Stability Chemical Stability Free-thiol Oxidation PTMHotspots Service Package Service Content Timeline Thermostability Aggregation Hydrophobicity Molecularweight (de-glycosylatedandglycosylated) Physiochemical assessment 8 weeks Stability (Freeze-thaw cycle, low pH, 40℃ accelerated degradation, matrix effect) Asparaginedeamidation Aspartate isomerization PTM hotspot identification & validation 8-10 weeks Tryptophanoxidation Hydrolysis N-glycosylation 9 www.GenScriptProBio.com

11. SMAB—Bispecific AntibodyPlatform GenScriptProprietaryBispecificAntibodyPlatform——SMAB Bispecific antibodies (bsAb) have become a focus of interest for therapeuticapplicationswithnearly85 commercialcandidates enteringtheclinical trialsand 3havingbeenapprovedto market. Single-domainantibody(sdAb,VHH) Proprietary linker + Monoclonal antibody (mAb) GenScriptSMAB(Single-domainantibodyfusedtomonoclonalAb) platform naturally combines the single domain antibody and the monoclonal antibody to make a bispecific antibody in symmetric format.Withthedesign conceptof “KeepingNatural”, SMAB platform gives good developability and biosuperiority which are comparableto monoclonal antibody. SMAB (Single-domainantibodyfusedtomonoclonalAb) VH • WhySingleDomainAntibody? • Potential ability to bind “hidden” epitopes GPCR, ionchannel, etc. • Highaffinity:canreachpMrange C1 H VL • Favorablebiophysicalproperties • Flexibility in modality design Bivalent,trivalent,tetravalent CL CH2 CH3 CoreAdvantagesofSMAB UniqueMolecular Flexibility Exceptional Developability Efficient Development CLDtiter>2g/L Yield>60% OnestepproteinApurity> 95% Solubility>25mg/ml Stability>95%after5times freeze-thaw PK half life 2-3 weeks Lowimmunogenicityrisk Flexibilitytomodulatedual target effect to achieve bestpotency PossibilityonADCC/CDC enhancement Uniqueness of sdAb to targetto“hidden”epitope 3-5 months for SMAB molecule development 10monthsforpreclinical development 1 plasmid system for CLD Noadditionalpurification Nopost-productionprocess Ourclientsinclude*: *Disclosed partners. www.GenScriptProBio.com10

12. Invitro Cell-basedBioassay ComprehensiveinvitroCell-basedBioassayPlatforms Antibodydrugsexerttheirtherapeuticeffectthroughdifferentmechanismsofaction(MOAs)inhumanbody.Validationofthese MOAs in vitro during early discovery is prerequisite to further drug development. GenScript has developed various in vitro cell-based bioassay platforms to accommodate such needs in both academia and industry. Assay methods are readily available for more than 30 hot immune-oncology targets and 9 Fc-γ-Receptors. IND-filing standard can be fulfilled upon request. 11 1 2 γ β α Reducecell growthrate Ca2+ cAMP Tissuemacrophage Tumorcell 10 9 Naturalkillercell AgonistAssayof Epinephrine onADRA1B AntagonistAssayofSampleAonADORA2A 120 GrowthInhibitionAssayofSampleBonCalu-1cells 120 100 100 100 80 %Inhibition 80 80 %Inhibition %Stim ulation 60 60 40 20 60 40 20 40 20 0 0 10-12 0 10-510-410-310-210-110-0101 10-10 10-8 10-6 [Epinephrine] (M) EC50 2.993e-008 10-1210-1110-1010-910-810-710-4 [SampleA](M) IC50 3.105e-009 GPCRantagonistassay 10-4 -20 [Sample B](M) IC50 0.001312 Growthinhibitionassay GPCRagonistassay NeutralizationAssayof anti-IL-6 antibody onSTAT3phosphorylationinTF-1cells 4-1BBAgonistAssay ofAnti-4-1BB antibody PD-1/PD-L1 BlockadeAssayofAnti-PD-1 antibody 800000 8000 40000 Lum inescence (RLU) Lum inescence (RLU) HTRF 665/620 Ratio 600000 6000 30000 400000 4000 20000 200000 2000 10000 0 0 0 10-410-310-210-1100101102103 Log10[Anti-4-BBantibody](nM) -7 -6 -5 -4 -3 [AntiIL-6antibody](mg/ml)(M) EC50 1.109e-005 Neutralizationassay -4 -2 0 2 -8 -2 Log10[AntiPD-1antibody](μg/ml)(M) EC50 0.1014 EC50 0.7164 Immunecheckpointagonistreporterassay Immunecheckpointblockadereporterassay 11www.GenScriptProBio.com

13. Invitro Cell-basedBioassay 5 Growthinhibitionassay GPCR-targeted agonist/antagonistassay Neutralizationassay Immunecheckpoint-targeted reportergeneassay Customized functional assay cell lineconstruction Immune cell stimulation and multiplexcytokinereleaseassay Mixedlymphocytereaction Complement-dependent cytotoxicityassay Antibody-dependentcell cytotoxicityassay Luciferase RE 7 Tcell 4 3 Peptide 6 Dendriticcell Antibody-dependentcellular phagocytosisassay Cellular characterizationassay byflowcytometry 8 IFN-γReleaseinMLRAssayofanti-PD-1antibody IL-2ReleaseinMLRAssayofanti-PD-1antibody ADCCAssayofanti-Claudin18.2antibody 3000 5000 80 IFN-γ (pg/ml) 4000 %TargetcellLysis IL-2 (pg/ml) 60 2000 3000 40 2000 1000 20 1000 0 0 10-510-410-310-210-1100 [Anti-PD-1 antibody](μg/ml) EC50 0.05280 10-510-410-310-210-1100 101102 101102 10-510-410-310-210-1100101102 [Anti-PD-1 antibody](μg/ml) EC50 0.009141 [Anti-Claudin18.2antibody](μg/ml) EC50 0.02690 -20 MLRassayIFN-γrelease MLRassayIL-2release ADCC assay Cellular Phagocytosis Assay of anti-CD47 antibody againstHL-60cells IFN-γ Release from PBMC stimulation assay of anti-Siglec-15antibody 2000 CDCAssayofanti-Claudin18.2antibody 80 100 %Phagocytosis %TargetCellLysis IFN-γ(pg/ml) 1500 80 60 60 1000 40 40 500 20 20 0 10-1 0 0 -4 -3 -2 -1 0 1 [Anti-CD47 antibody](μg/ml) EC50 0.06014 100 101 102 103 [Anti-Siglec-15 antibody](μg/ml) EC50 38.66 10-310-210-1 2 100101102 -20 [Anti-Claudin18.2antibody](μg/ml) EC50 0.3778 CDC assay Cellularphagocytosisassay PBMCstimulationassay www.GenScriptProBio.com12

14. Anti-IdiotypeAntibodyGeneration &ImmunoassayDevelopment OneStopSolutionfromAnti-idiotypeAntibodytoImmunoassayDevelopment An anti-idiotype antibody (anti-ID Ab) binds to the idiotype (specific combination of idiotopes present within an antibodies complement determining regions) of another antibody, usually an antibody drug. As anti-id Abs specifically bind to therapeutic antibodies, they act as a powerful tool for Pharmacokinetic analysis of antibodies. Anti-ID Abs are also commonly used as a reference standard for anti-drug antibodies (ADAs) in antibody drug immunogenicity (immune response,IG) studies. FeaturesofGenScriptAnti-IDAntibodiesService Fastdeliveryforanti-IDpAb Asfastas8weekswithguaranteedquantity Highsuccessrate >98%successratewith>400projects Applicationtailoredanti-IDmAb Fitforimmunoassaydevelopment Anti-IDAntibodiesPackageDetails Package Typical Application Starting Material Time (weeks) Deliverable 1-2mLsupernatant/parentalclone 5mLfinalsupernatant/subclone 3-5Hybridomacelllines 3-5purifiedAb/clone,2-5mg/clone Pilot sensitivity report (optional) COAreport Labeled antibody drug Anti-ID pAb Anti-id mAb Golden PackageforCapture ELISA ≥2mgtargetantibodydrug 0.5mgisotypecontrolor humanIgG 21-27 Antibody drug 1-2mLsupernatant/parentalclone 5mLfinalsupernatant/subclone 5-10Hybridomacelllines 5-10purifiedAb/clone,2-5mg/clone, Anti-id mAb pair and pilot sensitivity report(optional) COAreport Anti-id mAb Deluxe PackageforSandwith ELISA ≥2mgtargetantibodydrug 0.5mgisotypecontrolor humanIgG Labeled Anti-Fc Antibody drug 21-29 Anti-ID mAb Small scale affinity purification (optional) AffinitypurifiedpAb Pilotsensitivityreport(optional) COAreport Labeled Anti-ID mAb Antibody drug ≥45mgtargetantibodydrug ≥30mgisotypecontrolor humanIgG HumanIgGI:8-12 Othertype#:>13 Anti-id pAb GuranteedPackage Anti-ID mAb As detection reagent： Measure antibody drug concentrationinpatientserum samples ≥0.5mgantibodydrug ≥1mgdetectingantibody ≥1mgcaptureantibody PKELISA KitDevelopment 8-12 Report of feasibility analysis Finalreportofkitdevelopment Labelled anti-ID antibody Analyticalmethodsandkey As positive control： Measure·ADAconcentrationin patientserumsamples. Measure the level of neutralization antibody, analyze the affectofefficacy reagent instructions ≥1mgantibodydrug ≥1mgAnti-IDantibody ADAELISA KitDevelopment 8-12 Note:#Other type: including butnot limitedto peptide,protein, ADC,SvFv & bispecificantibody. 13www.GenScriptProBio.com

15. Inspire,AccelerateandCo-create BiomedicalInnovation

16. Email:cdmo@genscript.com Toll-Free:1-877-436-7274 Tel:1-732-885-9188 Fax:1-732-210-0262 www.GenScriptProBio.com