#1● GUARDANT™ Investor Day Presentation September 7, 2023 INVESTOR 20 DAY 23#2INVESTOR 20 DAY 23 GUARDANT™ Transforming patient lives across the continuum of care Helmy Eltoukhy, PhD co-Chief Executive Officer, co-Founder & Chair of the Board AmirAli Talasaz, PhD co-Chief Executive Officer & co-Founder#3Safe harbor and non-GAAP disclosures INVESTOR 20 DAY 23 Certain statements in this presentation and the accompanying oral commentary are forward-looking statements within the meaning of federal securities laws. These statements relate to future events or Guardant Health, Inc. (the "Company")'s future results and involve known and unknown risks, uncertainties and other factors that may cause the actual results, levels of activity, performance or achievements of the Company or its industry to be materially different from those expressed or implied by any forward-looking statements. In some cases, forward-looking statements can be identified by terminology such as "may," "will," "could," "would," "should," "to," "target," "expect," "plan," "anticipate," "intend," "believe," "estimate," "predict," "potential" or other comparable terminology. All statements other than statements of historical fact could be deemed forward-looking, including any expectations regarding the Company's commercial engine as a force multiplier for research and development initiatives; any projections of market opportunities; statements about the Company's ability to assess potential market opportunities or any statements about the Company's ability to successfully develop new products and services; any statements regarding expectations for future reimbursement opportunities; any statements regarding the Company's long-term expectations, including with respect to oncology, liquid biopsy, and other aspects of the Company's industry; any statements about launching planned new products and additional laboratories, including with respect to Guardant Reveal, CGP tissue assay, and laboratories outside the United States; any statements about the Company's ECLIPSE study; any statements regarding expectations for future regulatory approvals; any statements about historical results that may suggest trends for the Company's business; any statements of the plans, strategies, and objectives of management for future operations and directions; any statements of expectation or belief regarding future events, opportunities to drive future growth, potential markets or market size, or technology developments; and any statements of assumptions underlying any of the items mentioned. The Company has based these forward-looking statements on its current expectations, assumptions, estimates and projections. While the Company believes these expectations, assumptions, estimates and projections are reasonable, such forward-looking statements are only predictions and involve known and unknown risks and uncertainties, many of which are beyond the Company's control. These and other GUARDANT important factors may cause actual results, performance or achievements to differ materially from those expressed or implied by these forward-looking statements. The forward-looking statements in this presentation are made only as of the date hereof. For a further description of the risks and uncertainties that could cause actual results to differ from those expressed in these forward-looking statements, as well as risks relating to the business of the Company in general, see the Company's periodic filings with the Securities and Exchange Commission, including its Annual Report on Form 10-K for the year ended December 31, 2022, and in its other reports filed with or furnished to the Securities and Exchange Commission. Except as required by law, the Company assumes no obligation and does not intend to update these forward-looking statements or to conform these statements to actual results or to changes in the Company's expectations. This presentation also contains estimates and other statistical data made by independent parties and by the Company relating to market size, penetration and growth and other data about the Company's industry, which involve a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. In addition, projections, assumptions, and estimates of the Company's future performance and the future performance of the markets in which the Company operates are necessarily subject to a high degree of uncertainty and risk. In light of the foregoing, investors are urged not to rely on any forward-looking statement or third-party data in reaching any conclusion or making any investment decision about any securities of the Company. This presentation includes references to certain financial measures that are not calculated in accordance with GAAP. Reconciliation to the most directly comparable GAAP financial measure may be found in our most recent earnings release furnished to the SEC on August 3, 2023. 3#48:00 am 8:15 am 8:45 am Today's agenda Welcome and opening Data generation driving future expansion Leading in liquid biopsy for therapy selection 9:05 am 9:25 am Paving the way for tissue-free MRD and surveillance Commercial Platform 9:50 am Q&A 10:10 am Break 10:25 am Screening 11:00 am 11:55 am Panel: Seeing deeper with epigenomics Financials 12:10 pm Future/AI/ What's ahead 12:20 pm Q&A 12:45 pm Lunch GUARDANT INVESTOR 20 DAY 23 Helmy Eltoukhy (co-CEO) and AmirAli Talasaz (co-CEO) Darya Chudova (Chief Technology Officer) Craig Eagle (Chief Medical Officer) Helmy Eltoukhy (co-CEO) Chris Freeman (Chief Commercial Officer) AmirAli Talasaz (co-CEO) Hosted by Justin Odegaard (VP, Product Development) Mike Bell (Chief Financial Officer) Helmy Eltoukhy (co-CEO) and AmirAli Talasaz (co-CEO) 4#5GUARDANT Guardant Health was founded with the mission to give us all more time free from cancer GUARDANT INVESTOR 20 DAY 23 5#6On this mission to conquer cancer, our weapon of choice is data GUARDANT™ INVESTOR 20 DAY 23 6#7Paradigm shifts have driven exponential increases in data generation and acquisition 1015 1010 105 10⁰ 10-5 10-10 Relay Vacuum Tube { YYYYY 뮤 Transistor ሐ ሐ ሐ ሐ ሐ INVESTOR 20 DAY 23 Integrated Circuit 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 GUARDANT™ Electromechanical Kurzweil, Ray. The Singularity is Near [archive.org]. New York: Viking Books. 2005. 7#8GUARDANT™ cell-free DNA + other biomarkers INVESTOR 20 DAY 23 The Liquid Biopsy Paradigm has fueled exponential increases in cancer data and outcomes improvement 8#9Paradigm shifts are not easy Liquid biopsy... INVESTOR 20 DAY 23 ...cannot detect late- stage cancer in blood." GUARDANT™ ...is too expensive to run at scale. "I ...is unproven and unreliable." "I ...only detects uninformative cancer information in blood." "I ...will only be used for niche applications." " ...cannot achieve high performance for MRD without tissue." "I ...cannot detect Stage I-III cancers with high sensitivity." 9#10Product launches across the cancer care continuum GUARDANT 360 INVESTOR 20 DAY 23 Guardant Health GUARDANTOMNI IPO Founded GUARDANT 360 Response GUARDANT 360 CDX FDA-approval GUARDANT 360 TissueNext GUARDANTREVEAL shield™ GUARDANTINFINITY GUARDANTINFORM™ 2012 2014 2017 2018 2020 2021 2022 GUARDANT™ 10 10#11Screening Early Disease Detection Minimal Residual Disease Recurrence Detection & Surveillance Therapy Selection Advanced Cancer Care >120M Average-Risk Individuals Do I have cancer? GUARDANT™ >15M Early-Stage Patients and Survivors Cancer Detection Surgery +/- Adjuvant Do I still have cancer? >700K Advanced Cancer Patients INVESTOR 20 DAY 23 Recurrence 1st Line Tx 2nd Line Tx +TX Has my cancer returned? Am I responding to therapy? What kind of therapy is best for me? Shield™ LDT assay is intended to be complementary to and not a replacement for current recommended colorectal cancer screening methods. The Shield assay is a screening assay and not a replacement for a diagnostic colonoscopy. AACR Study, Cancer Prev Res (2020) 13 ACS Cancer Treatment & SurvivorshipFacts & Figures 2019-2021 American Cancer Society Cancer Facts and Statistics; SEER 11#12Screening Early Disease Detection Minimal Residual Disease Recurrence Detection & Surveillance Therapy Selection Advanced Cancer Care >120M Average-Risk Individuals shield™ GUARDANT™ Cancer Detection >15M Early-Stage Patients and Survivors Surgery +/- Adjuvant GUARDANTREVEAL Recurrence >700K Advanced Cancer Patients INVESTOR 20 DAY 23 1st Line Tx 2nd Line Tx +Tx FDA Approved GUARDANT 360CDX GUARDANT 360 GUARDANT 360 TissueNext GUARDANT 360 Response 12#13Screening Early Disease Detection Minimal Residual Disease Recurrence Detection & Surveillance Therapy Selection Advanced Cancer Care >120M Average-Risk Individuals shield™ GUARDANT™ Cancer Detection >15M Early-Stage Patients and Survivors Surgery +/- Adjuvant GUARDANTREVEAL Recurrence >700K Advanced Cancer Patients INVESTOR 20 DAY 23 1st Line Tx 2nd Line Tx +TX FDA Approved GUARDANT 360CDX GUARDANT 360 GUARDANT 360 TissueNext GUARDANT 360 Response 13#14Screening Early Disease Detection Minimal Residual Disease Recurrence Detection & Surveillance Therapy Selection Advanced Cancer Care >120M Average-Risk Individuals shield™ GUARDANT™ Cancer Detection >15M Early-Stage Patients and Survivors Surgery +/- Adjuvant GUARDANTREVEAL Recurrence >700K Advanced Cancer Patients INVESTOR 20 DAY 23 1st Line Tx 2nd Line Tx +Tx FDA Approved GUARDANT 360 CDx GUARDANT 360 GUARDANT 360 TissueNext GUARDANT 360 Response 14#15Screening Early Disease Detection Minimal Residual Disease Recurrence Detection & Surveillance Therapy Selection Advanced Cancer Care >120M Average-Risk Individuals shield™ GUARDANT™ Cancer Detection >15M Early-Stage Patients and Survivors Surgery +/- Adjuvant GUARDANTREVEAL Recurrence >700K Advanced Cancer Patients INVESTOR 20 DAY 23 1st Line Tx 2nd Line Tx +Tx FDA Approved GUARDANT 360 CDx GUARDANT 360 GUARDANT 360 TissueNext GUARDANT 360 Response 15#16INVESTOR 20 DAY 23 We have helped hundreds of thousands of patients and unlocked petabytes of clinical data Cumulative patient tests Current ordering oncologists 5 Bio-banked samples >500K >12K >500K Exponential genomic data generation¹ 20+ 500K+ Tests Petabytes GUARDANT™ 1. Guardant Bioinformatics Database, 2015 - August 2023 2015 Aug 2023 16#17Guardant today $548M 160+ 2023 Revenue Guidance Midpoint¹ 60+ Biopharma Partners Countries GUARDANT™ 1 FY 2023 Revenue guidance of $545 - $550M updated August 3, 2023 INVESTOR 20 DAY 23 600+ Global Patents & Patent Applications 17#18Our values drive us forward во Put patients first Our commitment to treat them as our own family Be stronger together Our commitment to teamwork & caring for each other A Blaze a trail Our commitment to innovation INVESTOR 20 Make every DAY 23 moment matter Our commitment to excellence, velocity and impact GUARDANT™ 18#1980% Great Place To WorkⓇ Certified MAY 2023-MAY 2024 Employee approval rating 195+ PhDs & MDS 1,700+ Employees 56% Female 60% Ethnically diverse > GUARDANT™ As of December 31, 2022 USA IM 3100 HANOVER LEVEL D RDANT ALUES INVESTOR 20 DAY 23 GUARDANT 19#20This is just the beginning... GUARDANT™ INVESTOR 20 DAY 20 20#21GUARDANT™ INVESTOR 20 DAY 23 Data generation driving future expansion Darya Chudova Chief Technology Officer#22Guardant Health pioneered liquid biopsy INVESTOR 20 DAY 23 5 GUARDANT™ Novel Next-generation biochemistry sequencing techniques Al-powered bioinformatics Patient report || MIM 22 22#23INVESTOR 20 DAY 23 Extending from advanced disease to early stage and screening required a technology paradigm shift. 23 23#24GUARDANT™ Smart Liquid Biopsy platform о The power of liquid biopsy Simple blood draw Enhanced by epigenomics • Deeper tumor sensing . • Tissue-site agnostic • Wider biological view Captures whole body heterogeneity • Captures temporal dynamics INVESTOR 20 DAY 23 . Delivering performance & scale Proprietary biochemistry with high sensitivity / specificity Efficient COGS Powered by data generation at scale Delivers 100X genomic breadth and >50X sensitivity with no additional cost 24#25INVESTOR 20 DAY 23 There are 37.2 trillion cells in the human body and they all share one genome 25 25#26INVESTOR 20 DAY 23 Epigenomics is the missing link in understanding human disease 26#27Methylation is a key determinant of the epigenomic state INVESTOR 20 DAY 23 Epigenomic state Gene Unmethylated Gene A may be functionally active controls how our cells Blood cell function ON Methylated Gene A is silenced Liver cell Single Genome Genome 10,000s of epigenomic switches OFF Variable methylation state Blood cell 0 0 1 0 1 0 1 0 1 Liver cell 0 1 1 0 0 0 1 0 1 ... 100s of cell types Liver cancer cell 0 1 1 0 1 1 1 1 GUARDANT Unique fingerprint of disease 27#28Epigenomic state change is wide throughout the genome 1,000s Of differentially methylated regions form cancer or cell type specific fingerprints CRC Healthy GUARDANT Differentially Methylated Regions 28 INVESTOR 20 DAY 23 Samples#29Number of detectable tumor alterations drives sensitivity Genomic analysis MD MD ID GUARDANT™ Epigenomic analysis |||| Tissue Informed Assays Up to 50 Tumor Alterations Smart Liquid Biopsy INVESTOR 20 DAY 23 | | |ID >1,000 Tumor Alterations 29 29#30Smart Liquid Biopsy unlocks both genomic and epigenomic state INVESTOR 20 DAY 23 Circulation Cell-free DNA in plasma VAN Methylation-based Encoding COOKI Smart Liquid Biopsy: Guardant's proprietary technology Sequencing 0623 09 Decoding Chr 1:501-688 ACGC...ATGTAA Feature Extraction Epigenetic changes Per-region Methylation State Genomic changes KRAS G12C Al-Powered Analysis: Quantify and Characterize Cancer State GUARDANT مصر Wet Lab Chr 3:9518-9698 CTT...TCTTATTAA Cell Type & Disease Fingerprinting 10 10 1 00 1 0 1 0 0 1 0 0 1 1 0 1 1 0 0 0 1 1 1 Compute 30 30#31Smart Liquid Biopsy: key technology differentiators INVESTOR 20 DAY 23 Single sample workflow for efficiency Genomic mutations + Epigenomic profiles GUARDANT™ Genome wide profiling >20X more detectable alterations1 Highly efficient molecule capture for optimal detection 3X more signal molecules captured² Background depletion for optimal cost 99% depletion for 7X sequencing cost savings² Continuous improvement powered by samples & data bank 500K samples, multiple cycles of 2X performance gains³ 1. In comparison to tissue-informed assays, based on Guardant's internal data, 2. In comparison to off-the-shelf bisulfite workflows, based on Guardant's internal data, 3. In comparison to previous versions of Guardant's workflows, based on Guardant's internal data 31#32Screening Early Disease Detection Minimal Residual Disease Recurrence Detection & Surveillance Therapy Selection Advanced Cancer Care >120M Average-Risk Individuals >15M Early-Stage Patients and Survivors Cancer Detection Surgery +/- Adjuvant 1 Do I have cancer? 2 Do I still have cancer? GUARDANT™ >700K Advanced Cancer Patients INVESTOR 20 DAY 23 Recurrence 1st Line Tx 2nd Line Tx +TX 3 Am I responding to therapy? 2 Has my cancer returned? 4 What kind of therapy is best for me? 32#331 Do I have cancer? Clinically relevant CRC detection capability achieved by epigenomics assay for screening applications 1,2 GUARDANT™ TM shield 1% Stage IV 0.1% 0.01% 0.001% Stage III Current Epigenomic Detection Limits³ Stage II INVESTOR 20 DAY 23 Detection Limits of Genomic Panels Stage 50X improvement 1. Avanzini et al., Sci Adv 6(50) (2020); CRC Tumor Fractions: https://www.biorxiv.org/content/10.1101/2022.01.17.476508v1.article-info.; Internal Data on File 2 Epigenomic detection limits corresponds to 50%-95% detection probability range established using in silico dilutions of clinical screening-relevant CRC samples at typical 20ng input and 90% specificity. 33 33#342 Do I still have cancer? Has my cancer returned? GUARDANTREVEAL Cancer type Clinically relevant Minimal Residual Disease (MRD) detection capability for tissue-free assay achieved by epigenomics at high specificity (>98%) GUARDANT™ CRC RD Lung Breast INVESTOR 20 DAY 23 Tumor Fraction Level for Reliable Detection1 at the most challenging input level of 5ng 0.01% 0.01% 0.015% Typical cfDNA amounts in early stage clinically relevant samples² Above 5ng >95% samples Above 30ng <20% samples Above 60ng < 5%samples 1. Reliable detection was established as 95% limit of detection using titrations of clinical samples and cell lines for an assay at MRD-relevant 98% specificity and the most challenging and clinically relevant input amount. 2. Derived from internal data 34#353 Am I responding to therapy? Should I switch therapy? High precision of tumor fraction estimates is attained in epigenomic assay based on 1,000s of alterations assessed GUARDANT 360 Response GUARDANTREVEAL INVESTOR 20 DAY 23 3X higher precision¹ of epigenomics enables to see therapy response clearer and make better patient management decisions Tumor Fraction, % 0.05 0.10 0.15 0.20 0.25 Genomic Assessment Before Treatment Point Estimate Confidence interval No change On Treatment Tumor Fraction, % 0.05 0.10 0.15 0.20 0.25 Epigenomic Assessment Point Estimate Confidence interval Significant change Before Treatment On Treatment GUARDANT™ Response in early phase trials Surrogate Endpoint Development Switching therapy based on lack of response 1 3X higher precision estimated in comparison to response tracking with 3 somatic mutations for a representative sample at 0.1% tumor fraction and typical input amount, based on internal data 35#364 What kind of therapy is best for me? Guardant360 powered by our Smart Liquid Biopsy platform. will offer the most comprehensive liquid biopsy for characterization of cancer GUARDANT 360 INVESTOR 20 DAY 23 Current best-in-class liquid biopsy for therapy selection and translational research Expanded genomic and epigenomic capability offered with Smart Liquid Biopsy Epigenome State Immune State Patient State issue of Origin Tumor ペ State SNVs/Indels Amplifications Copy Number Loss Fusions Large Rearrangements bTMB MSI HRD Virus Detection Regulatory Epigenome Immune State GUARDANT™ 36#37INVESTOR 20 DAY 23 4 What kind of therapy is best for me? Breast Cancer Expanded patient eligibility for targeted therapy through promoter methylation Epigenomics unlocks mechanisms of regulation that are invisible to genomic testing BRCA1 Samples BRCA1 Promoter Methy lated Loci ~24% of TNBC patients are associated with promoter methylation¹ Without analyzing both genomic and epigenomic alterations, patients potentially eligible for PARPi therapies would be missed² GUARDANT™ PARPI Poly adenosine diphosphate-ribose polymerase inhibitor; TNBC-triple negative breast cancer. 1. Glodzik D et al. Nat Commun. 2020. 2. Coyne et al. Onco Targets Ther 2022. 37#38INVESTOR 20 DAY 23 4 What kind of therapy is best for me? Colorectal Cancer Expanded patient eligibility for targeted therapy through promoter methylation Epigenomics unlocks mechanisms of regulation that are invisible to genomic testing MLH1 Promoter Methylated MLH1 Samples cancer type 3 37033671 3 37033791 3 37033861 3 37033804 3 37033911 3 37033971 3 37034008 3 37034031 3 37034091 3 37034129 3 37034151 3 37034211 37034246 3.37034271 3 37034331 3.37034364 3 37034391 337034451 Loci 3 37034478 3 37034511 3.37034571 3 37034509 3 37034631 MLH1 promoter methylation identified additional 7% of MSI-H patients missed by genomic testing alone. 3 37034691 3 37034716 337034751 3 37034811 3.37034871 3 37034031 3 37034947 3 37035051 3 37035068 These patients would be 3 37035111 3 37035171 3 37035184 3 37035231 3 37035291 3 37035302 eligible for FDA-approved I/O therapy options.1 GUARDANT™ MSI-H-Micro-satellite instability, High 1 https://www.accessdata.fda.gov/drugsatfda_docs/label/2021/125514s096lbl.pdf 88 38#39Screening Early Disease Detection Minimal Residual Disease Recurrence Detection & Surveillance Therapy Selection Advanced Cancer Care >120M Average-Risk Individuals >15M Early-Stage Patients and Survivors Cancer Detection Surgery +/- Adjuvant 1 Do I have cancer? 2 Do I still have cancer? GUARDANT™ >700K Advanced Cancer Patients INVESTOR 20 DAY 23 Recurrence 1st Line Tx 2nd Line Tx +TX 2 Has my cancer returned? 5 3 Am I responding to therapy? 4 What kind of therapy is best for me? What kind of cancer do I have? Where is my cancer? How is my immune system responding? 39 39#40Blood 5 Where is my cancer? cfDNA methylation encodes tissue of origin Tissue 1 0.8 Bladder 0.6 0.4. 0.2 Colon Breast 0 Colon Tissue-specific fingerprints are detectable with Smart Liquid Biopsy Lung GUARDANT™ Data from Loyfer et al., Nature 613 (2023) Lung Bladder INVESTOR 20 DAY 23 Breast 40 40#415 What kind of cancer do I have? cfDNA methylation encodes cancer subtype HR- INVESTOR 20 DAY 23 1.0 HR+/ 1.0 -0.8 -0.8 -0.6 HER2+ -0.6 -04 -0.2 -0.2 HR+ -0.0 -0.0 Fingerprints differentiating breast cancer subtypes are detectable with Smart Liquid Biopsy HR- HER2- Epigenomic profiles derived from plasma of breast cancer patients may enable precision diagnostics and potential for identifying novel response predictors GUARDANT™ 41 11#42Future unified platform will drive significant R&D efficiency and operating leverage Smart Liquid Biopsy INVESTOR 20 DAY 23 shield™ GUARDANTINFINITY GUARDANTREVEAL GUARDANT 360 GUARDANT 360 Response R&D efficiency • Leveraged performance improvements GUARDANT™ ⚫ Cross-development of new applications Operating leverage • Lower COGS • Fast turnaround time 42 42#43Power of More Data Learning from data for continuous improvement Technology paradigm shift for radical change in capability GUARDANT™ Tumor Fraction, % Continuous improvement INVESTOR 20 DAY 23 Continuous improvement GUARDANT 360CDX 1% 1% GUARDANTREVEAL shield™ 0.1% 0.01% 0.001% Source: Internal data on file 0.1% 0.01% Technology Paradigm Shift Data growth 0.001% Data growth 43 3#44Smart Liquid Biopsy will continue to unlock the rich landscape of blood-based markers INVESTOR 20 DAY 23 micro-vesicles exomeres NETS immune cells apoptotic bodies TEPS microbiome genome-wide fragmentation chromatin organization fragments ending point mutations topology exosomes epigenetic alterations copy number aberrations proteins CpG sites Microenvironmental Epigenetic and immune features influence GUARDANT™ Adapted from Van der Pol., Cancer Cell, 2019 rearrangements virome TLR receptors TFs nucleosomal occupancy mtDNA Blood Sample Genomic features Tumor-Specific | Derived targets 44#45GUARDANT™ INVESTOR 20 DAY 23 Leading in liquid biopsy for Therapy Selection Craig Eagle, MD Chief Medical Officer#46Screening Early Disease Detection Minimal Residual Disease Recurrence Detection & Surveillance Therapy Selection Advanced Cancer Care >120M Average-Risk Individuals shield™ GUARDANT™ Cancer Detection >15M Early-Stage Patients and Survivors Surgery +/- Adjuvant GUARDANTREVEAL Recurrence >700K Advanced Cancer Patients INVESTOR 20 DAY 23 1st Line Tx 2nd Line Tx +TX FDA Approved GUARDANT 360CDX GUARDANT 360 GUARDANT 360 TissueNext GUARDANT 360 Response 46 46#47Comprehensive portfolio for Therapy Selection with broad payer coverage INVESTOR 20 DAY 23 GUARDANT 360CDX GUARDANT 360 GUARDANT 360 Response 1st FDA-Approved Comprehensive Liquid Biopsy Next-Generation Liquid Biopsy Assay to Monitor Tx Response 1st Blood-Only Liquid Biopsy ♡ GUARDANT™ 9 Guardant internal data on file Reimbursed by Medicare GUARDANT 360 TissueNext Next-Generation Tissue Assay ♡#48Guardant360 in lung cancer Diagnosis with metastatic CD74-ROS1- positive lung cancer Entrectinib dose escalation (800 mg) Progression in brain Progression in brain and bones I Detection of ROS1 F2004V resistance mutation Progression in bones Progression in bones and lymph nodes Detection of ROS1 L2086F resistance mutation; undetectable F2004V clone H Crizotinib Entrectinib x 10 months x 34 months Undetectable L2086F and F2004V clones Lorlatinib monotherapy x 10 months Lorlatinib plus carboplatin/pemetrexed maintenance x 34 cycles Lorlatinib plus cabozantinib x 3 months Diagnosed with NSCLC, treated with ROS1-inhibitors Guardant360 identifies acquired, targetable alterations Guardant360 used throughout continuum of care to assess ctDNA at time of clinical progression From Guardant360 results, patient treated with combination therapy Assessment of ctDNA 6 weeks after treatment initiation showed likely molecular response GUARDANT™ Sakamoto et al. JCO PO, 2023. Jacob et al. 2021.https://doi.org/10.1016/j.heliyon.2020.e03841 INVESTOR 20 DAY 23 48 48#49425+ publications supporting use of Guardant360 Partnership with Top Thought Leaders 45 NCI-Designated Comprehensive Cancer Centers involved in publication generation GU All Others Pancreatic Reimbursement 30 Publications used to obtain Medicare coverage GUARDANT Breast Colorectal 425+ Publications Multi-Cancer Lung INVESTOR 20 DAY 23 Patient Outcomes 120+ Publications with patient outcomes involving targeted therapies Changing Guidelines 38 Publications included in successful NCCN submissions 49 49#50Because precision and speed impact patients ascopubs.org/journal/po JCO® Precision Oncology An American Society of Clinical Oncology Journal CGP results in 4x better patient outcomes Every month delayed in cancer treatment can raise risk of death by around 10%¹ ] ASCO KNOWLEDGE CONQUERS CANCER + Association Between Availability of Molecular Genotyping Results and Overall Survival in Patients With Advanced Nonsquamous Non-Small-Cell Lung Cancer Charu Aggarwal, MD, MPH; Melina E. Marmarelis, MD, MSCE; Wel-Ting Hwang, PhD, Dylan G. Scholes, BS, Tara L. McWilliams, MS: Aditi P. Singh, MD; Lova Sun, MD, MSCE: John Kosteva, MD; Michael R. Costello, MD; Roger B. Cohen, MD; Corey J. Langer, MD; Abigail Doucette, MPH; Peter N. Gabriel, MD, MSE; Lawrence N. Shulman, MD, FACP; Katharine A. Rendle, PhD, MSW, MPH; Jeffrey C. Thompson, MD: Justin E. Bekelman, MD; and Erica L. Carpenter, MBA, PhD INVESTOR 20 DAY 23 Association Between Availability of Molecular Genotyping Results and Overall Survival in Patients with Advanced Nonsquamous Non-Small-Cell Lung Cancer² OS (probability) 1.00 0.75 0.50 0.25 +Available testing group + Unavailable testing group Log-rank P<.0001 H 0 6 12 18 24 30 36 No. at risk: Time (months) Available testing group Unavailable testing group 65 261 206 154 91 42 14 0 27 14 7 6 2 0 GUARDANT™ 1. Hanna T P, King W D, Thibodeau S, Jalink M, Paulin G A, Harvey-Jones E et al. Mortality due to cancer treatment delay: systematic review and meta-analysis BMJ 2020; 371 :m4087 doi:10.1136/bmj.m4087 2. Aggarwal, Charu et al. "Association Between Availability of Molecular Genotyping Results and Overall Survival in Patients With Advanced Nonsquamous Non-Small-Cell Lung Cancer." JCO precision oncology vol. 7 (2023): e2300191. doi:10.1200/PO.23.00191 50 50#51GUARDANT 360 Response Overcomes limitations of existing tools used to measure treatment response INVESTOR 20 DAY 23 Accelerated insight into treatment response Measure ctDNA change and drug efficacy earlier than standard imaging Accelerates clinical trials and drug development Advantages of a tissue-free approach Overcome logistical challenges of tissue- informed approaches, such as tissue insufficiency, increased time due to procurement, and invasive procedures Improved sensitivity and precision with methylation Guardant360 Response on the Smart Liquid Biopsy platform will provide even deeper tumor sensing and higher precision Real-time clinical decision making Rapidly assess drug efficacy, enabling fast-fail drug development model Consider alternate treatments or dosing for non-responders GUARDANT™ 51#52Guardant360 Response can determine which patients are responding to therapies sooner than CT-Scans INVESTOR 20 DAY 23 ctDNA and RECIST identify responders... Molecular responders RECIST responders ...but ctDNA identifies them 8 weeks earlier GUARDANT™ 41% 36% 33% 24% 44% 44% Study A (solid tumors) Study A (NSCLC) Study C (solid tumors) 0 7 Median of 8 weeks ctDNA response RECIST response 15#53Advancing Guardant360 TissueNext with Al-powered digital pathology INVESTOR 20 DAY 23 GUARDANT 360 TissueNext GUARDANT GALAXY PD-L1 Only tissue CGP panel with an Al-powered scoring algorithm that improves PD-L1 detection by >20% in NSCLC1 Now validated for multiple cancers² Covered by Medicare for all advanced solid tumors³ GUARDANT™ Al = Artificial Intelligence. *Compared to manual pathologist interpretation in the most challenging cases in NSCLC. Including breast, colorectal, gastric, hepatobiliary, lung, pancreatic, prostate, and urothelial cancers. 1. https://www.ejcancer.com/article/S0959-8049(22)00215-5/fulltext. 2. https://www.annalsofoncology.org/article/S0923-7534(21)01146-7/fulltext Important Note: Guardant360 TissueNext and Guardant Galaxy PD-L1 tests were developed, and their performance characteristics determined, by Lunit. These tests have not been cleared or approved by the US FDA. 3. Coverage limited to LFS for PDL-1 test. 53 53#54FDA-approved targeted therapy options are continuing to rapidly expand across solid. tumors (7) INVESTOR 20 DAY 23 (11) 89 (12) 78 71 (10) 59 (2) (11) (5) 47 49 (6) 36 (6) 31 (5) 25 (3) (2) (1) (3) 11 13 14 19 (New) Cumulative (1) (2) (1) 1 (1) 3458 2001 2003 2004 2005 2006 2007 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 GUARDANT™ Zhong et al. Signal Transduction and Targeted Therapy, 2021. 54 54#55Spotlight on ESR1 ~67%-80% of breast cancers in women are ER+, HER2-1 INVESTOR 20 DAY 23 Emerging mutation with high unmet need fueling Guardant360 CDx growth Breast cancer is the second leading cause of cancer death in women ~298k new cases and ~44k deaths estimated in 2023 alone ER+ tumors have a high likelihood of developing ESR1 mutation ESR1 mutations are present in up to 40% of ER+, HER2- advanced breast cancers² ESR1 is an emergent mutation that develops after Breast Cancer treatment occurs Patients expressing ESR1 can be put on a new class of targeted therapy ORSERDU (elacestrant) is the first FDA approved ESR1 therapy Total of 6 ESR1 programs signed to date with biopharma partners GUARDANT™ 1 National Cancer Institute https://www.cancer.gov/types/breast/breast-hormone-therapy-fact-sheet; Accessed January 11, 2023; SEER Database;. 2 Brett, J.O., Spring, L.M., Bardia, A. et al. ESR1 mutation as an emerging clinical biomarker in metastatic hormone receptor-positive breast cancer. Breast Cancer Res 23, 85 (2021). https://doi.org/10.1186/s13058-021-01462-3 55 55#56The need for therapy selection in oncology is growing rapidly GUARDANT™ Larger patient population Earlier use of therapies Expanding utility in additional cancers Greater need for biomarker testing across all cancers Treatment Window More lines of therapies More tests per patient as survival improves 99 56 INVESTOR 20 DAY 23#57Advancing Therapy Selection with Smart Liquid Biopsy Gyn 14% Research CRC Pipeline 5% Lung 17% Gyn 10% RCC 12% 22K Samples Across >10 Indications Breast 14% Prostate 17% GUARDANT™ Internal data as of September 1, 2023 Lung 20% Multiple 17% Breast 24% Spanning 6,500 Patients Multiple 21% Prostate 17% INVESTOR 20 DAY 23 57#58GUARDANT™ Paving the way for tissue-free MRD Helmy Eltoukhy, PhD co-Chief Executive Officer & Chair INVESTOR 20 DAY 23#59Screening Early Disease Detection Minimal Residual Disease Recurrence Detection & Surveillance Therapy Selection Advanced Cancer Care >120M Average-Risk Individuals shield™ GUARDANT™ Cancer Detection >15M Early-Stage Patients and Survivors Surgery +/- Adjuvant GUARDANTREVEAL Recurrence >700K Advanced Cancer Patients INVESTOR 20 DAY 23 1st Line Tx 2nd Line Tx +Tx FDA Approved GUARDANT 360CDX GUARDANT 360 GUARDANT 360 TissueNext™ GUARDANT 360 Response 59 59#60INVESTOR 20 DAY 23 GUARDANTREVEAL The only tissue-free MRD test available clinically Currently in CRC, breast and lung ✅ Upgrade to Smart Liquid Biopsy this year $20B+ U.S. market in early development 15M+ Patients <3% Patients tested today GUARDANT™ 1 ACS Cancer Treatment & Survivorship Facts & Figures 2019-2021 2 Guardant assessment based on tissue availability post diagnosis. The ACS Cancer Treatment & SurvivorshipFacts & Figures 2019-2021 states 1/3 of the 15M cancer survivors were diagnosed in the last 5 years. Tissue availability significantly decreases over time. 60#61The future of MRD is tissue-free INVESTOR 20 DAY 23 Faster Decreased initial turnaround time to inform adjuvant decision making or to start initial surveillance Easier No need for tissue access for patients in the neoadjuvant, adjuvant settings or who are years out from surgery Powerful Ability to inform clinicians. with precision, detection of heterogeneous cancers, tracking of tumor evolution and more GUARDANT™ 61#62But tissue-free detection is hard GUARDANT™ INVESTOR 20 DAY 23 How can one reliably detect cancer with high sensitivity and specificity without tissue? 62 62#63Blazing a trail for a true liquid MRD test 1 2 3 INVESTOR 20 Revolutionary Smart Liquid. Biopsy technology achieving high sensitivity with >98% clinical specificity Clinical validation on thousands of patients across dozens of tumor types to secure reimbursement Leverage existing market-leading oncology commercial infrastructure to scale with speed GUARDANT™ DAY 23 63#641 How does our Smart Liquid Biopsy technology achieve high performance for MRD? GUARDANT™ CRC Healthy 1,000+ Differentially Methylated Regions GUARDANTREVEAL (Smart Liquid Biopsy) >1,000 alterations Current Medicare- Reimbursed MRD tests 16 48 INVESTOR 20 DAY 23 Low background methylation chemistry Genome- Machine-learning + wide detection + on 1,000s of samples High sensitivity & high specificity 64#65# of patients INVESTOR 20 DAY 23 2 Clinical validation of any new MRD test requires a significant number of samples with years of follow-up # of indications 2-4 years of follow up 10,000s of clinical samples GUARDANT™ 59 65#662 Near-term Clinical Validity & Utility Cohorts Plasma Timepoints 80K MRD samples for Smart Liquid Biopsy clinical studies Gastric Pancreatic GUARDANT™ INVESTOR 20 DAY 23 Indication Description Patients CRC COSMOS >300 >2,000 10 monitoring Breast Multi-center >1000 >3,000 17 Multi-center >300 >300 Solid tumor Lung Single center >300 >700 types Breast - TNBC Single center >100 >500 Breast Mixed - Single center >200 >1,500 Multi-center >400 >2,000 18K Multi-center >400 >2,000 Patients Head & Neck Multi-center >115 >700 99 66#67GUARDANT™ INVESTOR 20 DAY 23 New data Smart Liquid Biopsy MRD 67#68COSMOS-Colon Update: Stage II/III completely resected (RO) population RFS Based on 4 Week Post-Surgery ctDNA Detection INVESTOR 20 DAY 23 Probability of Recurrence-Free Survival 100 50 +/- ACT ctDNA Not Detected (n=121) HR 10.8 (95% CI, 1.98-60.5) ctDNA Detected (n=14) 0 12 24 36 Time Since Surgery (mo) No. at risk ctDNA not detected 121 ctDNA detected 14 115 10 98 6 12 10 36M RFS (95% CI) 80% Sensitivity prior to or at recurrence 99% Specificity (sample-level) Data to be included in Medicare CRC surveillance submission No. of ctDNA status Events / Total No. Median RFS 12M RFS (95% CI) 24M RFS (95% CI) Not Detected 11/121 NR Detected 9/14 18.0mo 95.0% (89.3-97.7) 64.3% (34.3-83.3) 90.7% (83.9-94.8) 40.2% 30.1% (15.1-64.4) (8.4-56.0) 90.7% (83.9-94.8) GUARDANT™ ACT = adjuvant chemotherapy, Clinical trial information: UMIN000037765 68#69• Highlights of additional MRD studies underway INVESTOR 20 DAY 23 Near-term readouts Breast Cancer Clinical Validity Study • Post-adjuvant chemoRx cohort Submitted to San Antonio Breast Cancer Symposium (SABCS) > 300 early breast cancer patients across all subtypes • Median follow-up of 66 months • GUARDANT™ PEGASUS De-Escalation Clinical Utility Trial (Standard of Care Chemotherapy) CRC Long-term readouts TRACC Part C De-Escalation Clinical Utility Trial (Standard of Care Chemotherapy) CRC • • Ph II single-arm study Ph III randomized control trial • Data readout submitted to ESMO • Study enrollment ongoing 140 high-risk stage II & stage III colon cancer patients after surgical resection Study fully enrolled in 2022. • • 1621 high-risk stage II & stage III colon cancer patients after surgical resection Expect to complete enrollment in early 2027 69 69#703 We can tap into our 380+ Oncology, and, over time, Screening commercial teams to efficiently commercialize MRD ASP Reimbursement-gated Volume Trajectory CRC surveillance Volume 7 800 Lung Breast GUARDANT™ INVESTOR 20 DAY 23 70#71The future of oncology is one precision medicine paradigm for all patients Biomarker driven therapies move earlier INVESTOR 20 DAY 23 Early Cancer Monitoring across all stages Smart Liquid Biopsy GUARDANT More lines of therapies Advanced Cancer 71#72Imagine a future in which a simple blood test offers comprehensive molecular, spatial and prognostic information streamlining patient care GUARDANT™ 010100 101000011 0100 010101 1010091 01010 0101 010 0101010101 00101 1010101 INVESTOR 20 DAY 23 0101010100010 10100010 10101010101010 10101 01010101000000011 111110 01010 101010 0101010 1010 01001010 72#73INVESTOR 20 DAY 23 Our Smart Liquid Biopsy Platform can make that vision a reality GUARDANT™ 73#74GUARDANT™ INVESTOR 20 DAY 23 A leading commercial platform in oncology Chris Freeman Chief Commercial Officer#75Setting a new standard for patient care and customer experience GUARDANT COMPLETE™ INVESTOR 20 DAY 23 IDOLI Cutting-Edge Products GUARDANT Operational Excellence Customer Service Payer Coverage A shared commercial infrastructure across the end-to-end product portfolio 75#76Significant untapped potential in the Therapy Selection market INVESTOR 20 DAY 23 700K Total Patients $10B Total Addressable Market GUARDANT™ Sources: Therapy selection TAM is Stage IV patients., Data from internal modeling that sources information from US Cancer Statistics; SEER, Cancer MPact®, NODA data, Treatment Architecture, peer-reviewed literature, and Guardant Health data on file. 76#77Guardant360 has established footholds in the major tumor types for Therapy Selection GUARDANT 19% NSCLC 240K 21% 15% Breast CRC 119K Total Patients TAM is Stage IV patients, Data from internal modeling that sources information from US Cancer Statistics; SEER, Cancer MPact®, NODA data, Treatment Architecture, peer-reviewed literature, and Guardant Health data on file. 103K INVESTOR 20 DAY 23 77#78Therapy Selection utilization will continue to grow 1 2 3 INVESTOR 20 DAY 23 Increase liquid and tissue adoption Unlock new actionable biomarkers and use cases Physicians are using CGP testing in earlier lines GUARDANT™ 78#79Industry-leading product portfolio with revolutionary technology GUARDANT 360CDX 1st FDA-Approved Comprehensive Liquid Biopsy GUARDANT 360 Next-Generation Liquid Biopsy Assay GUARDANT GUARDANTREVEAL 1st Blood-Only Recurrence Monitoring Assay Reimbursed by Medicare INVESTOR 20 DAY 23 GUARDANT 360 TissueNext Next-Generation Tissue Assay GUARDANT 360 Response 1st Blood-Only Liquid Biopsy to Monitor Tx Response 79#80Portfolio offering provides strategic advantage +139% INVESTOR 20 DAY 23 2020 GUARDANT™ 2021 2022 H1 2023 Market adoption of concurrent blood and tissue testing 69% Of oncologists choose their testing partner based on "one-stop-shop" ordering¹ *Stated use of liquid and tissue CGP prior to 1L NSCLC treatment. 2019-2022 are averages. 2023 includes Q1 and Q2 data. 1. Guardant360 Brand Tracker, Q2 2023. 80#81Guardant innovations have helped influence ~500K cancer care decisions GUARDANT™ INVESTOR 20 DAY 23 2016 2017 2018 2019 2020 2021 2022 81#82Best-in-class products are supported with best-in-class operations INVESTOR 20 DAY 23 5 days Median Guardant360 CDx turnaround time1 >60% of oncologists are motivated by a FAST turnaround time when choosing a testing partner² #1 Industry leading turnaround time for an FDA approved CGP GUARDANT™ 1. Guardant Health, data on file. 2. Guardant360 Brand Tracker, Q2 2023. 82#83Actionable information and speed saves patient lives INVESTOR 20 DAY 23 Association Between Availability of Molecular Genotyping Results and Overall Survival in Patients with Advanced Nonsquamous Non-Small-Cell Lung Cancer 4x Better patient outcomes with CGP testing 1.00 0.75 Every month delayed in cancer treatment can raise risk of death by around 10%¹ GUARDANT™ OS (probability) 0.50 0.25 + Available testing group + Unavailable testing group Log-rank P<.0001 0 6 12 18 24 30 36 Time (months) ASCO JCO® ascopubs.org/journal/pa Precision Oncology An American Society of Clinical Oncology Journal Association Between Availability of Molecular Genotyping Results and Overall Survival in Patients With Advanced Nonsquamous Non-Small Cell Lung Cancer Chau Aggarwal MD, MPH Melina E. Mamares, MD, MSCE. We-Ting Hwang Pho: Dylan G. Schelee, BS: Tara McWilliams, MS AP Singh, MD: Love Sun MD, MSCE: John Kosteva, MD. Michael F. Castelo, MD: Roger B Cohen MD: Carey J Langer ND Abigail On al Doccetic, MPH Peter N Gabriel, MD, MBE Lawrence N Shulman, MD, FACP Katharine A. Rende, PRO. MSW. MPH, Jettrey C. Thomson MD. Justin E. Sekian, MO, and Erica L Carpe MBA PO 1. Hanna T P, King W D, Thibodeau S, Jalink M, Paulin G A, Harvey-Jones E et al. Mortality due to cancer treatment delay: systematic review and meta-analysis BMJ 2020; 371 :m4087 doi:10.1136/bmj.m4087 2. Aggarwal, Charu et al. "Association Between Availability of Molecular Genotyping Results and Overall Survival in Patients With Advanced Nonsquamous Non-Small-Cell Lung Cancer." JCO precision oncology vol. 7 (2023): e2300191. doi:10.1200/PO.23.00191 83#84Commercial excellence begins with a world-class field team Key Account Team Research & Collaborations Managed Care Client Services Unified CRM Platform Field Sales Account Level Integration Medical Affairs Marketing INVESTOR 20 DAY 23 Genomic Specialists lili p MIX Remote Share of Voice1 #1 Share Share of Voice1 #1 #1 Rated Field Team1 #1 Support¹ Rated #1 In-Person GUARDANT 1. Guardant360 Brand Tracker Q2 2023; 250+ team rated first in customer satisfaction by HCPs for past 7 quarters; 50% more oncology interactions compared to closest CGP company. *Growth is ordering oncologists/quarter 84#85EMR integration accelerates access to critical information INVESTOR 20 DAY 23 AiKnowMed™ Clinical Information Solutions Epic ONCOEMR Our EMR partnerships will cover 65% of all oncologists in the U.S.1 EMR integration reduces oncologist ordering time by 75%2 Guardant will be EMR integrated in >400 accounts by end of 2023 GUARDANT™ 1. Guardant Health data on file 2. Lao-Min KS et al 85 595#86Broad coverage provides seamless access for patients INVESTOR 20 DAY 23 300M+ Covered lives for Guardant360 Approaching 200M Covered lives for TissueNext GUARDANT ❤aetna Cigna. FLORIDA blue california for Multi-Cancer Horizon HUMAN South Carolina SERVICES USA United Healthcare Humana. Medicare BlueCross Regence CareFirst MASSACHUSETTS UPMC BlueShield Association eviCore healthcare CONCERT GENETICS Geisinger Priority Health AIM Specialty Health. Elevance Health 98 86#87Guardant has created momentum for National Biomarker Testing Coverage INVESTOR 20 DAY 23 In many cases will support private payer coverage for both Therapy Selection and MRD GUARDANT™ As of August 13, 2023 State Biomarker Legislation Enacted (signed into law) Passed legislation (pending gubernatorial action) In current legislative process Introduced but did not advance 12 states enacted laws for biomarker testing 5+ states have current legislation in progress 87#88MRD market is largely untapped INVESTOR 20 DAY 23 15M+ $20B+ <3% Total Patients Total Addressable Market Current Testing Penetration GUARDANT™ Early + late stage monitoring TAM inclusive of stages II-IV and some stage I, depending on cancer type Revenue is based on 2026 projected ASP 88#89INVESTOR 20 DAY 23 MRD business can leverage the commercial infrastructure of Therapy Selection to scale at speed + Customer ☑ Access to Data EMR Integration + Key Account partnership Back End Operations Portal + Digital Ordering Sales & Dedicated Support Team Guardant Access Program + Managed Care Mobile Phlebotomy GUARDANT™ Customer base of 12,000 Oncologists 1. Guardant Health Brand Tracker, Q2 2023 #1 Field Force + Customer Satisfaction1 89#90Commercial excellence unlocks additional growth opportunities INVESTOR 20 DAY 23 GUARDANT COMPLETE™ GUARDANT™ Integrated account-level Biopharma collaborations partnerships Global expansion 00 90#91Biopharma partnerships fuel clinical growth INVESTOR 20 DAY 23 160+ Lifetime biopharma partners Including 19 of top 20 pharma Multiple active CDx collaborations CDX approvals help drive clinical growth (e.g., ESR1 for breast cancer) GUARDANT™ 91 17#92Global commercial organization INVESTOR 20 DAY 23 SEATTLE, WA REDWOOD CITY, CA PALO ALTO, CA SAN DIEGO, CA Guardant Health Inc. Countries with Reimbursement Coverage Countries with Testing Available GUARDANT™ SPRING, TX Partnership UK with Royal Marsden' Hospital London SPAIN Partnership with Vall d'Hebron Barcelona SINGAPORE Guardant Health AMEA HQ JAPAN 60+ Countries Partnership with Adicon Shanghai CHINA Guardant Health Japan Tokyo Lab footprint Spain, UK, China & Japan 380+ Oncology commercial team 92 92#93National reimbursement in Japan & lab launch in China taps into large global market Japan Potential for rapid growth: 1M new cancer cases per year¹, centralized care, <10% penetration of CGP market² Driving business: National reimbursement approval from the Japanese MHLW for Guardant360 CDx + efficient local sales model + strong ASP China Point of differentiation: China is a critical, strategic market for biopharma partnerships Strategic partnership for growth: 30+ biopharma clients have engaged with Guardant since partnership with Adicon lab INVESTOR 20 DAY 23 GUARDANT 93 1.International Agency for Research on Cancer. Japan. Globocan 2020. https://gco.iarc.fr/toaday/data/factsheets/populations/392-japan-fact-sheets.pdf 2. Japan C-CAT database#94Commercial excellence positions Guardant to lead the future of oncology testing INVESTOR 20 DAY 23 #1 ♡ Liquid biopsy CGP market share¹ Field team overall satisfaction² Share of voice1 1. Guardant360 Brand Tracker Q4 2022; 250+ team rated first in customer satisfaction by HCPs for past 7 quarters; 50% more oncology interactions compared to closest CGP company. *Growth is ordering oncologists/quarter and tests per oncologist/quarter, 2 Q2 2023 Brand Tracker 94#95GUARDANT™ Q&A INVESTOR 20 DAY 23#96GUARDANT™ Pioneering a new category of cancer screening AmirAli Talasaz, PhD co-Chief Executive Officer & co-Founder INVESTOR 20 DAY 23#97Screening Early Disease Detection Minimal Residual Disease Recurrence Detection & Surveillance Therapy Selection Advanced Cancer Care >120M Average-Risk Individuals shield™ GUARDANT™ Cancer Detection >15M Early-Stage Patients and Survivors Surgery +/- Adjuvant GUARDANTREVEAL Recurrence >700K Advanced Cancer Patients INVESTOR 20 DAY 23 1st Line Tx 2nd Line Tx +Tx FDA Approved GUARDANT 360CDX GUARDANT 360 GUARDANT 360 TissueNext™ GUARDANT 360 Response 97#98Blood-based screening will change the cancer screening landscape Metastatic 14% Survival Statistics from 26 different cancers comprising 87% of all cancers in U.S. QA ☑ INVESTOR 20 Pleasant Consumer Experience High Performance MCED Test Local 90% Survival Regional 65% Survival DAY 23 GUARDANT Sources: SEER.cancer.gov.. Siegel, et al. Cancer statistics, 2023. CA Cancer J Clin. 2023;73:17-48 98#99A successful screening modality requires four components GUARDANT™ 1 2 INVESTOR 20 DAY 23 High performance in detecting early- stage cancer Broad reimbursement & access Positive unit economics to scale 4 Patient preference 3 99 99#1002 INVESTOR 20 DAY 23 The future of screening is a high- performance blood-based test for multi-cancer 1 High performance in detecting early- stage cancer Positive unit economics to scale shield™ Broad reimbursement & access Patient preference 3 GUARDANT™ 4 100#101We strategically started with CRC as the first indication for Shield GUARDANT™ INVESTOR 20 DAY 23 2 Demonstrated high performance in detecting early- stage cancer 1 shield™ Established reimbursement pathway Positive unit economics to scale 4 CRC Clear patient preference for blood 3 101#102Lack of screening compliance significantly impacts lives lost to colorectal cancer INVESTOR 20 DAY 23 GUARDANT™ 50K Colorectal cancer deaths per year 1,2 76% of CRC deaths are in individuals not up to date with screening³ 1. Bibbins-Domingo K, et al; JAMA. 2016;315(23):2564-2575. 2. US Preventive Services Task Force. Screening for Colorectal Cancer: US Preventive Services Task Force Recommendation Statement. JAMA. 2021;325(19):1965-1977. doi:10.1001/jama.2021.6238 3. Doubeni CA, et al. Gastroenterology. 2019;156(1):63-74.e6 102#1032 INVESTOR 20 DAY 23 Smart Liquid Biopsy analyzes 1,000s of regions in cfDNA with leading sensitivity at low-cost 1 High performance in detecting early- stage cancer Positive unit economics to scale shield™ Broad reimbursement & access Patient preference 3 GUARDANT™ 4 103#104Shield is the first easy to use, highly accurate blood- based cancer screening test with proven efficacy in a pivotal trial GUARDANT™ INVESTOR 20 DAY 23 shield™ A new screening category 104#105ECLIPSE trial demonstrated efficacy 83% CRC Sensitivity 90% Specificity INVESTOR 20 DAY 23 ● 100% sensitivity stage II and stage III/IV • 81% CRC sensitivity at stage | - ||| • 55% sensitivity stage I ● 13% advanced adenoma sensitivity GUARDANT™ Source: Chung, D., Gray, D. M., Greenson, J., Gupta, S., Eagle, C., Hu, S., Talasaz, A., Issaka, R. B., Singh, H., Sinicrope, F. A., & Grady, W. (2023). 913e Clinical validation of a cell-free DNA blood-based test for colorectal cancer screening in an average risk population. Gastroenterology, 164(6), S. https://doi.org/10.1016/S0016-5085(23)04760-1 105#106Shield CRC performance is in range with other non-invasive guideline-recommended modalities INVESTOR 20 DAY 23 74-92% CRC sensitivity for current guideline-recommended tests 1,2 87-96% Specificity for current guideline-recommended tests 1,2 GUARDANT™ 1. Imperiale, et al. 2014. NEJM; 2 Knudsen, et al. 2021. JAMA 106#107Broad and equitable access is key to durable adoption and outcome improvements GUARDANT™ 1 2 INVESTOR 20 DAY 23 High performance in detecting early- stage cancer Positive unit economics to scale shield™ Broad reimbursement & access Patient preference 3 4 107#108Reimbursement pathway for Multi-Cancer Shield starts with colorectal cancer indication GUARDANT™ A shield Multi-Cancer ✓ shield CRC INVESTOR 20 DAY 23 108#109Reimbursement pathway for Shield starts with colorectal cancer indication INVESTOR 20 DAY 23 >shield™ CRC Clear pathway starting with CRC Medicare Coverage Blood-based CRC screening NCD with 3-year interval Private Coverage ACS and USPSTF guidelines Access ~120M individuals National Coverage Determination (NCD) Colorectal Cancer Screening Tests 210.3 Expand All | Collapse All Effective for dates of service on or after January 19, 2021, a blood-based biomarker test is covered as an appropriate colorectal cancer screening test once every 3 years for Medicare beneficiaries when performed in a Clinical Laboratory Improvement Act (CLIA)-certified laboratory, when ordered by a treating physician and when all of the following requirements are met: The patient is: ⚫ age 50-85 years, and, asymptomatic (no signs or symptoms of colorectal disease including but not limited to lower gastrointestinal pain, blood in stool, positive guaiac fecal occult blood test or fecal immunochemical test), and, at average risk of developing colorectal cancer (no personal history of adenomatous polyps, colorectal cancer, or inflammatory bowel disease, including Crohn's Disease and ulcerative colitis; no family history of colorectal cancers or adenomatous polyps, familial adenomatous polyposis, or hereditary nonpolyposis colorectal cancer). The blood-based biomarker screening test must have all of the following: • Food and Drug Administration (FDA) market authorization with an indication for colorectal cancer screening; and, ⚫proven test performance characteristics for a blood-based screening test with both sensitivity greater than or equal to 74% and specificity greater than or equal to 90% in the detection of colorectal cancer compared to the recognized standard (accepted as colonoscopy at this time), as minimal threshold levels, based on the pivotal studies included in the FDA labeling National Coverage Determination by CMS GUARDANT™ 109#110USPSTF recommendations are based on the harms and benefits of each testing modality Lifetime Colonoscopies and Life-Years Gained Real-world longitudinal adherence model for simulated cohort Model Parameters INVESTOR 20 DAY 23 Life-Years Gained per 1,000 individuals 300 250 200 150 100 50 Colonoscopy Shield mts DNA FIT 0 0 500 1000 1500 Colonoscopies per 1,000 individuals Screening CRC Interval 1-3 Specificity 2,3 Sensitivity2,3 One-Time Adherence 3-6 Colonoscopy 10 years 95% 86% 38% FIT 1 year 74% 96% 43% mtsDNA 3 years 92% 90% 65% shield™ 3 3 years 83% 90% 90% 2000 2500 1. Knudsen AB et al. "Colorectal Cancer Screening: An Updated Decision Analysis." USPSTF [Internet]. 2021. 2. Knudsen AB et al.. Estimation of benefits, burden, and harms of colorectal cancer screening Immunochemical Test Outreach on Colorectal Cancer Screening Completion: A Randomized Clinical Trial." JAMA 318, no. 9 (05 2017): 806-15. 5. J.P. Morgan Healthcare Conference 2018. 6. Akram A et al. "Replacing the Guaiac Fecal Occult Blood Test With the Fecal Immunochemical Test Increases Proportion of Individuals Screened in a Large Healthcare Setting." Clinical Gastroenterology and Hepatology 15, no. 8 (August 2017): 1265-1270.e1. GUARDANT strategies: modeling study for the US Preventative Services Task Force. Jama. 2016 Jun 21;315(23):2595-609. 3. Guardant Health Internal Data. 4. Singal AG et al. "Effect of Coloscopy Outreach vs Fecal 110#111Outcome model demonstrates that Shield has the highest averted rate of CRC deaths Lifetime Colonoscopies & CRC Deaths Averted Real-world longitudinal adherence model for simulated cohort Model parameters INVESTOR 20 DAY 23 CRC death averted per 1,000 individuals 16 14 12 10 10 8 6 4 2 FIT 0 0 500 Shield mts DNA 1000 1500 Colonoscopy Colonoscopies per 1,000 individuals Screening Interval1-3 CRC Sensitivity2,3 Specificity2,3 One-Time Adherence 3-6 Colonoscopy 10 years 95% 86% 38% FIT 1 year 74% 96% 43% mtsDNA 3 years 92% 90% 65% shield™ 3 years 83% 90% 90% 2000 2500 1. Knudsen AB et al. "Colorectal Cancer Screening: An Updated Decision Analysis." USPSTF [Internet]. 2021. 2. Knudsen AB et al.. Estimation of benefits, burden, and harms of colorectal cancer GUARDANT screening strategies: modeling study for the US Preventative Services Task Force. Jama. 2016 Jun 21;315(23):2595-609. 3. Guardant Health Internal Data. 4. Singal AG et al. "Effect of Coloscopy Outreach vs Fecal Immunochemical Test Outreach on Colorectal Cancer Screening Completion: A Randomized Clinical Trial." JAMA 318, no. 9 (05 2017): 806-15. 5. J.P. Morgan Healthcare Conference 2018. 6. Akram A et al. "Replacing the Guaiac Fecal Occult Blood Test With the Fecal Immunochemical Test Increases Proportion of Individuals Screened in a Large Healthcare Setting." Clinical Gastroenterology and Hepatology 15 no 8 (August 2017): 1265-1270 e1 111#112Blazing a trail to the first FDA approved and reimbursed CRC screening test INVESTOR 20 DAY 23 Launched Shield LDT ECLIPSE Readout Filed PMA with FDA Published staging data at DDW Launch Shield IVD-CRC TM shield May 2022 4Q' 22 1Q' 23 2Q' 23 2024 GUARDANT™ CRC Drives Medicare reimbursement with $0 co-pay Medicare & ADLT Status ACS Guidelines USPSTF Guidelines ADLT Pricing 2026 State-level payer reimbursement opportunity Drives private payer reimbursement with $0 co-pay 112#1132 INVESTOR 20 DAY 23 People want a more pleasant and convenient cancer screening option 1 High performance in detecting early- stage cancer Positive unit economics to scale shield™ Broad reimbursement & access 3 GUARDANT™ 4 Patient preference 113#114Successful screening requires both adherence and performance 120M Avg Risk Individuals Ages 45 - 851 Adherence Colonoscopy FIT Cologuard 38% 2 43% 3 65%4 70M Screened Individuals 5 INVESTOR 20 DAY 23 50M Unscreened Individuals5 X GUARDANT™ 1. AACR Study, Cancer Prev Res (2020) 13 2. Singal AG, Gupta S, Skinner CS, et al. Effect of Colonoscopy Outreach vs Fecal Immunochemical Test Outreach on Colorectal Cancer Screening Completion: A Randomized Clinical Trial. JAMA. 2017;318(9):806-815. doi:10.1001/jama.2017.11389 3. Cancer Prevention Research. Impact of Patient Adherence to Stool-Based Colorectal Cancer Screening and Colonoscopy Following a Positive Test on Clinical Outcomes, https://aacrjournals.org/cancerprevention research/article/14/9/845/666815/Impact-of-Patient-Adherence-to-Stool-Based [aacrjournals.org.. ACS Colorectal Cancer Facts 2020-2022, 4. EXACT Sciences presentation at Goldman Sachs 44th Annual Global Healthcare Conference, June 2023 5. ACS Colorectal Cancer Facts 2020-2022 114#115Shield addresses existing challenges to CRC screening Challenges in CRC screening 1-3 Addressed by Shield Long Colonoscopy wait times. Unpleasant experience Time consuming, multi-step patient participation INVESTOR 20 DAY 23 Simple blood draw GUARDANT™ 1. US Preventive Services Task Force. JAMA. 2021;325(19):1965-1977 2. Muthukrishanan M, et al. Prev Med Rep. 2019;15:00896. 3. Melson JE, et al. Clin Gastroenterol Hepatol. 2020 Nov;18(12):2667-2678.e2. 3. US Preventive Services Task Force. JAMA. 2021;325(19):1965 115#116INVESTOR 20 DAY 23 A new category of test will address the unmet need for patient preference 7 out of 10 Individuals who had a stool test would NOT choose stool again¹ Ⓒ 5 to 1 Unscreened individuals prefer blood over stool¹ D 90% Patient adherence to Shield LDT in >10K patients across >1,000 clinics² GUARDANT™ 1.2022 Patient Segmentation Market Research Survey, conducted by Guardant Health 2. Guardant data on file 116#117INVESTOR 20 DAY 23 Screening eligible individuals regularly engage with healthcare providers Blood-based screening is patient preferred and fits seamlessly into routine care Doctors visit for any reason in the last 12 months1 GUARDANT™ Ages 50 - 64 Ages 65+ 87% 95% Blood draw in the 85% last 12 months² 1.https://wwwn.cdc.gov/NHISDataQueryTool/SHS_adult/index.html. 2. Guardant Patient Segmentation, Q3 2022, N=1932 117#118Our technology, combined with a patient preferred modality, allows for a scalable business GUARDANT™ 2 INVESTOR 20 DAY 23 1 High performance in detecting early- stage cancer Positive unit economics to scale shield™ Broad reimbursement & access Patient preference 3 4 118#119Favorable gross margin pathway enabled by Medicare ADLT pricing $500 ASP One-year post-FDA approval, enabled by favorable ADLT pricing for Medicare beneficiaries $200 COGS INVESTOR 20 DAY 23 When processing 1 million samples per year, enabled by Shield technology and high-throughput automation GUARDANT™ These numbers are approximate based on internal modeling 119#120High adherence and patient preference. drives ~40% increased S&M productivity INVESTOR 20 DAY 23 [] cologuard shield™ Orders Placed 100 100 Adherence Orders Resulted 65%¹ 90%2 65 90 GUARDANT™ 1. 4. EXACT Sciences presentation at Goldman Sachs 44th Annual Global Healthcare Conference, June 2023 2. Guardant data on file 120#121Targeted commercial strategy for Shield launch in 2024 INVESTOR 20 DAY 23 High concentration of Medicare lives Maximize ASP States with coverage mandates post ACS guidelines GUARDANT™ *American Cancer Society (ACS) 누 Strong utilization of non-invasive screening Phlebotomy access Maximize efficiency & productivity 121#122Milestone-gated commercial roadmap to a blockbuster diagnostic brand At FDA approval 100-150 field team At USPSTF inclusion 300 field team At scale 700 field team INVESTOR 20 DAY 23 shield™ GUARDANT™ 122#1232 INVESTOR 20 DAY 23 Scalable commercial growth enables continuous improvement through data, biobank, clinical insights and real- world evidence 1 High performance in detecting early- stage cancer Positive unit economics to scale shield™ Broad reimbursement & access Patient preference 3 GUARDANT™ 4 123#124INVESTOR 20 DAY 23 Upgraded algorithm with demonstrated improved analytical sensitivity in detecting tumor signals at ~2x lower levels shield™ Version 2 GUARDANT™ 124#125GUARDANT™ INVESTOR 20 DAY 23 New data Shield V2 clinical data 125#126Clinical sensitivity of Shield V2 in a U.S.- based colonoscopy-screened cohort Prospective Study Results CRC Sensitivity N = 45 Specificity N = 1,458 INVESTOR 20 Sensitivity in Stage I/II: DAY 23 Shield CRC V1 - PMA device 84% (38/45) 91% Shield CRC V2 91% (41/45) 91% ECLIPSE CRC Sensitivity N = 65 83% GUARDANT Source: Guardant internal data Specificity N = 6,680 90% V1: 76% (19/25) V2: 88% (22/25) Similar AA performance 126#127Continuous improvement of Shield IVD - best-in-class blood-based CRC screening INVESTOR 20 DAY 23 TM shield GUARDANT™ *Pending successful regulatory-grade data readout for V2. Submit V2 supplemental PMA following approval of Shield* Potential for V2 approval in 2025 127#128Next step to Multi-Cancer is adding lung indication INVESTOR 20 DAY 23 GUARDANT™ D shield Multi-Cancer shield CRC + Lung shield™ CRC 128#129TM shield INVESTOR 20 DAY 23 Same test. Simple software upgrades. Enables new cancer indications. 129#130Reinventing screening for lung cancer with a simpler and accessible option 150K Lung cancer deaths 86% INVESTOR 20 DAY 23 12M per year, leading cause of cancer-related death¹ Of eligible individuals are unscreened1 Unscreened individuals² GUARDANT 1. Jonas DE, Reuland DS, Reddy SM, et al. Screening for Lung Cancer With Low-Dose Computed Tomography: An Evidence Review for the U.S. Preventive Services Task Force [Internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2021 Mar. (Evidence Synthesis, No. 198.) Available from: https://www.ncbi.nlm.nih.gov/books/NBK568573/ 2. American Lung Association: https://www.lung.org/media/press-releases/state-of-lung-cancer-2022#:~:text=The%202022%20%E2%80%9CState%20of%20Lung,rates%20as%20low%20as%201%25 130#131On track to complete Shield-Lung enrollment in 2025 >7K Currently enrolled Enrolling individuals who meet USPSTF Criteria for High-Risk Lung Cancer Screening1 Negative for lung cancer + One-year follow-up Low- dose CT + Lung cancer First endpoint readout in 2026 GUARDANT™ 1. Nguyen, et al. 2023. Screening for high frequency malignant disease (SHIELD)J Clin Oncol 41, 2023 (suppl 16; abstr TPS1610). 2.https://clinicaltrials.gov/study/NCT05117840 INVESTOR 20 DAY 23 131#132888 Enrolling 10,000 cancer-free individuals (+ Prospective interventional multi-cancer detection study IIDMA.... 2H 2024 Expected first patient enrollment Cancer Confirmed GUARDANT™ Diagnostic Evaluation Cancer Not Confirmed INVESTOR 20 DAY 23 Clinical Follow-up 2-Year Clinical Follow-up 132#133Blazing a trail to the first FDA approved and reimbursed Multi-Cancer test INVESTOR 20 DAY 23 shield GUARDANT TM CRC Lung Launched Shield LDT ECLIPSE Readout May 2022 4Q' 22 Filed PMA with FDA 1Q' 23 Staging data at DDW Launch Shield IVD-CRC 2Q' 23 2024 Multi-Cancer Drives NCD Medicare Reimbursement Medicare & ADLT Status ACS Guidelines ADLT Pricing Late 2023 / mid-2024 NCIRE-LUNG prospective study Readout 2024 USPSTF Guidelines 2026 State-level payer reimbursement opportunity Drives private payer reimbursement Starting enrollment in Multi-Cancer study 2025 2026 Complete Shield- Lung Enrollment Submit for FDA approval Shield-Lung 133#134A once in a lifetime opportunity to reinvent cancer screening GUARDANT™ INVESTOR 20 DAY 23 134#135GUARDANT™ Seeing deeper with epigenomics Dr. Justin Odegaard Vice President, Product Development INVESTOR 20 DAY 23#136GUARDANT™ Research Focus Epigenomics Single-cell method development High-throughput biochemistry Bioinformatics for understanding gene regulation Dr. William Greenleaf Professor of Genetics, Stanford University INVESTOR 20 DAY 23#137GUARDANT™ INVESTOR 20 DAY 23 Research Focus Epigenetic cfDNA-based biomarkers for advanced cancer patients Epigenetic mechanisms of therapeutic response and resistance in Prostate Cancer Dr. Jacob Berchuck Assistant Professor of Medicine, Harvard Medical School#138GUARDANT™ Research Focus Innovative biomarkers in lung cancer Liquid-biopsy assay development Data science Dr. Simon Heeke Assistant Professor, MD Anderson Cancer Center INVESTOR 20 DAY 23#139GUARDANT™ Research Focus Diabetes and pancreatic cancer Epigenetic liquid biopsies DNA methylation clocks Dr. Yuval Dor Professor, The Hebrew University of Jerusalem INVESTOR 20 DAY 23#140Today's panelists INVESTOR 20 DAY 23 Dr. Will Greenleaf Professor Dr. Jacob Burchuck Assistant Professor Stanford MEDICINE GUARDANT™ Dr. Simon Heeke Assistant Professor Dr. Yuval Dor Professor HARVARD MEDICAL SCHOOL THE UNIVERSITY OF TEXAS MD Anderson Cancer Center Making Cancer History THE HEBREW UNIVERSITY OF JERUSALEM 140#141GUARDANT™ INVESTOR 20 DAY 23 Balancing rapid revenue growth with financial discipline Mike Bell Chief Financial Officer#142Historical revenue growth fueled by core Therapy Selection business 49% Total Revenue CAGR $91M $214M $287M $450M $374M INVESTOR 20 Therapy Selection growth drivers Reimbursement coverage Regulatory approvals Clinical data Commercial strength Biopharma partnerships Portfolio expansion DAY 23 2018 2019 2020 2021 2022 GUARDANT™ 142#14388K 63K INVESTOR 20 DAY 23 125K Guardant360 has been the primary volume growth driver 29K 50K 2018 2019 2020 2021 2022 26K 10K 21K 19K 16K 2018 2019 2020 2021 2022 GUARDANT™ 44% Clinical Testing Volume CAGR 26% Biopharma Testing Volume CAGR 143#144Strong revenue growth and major Therapy Selection tailwinds in 1H 2023 $266M $205M 30% Total Revenue YoY Growth Recent Highlights INVESTOR 20 DAY 23 Guardant360 CDx breast FDA approval Guardant360 expanded reimbursement GUARDANT™ 1H 2022 1H 2023 Guardant360 Japan reimbursement Response Medicare coverage EMR integrations 144#145Therapy Selection has multiple growth drivers well beyond 2023 INVESTOR 20 DAY 23 Portfolio ASP increases GUARDANT 360 CDX GUARDANT 360 TissueNext GUARDANT 360 Response Future Guardant360 CDx approvals TissueNext & Response attachment GUARDANT - $ Market expansion GUARDANTINFINITY Infinity offering to biopharma partners International expansion, e.g., Japan, UK, China 145#146Leveraging existing infrastructure will enable Therapy Selection profitability INVESTOR 20 DAY 23 • Commercial • 380+ oncology commercial team • 160+ biopharma partnerships Regulatory Proven IVD and reimbursement expertise • Robust, well-established quality systems Operations Scaled logistical and operational backbone Existing lab capacity for future growth | || Research & Development Clinical data development engine Unified platform strategy International In-country operations Top-tier ex-US partners: UK, Spain, China Therapy Selection on track to be cash flow breakeven by YE 2023 GUARDANT™ 146#147FY 2023 financial targets focused on revenue growth and financial discipline INVESTOR 20 DAY 23 Revenue $545-$550M 21% -22% y/y growth OpEx < FY 2022 Leveraging existing infrastructure Free Cash Flow ~($350M) Reducing cash burn GUARDANT™ 147 Guidance issued on Q2 2023 earnings call August, 3, 2023. Free cash outflow is defined as net cash used in operating activities plus the cash outflow resulting from the purchase of property and equipment.#148Focus on Reveal reimbursement to increase ASP and accelerate volumes INVESTOR 20 DAY 23 2023 ASP GUARDANT™ Volume Incremental ASP Highly efficient MRD Business Model leveraging existing Therapy Selection. infrastructure 2028 from CRC ASP surveillance, lung, breast, etc. Hig Commercial Operations Medical Affairs Development International 148#1495-year financial targets for Therapy Selection & MRD INVESTOR 20 DAY 23 Revenue Growth >20% Combined Therapy Selection & MRD revenue CAGR (Total revenue excluding Screening) OpEx & CapEx $ Clinical ASPs by 2028 % Gross Margins . G360 > $3,000 Tissue > $2,000 • Response >$1,000 60-70% Combined Therapy Selection & MRD gross margin (Gross margin excluding screening) Reveal $1,000 $ Cash Flow • Leverage existing infrastructure • Therapy Selection cash flow breakeven end of 2023 GUARDANT™ • Combined Therapy Selection & MRD generates positive cash flow over cumulative 5-year period (Cash flow excluding Screening) 149#150Shield is poised to be a blockbuster diagnostic brand 2024 FDA approval Medicare reimbursement shield™ GUARDANT™ 2026 USPSTF Guidelines 2028 >1M tests >$500M revenue Highly efficient S&M spend Significant economies of scale as volume grows INVESTOR 20 DAY 23 150#151Balancing rapid Shield growth with measured spend over next 5 years Annual cash burn ~$200M over 5 years INVESTOR 20 DAY 23 • • $ ASP > $500 Medicare ADLT rate Incremental private payer coverage based on ACS recommendations Full private payer coverage following USPSTF guidelines GUARDANT™ R&D Lung and MCED • % Gross Margins Positive 1 year post launch . ~60% at 1M annual volume CapEx Low cost, high volume, automated lab operations Phased CapEx investments Leverage Smart Liquid Biopsy platform SG&A • Efficient sales & marketing model / milestone gated investments Leverage Guardant back-office infrastructure 151#1525-year total revenue targets. INVESTOR 20 DAY 23 GUARDANT™ >30% 5 Year CAGR >$2B In 2028 152#153Current cash provides runway to reach cash flow breakeven GUARDANT™ INVESTOR 20 DAY 23 Cash Flow YE Cash >$1B Breakeven 2023 2024 2025 2026 2027 2028 <$(350m) • Five Year Total Cash Burn <$1B Therapy Selection breakeven end of 2023 Combined Therapy Selection + MRD generates positive cash flow over cumulative 5-year period • Screening ~$200m annual cash burn 153#154INVESTOR 20 DAY 23 Grow profitable Therapy Selection business. Key financial targets Expand MRD reimbursement to increase ASP and accelerate volumes Balance rapid Screening revenue growth with measured spend Achieve >30% total revenue 5-year CAGR and >$2B in 2028 GUARDANT™ Reach cash flow breakeven by end of 2028 154#155GUARDANT™ INVESTOR 20 DAY 23 The future of transforming cancer care and beyond... Helmy Eltoukhy, PhD co-Chief Executive Officer & Chair AmirAli Talasaz, PhD co-Chief Executive Officer & co-Founder#156Cancer is not a linear journey Our ecosystem of tests will MRD synergistically work together GUARDANT™ Screening Therapy Selection INVESTOR 20 DAY 23 156#157Biologically rich data [000000] XXXXXX XXXXXX Mutations Chromosomal rearrangements Copy number aberrations -CH3 Methylation XXXXXXX XXXXXXX XXXXXXXXXXXX CH3 XXXXXX DNA fragment lengths INVESTOR 20 DAY 23 Comprehensive longitudinal characterization of tumor, whole body epigenomic profiles and immune response TSS Read depth coverage (tumor) Gene expression NNNNNNNNNA XXXXXX Virus sequences detection GUARDANT™ Figure from https://www.nature.com/articles/s41416-020-01047-5 Clinical relevance of blood-based ctDNA analysis: mutation detection and beyond 157#158INVESTOR 20 DAY 23 The power of genomic and epigenomic data is amplified by connections to real-world evidence GUARDANTINFORM >90% TM of commercial samples are linked to associated medical claims data1 Comorbidities Lines of therapy Treatment history ☆ Disease progression Time to next treatment × Treatment discontinuation Survival GUARDANT™ 1. Guardant INFORM database, Q3 2023 158#159INVESTOR 20 DAY 23 ASCO Daily News Clinical News From the American Society of Clinical Oncology Real-World Analysis Shows Utility of ctDNA Kinetics in Patients With Advanced Colorectal Cancer Real-world evidence from GuardantINFORM has been successfully used to validate novel signatures 10- 0.8 0.6 0.4 0.2 0.0 -responder -nonresponder 10- 0 200 400 600 800 1000 1200 timeline 0.8 0.6 0.41 20 0.2- responder nonresponder 0.0- 0 100 200 300 400 500 600 timeline Kaplan-Meier in molecular responders vs non-responders for patients receiving chemotherapy +/- VEGF. GUARDANT™ Kasi et al. Use of circulating tumor DNA (ctDNA) for early assessment of treatment response in patients with advanced colorectal cancer (mCRC): A real-world (RW) analysis. ASCO GI, 2023 159#160Data generation at scale ♡ Single Platform Scalable Cost-Efficient Configurable GUARDANT™ 314 INVESTOR 20 DAY 23 Expecting to sequence millions of clinical samples per year across average risk population and patients impacted by cancer 160#161Data Volume (PB) Data growth powering research INVESTOR 20 DAY 23 300 250 200 150 100 50 Largest consumer DB NIH Archive 0 2020 2012 2022 2023 2024 2025 2026 2027 2028 GUARDANT™ Source: NIH Archive and Guardant Health data on file 18-month doubling rate Guardant data growth is comparable to that of the largest NIH archive of genomic data 161#162Almost every disease has a visible fingerprint when viewed through the lens of epigenomics Neurodegenerative Disease. AD brain RNA RNA ANA DNA methylation Histone modifications Argonaute Non-coding R Rheumatoid Arthritis RA joint chromosome Epigenetic modifications Histone modifications DNA methylation poo0000000 Histone Histone Histone DNA acetylation methylation sumolyation methylation. me me me me Cardiovascular Disease Nucleus Unmethylated DNA (DNMT Methylated DNA "Соммтай INVESTOR 20 Readers Writers Erasers Methyl group Transcriptional Repression Inflammatory Bowel Disease https://www.sciencedirect.com/science/article/abs/pii/S1471489213000118 GUARDANT https://www.nature.com/articles/s41392-022-01055-2 | https://www.frontiersin.org/articles/10.3389/fgene.2018.00579/full https://www.researchgate.net/publication/282289965_DNA Methylation_Profiling_in_Inflammatory Bowel Disease_Provides_New_Insights_into_Disea se_Pathogenesis 36176675 (TIFA Chrome 16176675 (TIFAB Tarbes A CDMP Tinal probes on Ay Cold DMP السان DAY 23 162#163Our technology platform and commercial infrastructure can be leveraged across multiple diseases matory Screening and Therapy Selection Cancer INVESTOR 20 DAY 23 Cardiov beyond cancer and will reshape precision medicine The promise of precision medicine will be accessed through a single comprehensive blood test GUARDANT™ 163#164> GUARDANT™ Our continued success will expand our mission over time from one of conquering cancer to that of guarding wellness GUARDANT INVESTOR 20 DAY 23 164#165GUARDANT™ Q&A INVESTOR 20 DAY 23