Q4 2019 Earnings Results February 4, 2020 Forward-looking Statements

The projected financial results presented in the following slides represent management's estimates of Gilead’s future financial results. Statements included in this press release that are not historical in nature are forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Gilead cautions readers that forward-looking statements are subject to certain risks and uncertainties that could cause actual results to differ materially. These risks and uncertainties include: Gilead’s ability to achieve its anticipated full year 2020 financial results; Gilead’s ability to accelerate or sustain revenues for its antiviral and other programs; Gilead’s ability to realize the potential benefits of collaborations or licensing arrangements, including those with The Rockefeller University, Kyverna Therapeutics, Inc., Eisai Co., Ltd., Kiniksa Pharmaceuticals, Ltd. and Glympse Bio, Inc.; Gilead’s ability to initiate clinical trials in its currently anticipated timeframes; the risk that safety and efficacy data from clinical studies may not warrant further development of Gilead’s product candidates, including Yescarta in combination with mavrilimumab, 3BNC117, 10-1074, GS-6207 and product candidates evaluated for bridging fibrosis and compensated cirrhosis due to NASH; Gilead’s ability to submit new drug applications for new product candidates in the timelines currently anticipated; Gilead’s ability to receive regulatory approvals in a timely manner or at all, for new and current products, including FDA and MHLW approvals for filgotinib for the treatment of RA and FDA and European Commission approvals of KTE-X19 for the treatment of mantle cell lymphoma; Gilead’s ability to successfully commercialize its products, including expansion in China; the risk that private and public payers may be reluctant to provide, or continue to provide, coverage or reimbursement for new products; a larger than anticipated shift in payer mix to more highly discounted payer segments; market share and price erosion caused by the introduction of generic versions of Gilead products; the risk that physicians and patients may not see advantages of these products over other therapies and may therefore be reluctant to prescribe the products; and other risks identified from time to time in Gilead’s reports filed with the U.S. Securities and Exchange Commission (the SEC). In addition, Gilead makes estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses and related disclosures. Gilead bases its estimates on historical experience and on various other market specific and other relevant assumptions that it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. There may be other factors of which Gilead is not currently aware that may affect matters discussed in the forward-looking statements and may also cause actual results to differ significantly from these estimates. Further, results for the quarter and the year ended December 31, 2019 are not necessarily indicative of operating results for any future periods. Gilead directs readers to its press releases, Quarterly Report on Form 10-Q for the quarter ended September 30, 2019 and other subsequent disclosure documents filed with the SEC. Gilead claims the protection of the Safe Harbor contained in the Private Securities Litigation Reform Act of 1995 for forward-looking statements. All forward-looking statements are based on information currently available to Gilead and Gilead assumes no obligation to update or supplement any such forward-looking statements other than as required by law. Any forward-looking statements speak only as of the date hereof or as of the dates indicated in the statements. This presentation includes U.S. GAAP and non-GAAP financial measures, a complete reconciliation between these two measures is available on the Company’s website at www.gilead.com within the investor section. Management believes this non-GAAP information is useful for investors, when considered in conjunction with Gilead’s GAAP financial information, because management uses such information internally for its operating, budgeting and financial planning purposes. Non-GAAP information is not prepared under a comprehensive set of accounting rules and should only be used to supplement an understanding of Gilead’s operating results as reported under U.S. GAAP. Non-GAAP measures may be defined and calculated differently by other companies in the same industry.

2 Table of Contents

Pages Key Highlights 4 - 8

Financial Performance 9 - 26

Durable Core Business 29 - 41 Three Pillars of Gilead’s 42 - 48 Next Existing Pipeline Opportunities Chapter Strategy to Drive Additional Growth 49 - 53

Appendix 54 - 58

3 Key Highlights

4 Q4 2019 Earnings Call Highlights

• Key decisions made and new corporate strategy in place to drive Gilead’s next chapter • Solid financial performance with product sales of $22.1 billion for FY 2019 (2% YoY growth), at upper end of revised guidance • Durable HIV franchise delivering all-time high of $16.4 billion for FY 2019 (12% YoY growth) and $4.6 billion for Q4 2019 (9% QoQ growth) − Biktarvy® sales of $4.7 billion for FY 2019 (300% YoY growth) and $1.6 billion in Q4 2019 (25% QoQ growth) • Successful Descovy® for PrEP launch, ~27% of individuals on PrEP in the U.S. now on Descovy • Submitted filgotinib NDA for RA and launch preparations underway in the U.S., Europe and Japan • Dividend increase to $0.68 from $0.63 per share, effective Q1 2020 (fifth consecutive annual increase) • Additional $5.0 billion share repurchase authorization (in addition to $3.4 billion at year-end from prior authorization, $8.4 billion in total) • 2020 Financial Guidance - product sales of $21.8 - $22.2 billion and non-GAAP diluted EPS of $6.05 - $6.45 − Starting in 2020, Gilead will no longer regularly exclude stock-based compensation expense from its non-GAAP financial information − For comparability purposes, full year 2019 non-GAAP operating income and non-GAAP diluted earnings per share would have been $10.4 billion and $6.13, respectively, had stock-based compensation expense not been excluded

5 Key Decisions Have Laid the Foundation for Change

Made Kite Expanded Established Completed New Defined New Separate Operating Galapagos External Innovation Leadership Corporate Company Partnership Group Team Strategy

Mar Jul Sep Oct 2020Dec

2019

6 Diverse, Highly Experienced Leadership Team

Daniel O’Day Andrew Dickinson Brett A. Pletcher Christi Shaw Johanna Mercier Executive Chairman and Chief Financial Officer Executive Vice President, Chief Executive Officer, Kite Chief Commercial Officer Chief Executive Officer Corporate Affairs and General Counsel

Jyoti Mehra Merdad Parsey, Taiyin Yang, PhD William A. Lee, PhD Executive Vice President, MD, PhD Executive Vice President, Executive Vice President, Human Resources Chief Medical Officer Pharmaceutical Development Research and Manufacturing

7 Anticipated Milestones Through 2021

Axi-cel Axi-cel P3 2L DLBCL data Expected iNHL approval

Filgotinib Axi-cel Expected RA approvals in U.S., Europe, Japan Expected 2L DLBCL submission

Filgotinib Axi-cel P3 enrollment completion for CD P2 1L DLBCL data

Axi-cel Filgotinib Capsid inhibitor P2 iNHL data MANTA/MANTA-RAy enrollment completion Expected HTE submission

Capsid inhibitor GLPG-19721 GLPG-16902 P1 initiation for PrEP P2 OA data P3 IPF futility analysis data

Filgotinib KTE-X19 KTE-X19 P3 UC data Expected MCL approval Expected aALL approval

H1 2020 H2 2020 2021

HTE – heavily treatment-experienced. 1 Optionable partner program. 2 Optioned partner program.

8 Financial Performance

9 Financial Highlights: Q4 2019

in millions, except percentages and per share amounts Q4 2018 Q3 2019 Q4 2019 YoY Change QoQ Change Product Sales $5,681 $5,516 $5,796 2% 5% HIV1 4,065 4,202 4,577 13% 9% HCV 738 674 630 (15%) (7%) Yescarta 81 118 122 51% 3% Other Products2 797 522 467 (41%) (11%) Non-GAAP Costs and Expenses3 $3,228 $2,680 $3,567 11% 33% COGS4 1,257 759 1,406 12% 85% Product Gross Margin 78% 86% 76% R&D 939 954 1,029 10% 8% SG&A 1,032 967 1,132 10% 17% Operating Margin4 44% 52% 39% Effective Tax Rate 24% 22% 25% Non-GAAP Net Income3 $1,873 $2,224 $1,653 (12%) (26%) Non-GAAP Diluted EPS3 $1.44 $1.75 $1.30 (10%) (26%) Shares used in per share calculation-diluted 1,299 1,274 1,273 (2%) 0%

1 HIV includes Atripla, Biktarvy, Complera/Eviplera, Descovy, Emtriva, Genvoya, Odefsey, Stribild, revenue share Symtuza, Truvada, and Tybost. Revenue share Symtuza represents Gilead’s revenue from cobicistat (C), FTC and TAF in Symtuza (darunavir/C/FTC/TAF), a fixed dose combination product commercialized by Janssen. 2 Other products include AmBisome, Cayston, Hepsera, Letairis, Ranexa, Vemlidy, Viread, and Zydelig. 3 Non-GAAP financial information excludes acquisition-related, up-front collaboration and licensing, stock-based compensation and other expenses, fair value adjustments of equity securities and discrete tax charges or benefits associated with changes in 4 10 tax related laws and guidelines. In Q4 2019 and Q4 2018, COGS include inventory write-downs of $500 million and $410 million, respectively, for slow moving and excess raw material and work in process inventory primarily due to lower long-term demand for our HCV products. Financial Highlights: Full Year

in millions, except percentages and per share amounts 2018 2019 YoY Change Product Sales $21,677 $22,119 2% HIV1 14,627 16,438 12% HCV 3,686 2,936 (20%) Yescarta 264 456 73% Other Products2 3,100 2,289 (26%) Non-GAAP Costs and Expenses3 $10,716 $11,385 6% COGS4 3,590 3,539 (1%) Product Gross Margin 83% 84% R&D 3,518 3,770 7% SG&A 3,608 4,076 13% Operating Margin4 52% 49% Effective Tax Rate 20% 21% Non-GAAP Net Income3 $8,728 $8,466 (3%) Non-GAAP Diluted EPS3 $6.67 $6.63 (1%) Shares used in per share calculation-diluted 1,308 1,277 (2%)

1 HIV includes Atripla, Biktarvy, Complera/Eviplera, Descovy, Emtriva, Genvoya, Odefsey, Stribild, revenue share Symtuza, Truvada, and Tybost. Revenue share Symtuza represents Gilead’s revenue from cobicistat (C), FTC and TAF in Symtuza (darunavir/C/FTC/TAF), a fixed dose combination product commercialized by Janssen. 2 Other products include AmBisome, Cayston, Hepsera, Letairis, Ranexa, Vemlidy, Viread, and Zydelig. 3 Non-GAAP financial information excludes acquisition-related, up-front collaboration and licensing, stock-based compensation and other expenses, fair value adjustments of equity securities and discrete tax charges or benefits associated with 4 11 changes in tax related laws and guidelines. In FY 2019 and FY 2018, COGS include inventory write-downs of $547 million and $440 million, respectively, for slow moving and excess raw material and work in process inventory primarily due to lower long-term demand for our HCV products. Total Revenue

Q4 2019 up 1% from Q4 2018 driven by HIV and Yescarta, partially offset by HCV and other products1

in millions

$5,795 $5,879 $5,685 $5,604 $5,281

Q4 18 Q1 19 Q2 19 Q3 19 Q4 19

FX impact to revenue QoQ was unfavorable by $11 million (0.2%) and YoY was unfavorable by $13 million (0.2%). 1 Other products include AmBisome, Cayston, Hepsera, Letairis, Ranexa, Vemlidy, Viread, and Zydelig.

12 Total Product Sales

Q4 2019 up 2% from Q4 2018

By Therapeutic Area By Geography

in millions in millions $5,796 $5,796 $5,681 $5,607 $5,681 $5,516 $122 $5,607 $5,516 $81 $5,200 $120 $5,200 $440 $118 $467 $398 $512 $797 $96 $604 $513 $522 $522 $840 $696 $630 $813 $804 $738 $842 $674 $1,041 $882 $790

$4,577 $4,470 $4,516 $4,065 $4,041 $4,202 $4,054 $4,199 $3,618 $3,796

2 Q4 18 Q1 19 Q2 19 2 Q3 19 Q4 19 Q4 18 Q1 19 Q2 19 Q3 19 Q4 19

HIV HCV Other Products1 Yescarta U.S. Europe Other Int'l

1 Includes AmBisome, Cayston, Hepsera, Letairis, Ranexa, Vemlidy, Viread and Zydelig. 2 Q2 2019 product sales include a benefit of ~$160 million (mainly HIV ~$70 million, HCV ~$80 million and HBV ~$10 million) from adjustments for statutory rebates related to Europe sales made in prior years.

13 Non-GAAP Product Gross Margin

87.3% 87.3% 86.2% ● Q4 2019 decrease from Q3 2019 primarily 77.9% due to higher inventory write-downs 75.7% − Excluding unfavorable COGS impact primarily from inventory write-downs, non- GAAP product gross margin would have been ~87% in Q4 2019

● Q4 2019 decrease from Q4 2018 primarily due to higher inventory write-downs, partially offset by lower royalty expenses

− Excluding unfavorable COGS impact primarily from inventory write-downs, non- GAAP product gross margin would have Q4 18 Q1 19 Q2 19 Q3 19 Q4 19 been ~85% in Q4 2018

For the periods presented, non-GAAP product gross margin excludes acquisition-related, stock-based compensation and other expenses.

14 Non-GAAP R&D Expenses

Q4 2019 up 10% from Q4 2018 primarily due to higher personnel costs to support our cell therapy business and increased investment in research projects

in millions $1,029 $954 $939 $916 $871

Q4 18 Q1 19 Q2 19 Q3 19 Q4 19

For the periods presented, non-GAAP R&D expenses exclude acquisition-related, up-front collaboration and licensing, stock-based compensation and other expenses.

15 Non-GAAP SG&A Expenses

Q4 2019 up 10% from Q4 2018

in millions $1,132

$1,032 $1,015 ● Q4 2019 increase from Q4 2018 primarily $962 $967 due to higher Biktarvy and Descovy for PrEP U.S. promotional expenses and Japan business expansion expenses

● P&L impact of BPD fee (in millions)

− 2019 actual $247

− 2020 estimate $150-250

Q4 18 Q1 19 Q2 19 Q3 19 Q4 19

For the periods presented, non-GAAP SG&A expenses exclude acquisition-related, stock-based compensation and other expenses.

16 Non-GAAP Operating Margin

53.5% 52.8% 52.2%

44.3%

39.3% ● Q4 2019 non-GAAP operating margin would have been ~50% excluding unfavorable COGS impact primarily from inventory write-downs

● Q4 2018 non-GAAP operating margin would have been ~51% excluding unfavorable COGS impact from inventory write-downs

Q4 18 Q1 19 Q2 19 Q3 19 Q4 19

For the periods presented, non-GAAP operating margin excludes acquisition-related, up-front collaboration and licensing, stock-based compensation and other expenses.

17 Non-GAAP Diluted EPS

Q4 2019 down 10% from Q4 2018

2 1 $1.82 $1.76 $1.75 • Q4 2019 unfavorable ($0.47) due to COGS, primarily driven by inventory write-down $1.44 $1.30 − Excluding unfavorable COGS impact primarily from inventory write-downs, non- GAAP EPS would have been $1.77

• Q4 2018 unfavorable ($0.31) due to inventory write-down

− Excluding unfavorable COGS impact from inventory write-downs, non-GAAP EPS would have been $1.75

Q4 18 Q1 19 Q2 19 Q3 19 Q4 19

1 Q1 2019 EPS benefited $0.09 from favorable settlements with taxing authorities. 2 Q2 2019 EPS benefited $0.10 from adjustments for statutory rebates related to Europe sales made in prior years. For the periods presented, non- GAAP financial information excludes acquisition-related, up-front collaboration and licensing, stock-based compensation and other expenses, fair value adjustments of equity securities and discrete tax charges or benefits associated with changes in tax related laws and guidelines. 18 Other Select Financial Information

in millions, except days sales outstanding Sep 30, 2019 Dec 31, 2019 Cash, Cash Equivalents & Marketable Securities $25,051 $25,840 Operating Cash Flows During the Quarter $2,645 $2,581 Inventories1 $2,557 $2,067 Days Sales Outstanding (Accounts Receivable) 41 41 Share Repurchases During the Quarter2 $223 $105 Dividends Paid During the Quarter $804 $801 Interest Expense and Other Income (Expense), net ($86) ($121) (non-GAAP)3 Shares used in per share calculation – diluted 1,274 1,273 Shares used in per share calculation – basic 1,267 1,266

1 Includes both short- and long-term inventories. 2 Excludes commissions. 3 Excludes gains (losses) from equity securities.

19 Q4 2019 Shareholder Return

Repurchase Total Shareholder Dividend Dollar Dividend Average Amount Dollar Amount1 Shares Return per Share Purchase Price (in millions) (in millions) (in millions) Q1 2019 $817 $0.63 $833 12,372,891 $67.35 $1,650 Q2 2019 $800 $0.63 $588 8,940,430 $65.72 $1,388 Q3 2019 $804 $0.63 $223 3,419,049 $65.15 $1,027 Q4 2019 $801 $0.63 $105 1,616,679 $64.89 $906 YTD 2019 $3,222 $2.52 $1,749 26,349,049 $66.36 $4,971

Dividend Repurchase • Declared a quarterly dividend increase of 8% from • A $12.0 billion share repurchase program was authorized in January 2016, which we began in $0.63 to $0.68 per share, beginning in the first Q2 2016. Under this program, we purchased approximately 115.0 million shares at an average quarter of 2020. price of $74.77 for a total of approximately $8.6 billion to date. As of Q4 2019, there is $3.4 • The Q1 2020 quarterly dividend is payable on billion authorization remaining under the January 2016 program March 30, 2020 to stockholders of record as of the • Since 2012, we repurchased approximately 25% of shares outstanding (approximately 390 close of business on March 13, 2020. million shares) as of Q4 2019 • The Board authorized an additional $5.0 billion share repurchase authorization in January 2020, which will be utilized upon completion of the January 2016 repurchase program (in addition to $3.4 billion at year-end from prior authorization, $8.4 billion in total)

1 Excludes commissions.

20 GAAP to Non-GAAP Reconciliation of Outstanding Adjusted Debt and Adjusted EBITDA

in billions where applicable Dec 31, 2018 Mar 31, 2019 Jun 30, 2019 Sep 30, 2019 Dec 31, 2019 Senior Unsecured Notes and Floating Rate Borrowings, $27.32 $26.58 $26.08 $24.59 $24.59 net Debt Discounts, Premiums and Issuance Costs 0.18 0.17 0.17 0.16 0.16 Total Adjusted Debt1 $27.50 $26.75 $26.25 $24.75 $24.75

Last Twelve Months Ended Dec 31, 2018 Mar 31, 2019 Jun 30, 2019 Sep 30, 2019 Dec 31, 2019 Net Income attributable to Gilead $5.45 $5.89 $5.95 $2.69 $5.39 Add: Interest Expense & Other Income (expense), net 0.40 0.17 0.00 0.07 (0.87) Add: Tax 2.34 2.23 2.50 1.59 (0.20) Add: Depreciation 0.23 0.23 0.24 0.24 0.25 Add: Amortization 1.20 1.20 1.19 1.17 1.15 Add: In-process research and development impairment 0.82 0.82 0.82 0.82 0.80 Add: Upfront collaboration and licensing expenses 3.92 3.92 related to Galapagos Adjusted EBITDA2 $10.44 $10.53 $10.69 $10.51 $10.43

Adjusted Debt to Adjusted EBITDA ratio ~2.63x ~2.54x ~2.46x ~2.36x ~2.37x

1 Adjusted Debt amount shown at face value. 2 Represents the last twelve months of adjusted EBITDA. The adjusted EBITDA for the periods ending Q4 18, Q1 19, Q2 19, and Q3 19 has been recast to exclude IPR&D impairment of $820 million consistent with the current quarter presentation of an IPR&D impairment of $800 million. Total interest expense and amortization from all issued debt is expected to be approximately $950 million for full year 2020.

21 2020 Financial Guidance

22 Updated Guidance Approach

• Guidance metrics for 2020 now include EPS and operating income

• Starting in 2020, Gilead will no longer regularly exclude stock-based compensation expense from its non-GAAP financial information

• For comparability purposes, full year 2019 non-GAAP operating income and non-GAAP diluted earnings per share would have been $10.4 billion and $6.13, respectively, had stock-based compensation expense not been excluded

• Guidance is subject to a number of uncertainties including the impact of any future significant business development transactions and exclude both certain development milestones and options exercise fees as they are contingent on various future events, which have a high degree of uncertainty

23 Full Year 2020 Guidance

Starting in 2020, Gilead will no longer regularly exclude stock-based compensation expense from its non-GAAP financial information For comparability purposes, full year 2019 non-GAAP operating income and non-GAAP diluted earnings per share would have been $10.4 billion and $6.13, respectively, had stock-based compensation expense not been excluded

in millions, except percentages and per share amounts Provided on February 4, 2020 Product Sales $21,800 - $22,200 Non-GAAP Product Gross Margin 86% - 87% R&D Expense Mid-single digit percentage growth SG&A Expense Mid-single digit percentage growth Operating Income $10,100 - $10,800 Effective Tax Rate ~21% Diluted EPS $6.05 - $6.45 GAAP Diluted EPS $5.15 - $5.55

This guidance is subject to a number of risks and uncertainties. See Forward-Looking Statements on page 2.

24 2019 - 2020 Product Sales Guidance

in billions

$22.1 ($0.1) ($0.8) - ($1.0) $0.8 - $1.0 $21.8 - $22.2

• Adjustments for • U.S. Letairis and • U.S. HIV statutory rebates Ranexa Patent Treatment and related to Expiry Impact Prevention Europe (full year impact) • U.S. and China • Truvada generic Vemlidy growth entry (Q4 2020) • Cell Therapy U.S. ramp and Europe 2019 expansion 2020 Actual Guidance Range

This guidance is subject to a number of risks and uncertainties. See Forward-Looking Statements on page 2.

25 GAAP to Non-GAAP Reconciliation of Full Year 2020 Guidance1

Starting in 2020, Gilead will no longer regularly exclude stock-based compensation expense from its non-GAAP financial information For comparability purposes, full year 2019 non-GAAP operating income and non-GAAP diluted earnings per share would have been $10.4 billion and $6.13, respectively, had stock-based compensation expense not been excluded

in millions, except percentages and per share amounts Provided on February 4, 2020 Projected product gross margin GAAP to non-GAAP reconciliation: GAAP projected product gross margin 81% - 82% Acquisition-related expenses 5% Non-GAAP projected product gross margin 86% - 87% Projected operating income GAAP to non-GAAP reconciliation: GAAP projected operating income $8,980 - $9,680 Acquisition-related and up-front collaboration and licensing expenses 1,120 Non-GAAP projected operating income $10,100 - $10,800 Projected effective tax rate GAAP to non-GAAP reconciliation: GAAP projected effective tax rate ~23% Amortization of deferred tax assets and tax rate effects of adjustments noted above (2%) Non-GAAP projected effective tax rate ~21% Projected diluted EPS GAAP to non-GAAP reconciliation: GAAP projected diluted EPS $5.15 - $5.55 Acquisition-related, up-front collaboration and licensing expenses and amortization of deferred tax assets 0.90 Non-GAAP projected diluted EPS $6.05 - $6.45

1 Excludes the impact of any potential future acquisition-related, up-front collaboration and licensing and other expenses, fair value adjustments of equity securities and discrete tax charges or benefits associated with changes in tax related laws and guidelines as Gilead is unable to project such amounts.

26 Three Pillars of Gilead’s Next Chapter

27 Three Pillars of Gilead’s Next Chapter

Durable Core Existing Pipeline Strategy to Drive Business Opportunities Additional Growth + +

28 Building from Durable Core Business

Durable Core Existing Pipeline Strategy to Drive Business Opportunities Additional Growth + +

29 Robust Growth of HIV Business Despite Competitor Launches

• Antiviral world-leader HCV ‒ 15 launches in 10 years1 Other HIV • Robust HIV growth ‒ 14% CAGR since 20112 ‒ 13% growth Q4’18 – Q4’19

2011 2019

Prepared for • Treatment - 90-95% Gilead patients expected on F/TAF-based regimens by Q4’203 Truvada U.S. LOE • Prevention - 40-45% individuals on PrEP expected to be on Descovy by Q4’203

1 Complera, Viread, Truvada for PrEP, Stribild, Tybost, Vitekta, Sovaldi, Harvoni, Genvoya, Odefsey, Epclusa, Vemlidy, Vosevi, Biktarvy, Descovy for PrEP. 2 Q1 2011 through Q4 2019. 3 Expectations for U.S. patients.

30 HIV Franchise is Robust and Sustainable

Highly effective single tablet Statistically significant safety regimen for treatment improvements for prevention5

• Zero cases of treatment-emergent resistance • ~20% at-risk individuals on PrEP today6 and rapid start recommended1,2 • ~27% PrEP scripts are for Descovy • #1 prescribed HIV regimen and best HIV launch in history3,4

Expect Biktarvy to remain preferred treatment option for majority of patients through 2033

1 Biktarvy demonstrated zero cases of treatment-emergent resistance through 3 years in P3 clinical trials. 2 2018 DHHS treatment guidelines. 3 Biktarvy #1 prescribed HIV regimen in U.S. in Q4 2019. 4 Biktarvy best HIV launch in history in U.S. and certain other countries based on prescription volume. 5 Statistically significant advantages with respect to all six pre-specified secondary endpoints for renal and bone laboratory parameters in patients receiving Descovy compared to Truvada. 6 ~1.1m at-risk individuals in U.S., 234k on PrEP, Q4 2019. 31 Total HIV Product Sales

Q4 2019 up 13% from Q4 2018

in millions

$4,577 $4,202 $195 $4,065 $4,041 $210 $562 U.S. $151 $3,618 $187 $511 $558 ● Biktarvy was the most prescribed HIV regimen $219 $623 across all patients with sales of $1.4 billion in Q4 $569 2019

Europe $3,820 $3,403 $3,231 $3,434 ● Biktarvy launched in 29 markets and was the #1 $2,830 prescribed regimen for treatment-naïve and switch patients in Germany, France, Spain and Italy

Q4 18 Q1 19 Q2 19 Q3 19 Q4 19

U.S. Europe Other Int'l

32 Descovy (FTC/TAF)-Based HIV Worldwide Product Sales

Q4 2019 up 32% from Q4 2018 driven mainly by Biktarvy uptake

in millions $3,525 $125 $3,140 $435 $2,925 $104 $2,680 $84 $2,613 $436 $437 $37 $66 $387 $448 $363 $397 $358 $411 $342 $958 $978 $980

$1,015 $1,206

$1,570 $1,116 $1,259 $793 $578

Q4 18 Q1 19 Q2 19 Q3 19 Q4 19

Biktarvy Genvoya Descovy Odefsey Symtuza 1

1 Revenue share from Symtuza represents Gilead’s revenue from cobicistat (C), FTC and TAF in Symtuza (darunavir/C/FTC/TAF), a fixed dose combination product commercialized by Janssen.

33 Top Prescribed HIV Regimens

U.S. EU5

Naïve Switch All Patients Naïve Switch All Patients (Q4 2019) (Q4 2019) (Q4 2019) (Q4 2019) (Q4 2019) (Q4 2019)

1 Biktarvy Biktarvy Biktarvy 1 Biktarvy Biktarvy Other STR

STR containing 2 Genvoya Genvoya 2 Other STR Other STR Odefsey Gilead product STR containing 3 Other STR Other STR 3 Genvoya Odefsey Genvoya Gilead product STR containing 4 Other STR Genvoya Odefsey 4 Other Regimen Biktarvy Gilead product STR containing 5 Other STR Other STR 5 Atripla Genvoya Atripla Gilead product

Gilead STR

US Source: Ipsos Healthcare U.S. HIV Monitor & Scope Study Q4 2019. EU5 comprised of France, Spain, Italy, UK and Germany. EU Naïve & Switch Source: Ipsos HIV Scope Q4 2019. EU All Patient Source: Therapy Watch HIV Q4 2019.

34 Continued Adoption of Descovy (FTC/TAF)-Based Regimens

~87% of Gilead’s U.S. HIV Treatment Prescription Volume Comprised of Descovy (FTC/TAF)-Based Regimens 100%

90% ~87% 80%

70% TDF-based Regimens 60%

50%

40% Descovy 30% (FTC/TAF)-based

% of Gilead’sPrescription Volume for HIV Treatment 20% Regimens

10%

0% Q4 15 Q1 16 Q2 16 Q3 16 Q4 16 Q1 17 Q2 17 Q3 17 Q4 17 Q1 18 Q2 18 Q3 18 Q4 18 Q1 19 Q2 19 Q3 19 Q4 19

35 PrEP Use Continues to Grow in the U.S.

Individuals Taking PrEP

~1.1 million individuals in thousands 234 in U.S. could benefit 224 1 from PrEP 213 201 189

~27% individuals on PrEP ~20% currently on Descovy on PrEP today 40-45% individuals on PrEP expected to be on Descovy by Q4’20

2 Q4 18 Q1 19 Q2 19 Q3 19 Q4 19

Note all content on page specific to U.S. market. Source: IQVIA NPA/NSP, SHA Patient Longitudinal Data. Data are subject to restatement. 1 CDC (Centers for Disease Control and Prevention) 2019. 2 As of Q4 19, individuals taking PrEP in the U.S. includes both Truvada for PrEP and Descovy for PrEP.

36 Total HCV Product Sales by Geography

Q4 2019 down 15% from Q4 2018

in millions $842 $790 $738 $210 $674 $194 $140 $630 • U.S. retail market share at ~60%, up 18 $183 percentage points from January 2019 $142 $188 $203 $277 • Lower sales in Q4 2019 compared to Q4 2018 $111 $151 primarily due to competitive dynamics impacting net price

• Q4 2019 increase in Europe vs Q3 2019 due to $410 $393 $380 seasonality $355 $337

Q4 18 Q1 19 Q2 19 Q3 19 Q4 19

U.S. Europe Other Int'l

37 HCV Patient Initiations on Sofosbuvir-Based Regimens in U.S., Europe and Japan

Key market leadership with ~60% U.S. market share today1

in thousands 45 42 40 41 41

15 15 18 18 18

28 25 21 22 22

Q4 18 Q1 19 Q2 19 Q3 19 Q4 19

U.S. Europe Japan

1 Combined retail market share of Gilead branded or authorized generic partner products in U.S. Graph illustrates the estimated number of patients that started therapy with a Gilead HCV drug for each quarter. Patient numbers are subject to adjustments and exclude other international markets.

38 Additional Opportunities to Grow Antiviral Business

Accelerate HBV Drive China Growth

Achieve $1bn+ franchise by 2022 through 8 products approved since 2017 U.S. and China Vemlidy growth 4 listed on NRDL for Jan 2020 reimbursement1

1 8 products approved in China since Sept 2017 including Sovaldi, Epclusa, Genvoya, Vemlidy, Harvoni, Descovy, Biktarvy and Vosevi and 4 products added to National Reimbursement Drug List (NRDL) including Vemlidy, Epclusa, Genvoya, Harvoni for Jan 2020 reimbursement.

39 Cell Therapy Business Update

• Sales of $456 million for FY2019 (73% growth) and $122 million in Q4 2019 (3% QoQ growth)

• 3-year survival data showing longest term outcomes in 3L+ DLBCL in pivotal study

• ~2,500 R/R 3L+ DLBCL patients treated with Yescarta

• >168 centers authorized worldwide

KTE-X19 • Regulatory submissions to FDA and EMA for R/R mantle cell lymphoma

40 Key Drivers of Expected 2020 Cell Therapy Growth

Pioneering cell therapy platform to advance new therapies and drive long-term growth

Reimbursement Expanded Patient Access Yescarta Differentiation

• NTAP improvement (Q4 2019) • Implementation of Yescarta • 3 year Zuma 1 efficacy data and outpatient strategy Zuma 1 cohort 4 safety data • NTAP extension and X19 coverage (Q4 2020) • Enhanced site footprint in U.S., • Rapid (16 day) and reliable EU, CAN and AUS (97%) manufacturing in the U.S. • CAR T specific DRG (Q4 2020) • Community education to • Launch of TCF 04 to enhance enhance patient identification commercial manufacturing in and referrals Europe

41 Executing on Existing Pipeline Opportunities

Durable Core Existing Pipeline Strategy to Drive Business Opportunities Additional Growth + +

42 Overview of Clinical Pipeline Today

Phase 1 Phase 2 Phase 3 NDA/BLA/MAA

Viral Clinical Stage 2 Diseases 40 Programs1,2

Inflammatory Diseases NDA/BLA/MAA, P3 and 14 Registrational P2 trials

Fibrotic Diseases NMEs via in-licensing, 14 options, and product acquisitions

Oncology Breakthrough Therapy 4 Designations

1 Including in-licensing, options, and product acquisitions. 2 Changes since 01/13/20: SpringBank compound (GS-9992) program scheduled to terminate. 43 Reinforcing Commitment to HIV Leadership With Innovative Long-Acting Programs

Capsid Inhibitor as the Foundation

• Weekly oral potential Current Clinical Programs  • Monthly 6 month SQ with self-admin potential HTE2 P2/3

• Breakthrough Designation1 Treatment naïve P2 Treatment

• Registrational trial in HTE patients and phase 2 PrEP PC + trial in treatment naïve patients initiated Prevention

Committed to Developing Multiple Partner Agents

LA INSTI • LA NRTI • LA NNRTI • bNAbs

Capsid has the potential to be first- and best-in-class with multiple dosing options

1 GS-6207 received breakthrough therapy designation from FDA as a potential therapy for heavily treatment-experienced (HTE) people living with multi-drug resistant HIV. 2 Pivotal for HTE patients. Selected pre-clinical assets displayed. SQ – sub-cutaneous. HTE - heavily treatment-experienced. INSTI - Integrase Strand Transfer Inhibitor. NRTI - Nucleoside reverse transcriptase inhibitor. NNRTI - Non-nucleoside reverse transcriptase inhibitor. bNAbs - Broadly neutralizing antibodies. 44 Filgotinib Marks Expansion into Inflammation with Potential for 5 Launches in Next 4 Years

Filgotinib RA P3 Selective JAK-1 inhibitor with potential best-in-class profile UC P3

Strong efficacy for remission and demonstrated safety CD P3 at both doses; favorable benefit/risk profile at high dose PsA P3 Submitted for RA in U.S., Europe and Japan AS P2

P3 UC data in H1 2020 Uveitis P2

Prepared for competitive RA launch with highly experienced team

RA - Rheumatoid Arthritis. UC - Ulcerative Colitis. CD - Crohn’s Disease. PsA - Psoriatic Arthritis. AS - Ankylosing Spondylitis.

45 Building a Broad Inflammation and Fibrosis Portfolio with Galapagos Beyond Filgotinib

GLPG-16903 – IPF P3 GLPG-1972 – OA P2 GLPG-12054 – IPF P2 8 clinical GLPG-16903 – Systemic Sclerosis P2 programs1,2 GLPG-0555 – Inflammation P1 GLPG-39705 – Inflammation P1 GLPG-33125 – Inflammation P1 GLPG-3667 – Inflammation P1

Doubles Gilead’s R&D footprint GLPG-43995 – Inflammation PC and accelerates transformational >20 pre-clinical GLPG-4124 – Fibrosis PC therapy development programs2 GLPG-4259 – Inflammation PC GLPG-4471 – Inflammation PC

Cilo/Firco/Sel (FXR, ACC, ASK1) Combination – NASH P2 GS-4997 (ASK1 inhibitor) – DKD P2 GS-4875 (TPL2 inhibitor) – UC P2 Selected GS-5718 (IRAK4) – Inflammation PC programs GS-1427 (α4β7) – Inflammation PC SM inh. (Neutrophil target) – Inflam. PC SM inh. (Innate immunity target) – Inflam. PC Key: Fibrotic Diseases; Inflammatory Diseases 1 Excluding filgotinib. 2 Optionable partner programs, except for GLPG-1690 which is an optioned partner program. 3 Autotaxin inhibitor. 4 GPR84 antagonist. 5 Toledo - dual mechanism anti-inflammatory. IPF - Idiopathic Pulmonary Fibrosis. OA - Osteoarthritis. Selected pre-clinical and P1 assets displayed. 46 Oncology Strategy Focused on Immuno-Oncology

Building transformative therapies across complementary Immuno-Oncology platforms

Cell Therapy Non-Cell Therapy

Pioneering platform Transformative therapy Apply small molecule and biologics to advance new therapies and with potential for earlier lines development capabilities to IO drive long-term growth and additional indications1

1 Nearly half of r/r DLBCL patient alive three years after treatment with Yescarta in ZUMA-1 study. IO – Immuno-Oncology.

47 Oncology Pipeline Consists of 15 Clinical Programs and Growing

Building transformative therapies across complementary Immuno-Oncology platforms

Cell Therapy Non-Cell Therapy KTE-X19 CD-19 r/r MCL BLA/MAA Oral PD-L1 inhibitor (GS-4224) Solid tumors P1 Axi-cel CD-19 2L DLBCL P3 Anti-CD73/TGFβ TRAP (GS-1423)2 Solid tumors P1 Axi-cel CD-19 iNHL P21 Bi-specific mAb (AGEN1223)3,4 Multiple P1 Axi-cel CD-19 1L DLBCL P2 Anti-CD137 mAb (AGEN2373)4 Multiple P1 Axi-cel CD-19 DLBCL (+ritux. or lenal.) P21 Flt3R agonist (GS-3583) Solid tumors PC KTE-X19 Adult ALL P21 MCL1 inhibitor (GS-9716) Multiple PC KTE-X19 Pediatric ALL P21 Small molecule inh. (T cell target) Solid tumors PC KTE-X19 CLL P1 Small molecule inh. (TME target) Solid tumors PC Axi-cel DLBCL (utomilumab) P1 Monoclonal antibody (TME target) Solid tumors PC MAGE A3/A6 TCR Solid tumors P1 HPV-16 E7 TCR Solid tumors P1 Allogeneic CD-19 r/r DLBCL PC CLL-1 CAR T AML PC Dual antigen CAR T r/r DLBCL PC

1 Pivotal P2 study. 2 TME conditioning anti-CD73/TGFβ TRAP bifunctional fusion protein (GS-1423). 3 Bi-specific mAb targeting immunosuppressive regulatory T cells (AGEN1223). 4 Exclusive option to license rights from Agenus upon proof of concept data. ALL - Acute lymphocytic leukemia. CLL - Chronic lymphocytic leukemia. DLBCL - Diffuse large B-cell lymphoma. iNHL - Indolent non-Hodgkin lymphoma. MCL - Mantle cell lymphoma. r/r - relapsed refractory. iNHL - Indolent non-Hodgkin lymphoma. Selected pre-clinical assets displayed. 48 Strategy to Drive Additional Growth

Durable Core Existing Pipeline Strategy to Drive Business Opportunities Additional Growth + +

49 New Corporate Strategy to Drive Future Growth Term Ambitions Long - Bring 10+ Transformative Be the Biotech Employer and Deliver Shareholder Value in a Therapies to Patients by 2030 Partner of Choice Sustainable, Responsible Manner

Strengthen Portfolio Expand Internal and Increase Patient Access Continue to Evolve Strategy and Decision- External Innovation and Benefit our Culture Making Priorities Strategic Strategic

50 Focused on Growing from Core Areas of Strength

Core Strengths Disease Areas

Viral Inflammatory Diseases Diseases Immuno- Antivirals modulation Deep Expertise Emerging Expertise Fibrotic Oncology Diseases

51 We Will Continue to Pursue Tailored Transactions That Drive Strategic Value

Guiding Principles for Future Deals

• Focus on high quality science that build upon core areas of strength

• Prioritize clinical and commercial opportunities

33 • Pursue and execute: Strategic Partnerships & Investment Transactions Since Jan 2018 ‒ Partnerships from small to transformative in size

‒ Bolt-on acquisitions from small to medium in size

Changes since 01/13/20: Kyverna added

52 Three Pillars of Gilead’s Next Chapter

Durable Core Existing Pipeline Strategy to Drive Business Opportunities Additional Growth + +

Well positioned to maximize near-term opportunities and achieve long-term success

53 Appendix

54 Viral Disease Pipeline

Pre-Clinical Phase 1 Phase 2 Phase 3 Biktarvy HIV treatment pediatric1 Capsid inhibitor (GS-6207) HIV HTE Registrational for HTE2 Capsid inhibitor (GS-6207) HIV treatment naïve Vesatolimod (GS-9620, TLR-7 agonist) HIV cure Elipovimab (GS-9722, bNAb) HIV cure HIV Capsid inhibitor (GS-6207) PrEP Unboosted protease inhibitor (GS-1156) HIV treatment Long-acting oral combination therapy HIV treatment Hookipa vaccine HIV cure Selgantolimod (GS-9688,TLR-8 agonist) HBV cure PD-L1 inhibitor (GS-4224) HBV cure

HBV Hookipa vaccine (GS-6679) HBV cure SpringBank compound (GS-9992)3

1 Biktarvy HIV treatment pediatric label extension. 2 Registrational for heavily treatment-experienced (HTE) patients. 3 Changes since 01/13/20: SpringBank compound (GS-9992) program scheduled to terminate. Selected pre- clinical assets displayed.

55 Inflammatory Disease Pipeline

Pre-Clinical Phase 1 Phase 2 Phase 3 NDA/BLA/MAA Filgotinib (GS-6034, JAK-1 inhibitor) Rheumatoid arthritis NDA/MAA Filgotinib (GS-6034, JAK-1 inhibitor) Ulcerative colitis Filgotinib (GS-6034, JAK-1 inhibitor) Crohn’s disease Filgotinib (GS-6034, JAK-1 inhibitor) Psoriatic arthritis Filgotinib (GS-6034, JAK-1 inhibitor) Ankylosing spondylitis Filgotinib (GS-6034, JAK-1 inhibitor) Uveitis TPL2 inhibitor (GS-4875) Ulcerative colitis GLPG-19721 Osteoarthritis GLPG-05551 Inflammatory diseases GLPG-33121 Inflammatory diseases GLPG-39701 Inflammatory diseases GLPG-36671 Inflammatory diseases IRAK4 inhibitor (GS-5718) Inflammatory diseases Inflammatory Disease α4β7 inhibitor (GS-1427) Inflammatory diseases Small molecule inh. (Neutrophil target) Inflammatory diseases Small molecule inh. (Innate immunity target) Inflammatory diseases GLPG-43991 Inflammatory diseases GLPG-42591 Inflammatory diseases GLPG-44711 Inflammatory diseases GLPG-40591 Metabolic diseases

1 Optionable partner program. Selected pre-clinical assets displayed.

56 Fibrotic Disease Pipeline

Pre-Clinical Phase 1 Phase 2 Phase 3 Cilofexor (GS-9674, FXR agonist) PSC GLPG-16901 Idiopathic pulmonary fibrosis Cilofexor (FXR agonist), Firsocostat (ACC NASH inh.), Selonsertib (ASK1 inh.) combinations Selonsertib (GS-4997, ASK1 inhibitor) DKD GLPG-16901 Systemic sclerosis

Fibrotic Disease GLPG-12052 Idiopathic pulmonary fibrosis GLPG-41242 Fibrosis

1 Optioned partner program. 2 Optionable partner program. Selected pre-clinical assets displayed.

57 Oncology Pipeline

Pre-Clinical Phase 1 Phase 2 Phase 3 NDA/BLA/MAA KTE-X19 MCL BLA/MAA Axi-cel 2L DLBCL Axi-cel Indolent NHL Pivotal Axi-cel 1L DLBCL Axi-cel DLBCL (+rituximab or lenalidomide) Pivotal KTE-X19 Adult ALL Pivotal KTE-X19 Pediatric ALL Pivotal KTE-X19 CLL Axi-cel DLBCL (utomilumab) Cell TherapyCell KITE-718 (MAGE A3/A6) Solid tumor KITE-439 (HPV E7) Solid tumor Allogeneic CD-19 r/r DLBCL CLL-1 CAR T AML Dual antigen CAR T r/r/ DLBCL Oral PD-L1 inhibitor (GS-4224) Solid tumor anti-CD73/TGFβ TRAP (GS-1423)1 Solid tumor Bi-specific mAb (AGEN1223)2,3,4 Multiple Anti-CD137 mAb (AGEN2373)3,4 Multiple Flt3R agonist (GS-3583) Solid tumors

Cell TherapyCell MCL1 inhibitor (GS-9716) Multiple Small molecule inhibitor (T cell target) Solid Tumors Non - Small molecule inhibitor (TME target) Solid Tumors Monoclonal antibody (TME target) Solid Tumors

1 TME conditioning anti-CD73/TGFβ TRAP bifunctional fusion protein (GS-1423). 2 Bi-specific mAb targeting immunosuppressive regulatory T cells (AGEN1223). 3 Exclusive option to license rights from Agenus upon proof of concept data. 4 Optionable partner program. ALL - Acute lymphocytic leukemia. CLL - Chronic lymphocytic leukemia. DLBCL - Diffuse large B-cell lymphoma. iNHL - Indolent non-Hodgkin lymphoma. MCL - Mantle cell lymphoma. r/r - relapsed refractory. iNHL - Indolent non-Hodgkin lymphoma. Selected pre-clinical assets displayed. 58 Q4 2019 Earnings Results February 4, 2020