Investor Presentation June 2015

Merck & Co., Inc.

Forward-Looking Statement of Merck & Co., Inc., Kenilworth, NJ, USA

This presentation of Merck & Co., Inc., Kenilworth, NJ, USA (the Company) includes forward-looking statements within the meaning of the safe harbor provisions of the United States Private Securities Litigation Reform Act of 1995. These statements are based upon the current beliefs and expectations of the Companys management and are subject to significant risks and uncertainties. There can be no guarantees with respect to pipeline products that the products will receive the necessary regulatory approvals or that they will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.

Risks and uncertainties include, but are not limited to, general industry conditions and competition; general economic factors, including interest rate and currency exchange rate fluctuations; the impact of pharmaceutical industry regulation and healthcare legislation in the United States and internationally; global trends toward healthcare cost containment; technological advances, new products and patents attained by competitors; challenges inherent in new product development, including obtaining regulatory approval; the Companys ability to accurately predict future market conditions; manufacturing difficulties or delays; financial instability of international economies and sovereign risk; dependence on the effectiveness of the Companys s patents and other protections for innovative products; and the exposure to litigation, including patent litigation, and/or regulatory actions.

The Company undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise. Additional factors that could cause results to differ materially from those described in the forward-looking statements can be found in the Companys 2014 Annual Report on Form 10-K and the companys other filings with the Securities and Exchange Commission (SEC) available at the SECs Internet site (www.sec.gov).

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Merck is Positioned for Long-Term Growth through Innovation

Premier Research-Driven Biopharmaceutical Company

New Focused Model Suite of Opportunities

Improving Operating Model

Accelerating BD Strategy

Four Key Growth Platforms

Multiple New Product Launches

Programs in Areas with Large Unmet Needs

Advancing Innovative Pipeline

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Investing Behind Products and Programs with the Greatest Returns Focus on Candidates with Unambiguous Promotable Advantages Resourcing Launch Opportunities Prioritization of Investment Leading to Overall Reduction in OpEx

New Focused Model is Driving Growth and Productivity

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Corporate

Commercial

Operating Expense

On track for $2.5B of cost savings by end of 2015 vs. 2012 base

Investing Behind the Best Sources of Growth Rigorous Portfolio Prioritization: Retaining Animal Health Divesting Non-Core Assets, including Consumer Care and Ophthalmics Acquiring Complementary Assets, including Idenix and Cubist

4 Priority Commercial Areas Top 10 Priority Markets Integrated Oncology Business Unit

Total deaths from diabetes are projected to increase by 50% in the next 10 years

Antibiotic-resistant bacteria infects over 2 million Americans annually, resulting in 23,000 deaths

HOSPITAL ACUTE CARE

DIABETES

Prevention of disease through vaccination is cost effective

VACCINES

Every year, 8 million people die from cancer worldwide

ONCOLOGY

Focused Areas Provide a Platform for Growth

5 Sources: CDC, WHO

Growth from Core Commercial Areas and Launches

Diabetes Hospital Acute Care Oncology Vaccines

KEYTRUDA (Melanoma) KEYTRUDA (NSCLC) BELSOMRA GARDASIL9 ZERBAXA

Core Focus Areas

Current and Near-term Launches

Potential Future Launches

Sales

Innovation MK-5172A (HCV)

Odanacatib (Osteoporosis)

Omarigliptin (Diabetes)

Anacetrapib (Atherosclerosis)

Doravirine (HIV)

MK-8931 (Alzheimers Disease)

Biosimilars Immunology Oncology Insulin

WAVE 1 WAVE 2

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$83mm in 1Q 2015 sales

Vast majority of ipilimumab-refractory melanoma patients being treated with KEYTRUDA

Strong access in labeled indication

Broad acceptance of KEYTRUDA in NCCN melanoma treatment guidelines

Launching New Products in Large Markets

Now launching in U.S. and Japan

~5,500 weekly prescriptions (mid-June)1

Achieved positive coverage decisions for ~50mm commercial lives, half with no step edit

Launch ongoing in U.S.

Beginning to see formulary additions

Growing issues with Gram-negative pathogens, including certain resistant species, driving positive discussions and positive formulary uptake

1. Source: IMS.

Merck is Advancing its Innovative Pipeline

2015 2016 2017 2018 2019+ 2014

KEYTRUDA NSCLC (KN-010)

Grazoprevir / Elbasvir (Hepatitis C)

KEYTRUDA Bladder Cancer (KN-045)

Anacetrapib (Atherosclerosis)

Actoxumab / Bezlotoxumab (C. Diff. Infection)

Ertugliflozin* (SGLT-2 Inhibitor)

Letermovir (HCMV prophylaxis)

BACE Inhibitor (Alzheimers Disease)

Surotomycin (C. Diff. Infection)

Earliest study primary completion date per clinicaltrials.gov Latest study primary completion date per clinicaltrials.gov

KEYTRUDA Head & Neck Cancer (KN-040)

Omarigliptin* (once weekly DPP-4)

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Doravirine (HIV)

* Light green arrow reflects CV outcomes studies for Omarigliptin and Ertugliflozin.

Dates per clinicaltrials.gov as of 5/19/2015

KEYTRUDA: Building a Foundation with Monotherapy

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Over 30 Different Tumor Types Under Investigation

Melanoma NSCLC

Mesothelioma SCLC

Esophageal Ovarian Renal

Colorectal

Head and Neck Bladder Gastric TNBC

Hodgkins Lymphoma

Wave 1 Wave 2 Wave 3

Overall Response Rate in Advanced NSCLC by PD-L1 Proportion Score (KEYNOTE-001)

45.2 43.9 50.0 16.5 15.6 19.2 10.7 9.1 16.7 0

102030405060708090

100

OR

R (9

5% C

I), %

PS 50% PS 1-49% PS

Lung Cancer: Largest Global Incidence and Worst Mortality

Source: GLOBOCAN 2012: Estimated cancer incidence, mortality and prevalence worldwide, in 2012.

0 500,000 1,000,000 1,500,000 2,000,000

Lung Breast

Colorectum Prostate Stomach

LiverHead & Neck

CervixEsophagus

Bladder Non-Hodgkin's lymphoma

Leukemia Pancreas

KidneyEndometrium

Thyroid Brain & CNS

Ovary Melanoma

Gallbladder Multiple myeloma

Hodgkin's lymphoma

IncidenceMortality

Number of Cancer Cases Per Year

Incidence of Lung Cancer ~8x Melanoma

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Improving Efficacy with Selective Combination Therapy

Standard Therapies

Targeted Therapies

Immuno-modulators

Novel Vaccines

Combination Strategy More than 40 Combinations Under Investigation

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REGISTRATION

Broad Pipeline is Advancing Rapidly

EARLY CLINICAL DEVELOPMENT

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KEYTRUDA NMEs

Over 30 Different Tumors Over 40 Different Combinations

MK-8628 (BET inhibitor): Solid tumors, hematologic malignancies

MK-4166 (Anti-GITR): Solid tumors

MK-1966 (anti-IL-10) + SD-101 (Dynavax): Solid and hematological tumors*

Melanoma 1L (KN006) 2L (KN002) Adjuvant (KN054) T-Vec combination (Amgen)*

NSCLC 1L (KN024) 1L (KN042) 2/3 L (KN010)

Head and Neck 1L + chemo/cetuximab (KN048) 2L (KN040) 3L (KN055)

Bladder 1L (KN052) 2L (KN045)

Gastric 2L (KN061) 3L (KN059)

Colorectal 3L MSI-high (KN164)*

Triple Negative Breast 2L (KN086)

RRcHL 3L (KN087)

*Planned

Merck Oncology: Broad Universe of Partnerships

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Potential Launches in Multiple Tumor Types

OTHERS

BLADDER

MELANOMA

HEAD & NECK

NON-SMALL- CELL LUNG

GASTRIC

CLASSICAL HODGKINS LYMPHOMA

TRIPLE NEGATIVE BREAST CANCER

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ADVANCED PLEURAL

MESOTHELIOMA

Initial market entry in metastatic melanoma Potential second indication in non-small-cell lung cancer Possible application in up to 30 different types of tumors

High rates of efficacy* demonstrated against key genotypes High barrier to resistance and activity against common resistance-

associated variants of HCV Single tablet given once-daily, no significant food effect Breakthrough designation from FDA for selected populations File submitted to FDA (May 28, 2015)

HCV NS3/4A inhibitor (100 mg once-daily, oral)

All-oral, once-daily, fixed-dose tablet

HCV NS5A inhibitor (50 mg, once-daily, oral)

Grazoprevir/Elbasvir regimen for the treatment of HCV infection

Grazoprevir (MK-5172)

Elbasvir (MK-8742)

*Defined as Sustained Virologic Response 12 weeks post-treatment, or SVR12. 16

C-CREST: Phase 2 program evaluates two different 3-drug regimens Designed to target broad range of genotypes Starts with 8 week regimens, and based on the results, will proceed to

investigate shorter durations

Looking to the future: The Merck triplet regimens

HCV NS5B Nucleoside inhibitor

HCV NS3/4A inhibitor HCV NS5A inhibitor

Grazoprevir (MK-5172)

Elbasvir (MK-8742) or

MK-8402 MK-3682

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~$30 billion global atherosclerosis market1

Phase 3 fully enrolled

Oral, once-daily, tablet being tested as additive therapy to statins

Study completion targeted for early 2017

~6 million people expected to have Alzheimers Disease in U.S. by 20202

Two Phase 3 studies enrolling mild-to-moderate or prodromal patients

BACE inhibitor prevents the formation of A-Beta peptides

First study completion targeted for early 2017

Anacetrapib: CETP Inhibitor for CV disease

BACE Inhibitor for Alzheimers Disease

Merck has Phase 3 Studies in Large Markets with Unmet Need

18 1. Source: IMS. 2. Source: 2014 Alzheimers Disease Facts and Figures, Alzheimers Association.

Mercks BD Strategy is Adding Value and Increasing Focus

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Idenix (HCV) Cubist (Hospital Care) OncoEthix (Oncology) Multiple Oncology

collaborations NewLink (Ebola Vaccine) Bayer CV collaboration NGM collaboration1 Moderna collaboration

Consumer Care Ophthalmology Saphris Diversified Brands (Aspen) Anti-IL-23

Acquiring

Divesting

1. Collaboration focused on Diabetes, Metabolic Dysregulation, and Oncology.

Merck Will Invest in the Business While Returning Cash to Shareholders

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5

17

-10

15

5

Cumulative Capital Allocation (2012-2014)

R&D1

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1. Non-GAAP R&D, as reported. 2. Change in Accounts Receivable, Inventories, and Trade Accounts Payable as reported on the Cash Flow Statement. 3. Acquisitions as reported on the Cash Flow Statement. 4. Divestitures as reported on the Cash Flow Statement, net of cash tax.

Invest excess cash in BD above hurdle rate; Otherwise return cash to shareholders

Fund the Business and Pay the Dividend

Capex & Working Capital

Change2

Dividend Share Repurchase

BD3

Divestitures4

$ billions

Merck is Creating Value and Returning Cash to Shareholders

0

5

10

15

2014 2013 2012 2011 2010

Dividends Paid Share Repurchase

$ bi

llion

s

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Dividends and share repurchases > 90% of Free Cash Flow

~$3B share repurchases annually (historically)

Grow dividend per share annually

2015: Merck Looking Forward to...

Growth in core areas

Multiple product launches ongoing

Near-term regulatory action for key programs

Targeting business development to drive long-term value

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Merck & Co., Inc.Forward-Looking Statement of Merck & Co., Inc., Kenilworth, NJ, USAMerck is Positioned for Long-Term Growth through InnovationNew Focused Model is Driving Growth and ProductivityFocused Areas Provide a Platform for GrowthGrowth from Core Commercial Areas and LaunchesLaunching New Products in Large MarketsMerck is Advancing its Innovative PipelineKEYTRUDA: Building a Foundation with MonotherapyOverall Response Rate in Advanced NSCLCby PD-L1 Proportion Score (KEYNOTE-001)Lung Cancer: Largest Global Incidence and Worst MortalityImproving Efficacy with Selective Combination TherapyBroad Pipeline is Advancing RapidlyMerck Oncology: Broad Universe of PartnershipsPotential Launches in Multiple Tumor TypesGrazoprevir/Elbasvir regimen for the treatment of HCV infectionLooking to the future: The Merck triplet regimensMerck has Phase 3 Studies in Large Markets with Unmet NeedMercks BD Strategy is Adding Value and Increasing FocusMerck Will Invest in the Business While Returning Cash to ShareholdersMerck is Creating Value and Returning Cash to Shareholders2015: Merck Looking Forward to...