VOL. XCIV, NO. 247

★ MOAT STOCKS & COMPETITIVE ADVANTAGES ★

PRICE: 5 CENTS

Tuesday, December 23, 2025

Merck & Co., Inc.

MRK · New York Stock Exchange

active
Market cap (USD)$250.9B
SectorHealthcare
CountryUS
Data as of
Moat score
71/ 100

Weighted average of segment moat scores, combining moat strength, durability, confidence, market structure, pricing power, and market share.

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Overview

Merck & Co., Inc. is a research-driven biopharmaceutical company with two reportable segments: Pharmaceutical and Animal Health. The Pharmaceutical segment is anchored by patented, differentiated medicines and vaccines, where intellectual property/exclusivity and regulatory barriers underpin returns, with additional support from complex biologics/vaccine manufacturing know-how. Animal Health combines veterinary medicines/vaccines with connected identification, traceability and monitoring solutions, benefiting from global scope plus workflow integration in technology offerings. Key erosion risks include blockbuster patent cliffs (especially Keytruda later this decade) and sustained net-price pressure from payers and government policy.

Primary segment

Pharmaceutical

Market structure

Competitive

Market share

HHI:

Coverage

2 segments · 4 tags

Updated 2025-12-22

Segments

Pharmaceutical

Branded prescription pharmaceuticals & human vaccines

Revenue

89.5%

Structure

Competitive

Pricing

moderate

Share

Peers

AZNBMYJNJLLY+3

Animal Health

Veterinary pharmaceuticals, vaccines, and animal health technology (ID/traceability/monitoring)

Revenue

9.2%

Structure

Oligopoly

Pricing

moderate

Share

8%-10% (implied)

Peers

ELANVETO.PAVIRP.PAZTS

Moat Claims

Pharmaceutical

Branded prescription pharmaceuticals & human vaccines

Revenue_share is computed using FY2024 total sales and reported segment sales; operating_profit_share uses Merck's segment profit measure (not GAAP operating income).

Competitive

IP Choke Point

Legal

Strength: 5/5 · Durability: medium · Confidence: 5/5 · 3 evidence

Patents + regulatory exclusivities (e.g., data/pediatric exclusivity) create time-limited monopoly periods for key products; loss of exclusivity typically triggers rapid generic/biosimilar erosion.

Erosion risks

  • Patent cliffs for blockbuster products (e.g., Keytruda) and accelerated generic/biosimilar uptake
  • Patent challenges / adverse court outcomes / weaker IP regimes in some markets
  • Government price-setting or reimbursement reforms compressing economics even before loss of exclusivity

Leading indicators

  • Key patent & regulatory exclusivity expiry calendar (per product/region)
  • Paragraph IV / biosimilar litigation filings and outcomes
  • Medicare negotiation inclusion and negotiated price effective dates under the IRA

Counterarguments

  • Exclusivity is finite; large rivals can take share quickly at/after LOE via generics/biosimilars or superior new therapies
  • Policy-driven pricing and payer controls can weaken realized pricing power even within exclusivity windows

Regulated Standards Pipe

Legal

Strength: 4/5 · Durability: durable · Confidence: 4/5 · 1 evidence

Drug/vaccine discovery, clinical trials, manufacturing, and marketing are heavily regulated; approval timelines and compliance create high barriers to entry and slow competitive replication.

Erosion risks

  • Regulatory setbacks (e.g., Complete Response Letters), labeling restrictions, safety issues
  • Evolving trial standards increasing cost/time to approval
  • Manufacturing quality findings leading to supply constraints

Leading indicators

  • Regulatory submission/approval cadence for late-stage pipeline
  • Inspection outcomes (e.g., Form 483s, warning letters) and recall/shortage events
  • Clinical readouts for major lifecycle-management programs

Counterarguments

  • Regulation is an industry-wide barrier; other large pharma have comparable regulatory capability
  • Breakthrough modalities can let entrants leapfrog incumbents despite high regulatory hurdles

Capex Knowhow Scale

Supply

Strength: 3/5 · Durability: medium · Confidence: 4/5 · 1 evidence

Biologics and vaccine manufacturing requires specialized facilities, validation, and quality systems; scale and process know-how help reliability, speed, and cost over time.

Erosion risks

  • CDMO capacity expansion reducing scarcity of complex manufacturing
  • Process standardization and platform technologies lowering replication costs
  • Regulatory/quality failures causing supply disruptions

Leading indicators

  • Capacity expansion/tech transfer announcements (internal + competitors + CDMOs)
  • Manufacturing deviation rates and product supply continuity
  • Unit-cost trends for key biologics/vaccines where disclosed

Counterarguments

  • Other top pharma and CDMOs can replicate complex manufacturing capabilities over time
  • Manufacturing advantage matters less if competing clinical profiles are superior

Animal Health

Veterinary pharmaceuticals, vaccines, and animal health technology (ID/traceability/monitoring)

Revenue_share is computed using FY2024 total sales and reported segment sales; operating_profit_share uses Merck's segment profit measure (not GAAP operating income).

Oligopoly

Scope Economies

Supply

Strength: 3/5 · Durability: durable · Confidence: 3/5 · 1 evidence

Broad portfolio spanning biopharmaceuticals and technology solutions, plus global commercial footprint, supports cross-selling and channel leverage across species and geographies.

Erosion risks

  • Portfolio gaps vs. peers in high-growth companion animal categories
  • Channel shifts (direct-to-consumer, online pharmacies) reducing traditional vet/channel leverage
  • M&A by rivals expanding competing portfolios and scope

Leading indicators

  • New product launches and label expansions in companion animal (parasites, dermatology, OA pain)
  • Geographic expansion and distributor/channel partnerships
  • Mix shift toward higher-margin companion animal franchises

Counterarguments

  • Animal health peers also have broad portfolios and global reach; scope may not translate into superior economics
  • Product innovation cycles can outweigh portfolio breadth

Data Workflow Lockin

Demand

Strength: 3/5 · Durability: durable · Confidence: 3/5 · 2 evidence

Livestock identification, traceability, and monitoring solutions integrate into farm workflows; switching can require hardware replacement and data migration, creating operational lock-in.

Erosion risks

  • Commoditization of hardware tags/sensors and emergence of open standards
  • Interoperability improvements lowering switching costs
  • Lower-cost entrants bundling hardware + software

Leading indicators

  • Technology solutions revenue growth vs. pure biopharma products
  • Customer retention/renewal metrics (if disclosed) and product attach rates
  • Adoption of industry interoperability standards

Counterarguments

  • Farmers may multi-source and resist proprietary ecosystems; lock-in may be weaker than in enterprise software
  • Competitors can win via better analytics or lower total cost of ownership

Regulated Standards Pipe

Legal

Strength: 3/5 · Durability: durable · Confidence: 3/5 · 1 evidence

Veterinary medicines and vaccines must satisfy regulatory standards for safety, efficacy, manufacturing, and labeling; approvals and quality compliance slow entrants and protect incumbents.

Erosion risks

  • Regulatory changes that speed approvals or increase reliance on real-world evidence
  • Adverse events leading to label restrictions or withdrawal
  • Increased scrutiny on antimicrobial use in livestock

Leading indicators

  • Regulatory approvals for new veterinary biologics/pharma and major label expansions
  • Inspection outcomes and manufacturing quality events
  • Policy changes on livestock antibiotic usage

Counterarguments

  • Regulatory barriers are shared across incumbents; not uniquely advantaging Merck vs. Zoetis/Boehringer/Elanco
  • Some categories can face faster generic competition and pricing pressure

Evidence

sec_filing
Merck & Co., Inc. Form 10-K (FY ended 2024-12-31) - Patent protection / market exclusivity discussion

Patent protection is considered... of material importance.

Company states patent protection is material to marketing human and animal health products; supports IP-based moat framing.

sec_filing
Merck & Co., Inc. Form 10-K (FY ended 2024-12-31) - Loss of exclusivity risk

...significant and rapid loss of sales...

Company highlights rapid sales declines as products lose market exclusivity; reinforces time-limited nature and cliff risk of the moat.

sec_filing
Merck & Co., Inc. Form 10-K (FY ended 2024-12-31) - Key product market exclusivity table

10-K lists key product market exclusivity; KEYTRUDA compound patent expiry is shown as 2028 in the U.S. (and 2028 in the EU), illustrating the scale and timing of the largest patent cliff.

sec_filing
Merck & Co., Inc. Form 10-K (FY ended 2024-12-31) - Regulatory environment

...subject to extensive regulation...

Company describes its activities (development, manufacturing, marketing) as subject to extensive regulation by FDA and other authorities.

sec_filing
Merck & Co., Inc. Form 10-K (FY ended 2024-12-31) - Biologics/vaccines manufacturing complexity

Company notes manufacturing biologics/vaccines is complex and requires specifically designed facilities and sophisticated quality control systems.

Showing 5 of 12 sources.

Risks & Indicators

Erosion risks

  • Patent cliffs for blockbuster products (e.g., Keytruda) and accelerated generic/biosimilar uptake
  • Patent challenges / adverse court outcomes / weaker IP regimes in some markets
  • Government price-setting or reimbursement reforms compressing economics even before loss of exclusivity
  • Regulatory setbacks (e.g., Complete Response Letters), labeling restrictions, safety issues
  • Evolving trial standards increasing cost/time to approval
  • Manufacturing quality findings leading to supply constraints

Leading indicators

  • Key patent & regulatory exclusivity expiry calendar (per product/region)
  • Paragraph IV / biosimilar litigation filings and outcomes
  • Medicare negotiation inclusion and negotiated price effective dates under the IRA
  • Regulatory submission/approval cadence for late-stage pipeline
  • Inspection outcomes (e.g., Form 483s, warning letters) and recall/shortage events
  • Clinical readouts for major lifecycle-management programs
Created 2025-12-22
Updated 2025-12-22

Curation & Accuracy

This directory blends AI‑assisted discovery with human curation. Entries are reviewed, edited, and organized with the goal of expanding coverage and sharpening quality over time. Your feedback helps steer improvements (because no single human can capture everything all at once).

Details change. Pricing, features, and availability may be incomplete or out of date. Treat listings as a starting point and verify on the provider’s site before making decisions. If you spot an error or a gap, send a quick note and I’ll adjust.