Can Merck Grow Beyond KEYTRUDA? WINREVAIR, KEYTRUDA QLEX and the Next-Generation Pipeline

Summary

Merck's biggest strategic question is increasingly straightforward:

Can the company build enough new growth before conventional KEYTRUDA faces significant loss-of-exclusivity pressure?

The answer will likely depend on a portfolio rather than one replacement drug.

Important candidates include:

• KEYTRUDA QLEX;
• WINREVAIR;
• WELIREG;
• LIPFENDRA;
• OHTUVAYRE;
• new oncology assets;
• individualized cancer therapy;
• HIV programs;
• immunology and ophthalmology assets.

Merck says its potential new growth drivers represent more than $70 billion of non-risk-adjusted annual sales opportunity by the mid-2030s.

For MRKON, the key question is how much of that theoretical pipeline opportunity eventually becomes real commercial revenue.

Why Merck Needs New Growth Drivers

KEYTRUDA remains extraordinarily successful.

But concentration creates vulnerability.

In Q2 2026:

Merck total sales: $16.607B

KEYTRUDA + QLEX: $8.366B

A company with roughly half of quarterly revenue tied to one franchise needs diversification well before major exclusivity changes arrive.

1. KEYTRUDA QLEX

QLEX is already moving from pipeline story to commercial product.

Sales rose from $128 million in Q1 2026 to $463 million in Q2.

Its longer listed U.S. compound-patent protection—2043 versus 2028 for conventional KEYTRUDA—makes it strategically important.

However, future adoption needs to be measured rather than assumed.

2. WINREVAIR

WINREVAIR is one of the strongest examples of diversification already appearing in reported revenue.

Q2 2026 sales reached $588 million, up 75%.

Its opportunity could also broaden.

Positive Phase 2 CADENCE data supported moving into Phase 3 development for CpcPH-HFpEF, a distinct population with no specifically approved therapy.

Successful indication expansion could meaningfully increase the franchise's long-term value.

3. WELIREG

WELIREG generated $271 million in Q2 2026, up 67%.

It is another example of Merck building oncology revenue outside KEYTRUDA itself.

No single smaller oncology product needs to replace KEYTRUDA if several franchises scale simultaneously.

4. LIPFENDRA and Cardiometabolic Expansion

Merck received U.S. FDA approval in 2026 for LIPFENDRA, enlicitide, an oral PCSK9 inhibitor designed to reduce LDL cholesterol in adults with hypercholesterolemia.

The strategic attraction is clear:

cardiovascular markets can be very large, and a successful oral therapy could diversify Merck away from oncology.

But commercial success will depend on:

• physician adoption;
• payer access;
• competition;
• adherence;
• pricing.

5. OHTUVAYRE Adds Respiratory Exposure

OHTUVAYRE generated $204 million in Q2 2026, according to Merck's product sales table.

The product expands Merck's presence in respiratory medicine and contributes to a broader cardiometabolic/respiratory growth platform.

6. Individualized Cancer Therapy Could Extend Merck's Oncology Leadership

Merck's partnership with Moderna around intismeran autogene is potentially important because it combines personalized cancer treatment with KEYTRUDA.

The Phase 3 INTerpath-001 study met both RFS and DMFS endpoints in resected high-risk melanoma.

If approved, the platform could:

• create a differentiated treatment approach;
• extend the KEYTRUDA ecosystem;
• provide a new oncology growth franchise.

Commercial execution remains unproven, however.

7. Antibody-Drug Conjugates Could Become Another Growth Pillar

Merck is investing heavily in antibody-drug conjugates and other next-generation oncology approaches.

These therapies attempt to deliver cancer-killing agents more selectively to tumor cells.

For investors, the important question is not how many pipeline assets Merck owns.

It is how many eventually produce:

positive Phase 3 data → approval → meaningful commercial sales.

8. HIV Can Diversify the Business Further

Merck continues advancing HIV treatment regimens, including islatravir-based approaches.

Its Q2 2026 update reported positive Phase 3 results for a once-weekly investigational oral HIV regimen of islatravir and lenacapavir in collaboration with Gilead.

A successful long-acting or less-frequent treatment franchise could open another substantial market outside oncology.

9. Acquisitions Are Part of the Replacement Strategy

Merck has used acquisitions to add pipeline assets rather than relying exclusively on internal R&D.

Its 2026 Terns Pharmaceuticals acquisition added MK-4208, formerly TERN-701, an investigational hematology asset.

Business development allows Merck to buy additional shots on goal.

It also creates risk:

• acquisition premiums;
• integration;
• clinical failure;
• impairment.

What Does the >$70B Pipeline Figure Actually Mean?

Merck's shareholder presentation states that potential new growth drivers could represent more than $70 billion in non-risk-adjusted annual sales by the mid-2030s.

Two words matter:

non-risk-adjusted.

Suppose five experimental drugs each have potential peak sales of $5 billion.

Adding them together produces $25 billion of theoretical opportunity.

But if each has only a 50% probability of reaching successful commercial scale, treating the whole $25 billion as certain would overstate the value.

This is why pharmaceutical investors use probability-adjusted forecasts.

How to Judge Whether Merck's Diversification Is Working

Watch four stages:

Stage 1: Clinical Validation

Are late-stage trials succeeding?

Stage 2: Regulatory Conversion

Are successful trials turning into approvals?

Stage 3: Launch Execution

Are doctors and patients actually adopting the products?

Stage 4: Revenue Scale

Are new franchises becoming large enough to matter relative to KEYTRUDA?

Sarah Chen: Merck Does Not Need Another KEYTRUDA

According to MEXC senior analyst Sarah Chen, investors sometimes frame the replacement challenge incorrectly.

"Merck does not necessarily need one drug that recreates $30 billion-plus of annual KEYTRUDA sales. A portfolio of five or ten meaningful franchises can create a more diversified earnings base."

That would arguably improve the quality of the revenue mix.

"The real test is whether enough pipeline programs become commercially relevant before KEYTRUDA erosion becomes material. WINREVAIR and QLEX matter because they are already generating measurable revenue. Other pipeline programs still require more probability discounting."

How This Connects to MRKON

MRKON ultimately reflects MRK's equity economics.

The long-term chain is:

pipeline success

↓

new product revenue

↓

reduced KEYTRUDA dependence

↓

Merck earnings durability

↓

MRK valuation

↓

MRKON

That makes pipeline diversification one of the most important long-term MRKON themes.

FAQ

Can Merck grow after KEYTRUDA loses exclusivity?

Possibly, but the outcome depends on QLEX conversion, new product launches, clinical success and commercial execution.

What is Merck's biggest newer product?

WINREVAIR is already one of the most important newer franchises, with Q2 2026 sales of $588 million.

What does Merck's $70B pipeline opportunity mean?

It is a non-risk-adjusted estimate of potential annual sales opportunity by the mid-2030s, not a guaranteed revenue forecast.

Can KEYTRUDA QLEX help after 2028?

It may help extend the franchise, but future competitive dynamics and adoption still matter.

Why does this matter for MRKON?

Because MRKON provides economic exposure linked to MRK, whose long-term valuation depends heavily on Merck's post-KEYTRUDA growth.

Conclusion

Merck's future is unlikely to depend on finding one replacement for KEYTRUDA.

The more realistic strategy is portfolio replacement:

QLEX

WINREVAIR

WELIREG

cardiometabolic drugs

individualized cancer therapy

ADCs

HIV

immunology

new acquisitions

The success or failure of that diversification will increasingly determine MRK—and therefore MRKON—through the late 2020s and into the 2030s.