Labcorp Launches FDA-Approved Companion Diagnostic to Identify Patients with Ovarian Cancer Eligible for KEYTRUDA®

Labcorp (NYSE: LH) announced nationwide availability of Agilent's PD-L1 IHC 22C3 pharmDx on April 22, 2026, the only FDA‑approved companion diagnostic to identify patients with platinum‑resistant ovarian cancer eligible for Merck's KEYTRUDA therapies.

Rhea-AI Summary

Labcorp (NYSE: LH) announced nationwide availability of Agilent's PD-L1 IHC 22C3 pharmDx on April 22, 2026, the only FDA‑approved companion diagnostic to identify patients with platinum‑resistant ovarian cancer eligible for Merck's KEYTRUDA therapies.

Labcorp joined Agilent's Early Validation Program to prepare standardized training and rapid rollout following the FDA's February approvals of KEYTRUDA and KEYTRUDA QLEX alongside the diagnostic.

Positive

• Nationwide availability of FDA‑approved companion diagnostic (Apr 22, 2026)
• Enables identification of patients eligible for KEYTRUDA and KEYTRUDA QLEX
• Participation in Agilent Early Validation Program supported rapid testing rollout

Negative

• None.

Argus Apr 22 session

-0.29% close to close Open Argus

Details

News Market Reaction – LH

In the Apr 22 session, LH declined 0.29%, reflecting a mild negative market reaction.

Data tracked by StockTitan Argus on the day of publication.

Market Context

This announcement highlights Labcorp’s nationwide rollout of an FDA-approved PD-L1 companion diagnos...

Analysis

This announcement highlights Labcorp’s nationwide rollout of an FDA-approved PD-L1 companion diagnostic to identify patients with platinum-resistant ovarian cancer eligible for KEYTRUDA-based regimens. It adds to a recent stream of product, partnership and innovation news, alongside solid 2025 financial metrics such as revenue of $14.0 billion and adjusted EPS of $16.44. Investors may watch adoption of this test, oncology volumes, and upcoming Q1 2026 results for indications of financial impact.

Key Figures

2025 Revenue: $14.0 billion Diluted EPS 2025: $10.46 Adjusted EPS 2025: $16.44 +5 more

2025 Revenue

$14.0 billion

Reported in 2026 DEF 14A, vs prior year

Diluted EPS 2025

$10.46

Reported in 2026 DEF 14A, vs $8.84 prior year

Adjusted EPS 2025

$16.44

Reported in 2026 DEF 14A, vs $14.57 prior year

Free cash flow 2025

$1.2 billion

Reported in 2026 DEF 14A, vs $1.1 billion prior year

Quarterly dividend

$0.72 per share

Declared payable on June 11, 2026

Share price

$273.42

Pre-news price context on article date

Ovarian cancer recurrence

80%

Approximate recurrence rate after initial therapy cited in article

Daily move

1.57%

24-hour price change prior to this news

Historical Context

5 past events · Latest: Apr 15

5 events

1. Apr 15

   Product launch

   24h Move

   -0.8%

   Launch of FDA-cleared rapid fentanyl urine test with 10-minute results.

2. Apr 14

   AI data platform

   24h Move

   +1.8%

   AI-powered real-world data platform to accelerate Alzheimer’s research.

3. Apr 13

   Strategic collaboration

   24h Move

   +1.3%

   Collaboration with CHOP to advance pediatric diagnostics nationwide.

4. Apr 09

   Dividend declaration

   24h Move

   -0.5%

   Quarterly cash dividend of $0.72 per share announced.

5. Mar 31

   Earnings date set

   24h Move

   +2.2%

   Scheduled release of Q1 2026 results and webcast details.

24h Move is the share-price change in the day after each event; other market factors may also have contributed.

Key Terms

companion diagnostic, u.s. food and drug administration (fda), pd-l1, ihc, +4 more

8 terms

companion diagnostic medical

"the only companion diagnostic approved by the U.S. Food and Drug Administration"

A companion diagnostic is a medical test designed to identify which patients are likely to benefit from a specific drug or medical treatment, much like a key that shows whether a particular lock will open. For investors, these tests matter because they can increase a drug’s chances of approval and market uptake, create a separate revenue stream, and reduce commercial risk by matching treatments to the patients most likely to respond.

u.s. food and drug administration (fda) regulatory

"the only companion diagnostic approved by the U.S. Food and Drug Administration (FDA)"

The U.S. Food and Drug Administration (FDA) is a government agency responsible for protecting public health by ensuring the safety and effectiveness of food, medicines, vaccines, and other health-related products. For investors, the FDA’s decisions can significantly impact companies in the healthcare and food industries, as approval or rejection of products can influence a company's success and stock performance.

pd-l1 medical

"Agilent Technologies' PD-L1 IHC 22C3 pharmDx, the only companion diagnostic"

PD-L1 is a protein found on the surface of some cells that acts like a stop sign for the immune system, telling certain immune cells to back off. It matters to investors because many cancer drugs and diagnostic tests target or measure PD-L1 to unlock immune responses or predict which patients will benefit, affecting clinical success, regulatory approval, and potential sales in the oncology market.

ihc medical

"Agilent Technologies' PD-L1 IHC 22C3 pharmDx, the only companion diagnostic"

Immunohistochemistry (IHC) is a laboratory technique that uses labeled antibodies to detect and visually highlight specific proteins inside tissue samples, producing stained patterns pathologists can see under a microscope. For investors, IHC matters because it helps confirm whether a drug or diagnostic hits the intended target in real patient tissues and can support patient selection, clinical trial design and regulatory filings — essentially acting like a map that shows where a therapy is likely to work and reducing clinical and regulatory risk.

pd-1 inhibitors medical

"the first FDA-approved PD-1 inhibitors available as part of a complete treatment regimen"

PD-1 inhibitors are drugs that block a “brake” protein on immune cells so the body’s own defenses can recognize and attack cancer cells. They matter to investors because successes or failures in clinical trials, regulatory approvals, or wider use can sharply change a drug maker’s revenue prospects and valuation; safety problems or competition can similarly affect future earnings and stock price.

platinum-resistant ovarian cancer medical

"patients with platinum-resistant ovarian cancer who may be eligible for Merck's KEYTRUDA"

A form of ovarian cancer that stops responding to standard platinum-based chemotherapy, typically when the disease returns within about six months after treatment; think of it like a pest becoming resistant to a once-effective pesticide. It matters to investors because this resistance creates a large unmet medical need, shaping demand for new drugs, clinical trial strategies, regulatory priority and potential pricing — all of which can materially affect company value and market opportunity.

overall survival medical

"found to reduce the risk of disease progression and improve overall survival"

Overall survival is the average or median length of time patients remain alive after starting a treatment or entering a clinical study, measured regardless of cause of death. Investors care because it is a clear, hard measure of a therapy’s real-world benefit — like timing how long a new battery actually runs — and strong improvements in overall survival can drive regulatory approval, market adoption and revenue potential.

early validation program technical

"Labcorp participated in Agilent Technologies' Early Validation Program to help support rapid"

An early validation program is a structured effort to test a new product, technology, or clinical idea with real users, patients, or regulators before full development and commercial launch. Think of it as a dress rehearsal that checks whether the concept works, is safe, and meets buyer or regulator expectations; for investors, successful early validation lowers technical, regulatory and market risk and provides evidence that supports funding, timelines, and realistic valuation.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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BURLINGTON, N.C., April 22, 2026 /PRNewswire/ -- Labcorp (NYSE: LH), a global leader of innovative and comprehensive laboratory services, today announced the nationwide availability of Agilent Technologies' PD-L1 IHC 22C3 pharmDx, the only companion diagnostic approved by the U.S. Food and Drug Administration (FDA) to identify patients with platinum-resistant ovarian cancer who may be eligible for Merck's KEYTRUDA®.ⁱ KEYTRUDA (pembrolizumab) and KEYTRUDA QLEX™ (pembrolizumab and berahyaluronidase alfa-pmph) are the first FDA-approved PD-1 inhibitors available as part of a complete treatment regimen for eligible patients with platinum-resistant ovarian cancer.ⁱⁱ

Helping Patients Access Critical New Treatment Options
Approximately 80% of individuals with ovarian cancer experience recurrence after initial therapy, and many develop resistance to platinum-based chemotherapy, leading to limited treatment options and poor survival outcomes. The approval of KEYTRUDA and KEYTRUDA QLEX in this setting introduces meaningful new treatment options that have been found to reduce the risk of disease progression and improve overall survival.ⁱⁱⁱ Labcorp's nationwide availability of PD-L1 IHC 22C3 pharmDx enables clinicians to quickly identify patients who may benefit from these newly approved treatments.

"Platinum-resistant ovarian cancer is incurable, and current treatment options offer limited and short-lived benefits for patients—making it one of the most challenging forms of the disease to treat," said Dr. Marcia Eisenberg, Ph.D., chief scientific officer at Labcorp. "By making this companion diagnostic available nationwide, Labcorp is helping clinicians rapidly identify eligible patients and connecting them with a therapy that offers new hope."

Supporting Early Access Following FDA Approvals
Following the FDA's February approval of KEYTRUDA and KEYTRUDA QLEX alongside PD-L1 IHC 22C3 pharmDx,ⁱⁱ Labcorp participated in Agilent Technologies' Early Validation Program to help support rapid testing availability. Through standardized training and readiness activities, Labcorp was prepared to expand nationwide access quickly following approval.

For more information about Labcorp's Oncology solutions, contact us at https://oncology.labcorp.com/contact-us.

About Labcorp
Labcorp (NYSE: LH) is a global leader of innovative and comprehensive laboratory services that helps doctors, hospitals, pharmaceutical companies, researchers and patients make clear and confident decisions. We provide insights and advance science to improve health and improve lives through our unparalleled diagnostics and drug development laboratory capabilities. The company's nearly 71,000 employees serve clients in approximately 100 countries, provided support for more than 85% of the new drugs and therapeutic products approved by the FDA in 2025 and performed more than 750 million tests for patients around the world. Learn more at www.labcorp.com.

KEYTRUDA® is a registered trademark and KEYTRUDA QLEX™ is a registered trademark of Merck Sharp & Dohme LLC., a subsidiary of Merck & Co., Inc., Rahway, NJ, USA

ⁱThe FDA approved the PD-L1 IHC 22C3 pharmDx test from Agilent Technologies as a companion diagnostic that detects PD-L1 expression in epithelial ovarian, fallopian tube, or primary peritoneal carcinoma (EOC), and is indicated as an aid in identifying patients for treatment with KEYTRUDA, Merck's anti-PD-1 therapy.

ⁱⁱThe FDA simultaneously approved KEYTRUDA (pembrolizumab) and KEYTRUDA QLEX (pembrolizumab and berahyaluronidase alfa-pmph) plus paclitaxel, with or without bevacizumab, for the treatment of adults with PD-L1+ (Combined Positive Score [CPS] ≥1), as determined by an FDA-authorized test, platinum-resistant epithelial ovarian, fallopian tube or primary peritoneal carcinoma, who have received one or two prior systemic treatment regimens.

ⁱⁱⁱThe Phase 3 KEYNOTE‑B96 (ENGOT‑ov65) trial showed KEYTRUDA plus paclitaxel, with or without bevacizumab, demonstrated a statistically significant and clinically meaningful improvement in progression-free survival (PFS), the trial's primary endpoint, and overall survival (OS), a key secondary endpoint, for patients with platinum-resistant recurrent ovarian cancer whose tumors expressed PD-L1 (CPS ≥1) compared to placebo plus paclitaxel, with or without bevacizumab.

View original content to download multimedia:https://www.prnewswire.com/news-releases/labcorp-launches-fda-approved-companion-diagnostic-to-identify-patients-with-ovarian-cancer-eligible-for-keytruda-302749466.html

SOURCE Labcorp

FAQ

What did Labcorp announce on April 22, 2026 regarding ovarian cancer testing (LH)?

Labcorp announced nationwide availability of Agilent's FDA‑approved PD‑L1 IHC 22C3 pharmDx companion diagnostic. According to the company, this test identifies patients with platinum‑resistant ovarian cancer who may be eligible for KEYTRUDA and KEYTRUDA QLEX following February FDA approvals.

How does the PD‑L1 IHC 22C3 pharmDx test affect eligibility for KEYTRUDA (LH)?

The test helps clinicians identify patients whose tumors express PD‑L1 and may benefit from KEYTRUDA treatment. According to the company, PD‑L1 IHC 22C3 pharmDx is the FDA‑approved companion diagnostic for this indication in platinum‑resistant ovarian cancer.

When were KEYTRUDA and KEYTRUDA QLEX approved alongside the companion diagnostic for ovarian cancer?

The FDA approved KEYTRUDA and KEYTRUDA QLEX alongside PD‑L1 IHC 22C3 pharmDx in February 2026. According to the company, those approvals created a new treatment option for eligible patients with platinum‑resistant ovarian cancer.

What role did Labcorp play in making the companion diagnostic available nationwide (LH)?

Labcorp participated in Agilent's Early Validation Program and completed standardized training to expand testing quickly. According to the company, these readiness activities supported rapid nationwide availability after FDA approval.

Who are the patients targeted by the PD‑L1 IHC 22C3 pharmDx test offered by Labcorp (LH)?

The test targets patients with platinum‑resistant ovarian cancer to identify those who may be eligible for PD‑1 inhibitor therapy. According to the company, many patients face recurrence and limited options after platinum‑based chemotherapy.

How can clinicians access Labcorp's PD‑L1 IHC 22C3 pharmDx testing services (LH)?

Clinicians can order the companion diagnostic through Labcorp's oncology testing channels for nationwide processing. According to the company, additional information and contact options are available via Labcorp's oncology services site.