Merck Highlights New Long-Term Data and Advancements Across Broad Oncology Portfolio and Pipeline Research at ASCO 2026

Five-year follow-up data from KEYNOTE-942 underscore the continued potential of intismeran autogene (mRNA-4157 or V940) in combination with KEYTRUDA^® (pembrolizumab) for patients with resected high-risk melanoma

Results from the final analysis of KEYNOTE-522, evaluating KEYTRUDA in combination with chemotherapy, demonstrate continued survival benefit for patients with high-risk early-stage triple-negative breast cancer (TNBC)

New data for sacituzumab tirumotecan (sac-TMT), an investigational TROP2‑directed antibody‑drug conjugate, add to ongoing research of novel treatment approaches for patients with non‑small cell lung cancer

Data from ASCENT-04/KEYNOTE-D19, evaluating KEYTRUDA plus Trodelvy^® (sacituzumab govitecan-hziy) for patients with metastatic TNBC, will be featured in the official ASCO 2026 Press Program

RAHWAY, N.J.--(BUSINESS WIRE)--$MRK #MRK--Merck (NYSE: MRK), known as MSD outside of the United States and Canada, today announced new research from more than 100 abstracts across over 25 types of cancer from the company’s comprehensive oncology portfolio and pipeline will be presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting (May 29-June 2). The data reinforce the long-term impact of KEYTRUDA^® (pembrolizumab), Merck’s anti-PD-1 therapy, and Merck’s rapidly advancing pipeline across multiple tumor types and stages of disease, highlighting the company’s leadership in oncology and commitment to advancing innovative oncology research.

“During ASCO, we will present data that showcase the strong momentum in our oncology pipeline, including long-term data for intismeran autogene, our investigational individualized neoantigen therapy (INT),” said Dr. Marjorie Green, senior vice president and head of oncology global clinical development, Merck Research Laboratories. “We look forward to sharing new research for our oncology medicines and novel treatment approaches, such as our INT and antibody-drug conjugates, which may help address significant unmet medical needs for patients living with cancer.”

Key data from Merck’s portfolio and pipeline to be presented:

• Five-year follow-up data from the Phase 2b KEYNOTE-942 trial evaluating intismeran autogene in combination with KEYTRUDA for patients with high-risk melanoma following complete resection (Abstract #9500, Oral abstract session: Melanoma/skin cancers).¹
• Final analysis results from the Phase 3 KEYNOTE-522 trial evaluating KEYTRUDA in combination with chemotherapy as pre-operative treatment and then continuing as a single agent after surgery for the treatment of patients with high-risk early-stage triple-negative breast cancer (TNBC) (Abstract #507, Oral abstract session: Breast cancer – local/regional/adjuvant).
• Data from the Phase 3 OptiTROP-Lung05 trial conducted in China, led by Kelun-Biotech, evaluating sac-TMT plus KEYTRUDA in advanced non-small cell lung cancer (Abstract #8506, Oral abstract session: Lung cancer – non-small cell metastatic).²
• Progression-free survival data from the Phase 3 ASCENT-04/KEYNOTE-D19 study evaluating KEYTRUDA plus Trodelvy (sacituzumab govitecan-hziy) in previously untreated PD-L1-positive metastatic TNBC ​​(Abstract #LBA1000, Oral abstract session: Breast cancer – metastatic).​³

Merck investor event

Merck will hold an Oncology Investor Event to coincide with the 2026 ASCO Annual Meeting on Monday, June 1, 2026, 6 p.m. CT, during which senior management will provide an update on the company’s oncology strategy and program. The event will take place in Chicago, Ill., and will be accessible via webcast. Investors, analysts, members of the media and the general public are invited to listen to a webcast of the presentation via this weblink. All participants may join the call by dialing (800) 369-2154 (U.S. and Canada Toll-Free) or (517) 308-9422 and using the access code 8711041.

Details on abstracts listed above and additional key abstracts for Merck

¹ In collaboration with Moderna
² Led by Kelun-Biotech, conducted in China
³ In collaboration with Gilead. Trodelvy is a registered trademark of Gilead Sciences, Inc., or its related companies.
⁴ In collaboration with Astellas/Pfizer
⁵ Sponsored by U.S. National Cancer Institute (NCI)/led by Alliance for Clinical Trials in Oncology
⁶ Sponsored by U.S. National Cancer Institute (NCI)/led by NRG Oncology
⁷ In collaboration with Daiichi Sankyo

About intismeran autogene (mRNA-4157 or V940)

Intismeran autogene is a novel investigational messenger RNA (mRNA)-based individualized neoantigen therapy (INT) consisting of a synthetic mRNA coding for up to 34 neoantigens that is designed and produced based on the unique mutational signature of the DNA sequence of the patient’s tumor. Upon administration into the body, the algorithmically derived and RNA-encoded neoantigen sequences are endogenously translated and undergo natural cellular antigen processing and presentation, a key step in adaptive immunity. Individualized neoantigen therapies are designed to train and activate an antitumor immune response by generating specific T-cell responses based on the unique mutational signature of a patient’s tumor.

About sacituzumab tirumotecan (sac-TMT)

Sac-TMT is an investigational TROP2-directed ADC with a belotecan-derived topoisomerase I inhibitor payload and a bifunctional linker designed with the potential to maximize payload delivery to tumor cells and minimize payload loss while circulating in the body. Sac-TMT is the only TROP2 ADC designed with a focus on both ends of the linker.

TROP2 is overexpressed on tumor cells compared to healthy cells in many common cancers, and through the TroFuse clinical development program, Merck is evaluating sac-TMT in 17 ongoing global Phase 3 trials across multiple tumor types, the broadest range of disease and treatment settings compared to any TROP2-directed ADC to date. The TroFuse development program spans early‑to-late‑stage disease in more than nine disease areas and includes more than 15,000 patients worldwide. Numerous Phase 3 trials are exploring sac-TMT as monotherapy and in combination with immunotherapies, aiming to improve survival and quality of life for patients with advanced and earlier-stage cancers.

About raludotatug deruxtecan (R-DXd)

Raludotatug deruxtecan is an investigational, potential first-in-class CDH6 directed ADC. Designed using Daiichi Sankyo’s proprietary DXd ADC Technology, raludotatug deruxtecan is comprised of a humanized anti-CDH6 IgG1 monoclonal antibody attached to a number of topoisomerase I inhibitor payloads (an exatecan derivative, DXd) via tetrapeptide-based cleavable linkers.

About KEYTRUDA^® (pembrolizumab) injection for intravenous use, 100 mg

KEYTRUDA is an anti-programmed death receptor-1 (PD-1) therapy that works by increasing the ability of the body’s immune system to help detect and fight tumor cells. KEYTRUDA is a humanized monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2, thereby activating T lymphocytes which may affect both tumor cells and healthy cells.

Merck has the industry’s largest immuno-oncology clinical research program. There are currently more than 2,800 trials studying KEYTRUDA across a wide variety of cancers and treatment settings. The KEYTRUDA clinical program seeks to understand the role of KEYTRUDA across cancers and the factors that may predict a patient's likelihood of benefitting from treatment with KEYTRUDA, including exploring several different biomarkers.

Selected KEYTRUDA^® (pembrolizumab) Indications in the U.S.

Melanoma

KEYTRUDA is indicated for the treatment of patients with unresectable or metastatic melanoma.

KEYTRUDA is indicated for the adjuvant treatment of adult and pediatric (12 years and older) patients with Stage IIB, IIC, or III melanoma following complete resection.

Non-Small Cell Lung Cancer

KEYTRUDA, in combination with pemetrexed and platinum chemotherapy, is indicated for the first-line treatment of patients with metastatic nonsquamous non-small cell lung cancer (NSCLC), with no EGFR or ALK genomic tumor aberrations.

KEYTRUDA, in combination with carboplatin and either paclitaxel or paclitaxel protein-bound, is indicated for the first-line treatment of patients with metastatic squamous NSCLC.

KEYTRUDA, as a single agent, is indicated for the first-line treatment of patients with NSCLC expressing PD-L1 [Tumor Proportion Score (TPS) ≥1%] as determined by an FDA-authorized test, with no EGFR or ALK genomic tumor aberrations, and is:

• Stage III where patients are not candidates for surgical resection or definitive chemoradiation, or
• metastatic.

KEYTRUDA, as a single agent, is indicated for the treatment of patients with metastatic NSCLC whose tumors express PD-L1 (TPS ≥1%) as determined by an FDA-authorized test, with disease progression on or after platinum-containing chemotherapy. Patients with EGFR or ALK genomic tumor aberrations should have disease progression on FDA-approved therapy for these aberrations prior to receiving KEYTRUDA.

KEYTRUDA is indicated for the treatment of patients with resectable (tumors ≥4 cm or node positive) NSCLC in combination with platinum-containing chemotherapy as neoadjuvant treatment, and then continued as a single agent as adjuvant treatment after surgery.

KEYTRUDA, as a single agent, is indicated as adjuvant treatment following resection and platinum-based chemotherapy for adult patients with Stage IB (T2a ≥4 cm), II, or IIIA NSCLC.

Urothelial Cancer

KEYTRUDA, in combination with enfortumab vedotin, is indicated for the treatment of adult patients with locally advanced or metastatic urothelial cancer.

KEYTRUDA, as a single agent, is indicated for the treatment of patients with locally advanced or metastatic urothelial carcinoma:

• who are not eligible for any platinum-containing chemotherapy, or
• who have disease progression during or following platinum-containing chemotherapy or within 12 months of neoadjuvant or adjuvant treatment with platinum-containing chemotherapy.

KEYTRUDA, in combination with enfortumab vedotin, as neoadjuvant treatment and then continued after cystectomy as adjuvant treatment, is indicated for the treatment of adult patients with muscle invasive bladder cancer (MIBC) who are ineligible for cisplatin-containing chemotherapy.

KEYTRUDA, as a single agent, is indicated for the treatment of patients with Bacillus Calmette-Guerin (BCG)-unresponsive, high-risk, non-muscle invasive bladder cancer (NMIBC) with carcinoma in situ (CIS) with or without papillary tumors who are ineligible for or have elected not to undergo cystectomy.

Gastric Cancer

KEYTRUDA, in combination with trastuzumab, fluoropyrimidine- and platinum-containing chemotherapy, is indicated for the first-line treatment of adults with locally advanced unresectable or metastatic HER2-positive gastric or gastroesophageal junction (GEJ) adenocarcinoma whose tumors express PD-L1 (CPS ≥1) as determined by an FDA-authorized test.

KEYTRUDA, in combination with fluoropyrimidine- and platinum-containing chemotherapy, is indicated for the first-line treatment of adults with locally advanced unresectable or metastatic HER2-negative gastric or gastroesophageal junction (GEJ) adenocarcinoma whose tumors express PD-L1 (CPS ≥ 1) as determined by an FDA-authorized test.

Renal Cell Carcinoma

KEYTRUDA, in combination with axitinib, is indicated for the first-line treatment of adult patients with advanced renal cell carcinoma (RCC).

KEYTRUDA is indicated for the adjuvant treatment of patients with RCC at intermediate-high or high risk of recurrence following nephrectomy, or following nephrectomy and resection of metastatic lesions.

Endometrial Carcinoma

KEYTRUDA, in combination with carboplatin and paclitaxel, followed by KEYTRUDA as a single agent, is indicated for the treatment of adult patients with primary advanced or recurrent endometrial carcinoma.

KEYTRUDA, as a single agent, is indicated for the treatment of adult patients with advanced endometrial carcinoma that is MSI-H or dMMR, as determined by an FDA-authorized test, who have disease progression following prior systemic therapy in any setting and are not candidates for curative surgery or radiation.

Triple-Negative Breast Cancer

KEYTRUDA is indicated for the treatment of patients with high-risk early-stage triple-negative breast cancer (TNBC) in combination with chemotherapy as neoadjuvant treatment, and then continued as a single agent as adjuvant treatment after surgery.

KEYTRUDA, in combination with chemotherapy, is indicated for the treatment of patients with locally recurrent unresectable or metastatic TNBC whose tumors express PD-L1 (CPS ≥10) as determined by an FDA-authorized test.

Ovarian Cancer

KEYTRUDA, in combination with paclitaxel, with or without bevacizumab, is indicated for the treatment of adult patients with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal carcinoma whose tumors express PD-L1 (CPS ≥1) as determined by an FDA-authorized test, and who have received one or two prior systemic treatment regimens.

See additional selected KEYTRUDA indications in the U.S. after the Selected Important Safety Information.

Selected Important Safety Information for KEYTRUDA

Severe and Fatal Immune-Mediated Adverse Reactions

KEYTRUDA is a monoclonal antibody that belongs to a class of drugs that bind to either the programmed death receptor-1 (PD-1) or the programmed death ligand 1 (PD-L1), blocking the PD-1/PD-L1 pathway, thereby removing inhibition of the immune response, potentially breaking peripheral tolerance and inducing immune-mediated adverse reactions. Immune-mediated adverse reactions, which may be severe or fatal, can occur in any organ system or tissue, can affect more than one body system simultaneously, and can occur at any time after starting treatment or after discontinuation of treatment. Important immune-mediated adverse reactions listed here may not include all possible severe and fatal immune-mediated adverse reactions.

Monitor patients closely for symptoms and signs that may be clinical manifestations of underlying immune-mediated adverse reactions. Early identification and management are essential to ensure safe use of anti–PD-1/PD-L1 treatments. Evaluate liver enzymes, creatinine, and thyroid function at baseline and periodically during treatment. For patients with TNBC treated with KEYTRUDA in the neoadjuvant setting, monitor blood cortisol at baseline, prior to surgery, and as clinically indicated. In cases of suspected immune-mediated adverse reactions, initiate appropriate workup to exclude alternative etiologies, including infection. Institute medical management promptly, including specialty consultation as appropriate.

Withhold or permanently discontinue KEYTRUDA depending on severity of the immune-mediated adverse reaction. In general, if KEYTRUDA requires interruption or discontinuation, administer systemic corticosteroid therapy (1 to 2 mg/kg/day prednisone or equivalent) until improvement to Grade 1 or less. Upon improvement to Grade 1 or less, initiate corticosteroid taper and continue to taper over at least 1 month. Consider administration of other systemic immunosuppressants in patients whose adverse reactions are not controlled with corticosteroid therapy.

Immune-Mediated Pneumonitis

KEYTRUDA can cause immune-mediated pneumonitis. The incidence is higher in patients who have received prior thoracic radiation. Immune-mediated pneumonitis occurred in 3.4% (94/2799) of patients receiving KEYTRUDA, including fatal (0.1%), Grade 4 (0.3%), Grade 3 (0.9%), and Grade 2 (1.3%) reactions. Systemic corticosteroids were required in 67% (63/94) of patients. Pneumonitis led to permanent discontinuation of KEYTRUDA in 1.3% (36) and withholding in 0.9% (26) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement; of these, 23% had recurrence. Pneumonitis resolved in 59% of the 94 patients.

Pneumonitis occurred in 8% (31/389) of adult patients with cHL receiving KEYTRUDA as a single agent, including Grades 3-4 in 2.3% of patients. Patients received high-dose corticosteroids for a median duration of 10 days (range: 2 days to 53 months). Pneumonitis rates were similar in patients with and without prior thoracic radiation. Pneumonitis led to discontinuation of KEYTRUDA in 5.4% (21) of patients. Of the patients who developed pneumonitis, 42% interrupted KEYTRUDA, 68% discontinued KEYTRUDA, and 77% had resolution.

Pneumonitis occurred in 7% (41/580) of adult patients with resected NSCLC who received KEYTRUDA as a single agent for adjuvant treatment of NSCLC, including fatal (0.2%), Grade 4 (0.3%), and Grade 3 (1%) adverse reactions. Patients received high-dose corticosteroids for a median duration of 10 days (range: 1 day to 2.3 months). Pneumonitis led to discontinuation of KEYTRUDA in 26 (4.5%) of patients. Of the patients who developed pneumonitis, 54% interrupted KEYTRUDA, 63% discontinued KEYTRUDA, and 71% had resolution.

Immune-Mediated Colitis

KEYTRUDA can cause immune-mediated colitis, which may present with diarrhea. Cytomegalovirus infection/reactivation has been reported in patients with corticosteroid-refractory immune-mediated colitis. In cases of corticosteroid-refractory colitis, consider repeating infectious workup to exclude alternative etiologies. Immune-mediated colitis occurred in 1.7% (48/2799) of patients receiving KEYTRUDA, including Grade 4 (<0.1%), Grade 3 (1.1%), and Grade 2 (0.4%) reactions. Systemic corticosteroids were required in 69% (33/48); additional immunosuppressant therapy was required in 4.2% of patients. Colitis led to permanent discontinuation of KEYTRUDA in 0.5% (15) and withholding in 0.5% (13) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement; of these, 23% had recurrence. Colitis resolved in 85% of the 48 patients.

Hepatotoxicity and Immune-Mediated Hepatitis

KEYTRUDA as a Single Agent

KEYTRUDA can cause immune-mediated hepatitis. Immune-mediated hepatitis occurred in 0.7% (19/2799) of patients receiving KEYTRUDA, including Grade 4 (<0.1%), Grade 3 (0.4%), and Grade 2 (0.1%) reactions. Systemic corticosteroids were required in 68% (13/19) of patients; additional immunosuppressant therapy was required in 11% of patients. Hepatitis led to permanent discontinuation of KEYTRUDA in 0.2% (6) and withholding in 0.3% (9) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement; of these, none had recurrence. Hepatitis resolved in 79% of the 19 patients.

KEYTRUDA With Axitinib

KEYTRUDA in combination with axitinib can cause hepatic toxicity. Monitor liver enzymes before initiation of and periodically throughout treatment. Consider monitoring more frequently as compared to when the drugs are administered as single agents. For elevated liver enzymes, interrupt KEYTRUDA and axitinib, and consider administering corticosteroids as needed. With the combination of KEYTRUDA and axitinib, Grades 3 and 4 increased alanine aminotransferase (ALT) (20%) and increased aspartate aminotransferase (AST) (13%) were seen at a higher frequency compared to KEYTRUDA alone.

Media Contacts:

Julie Cunningham
julie.cunningham@merck.com

Justine Moore
(347) 281-3754

Investor Contacts:

Peter Dannenbaum
(732) 594-1579

Steven Graziano
(732) 594-1583