Mechanism of Action: Letermovir is a CMV DNA terminase complex inhibitor.

Mechanism of Action: Patritumab deruxtecan is an investigational antibody-drug conjugate that consists of a fully human anti-HER3 IgG1 monoclonal antibody linked to a topoisomerase I inhibitor payload.

Patritumab deruxtecan is being developed in collaboration with Daiichi Sankyo.

Mechanism of Action: Ifinatamab deruxtecan is an investigational antibody-drug conjugate that consists of a humanized anti-B7-H3 IgG1 monoclonal antibody linked to a topoisomerase I inhibitor payload.

Ifinatamab deruxtecan is being developed in collaboration with Daiichi Sankyo.

Mechanism of Action: MK-7240 is an investigational humanized monoclonal antibody directed to tumor necrosis factor (TNF)-like ligand 1A (TL1A).

MK-7240 was acquired as part of the acquisition of Prometheus Biosciences, Inc.

Mechanism of Action: Bomedemstat is an investigational lysine-specific demethylase-1 (LSD1) inhibitor.

Bomedemstat was acquired as part of the acquisition of Imago BioSciences, Inc.

Mechanism of Action: Pembrolizumab is a monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2, releasing PD-1 pathway-mediated inhibition of the immune response.

Description: V181 is an investigational quadrivalent dengue vaccine.

Mechanism of Action: MK-5684 is an investigational oral inhibitor of cytochrome P450 11A1.

MK-5684 is being developed in collaboration with Orion.

Mechanism of Action: Lenvatinib is a kinase inhibitor that inhibits the kinase activities of vascular endothelial growth factor (VEGF) receptors VEGFR1 (FLT1), VEGFR2 (KDR), and VEGFR3 (FLT4). Lenvatinib inhibits other kinases that have been implicated in pathogenic angiogenesis, tumor growth, and cancer progression in addition to their normal cellular functions, including fibroblast growth factor (FGF) receptors FGFR1, 2, 3, and 4; platelet derived growth factor receptor alpha (PDGFRα), KIT, and RET.

LENVIMA is being developed in combination with KEYTRUDA.

LENVIMA is being developed in collaboration with Eisai.

Mechanism of Action: MK-2870 is an investigational antibody-drug conjugate that consists of an antibody-targeting trophoblast cell-surface antigen 2 (TROP2) linked to a belotecan-derived payload.

MK-2870 is being developed as monotherapy and/or in combination with KEYTRUDA.

MK-2870 is being developed in collaboration with Sichuan Kelun-Biotech.

Mechanism of Action: Islatravir is an investigational nucleoside reverse transcriptase translocation inhibitor of HIV-1. Lenacapavir is an investigational, long-acting HIV-1 capsid inhibitor.

MK-8591D is on FDA partial clinical hold for higher doses than those used in current clinical trials.

Islatravir is being developed under an agreement with the Yamasa Corporation. The combination of islatravir and lenacapavir is being developed in a collaboration with Gilead Sciences, Inc.

Mechanism of Action: Vibostolimab is an investigational monoclonal antibody that binds to the T cell immunoreceptor with Ig and ITIM domains (TIGIT) and inhibits interactions with its ligands. Pembrolizumab is a monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2, releasing PD-1 pathway-mediated inhibition of the immune response.

Mechanism of Action: MK-4830 is an investigational monoclonal antibody that inhibits the binding of Immunoglobulin-like transcript 4 (ILT-4) to its ligands.

MK-4830 is being developed in combination with KEYTRUDA.

MK-4830 is being developed under an agreement with Agenus Inc.

Mechanism of Action: MK-0616 is an investigational inhibitor of Proprotein convertase subtilisin/kexin type 9 (PCSK9).

MK-0616 is being developed under an agreement with UCB Pharmaceuticals.

Mechanism of Action: Sotatercept is an investigational soluble activin receptor type IIA fusion protein that binds to activins and growth differentiation factors.

Sotatercept was acquired as part of the acquisition of Acceleron.

Mechanism of Action: Favezelimab is an investigational anti-lymphocyte activation gene-3 (LAG-3) antibody designed to restore T cell effector function by preventing LAG-3 from binding to its primary ligand, major histocompatibility complex (MHC) class II molecules. Pembrolizumab is a monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2, releasing PD-1 pathway-mediated inhibition of the immune response.

Mechanism of Action: Belzutifan is an inhibitor of hypoxia-inducible factor 2 alpha (HIF-2α). Belzutifan binds to HIF-2α, and in conditions of hypoxia or impairment of VHL protein function, belzutifan inhibits the HIF-2α-HIF-1β interaction, leading to reduced transcription and expression of HIF-2α target genes.

WELIREG is being developed as a monotherapy and/or in combination with KEYTRUDA.

WELIREG was acquired as part of the acquisition of Peloton Therapeutics, Inc.

Mechanism of Action: Boserolimab is an investigational monoclonal antibody that binds and activates CD27.

Boserolimab is being developed in combination with KEYTRUDA.

Boserolimab is being developed under an agreement with Chinook Therapeutics.

Mechanism of Action: Zilovertamab vedotin is an investigational antibody-drug conjugate that consists of a ROR1-targeting antibody linked to monomethyl auristatin E (MMAE)-containing payload.

Zilovertamab vedotin was acquired as part of the acquisition of VelosBio.

Mechanism of Action: Pembrolizumab is a monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2, releasing PD-1 pathway-mediated inhibition of the immune response.

**Select KEYTRUDA clinical trials are shown.

Mechanism of Action: Efinopegdutide is an investigational dual GLP-1/glucagon receptor agonist.

Efinopegdutide is being developed under an agreement with Hanmi Pharmaceutical.

Mechanism of Action: MK-2060 is an investigational monoclonal antibody that inhibits the activation of Factor XI and activity of Factor XIA.

MK-2060 is being developed under an agreement with Adimab.

Mechanism of Action: Quavonlimab is an investigational monoclonal antibody that binds to CTLA-4 and inhibits interaction with its ligands. Pembrolizumab is a monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2, releasing PD-1 pathway-mediated inhibition of the immune response.

Quavonlimab is being developed under an agreement with Akeso, Inc.

Mechanism of Action: Tucatinib is a tyrosine kinase inhibitor of HER2.

TUKYSA is being developed in collaboration with Seagen.

Mechanism of Action: MK-5475 is an investigational stimulator of soluble Guanylate Cyclase (sGC).

Mechanism of Action: Olaparib is an inhibitor of poly (ADP-ribose) polymerase (PARP) enzymes, including PARP1, PARP2, and PARP3.

LYNPARZA is being developed as a monotherapy and/or in combination with KEYTRUDA.

LYNPARZA is being developed in collaboration with AstraZeneca.

Mechanism of Action: Islatravir is an investigational nucleoside reverse transcriptase translocation inhibitor of HIV-1. MK-8507 is an investigational non-nucleoside reverse transcriptase translocation inhibitor of HIV-1.

MK-8591B is on FDA clinical hold.

Islatravir is being developed under an agreement with the Yamasa Corporation.

Mechanism of Action: V940 is an investigational mRNA-based individualized neoantigen therapy targeting tumor associated antigens expressed by a patient’s cancer cells.

V940 is being developed in combination with KEYTRUDA.

V940 is being developed in collaboration with Moderna.

Description: V116 is an investigational 21 valent pneumococcal conjugate vaccine.

Mechanism of Action: Molnupiravir is an investigational antiviral ribonucleoside prodrug of N-hydroxycytidine (NHC). NHC triphosphate is incorporated into viral RNA by viral RNA polymerase and results in an accumulation of errors in the viral genome leading to inhibition of replication.

LAGEVRIO is being developed under an agreement with Ridgeback Biotherapeutics LP. LAGEVRIO is available in the U.S. under Emergency Use Authorization.

Mechanism of Action: Islatravir is an investigational nucleoside reverse transcriptase translocation inhibitor of HIV-1. Doravirine is a pyridinone non-nucleoside reverse transcriptase translocation inhibitor of HIV-1.

MK-8591A is on FDA partial clinical hold for higher doses than those used in current clinical trials.

Islatravir is being developed under an agreement with the Yamasa Corporation.

Mechanism of Action: Favezelimab is an investigational anti-lymphocyte activation gene-3 (LAG-3) antibody designed to restore T cell effector function by preventing LAG-3 from binding to its primary ligand, major histocompatibility complex (MHC) class II molecules.

Favezelimab is being developed in combination with KEYTRUDA.

Mechanism of Action: Quavonlimab is an investigational monoclonal antibody that binds to CTLA-4 and inhibits interaction with its ligands.

Quavonlimab is being developed in combination with KEYTRUDA.

Quavonlimab is being developed under an agreement with Akeso, Inc.

Mechanism of Action: Nemtabrutinib is an investigational reversible, non-covalent Bruton’s tyrosine kinase (BTK) inhibitor that is being studied for the suppression of oncogenic B-cell receptor signaling with activity against wild-type BTK and BTK pathway mutants.

Nemtabrutinib was acquired as part of the acquisition of ArQule, Inc.

Mechanism of Action: Gefapixant is an investigational P2X3 receptor antagonist.

*In July 2023, the FDA accepted Merck’s resubmission of the NDA for gefapixant following the Company’s response to the CRL received in January 2022.

Gefapixant was acquired as part of the acquisition of Afferent Pharmaceuticals.

Mechanism of Action: Clesrovimab is an investigational respiratory syncytial virus (RSV) fusion (F) glycoprotein neutralizing monoclonal antibody.

Mechanism of Action: MK-8189 is an investigational inhibitor of phosphodiesterase 10A (PDE10A).

MK-8189 is being developed under an agreement with Royalty Pharma. Phase 2b development costs are being co-funded.