Acquisitions, Research Collaborations and Licensing Agreements	6 Months Ended
Jun. 30, 2026
Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract]
Acquisitions, Research Collaborations and Licensing Agreements	Acquisitions, Research Collaborations and Licensing Agreements The Company continues to pursue acquisitions and the establishment of external alliances such as research collaborations and licensing agreements to complement its internal research capabilities. These arrangements often include upfront payments; expense reimbursements or payments to the third party; milestone, royalty or profit share arrangements contingent upon the occurrence of certain future events linked to the success of the asset in development; and can also include option and continuation payments. The Company also reviews its marketed products and pipeline to examine candidates which may provide more value through out-licensing and, as part of its portfolio assessment process, may also divest certain assets. Pro forma financial information for acquired businesses is not presented if the historical financial results of the acquired entity are not significant when compared with the Company’s financial results. 2026 Transactions In July 2026, Merck acquired TARGAN, a privately held company developing and commercializing biodevice solutions to improve performance outcomes for the poultry industry, for approximately $650 million. The acquisition is expected to broaden Merck Animal Health’s portfolio in commercial poultry operations with WingScan, an automated solution that uses vision technology for gender identification. This acquisition also brings the capability for a high-speed precision ocular spray technology, which administers respiratory and coccidiosis vaccines, among others, to day-old chicks. In addition, TARGAN has the potential to develop additional biodevices within poultry and other livestock species. Merck recorded an unrealized gain of $71 million to Other (income) expense, net in the second quarter and first six months of 2026 related to an existing investment that Merck held in TARGAN. The Company expects to account for the transaction as a business combination. There are no future contingent payments associated with the acquisition. In June 2026, the U.S. Food and Drug Administration (FDA) approved Welireg (belzutifan) in combination with Keytruda (pembrolizumab) or Keytruda Qlex (pembrolizumab and berahyaluronidase alfa) for the adjuvant treatment of certain adult patients with clear cell renal cell carcinoma following nephrectomy. The approval of this combination therapy triggered a $50 million regulatory milestone payment to former Peloton Therapeutics, Inc. (Peloton) shareholders, which was made in July 2026. Additionally, following FDA approval, the Company determined that it was probable that sales of Welireg in the future would trigger a $100 million sales-based milestone payment from Merck to former Peloton shareholders. Accordingly, in the second quarter of 2026, Merck recorded a $100 million non-current liability for the potential future sales-based milestone payment. In addition, Merck recorded a $192 million increase to the intangible asset related to Welireg (included in Other Intangibles, Net) associated with these milestones. The intangible asset is being amortized over its estimated useful life through August 2031. Merck also recorded $65 million of cumulative amortization catch-up expense to Cost of sales in the second quarter and first six months of 2026 related to the recognition of the sales-based milestone. Former Peloton shareholders remain eligible to receive up to $900 million of sales-based milestones. In May 2026, Merck acquired Terns Pharmaceuticals, Inc. (Terns), a clinical-stage oncology company, for $6.8 billion (including $606 million of payments to settle share-based equity awards of which $433 million related to unvested equity awards). Through this acquisition, Merck acquired Terns’ lead candidate, MK-4208 (formerly TERN-701), a novel investigational oral allosteric BCR::ABL1 tyrosine kinase inhibitor (TKI) currently being evaluated in a Phase 1/2 trial for patients with Philadelphia chromosome-positive, chronic phase chronic myeloid leukemia previously treated with at least one prior TKI and who experienced treatment failure, suboptimal response or treatment intolerance. The transaction was accounted for as an asset acquisition because MK-4208 accounted for substantially all of the fair value of the gross assets acquired (excluding cash and deferred income taxes). Merck recorded a charge of $5.7 billion to Research and development expenses (which primarily represented acquired in-process research and development [IPR&D] with no alternative future use) in the second quarter and first six months of 2026, as well as net assets of $1.1 billion, including cash of $505 million, investments of $487 million, deferred tax assets of $190 million, and other net liabilities of $105 million. There are no future contingent payments associated with the acquisition. In January 2026, Merck acquired Cidara Therapeutics, Inc. (Cidara), a biotechnology company developing drug-Fc conjugate (DFC) therapeutics, for $9.2 billion (including $570 million of payments to settle share-based equity awards of which $406 million related to unvested equity awards). Cidara’s lead DFC candidate, MK-1406 (formerly CD388), is a long-acting antiviral designed to prevent seasonal and pandemic influenza. MK-1406 is currently being evaluated in a Phase 3 trial among adult and adolescent participants who are at higher risk of developing complications from influenza. The transaction was accounted for as an asset acquisition because MK-1406 accounted for substantially all of the fair value of the gross assets acquired (excluding cash and deferred income taxes). Merck recorded a charge of $9.0 billion to Research and development expenses (which primarily represented acquired IPR&D with no alternative future use) in the first six months of 2026, as well as net assets of $332 million. Under a previous license agreement between Cidara and J&J Innovative Medicine (a Johnson & Johnson company, previously Janssen Pharmaceuticals, Inc.), which was assumed by Merck, J&J Innovative Medicine is eligible to receive up to $105 million in regulatory milestones and up to $455 million in sales-based milestones related to MK-1406. 2025 Transactions In October 2025, Merck and Blackstone Life Sciences (Blackstone) entered into a funding arrangement under which Blackstone will pay Merck $700 million in the fourth quarter of 2026 (which is non-refundable, subject to the termination provisions of the agreement) to fund a portion of the Company’s development costs for MK-2870, sacituzumab tirumotecan (sac-TMT), expected to be incurred throughout 2026. Under the terms of the agreement, Merck recognized $200 million and $400 million of funding in the second quarter and first six months of 2026, respectively, as a reduction to Research and development expenses, as well as a corresponding $400 million receivable from Blackstone, which is included in Other current assets. Upon receipt of regulatory approval for an indication in the U.S. for first-line triple-negative-breast cancer (TroFuse-011 trial), Blackstone will be eligible to receive low-to-mid single-digit royalties on net sales of sac-TMT subsequent to such approval across all approved indications in Merck’s marketing territories. Sac-TMT is an investigational trophoblast cell-surface antigen 2 (TROP2)-directed antibody drug conjugate (ADC) being developed as part of an exclusive license and collaboration agreement with Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (Kelun-Biotech) that is currently in clinical development for the treatment of a variety of cancers. The agreement between Merck and Kelun-Biotech with respect to sac-TMT is unchanged by the agreement with Blackstone. Merck retained decision-making authority and control over the development, manufacturing, and commercial activities relating to sac-TMT provided for in the agreement with Kelun-Biotech, and Blackstone did not receive any rights to sac-TMT. In May 2025, Merck and Jiangsu Hengrui Pharmaceuticals Co., Ltd. (Hengrui Pharma) closed an exclusive license agreement for MK-7262 (HRS-5346), an investigational oral small molecule Lipoprotein(a) inhibitor. Under the agreement, Hengrui Pharma granted Merck exclusive rights to develop, manufacture and commercialize MK-7262 (HRS-5346) worldwide, excluding the Greater China region. The agreement provided for an upfront payment of $200 million, which was recorded as a charge to Research and development expenses in the second quarter and first six months of 2025. Hengrui Pharma is also eligible to receive future contingent developmental milestone payments of up to $92.5 million, regulatory milestone payments of up to $177.5 million and sales-based milestone payments of up to $1.5 billion, as well as tiered royalties ranging from a mid-single-digit rate to a low-double-digit rate on future net sales of MK-7262 (HRS-5346), if approved. In March 2025, Merck acquired the Dundalk, Ireland facility of WuXi Vaccines (a wholly owned subsidiary of WuXi Biologics), which was accounted for as an asset acquisition. Merck paid $437 million at closing which, combined with previous consideration transferred under a prior manufacturing arrangement with WuXi Vaccines related to this facility, resulted in $759 million being recorded as assets under construction within Property, Plant and Equipment. There are no future contingent payments associated with the acquisition.

The Company continues to pursue acquisitions and the establishment of external alliances such as research collaborations and licensing agreements to complement its internal research capabilities. These arrangements often include upfront payments; expense reimbursements or payments to the third party; milestone, royalty or profit share arrangements contingent upon the occurrence of certain future events linked to the success of the asset in development; and can also include option and continuation payments. The Company also reviews its marketed products and pipeline to examine candidates which may provide more value through out-licensing and, as part of its portfolio assessment process, may also divest certain assets. Pro forma financial information for acquired businesses is not presented if the historical financial results of the acquired entity are not significant when compared with the Company’s financial results.

In July 2026, Merck acquired TARGAN, a privately held company developing and commercializing biodevice solutions to improve performance outcomes for the poultry industry, for approximately $650 million. The acquisition is expected to broaden Merck Animal Health’s portfolio in commercial poultry operations with WingScan, an automated solution that uses vision technology for gender identification. This acquisition also brings the capability for a high-speed precision ocular spray technology, which administers respiratory and coccidiosis vaccines, among others, to day-old chicks. In addition, TARGAN has the potential to develop additional biodevices within poultry and other livestock species. Merck recorded an unrealized gain of $71 million to Other (income) expense, net in the second quarter and first six months of 2026 related to an existing investment that Merck held in TARGAN. The Company expects to account for the transaction as a business combination. There are no future contingent payments associated with the acquisition.

In June 2026, the U.S. Food and Drug Administration (FDA) approved Welireg (belzutifan) in combination with Keytruda (pembrolizumab) or Keytruda Qlex (pembrolizumab and berahyaluronidase alfa) for the adjuvant treatment of certain adult patients with clear cell renal cell carcinoma following nephrectomy. The approval of this combination therapy triggered a $50 million regulatory milestone payment to former Peloton Therapeutics, Inc. (Peloton) shareholders, which was made in July 2026. Additionally, following FDA approval, the Company determined that it was probable that sales of Welireg in the future would trigger a $100 million sales-based milestone payment from Merck to former Peloton shareholders. Accordingly, in the second quarter of 2026, Merck recorded a $100 million non-current liability for the potential future sales-based milestone payment. In addition, Merck recorded a $192 million increase to the intangible asset related to Welireg (included in Other Intangibles, Net) associated with these milestones. The intangible asset is being amortized over its estimated useful life through August 2031. Merck also recorded $65 million of cumulative amortization catch-up expense to Cost of sales in the second quarter and first six months of 2026 related to the recognition of the sales-based milestone. Former Peloton shareholders remain eligible to receive up to $900 million of sales-based milestones.

In May 2026, Merck acquired Terns Pharmaceuticals, Inc. (Terns), a clinical-stage oncology company, for $6.8 billion (including $606 million of payments to settle share-based equity awards of which $433 million related to unvested equity awards). Through this acquisition, Merck acquired Terns’ lead candidate, MK-4208 (formerly TERN-701), a novel investigational

oral allosteric BCR::ABL1 tyrosine kinase inhibitor (TKI) currently being evaluated in a Phase 1/2 trial for patients with Philadelphia chromosome-positive, chronic phase chronic myeloid leukemia previously treated with at least one prior TKI and who experienced treatment failure, suboptimal response or treatment intolerance. The transaction was accounted for as an asset acquisition because MK-4208 accounted for substantially all of the fair value of the gross assets acquired (excluding cash and deferred income taxes). Merck recorded a charge of $5.7 billion to Research and development expenses (which primarily represented acquired in-process research and development [IPR&D] with no alternative future use) in the second quarter and first six months of 2026, as well as net assets of $1.1 billion, including cash of $505 million, investments of $487 million, deferred tax assets of $190 million, and other net liabilities of $105 million. There are no future contingent payments associated with the acquisition.

In January 2026, Merck acquired Cidara Therapeutics, Inc. (Cidara), a biotechnology company developing drug-Fc conjugate (DFC) therapeutics, for $9.2 billion (including $570 million of payments to settle share-based equity awards of which $406 million related to unvested equity awards). Cidara’s lead DFC candidate, MK-1406 (formerly CD388), is a long-acting antiviral designed to prevent seasonal and pandemic influenza. MK-1406 is currently being evaluated in a Phase 3 trial among adult and adolescent participants who are at higher risk of developing complications from influenza. The transaction was accounted for as an asset acquisition because MK-1406 accounted for substantially all of the fair value of the gross assets acquired (excluding cash and deferred income taxes). Merck recorded a charge of $9.0 billion to Research and development expenses (which primarily represented acquired IPR&D with no alternative future use) in the first six months of 2026, as well as net assets of $332 million. Under a previous license agreement between Cidara and J&J Innovative Medicine (a Johnson & Johnson company, previously Janssen Pharmaceuticals, Inc.), which was assumed by Merck, J&J Innovative Medicine is eligible to receive up to $105 million in regulatory milestones and up to $455 million in sales-based milestones related to MK-1406.

In October 2025, Merck and Blackstone Life Sciences (Blackstone) entered into a funding arrangement under which Blackstone will pay Merck $700 million in the fourth quarter of 2026 (which is non-refundable, subject to the termination provisions of the agreement) to fund a portion of the Company’s development costs for MK-2870, sacituzumab tirumotecan (sac-TMT), expected to be incurred throughout 2026. Under the terms of the agreement, Merck recognized $200 million and $400 million of funding in the second quarter and first six months of 2026, respectively, as a reduction to Research and development expenses, as well as a corresponding $400 million receivable from Blackstone, which is included in Other current assets. Upon receipt of regulatory approval for an indication in the U.S. for first-line triple-negative-breast cancer (TroFuse-011 trial), Blackstone will be eligible to receive low-to-mid single-digit royalties on net sales of sac-TMT subsequent to such approval across all approved indications in Merck’s marketing territories. Sac-TMT is an investigational trophoblast cell-surface antigen 2 (TROP2)-directed antibody drug conjugate (ADC) being developed as part of an exclusive license and collaboration agreement with Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (Kelun-Biotech) that is currently in clinical development for the treatment of a variety of cancers. The agreement between Merck and Kelun-Biotech with respect to sac-TMT is unchanged by the agreement with Blackstone. Merck retained decision-making authority and control over the development, manufacturing, and commercial activities relating to sac-TMT provided for in the agreement with Kelun-Biotech, and Blackstone did not receive any rights to sac-TMT.

In May 2025, Merck and Jiangsu Hengrui Pharmaceuticals Co., Ltd. (Hengrui Pharma) closed an exclusive license agreement for MK-7262 (HRS-5346), an investigational oral small molecule Lipoprotein(a) inhibitor. Under the agreement, Hengrui Pharma granted Merck exclusive rights to develop, manufacture and commercialize MK-7262 (HRS-5346) worldwide, excluding the Greater China region. The agreement provided for an upfront payment of $200 million, which was recorded as a charge to Research and development expenses in the second quarter and first six months of 2025. Hengrui Pharma is also eligible to receive future contingent developmental milestone payments of up to $92.5 million, regulatory milestone payments of up to $177.5 million and sales-based milestone payments of up to $1.5 billion, as well as tiered royalties ranging from a mid-single-digit rate to a low-double-digit rate on future net sales of MK-7262 (HRS-5346), if approved.

In March 2025, Merck acquired the Dundalk, Ireland facility of WuXi Vaccines (a wholly owned subsidiary of WuXi Biologics), which was accounted for as an asset acquisition. Merck paid $437 million at closing which, combined with previous consideration transferred under a prior manufacturing arrangement with WuXi Vaccines related to this facility, resulted in $759 million being recorded as assets under construction within Property, Plant and Equipment. There are no future contingent payments associated with the acquisition.