Genmab and Incyte Announce Clinical Trial Collaboration in Metastatic Colorectal Cancer

Media Release COPENHAGEN, Denmark and WILMINGTON, Del.; October 24, 2026

Phase 1/2 study will evaluate petosemtamab plus INCB161734 and standard-of-care chemotherapy in first-line KRAS G12D-mutated metastatic colorectal cancer (mCRC) Genmab A/S (Nasdaq: GMAB) and Incyte (Nasdaq: INCY) today announced a clinical trial collaboration to evaluate petosemtamab, Genmab’s investigational IgG1-bispecific antibody targeting the epidermal growth factor receptor (EGFR) and leucine-rich repeat containing G-protein-coupled receptor 5 (LGR5), in combination with INCB161734, Incyte’s investigational, potent and selective KRAS G12D inhibitor, and standard-of-care chemotherapy as a first-line treatment for patients with metastatic colorectal cancer harboring a KRAS G12D mutation, an area with substantial unmet medical need. “This collaboration supports our broader development strategy for petosemtamab as we explore its potential across treatment settings and in novel combinations,” said Judith Klimovsky, M.D., Executive Vice President and Chief Development Officer, Genmab. “Partnering with Incyte enables us to evaluate this investigational combination in patients with KRAS G12D-mutated metastatic colorectal cancer, reflecting our commitment to research collaborations aimed at expanding potential treatment options for more patients.” “Metastatic colorectal cancer remains difficult-to-treat, underscoring the importance of evaluating novel combinations grounded in complementary scientific approaches with the potential to enhance efficacy,” said Pablo J. Cagnoni, M.D., President, Incyte and Global Head of Research and Development. “Our collaboration with Genmab will explore the potential of combining KRAS G12D inhibition with LGR5-targeted EGFR inhibition and standard-of-care chemotherapy, with the goal of advancing a new first-line treatment approach for patients with metastatic colorectal cancer.” Under the collaboration, Genmab will conduct the Phase 1/2 study evaluating petosemtamab in combination with INCB161734 and standard-of-care chemotherapy in patients with KRAS G12D-mutated mCRC in the first-line setting. Incyte will co-fund the study and provide clinical supply of INCB161734. KRAS mutations occur in approximately 40% of colorectal cancers, with G12D being the most common KRAS mutation. These cancers are associated with poor prognosis, underscoring the need for new treatment approaches. The collaboration reflects a shared focus on investigating whether agents with distinct and potentially complementary mechanisms, combined with standard-of-care chemotherapy, may offer a path toward a new treatment option for patients with KRAS G12D-mutated metastatic colorectal cancer. About Petosemtamab (GEN1158) Petosemtamab is an investigational human IgG1-based bispecific antibody targeting the EGFR and the LGR5 and designed to support multiple anti-tumor mechanisms. It inhibits EGFR-mediated signaling by engaging a unique site on the receptor to prevent ligand binding. In addition, petosemtamab triggers EGFR degradation in cancer stem-like cells expressing both EGFR and LGR5. Petosemtamab is also engineered to enhance innate immune-mediated activity through interactions with macrophages and natural killer cells. It is currently being investigated in head and neck squamous cell carcinoma (HNSCC) and other solid tumors, including colorectal cancer (CRC). Petosemtamab is being evaluated in combination with chemotherapy in two Phase 3 trials in first- and second-line RAS/BRAF wild-type metastatic CRC. Please visit https://clinicaltrials.gov/ for more information. About INCB161734 INCB161734 is an investigational, novel, selective and orally bioavailable small molecule ON/OFF KRAS G12D inhibitor. KRAS is one of the most frequently altered oncogenic drivers across solid tumors, and the KRAS G12D mutation is among the most common KRAS alterations, occurring in approximately 40% of pancreatic ductal adenocarcinoma (PDAC) cases and approximately 15% of colorectal cancer (CRC) cases. INCB161734 is being evaluated in the global Phase 3 DAWN-303 (NCT07522073) study which is currently enrolling patients with previously untreated KRAS G12D-mutated pancreatic ductal adenocarcinoma (PDAC) to further evaluate the efficacy and safety of INCB161734 in combination with standard-of-care (SoC) chemotherapy. INCB161734 is also being evaluated as a monotherapy and in combination with standard-of-care (SoC) chemotherapy (gemcitabine/nab-paclitaxel [GEMNabP] or modified FOLFIRINOX [mFOLFIRINOX]), in an ongoing open-label Phase 1 study across KRAS G12D-mutated solid tumors (NCT06179160). About Genmab Genmab is an international biotechnology company dedicated to improving the lives of people with cancer and other serious diseases through innovative antibody medicines. For over 25 years, its passionate, innovative and collaborative team has advanced a broad range of antibody-based therapeutic formats, including bispecific antibodies, antibody–drug conjugates (ADCs), immune-modulating antibodies and other next-generation modalities. Genmab’s science powers eight approved antibody medicines, and the company is advancing a strong late-stage clinical pipeline, including wholly owned programs, with the goal of delivering transformative medicines to patients. Established in 1999, Genmab is headquartered in Copenhagen, Denmark, with international presence across North America, Europe and Asia Pacific. For more information, please visit Genmab.com or follow us on LinkedIn, X, Facebook and Instagram. About Incyte® Incyte is redefining what’s possible in biopharmaceutical innovation. Through deep scientific expertise and a relentless focus on patients, we have built an established portfolio of first-in-class medicines and an extensive portfolio of next-generation medicines across our key franchises: Hematology, Oncology and Inflammation & Autoimmunity. To learn more, visit Incyte.com and Investor.Incyte.com. Follow us on social media: LinkedIn, X and Instagram. Genmab Contacts Media: Jyoti Sharma, Director, Global Communications & Corporate Affairs T: +1 609 480 9844; E: jysh@genmab.com Investor Relations: Andrew Carlsen, Vice President, Head of Investor Relations T: +45 3377 9558; E: acn@genmab.com Incyte Contacts Media: media@incyte.com Investors: ir@incyte.com Genmab Forward-Looking Statements This Media Release contains forward looking statements. The words “believe,” “expect,” “anticipate,” “intend” and “plan” and similar expressions identify forward looking statements. Actual results or performance may differ materially from any future results or performance expressed or implied by such statements. The important factors that could cause our actual results or performance to differ materially include, among others, risks associated with preclinical and clinical development of products, uncertainties related to the outcome and conduct of clinical trials including unforeseen safety issues, uncertainties related to product manufacturing, the lack of market acceptance of our products, our inability to manage growth, the competitive environment in relation to our business area and markets, our inability to attract and retain suitably qualified personnel, the unenforceability or lack of protection of our patents and proprietary rights, our relationships with affiliated entities, changes and developments in technology which may render our products or technologies obsolete, and other factors. For a further discussion of these risks, please refer to the risk management sections in Genmab’s most recent financial reports, which are available on www.genmab.com and the risk factors included in Genmab’s most recent Annual Report on Form 20-F and other filings with the U.S. Securities and Exchange Commission (SEC), which are available at www.sec.gov. Genmab does not undertake any obligation to update or revise forward looking statements in this Media Release nor to confirm such statements to reflect subsequent events or circumstances after the date made or in relation to actual results, unless required by law. Genmab A/S and/or its subsidiaries own the following trademarks: Genmab^{®}; the Y-shaped Genmab logo^{®}; Genmab in combination with the Y-shaped Genmab logo^{®}; HuMax^{®}; DuoBody^{®}; HexaBody^{®}; DuoHexaBody^{®}, HexElect^{® }and KYSO^{®}. Incyte Forward-Looking Statements This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 and other federal securities laws, including statements regarding Incyte’s clinical trial collaboration with Genmab; the design, initiation, timing, conduct, sponsorship and funding of the planned studies; the potential presented by INCB161734, petosemtamab and the combination of these investigational therapies with standard-of-care chemotherapy; the potential for the combination to provide a new treatment option for patients with first-line KRAS G12D-mutated metastatic colorectal cancer; expectations regarding the initiation, timing, progress and results of ongoing and planned clinical trials for INCB161734; whether or when INCB161734, petosemtamab or any combination regimen will be approved or commercially available for use in humans anywhere in the world; Incyte’s oncology portfolio and development strategy; and Incyte’s aspirations and goals as set forth under the heading “About Incyte.” Actual results may differ materially from those indicated in the forward-looking statements as a result of various important factors, including whether preclinical or early clinical results will be replicated in later-stage or larger clinical trials; the sufficiency of clinical trial data to meet applicable regulatory standards or warrant continued development; the ability to enroll sufficient numbers of subjects in clinical trials and to enroll subjects in accordance with planned schedules; changes in clinical development plans; actions of regulatory agencies, which may affect the initiation, timing and progress of clinical trials and regulatory approval; the efficacy or safety of Incyte’s products and product candidates; Incyte’s ability to successfully develop and commercialize its product candidates; Incyte’s reliance on third parties and collaboration partners, including with respect to the planned studies described herein; the availability and effectiveness of competing treatments; Incyte’s ability to obtain and maintain protection of intellectual property for its products and technology; greater than expected expenses, including expenses relating to clinical development, litigation or strategic activities; and those risks and uncertainties discussed in greater detail in Incyte’s reports filed with the U.S. Securities and Exchange Commission, including its annual report on Form 10-K for the year ended December 31, 2025 and its quarterly report on Form 10-Q for the quarter ended June 30, 2026. Incyte disclaims any intent or obligation to update these forward-looking statements. 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