YMAB Y mAbs Therapeutics Inc

Y-mAbs Therapeutics, Inc. (the “Company” or “Y-mAbs”) (Nasdaq: YMAB), a commercial-stage biopharmaceutical company focused on the development and commercialization of novel radioimmunotherapy and antibody-based therapeutic products for the treatment of cancer, today announced the acceptance of four abstracts at the 2024 American Society of Clinical Oncology (“ASCO”) Annual Meeting, taking place May 31 – June 4, 2024 in Chicago, IL.

“This year’s ASCO presentations feature our ongoing efforts to grow and diversify our portfolio,” said Mike Rossi, President and Chief Executive Officer. "From our investigational SADA PRIT Technology Platform to our approved therapy, DANYELZA® (naxitamab-gqgk), for relapsed or refractory high-risk neuroblastoma, we look forward to demonstrating the many ways in which we are expanding and refining the promise of next-generation radioimmunotherapy and antibody-based therapies to improve patient lives."

The following abstract will present data on the Company’s investigational Self-Assembly DisAssembly (“SADA™”) ​Pretargeted Radioimmunotherapy (“PRIT™”) platform:

Abstract Title: Preclinical characterization of pretargeted radioimmunotherapy (PRIT) with GD2-SADA, a self-assembling and disassembling bispecific fusion proteinFormat: Abstract Publication

The following abstracts will present data on DANYELZA® (naxitamab-gqgk), the Company's approved therapy for the treatment of pediatric patients with relapsed or refractory high-risk neuroblastoma, which is currently also being evaluated for the treatment of osteosarcoma and other GD2-positive tumors:

Abstract Title: Patterns of improvement following initial response in patients treated with naxitamab for relapsed/refractory high-risk neuroblastomaPoster Number: #10033Format: Poster Presentation

Abstract Title: Naxitamab-related adverse events within and across treatment cycles in patients with relapsed/refractory (R/R) high-risk neuroblastomaPoster Number: #10032Format: Poster PresentationAbstract Title: Naxitamab chemo-immunotherapy regimens other than with irinotecan/temozolomide for patients with relapsed/refractory high-risk neuroblastomaPoster Number: #10037 (Independent Research)Format: Poster Presentation

Y-mAbs will be available for comment at booth #35151 on the Exhibition Floor of McCormick Place.

Researchers at Memorial Sloan Kettering Cancer Center (“MSK”) developed DANYELZA® (naxitamab-gqgk), which is exclusively licensed by MSK to Y-mAbs. MSK has institutional financial interests in the compound and Y-mAbs. Researchers at MSK, including Dr. Nai-Kong Cheung, developed the SADA technology for radioimmunotherapy, which is exclusively licensed by MSK to Y-mAbs. Dr. Cheung has intellectual property rights and interests in the technology, and as a result of this licensing arrangement, MSK has institutional financial interests in the technology.

About DANYELZA® (naxitamab-gqgk)DANYELZA® (naxitamab-gqgk) is indicated, in combination with granulocyte-macrophage colony-stimulating factor ("GM-CSF"), for the treatment of pediatric patients 1 year of age and older and adult patients with relapsed or refractory high-risk neuroblastoma in the bone or bone marrow who have demonstrated a partial response, minor response, or stable disease to prior therapy. This indication was approved under accelerated approval based on overall response rate and duration of response. Continued approval for this indication may be contingent upon verification and description of clinical benefits in a confirmatory trial. DANYELZA® includes a Boxed Warning for serious infusion-related reactions, such as cardiac arrest and anaphylaxis, and neurotoxicity, such as severe neuropathic pain and transverse myelitis. See full Prescribing Information for complete Boxed Warning and other important safety information.

About Y-mAbs Y-mAbs is a commercial-stage biopharmaceutical company focused on the development and commercialization of novel, radioimmunotherapy and antibody-based therapeutic cancer products. The Company’s technologies include its investigational Self-Assembly DisAssembly (“SADA”) ​Pretargeted Radioimmunotherapy Platform (“PRIT”)​ and bispecific antibodies generated using the Y-BiClone platform. The Company’s broad and advanced product pipeline includes the anti-GD2 therapy DANYELZA® (naxitamab-gqgk), the first FDA-approved treatment for patients with relapsed or refractory high-risk neuroblastoma in the bone or bone marrow after a partial response, minor response, or stable disease to prior therapy.

Forward-Looking StatementsStatements in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Such statements include, but are not limited to, statements about our business model, including financial outlook for 2023 and beyond, including estimated operating expenses, cash burn and DANYELZA product revenue and sufficiency of cash resources and related assumptions; implied and express statements regarding the future of the Company’s business, including with respect to expansion and its goals; the Company’s plans and strategies, development, commercialization and product distribution plans, including potential partnerships; expectations with respect to the Company’s products and product candidates, including potential territory and label expansion of DANYELZA and the potential market opportunity related thereto and potential benefits thereof, and the potential of the SADA Technology and potential benefits and applications thereof; statements with respect to DANYELZA as a growing commercial product and SADA as a differentiated radioimmunotherapy platform positioning the Company on a path to potentially transform the treatment paradigm for a variety of cancers and improve patients’ lives; expectations relating to key anticipated development milestones, including potential expansion of international commercialization efforts with respect to DANYELZA development efforts and the SADA Technology, including potential indications and applications, and the timing thereof; expectations with respect to current and future clinical and pre-clinical studies and the Company’s research and development programs, including with respect to timing and results; expectations related to the timing of the initiation and completion of regulatory submissions; additional product candidates and technologies; expectations regarding collaborations or strategic partnerships and the potential benefits thereof; expectations related to the use of cash and cash equivalents, and the need for, timing and amount of any future financing transaction; expectations with respect to the Company’s future financial performance; and other statements that are not historical facts. Words such as ‘‘anticipate,’’ ‘‘believe,’’ “contemplate,” ‘‘continue,’’ ‘‘could,’’ ‘‘estimate,’’ ‘‘expect,’’ “hope,” ‘‘intend,’’ ‘‘may,’’ ‘‘might,’’ ‘‘plan,’’ ‘‘potential,’’ ‘‘predict,’’ ‘‘project,’’ ‘‘should,’’ ‘‘target,’’ “will”, ‘‘would’’, “guidance,” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Our product candidates and related technologies are novel approaches to cancer treatment that present significant challenges. Actual results may differ materially from those indicated by such forward-looking statements as a result of various factors, including but not limited to: risks associated with the Company’s financial condition and need for additional capital; the risks that actual results of the Company’s restructuring plan and revised business plan will not be as expected; risks associated with the Company’s development work; cost and success of the Company’s product development activities and clinical trials; the risks of delay in the timing of the Company’s regulatory submissions or failure to receive approval of its drug candidates; the risks related to commercializing any approved pharmaceutical product including the rate and degree of market acceptance of product candidates; development of sales and marketing capabilities and risks associated with failure to obtain sufficient reimbursement for products; the risks related to the Company’s dependence on third parties including for conduct of clinical testing and product manufacture; the Company’s inability to enter into partnerships; the risks related to government regulation; risks related to market approval, risks associated with protection of the Company’s intellectual property rights; risks related to employee matters and managing growth; risks related to the Company’s common stock, risks associated with macroeconomic conditions, including the conflict between Russia and Ukraine and sanctions related thereto, the state of war between Israel and Hamas and the related risk of a larger regional conflict, inflation, increased interest rates, uncertain global credit and capital markets and disruptions in banking systems; and other risks and uncertainties affecting the Company including those described in the "Risk Factors" section included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023, the Company’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2023 and future filings and reports by the Company. Any forward-looking statements contained in this press release speak only as of the date hereof, and the Company undertakes no obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise.

DANYELZA®, OMBLASTYS® and Y-mAbs® are registered trademarks of Y-mAbs Therapeutics, Inc.

Investor Contact:Courtney DuganVP, Head of Investor Relationscdu@ymabs.com