Petosemtamab in combination with pembrolizumab in 1L HNSCC initial interim clinical data at 2024 ASCO Annual Meeting; preparing for a potential phase 3 trial Zeno BLA accepted for priority review by the FDA for the treatment of NRG1+ NSCLC and PDAC Based on the Company's current operating plan, existing cash, cash equivalents and marketable securities expected to fund Merus' operations into 2027 UTRECHT, The Netherlands and CAMBRIDGE, Mass., May 08, 2024 (GLOBE NEWSWIRE) -- Merus N.V. (NASDAQ:MRUS) (Merus, the Company, we, or our), a clinical-stage oncology company developing innovative, full-length multispecific antibodies (Biclonics® and Triclonics®), today announced financial results for the first quarter and provided a business update. "At the upcoming 2024 ASCO meeting, we are looking forward to presenting multiple datasets including the first clinical data on safety and efficacy of petosemtamab in combination with pembrolizumab in previously untreated head and neck cancer. With petosemtamab, we continue to believe we have the opportunity to significantly improve the lives of patients with both previously treated, as well as newly diagnosed, head and neck cancer and thus, it remains the focus of the company's resources," said Bill Lundberg, M.D., President, Chief Executive Officer of Merus. "Additionally, we are thrilled that Zeno's BLA has been accepted for priority review, a tremendous milestone for Merus representing our first Biclonics® advancing from discovery to marketing application." Petosemtamab (MCLA-158: EGFR x LGR5 Biclonics®): Solid Tumors1L head & neck squamous cell carcinoma (HNSCC) in combination with pembrolizumab ongoing, presentation at 2024 ASCO; previously treated (2L+) HNSCC phase 3 registration trial planned to initiate mid-2024 and dose comparison of petosemtamab monotherapy 1100 vs 1500 mg in 2L+ HNSCC ongoing; planned initiation of 2L colorectal cancer (CRC) cohort in 2024 An abstract entitled: Petosemtamab (MCLA-158) with pembrolizumab as first-line (1L) treatment of recurrent/metastatic (r/m) head and neck squamous cell carcinoma (HNSCC): Phase 2 study was accepted for rapid oral session presentation at 2024 ASCO. Merus plans to report initial interim efficacy and safety data from this cohort. Merus continues to evaluate patients with untreated advanced PD-L1+ HNSCC treated with petosemtamab 1500 mg in combination with pembrolizumab. Initial safety data from this single arm cohort may support the initiation of a 1L phase 3 trial with this combination. Among the initial patients dosed in the 1L combination cohort, the safety profile has been observed to be generally favorable. Merus plans to initiate a phase 3 clinical trial in mid-2024 to evaluate petosemtamab monotherapy in 2L+ HNSCC. In the planned trial, patients will be randomized to petosemtamab monotherapy or investigators' choice of single agent chemotherapy or cetuximab. Merus believes a randomized registration trial in HNSCC with an overall response rate (ORR) endpoint could potentially support accelerated approval and the overall survival (OS) results from the same study could potentially verify its clinical benefit to support regular approval. Merus continues to evaluate approximately 40 patients treated with petosemtamab monotherapy at either 1100 or 1500 mg dose levels to confirm a suitable dose for future potential phase 3 trials. Merus plans to share clinical data from this cohort in the second half of 2024. At the American Association of Cancer Research (AACR) Annual Meeting 2023, Merus provided interim data on 49 2L+ HNSCC patients that were treated with petosemtamab at the recommended phase 2 dose of 1500 mg intravenous every two weeks. Merus plans to provide updated efficacy, durability and safety data of this cohort in the second half of 2024. In 2024, Merus is planning to initiate the evaluation of petosemtamab with standard chemotherapy in 2L CRC. Zenocutuzumab (Zeno or MCLA-128: HER2 x HER3 Biclonics®): NRG1 fusion-positive (NRG1+) lung, pancreatic and other solid tumorsZeno BLA for treatment of NRG1+ NSCLC and PDAC accepted for priority review by the FDA The U.S. Food and Drug Administration (FDA) has accepted for priority review a Biologics License Application (BLA) for the bispecific antibody zenocutuzumab (Zeno) in patients with NRG1+ non-small cell lung cancer (NSCLC) and pancreatic (PDAC) cancer. If approved, Zeno will be the first and only targeted therapy for patients with NRG1+ NSCLC and PDAC. The Company is also conducting ongoing translational work on potential biomarkers outside of NRG1+ cancer which may support development opportunities for Zeno in additional areas of unmet need.  Merus presented a pre-clinical poster: Zenocutuzumab, a HER2xHER3 bispecific antibody, is effective in cancer models with high NRG1 expression at the AACR Annual Meeting 2024. Merus believes that obtaining a commercialization partnership agreement will be an essential step in bringing Zeno to patients with NRG1+ cancer, if approved. MCLA-129 (EGFR x c-MET Biclonics®): Solid TumorsInvestigation of MCLA-129 continues in the MET ex14 NSCLC expansion cohort in the phase 1/2 trial; MCLA-129 in combination with chemotherapy in 2L+ EGFR mutant (EGFRm) NSCLC planned to start in 2024 An abstract entitled: Efficacy and safety of MCLA-129, an anti-EGFR/c-MET bispecific antibody, in non-small-cell lung cancer (NSCLC) with c-MET exon 14 skipping mutations (METex14) was accepted for poster presentation at 2024 ASCO. We plan to start a cohort investigating MCLA-129 in combination with chemotherapy in 2L+ EGFRm NSCLC in 2024. We also remain interested in exploring partnering MCLA-129 to sufficiently resource the development of MCLA-129 and potential benefit it may have for patients. MCLA-129 is subject to a collaboration and license agreement with Betta Pharmaceuticals Co. Ltd. (Betta), which permits Betta to develop MCLA-129 and potentially commercialize exclusively in China, while Merus retains global rights outside of China. An abstract sponsored by Betta entitled: Efficacy and safety of MCLA-129, an EGFR/c-MET bispecific antibody, in advanced non-small cell lung cancer (NSCLC) was accepted for poster presentation at 2024 ASCO. MCLA-145 (CD137 x PD-L1 Biclonics®): Solid Tumors Investigation continues of the phase 1 trial of MCLA-145 in combination with pembrolizumab An abstract entitled: Phase I study of MCLA-145, a bispecific antibody targeting CD137 and PD-L1, in solid tumors, as monotherapy or in combination with pembrolizumab was accepted for rapid oral session presentation at 2024 ASCO. ResearchAt the 20th Annual PEGS Boston meeting on May 14th, Merus plans to present preclinical validation of the compatibility and favorable pharmaceutical properties of Biclonics® conjugated with a range of linkers and payloads to generate antibody-drug conjugates (ADClonicsTM), demonstrating our platform and format holds the potential for improved binding selectivity, internalization and cancer cell killing activity. Company NewsEffective May 7, 2024, Jason Haddock was appointed to the Merus Board of Directors. Most recently, he served as Chief Financial Officer (CFO) at Archer Dx from May to August 2020 until it was acquired by Invitae Corporation. From 2016 to 2019, he served as CFO of Array BioPharma, Inc. and from 2015 to 2016, Mr. Haddock served as CFO and Chief Operating Officer (COO) of BERG. Mr. Haddock spent 15 years (2001-2015) at Bristol-Myers Squibb in a variety of finance, strategic, commercial and business development capacities, including CFO and COO roles for business units in Asia Pacific, Europe and the United States. He currently serves on the board of directors of PYC Therapeutics. Mr. Haddock holds a BS in accounting from Illinois State University and an Executive MBA from Washington University in St. Louis. Collaborations Incyte CorporationSince 2017, Merus has been working with Incyte Corporation (Incyte) under a global collaboration and license agreement focused on the research, discovery and development of bispecific antibodies utilizing Merus' proprietary Biclonics® technology platform. For each program under the collaboration, Merus receives reimbursement for research activities and is eligible to receive potential development, regulatory and commercial milestones and sales royalties for any products, if approved. During the first quarter of 2024, Merus achieved a milestone of $1 million for candidate nomination and expects to receive payment in the second quarter of 2024. This is the fifth program to obtain candidate nomination under the collaboration. Eli Lilly and CompanyIn January 2021, Merus and Eli Lilly and Company (Lilly), announced a research collaboration and exclusive license agreement to develop up to three CD3-engaging T-cell re-directing bispecific antibody therapies utilizing Merus' Biclonics® platform and proprietary CD3 panel along with the scientific and rational drug design expertise of Lilly. The collaboration is progressing well with three programs ongoing at various stages of preclinical development. Gilead SciencesIn March 2024, Merus and Gilead Sciences announced a collaboration to discover novel antibody based trispecific T-cell engagers using Merus' patented Triclonics® platform. Under the terms of the agreement, Merus will lead early-stage research activities for two programs, with an option to pursue a third. Gilead will have the right to exclusively license programs developed under the collaboration after the completion of select research activities. If Gilead exercises its option to license any such program from the collaboration, Gilead will be responsible for additional research, development and commercialization activities for such program. Merus received an equity investment by Gilead of $25 million in Merus common shares and an upfront payment of $56 million. On April 9, 2024, Merus received U.S. Patent Number 11,952,424 covering our proprietary Triclonics® format, related to a trispecific antibody comprising a common light chain, capable of binding at least three different epitopes or antigens. Cash Runway, existing cash, cash equivalents and marketable securities expected to fund Merus' operations into 2027 As of March 31, 2024, Merus had $398.7 million cash, cash equivalents and marketable securities. Based on the Company's current operating plan, the existing cash, cash equivalents and marketable securities are expected to fund Merus' operations into 2027. First Quarter 2024 Financial Results We ended the first quarter with cash, cash equivalents and marketable securities of $398.7 million compared to $411.7 million at December 31, 2023. The decrease was primarily the result of cash used to fund the operations partially offset by equity investment from Gilead Sciences. Collaboration revenue for the three months ended March 31, 2024 decreased by $5.6 million as compared to the three months ended March 31, 2023, primarily as a result of lower cost reimbursement revenue. Research and development expense for the three months ended March 31, 2024 increased by $3.7 million as compared to the three months ended March 31, 2023, primarily as a result of an increase in clinical and manufacturing costs related to our programs. General and administrative expense for the three months ended March 31, 2024 increased by $0.7 million as compared to the three months ended March 31, 2023, primarily as a result of increases in personnel related costs partially offset by decrease in facility and consulting costs. Other income (loss), net consists of interest earned and fees paid on our cash and cash equivalents held on account, accretion of investment earnings and net foreign exchange (losses) gains on our foreign denominated cash, cash equivalents and marketable securities. Other gains or losses relate to the issuance and settlement of financial instruments. MERUS N.V. CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Amounts in thousands, except share and per share data)           March 31,2024     December 31,2023   ASSETS             Current assets:             Cash and cash equivalents   $