Merus Announces Publication of an Abstract on Preclinical Mechanism of Action of MCLA-129 Selected for Poster Presentation at the AACR Annual Meeting 2023

UTRECHT, The Netherlands and CAMBRIDGE, Mass., March 14, 2023 (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 the publication of an abstract highlighting the preclinical evaluation of the bispecific antibody MCLA-129 for poster presentation at the American Association for Cancer Research (AACR) Annual Meeting 2023 taking place in Orlando, Florida April 14-19, 2023.

The abstract and presentation describe the mechanism of action of MCLA-129, an antibody-dependent cellular cytotoxicity (ADCC) enhanced Biclonics^® that targets epidermal growth factor receptor (EGFR) and c-MET in non-small cell lung cancer (NSCLC) and other solid tumors in comparison to the EGFR x c-MET bispecific antibody amivantamab. MCLA-129 is a Biclonics^® common light chain bispecific antibody with multiple mechanisms of action, including inhibition of EGFR and c-MET ligand binding, which is observed in preclinical assays to have antibody-dependent cellular phagocytosis and ADCC comparable or more potent than amivantamab.

Presentation Details:

MCLA-129

Title: Preclinical evaluation of MCLA-129, a bispecific antibody targeting EGFR and c-MET on solid tumor cells, in comparison with amivantamab
Session Category: Experimental and Molecular Therapeutics
Session: Targeting Protein Kinases and Phosphatases for Therapy 1
Date: Tuesday, April 18, 2023
Time: 1:30-5:30 p.m. ET
Poster #: 12
Abstract #: 4999

The full abstract is available on the AACR website. The poster will be available on the Merus website at the start of the session.

MCLA-129 is in clinical development in a phase 1/2, open-label clinical trial evaluating MCLA-129 monotherapy in EGFRex20 NSCLC, MetEx14 NSCLC, and in head and neck squamous cell carcinoma, as well as in combination with Tagrisso (osimertinib) in treatment naïve EGFR mutant (m) NSCLC and in EGFRm NSCLC that has progressed on Tagrisso.

MCLA-129 is subject to a collaboration and license agreement with Betta Pharmaceuticals Co. Ltd. (Betta), which permits Betta to exclusively develop MCLA-129 and potentially commercialize exclusively in China, while Merus retains global rights outside of China.

About MCLA-129
MCLA-129 is an antibody-dependent cellular cytotoxicity-enhanced Biclonics^® that is designed to inhibit the EGFR and c-MET signaling pathways in solid tumors. Preclinical data have shown that MCLA-129 can effectively treat TKI-resistant non-small cell lung cancer (NSCLC) in xenograft models of cancer. MCLA-129 is designed to have two complementary mechanisms of action: blocking growth and survival pathways to stop tumor expansion and recruitment and enhancement of immune effector cells to eliminate the tumor.

About Merus N.V.
Merus is a clinical-stage oncology company developing innovative full-length human bispecific and trispecific antibody therapeutics, referred to as Multiclonics^®. Multiclonics^® are manufactured using industry standard processes and have been observed in preclinical and clinical studies to have several of the same features of conventional human monoclonal antibodies, such as long half-life and low immunogenicity. For additional information, please visit Merus’ website, http://www.merus.nl and https://twitter.com/MerusNV.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements contained in this press release that do not relate to matters of historical fact should be considered forward-looking statements, including without limitation statements regarding the clinical development of MCLA-129, preclinical activity and mechanisms of action or comparisons to third party moieties. These forward-looking statements are based on management’s current expectations. These statements are neither promises nor guarantees, but involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including, but not limited to, the following: our need for additional funding, which may not be available and which may require us to restrict our operations or require us to relinquish rights to our technologies or Biclonics^®, Triclonics^® and multispecific antibody candidates; potential delays in regulatory approval, which would impact our ability to commercialize our product candidates and affect our ability to generate revenue; the lengthy and expensive process of clinical drug development, which has an uncertain outcome; the unpredictable nature of our early stage development efforts for marketable drugs; potential delays in enrollment of patients, which could affect the receipt of necessary regulatory approvals; our reliance on third parties to conduct our clinical trials and the potential for those third parties to not perform satisfactorily; impacts of the COVID-19 pandemic; we may not identify suitable Biclonics^® or bispecific antibody candidates under our collaborations or our collaborators may fail to perform adequately under our collaborations; our reliance on third parties to manufacture our product candidates, which may delay, prevent or impair our development and commercialization efforts; protection of our proprietary technology; our patents may be found invalid, unenforceable, circumvented by competitors and our patent applications may be found not to comply with the rules and regulations of patentability; we may fail to prevail in potential lawsuits for infringement of third-party intellectual property; and our registered or unregistered trademarks or trade names may be challenged, infringed, circumvented or declared generic or determined to be infringing on other marks.

These and other important factors discussed under the caption “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2022 filed with the Securities and Exchange Commission, or SEC, on February 28, 2023, and our other reports filed with the SEC, could cause actual results to differ materially from those indicated by the forward-looking statements made in this press release. Any such forward-looking statements represent management’s estimates as of the date of this press release. While we may elect to update such forward-looking statements at some point in the future, we disclaim any obligation to do so, even if subsequent events cause our views to change, except as required under applicable law. These forward-looking statements should not be relied upon as representing our views as of any date subsequent to the date of this press release.

Biclonics^®, Triclonics^® and Multiclonics^® are registered trademarks of Merus N.V.