Merus Announces Publication of Abstracts for Presentation at the 2024 ASCO® Annual Meeting

MCLA-145 monotherapy and in combination with pembrolizumab rapid oral session presentation: June 2, 2024, 11:30 a.m.-1:00 p.m. CT

• MCLA-129 in NSCLC with c-MET exon 14 skipping mutations poster presentation: June 3, 2024, 1:30-4:30 p.m. CT

UTRECHT, The Netherlands and CAMBRIDGE, Mass., May 23, 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 the publication of an abstract regarding MCLA-145 and an abstract regarding MCLA-129 at the 2024 American Society of Clinical Oncology^® (ASCO^®) Annual Meeting taking place in Chicago May 31-June 4, 2024. Both abstracts can be found on the 2024 ASCO^® website.

“We continue to be proud of our Multiclonics^® technology platforms’ ability to develop bispecific antibodies for clinical investigation with the potential to impact patients’ lives,” said Bill Lundberg, M.D., President, Chief Executive Officer of Merus. “MCLA-129 continues to show strong monotherapy activity in EGFR mutant non-small cell lung cancer, and MCLA-145 is now the fourth molecule based on our technology to demonstrate clinical activity. We are looking forward to providing additional detail at 2024 ASCO^®.”

MCLA-145 (CD137 x PD-L1 Biclonics^®): Solid Tumors
Interim data included in the abstract describe data from patients (pts) with advanced/metastatic solid tumors who received MCLA-145 as monotherapy every two weeks (Q2W) in 21 day cycles or every three weeks (Q3W) in 28 day cycles. Pts treated with the combination of MCLA-145 and pembrolizumab had cancers that either relapsed after PD-(L)1 therapies or were immunotherapy naïve.

Rapid oral presentation title: Phase I study of MCLA-145, a bispecific antibody targeting CD137 and PD-L1, in solid tumors, as monotherapy or in combination with pembrolizumab
Observations in the abstract include:  

• As of a December 4, 2023 data cutoff date, 72 pts with multiple cancer types were treated; 25% of pts had non-small cell lung cancer (NSCLC); 3 pts were continuing combination therapy
• Monotherapy: 53 pts were treated across 8 dose levels
  • 47 pts 0.4-75 mg Q2W
  • 6 pts 40 mg Q3W
  • The recommended dose for expansion (RDE) was established at 40 mg Q3W
  • In 52 pts evaluable for response
• 5 partial responses (PRs) were observed in a variety of tumor types including: glioblastoma (ongoing>3 years), sarcoma, cervical, anal, and gastric cancer (treated for 2-11 month (mo)) by Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. per investigator assessment
• Combination: 19 pts were treated with MCLA-145 10, 25 or 40 mg plus pembrolizumab Q3W
  • The RDE was established at 40 mg Q3W
  • In 19 pts evaluable for response
    • 1 complete response was observed in PD-L1+ NSCLC (treated 6+ mo) and 1 PR in Merkel cell carcinoma (treated 12+ mo); both after prior immunotherapy
    • 68% disease control rate was observed
• MCLA-145 monotherapy or in combination with pembrolizumab had a well-tolerated and manageable safety profile at the RDE of 40 mg Q3W

Presentation Details:
Abstract #: 2520 
Session Title: Developmental Therapeutics—Immunotherapy 
Session Date and Time: June 2, 2024, 11:30 a.m.-1:00 p.m. CT 

MCLA-129 (EGFR x c-MET Biclonics^®): Solid Tumors
The abstract describes a cohort of patients with advanced/metastatic METex14 NSCLC previously treated with standard therapies, and who were either c-MET TKI-naïve or who progressed on c-MET TKI.

Safety and efficacy data will be included in the poster presentation at 2024 ASCO^®.

Poster presentation title: 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)
Presentation Details:
Abstract #: 8583 
Session Title: Lung Cancer—Non-Small Cell Metastatic 
Session Date and Time: June 3, 2024, 1:30-4:30 p.m. CT

As full presentations become available at the 2024 ASCO^® Annual Meeting, they will contemporaneously be available on the Merus website. 

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, https://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 our clinical candidates, including MCLA-145 and MCLA-129, future clinical trial results or interim data, clinical activity and safety profile, and development plans in the on-going trials and described in forthcoming posters or presentations; the ability of our Multiclonics^® platforms’ to develop bispecific antibodies for clinical investigation having potential to impact patients’ lives; the future activity of MCLA-129 in EGFR mutant non-small cell lung cancer or MCLA-145 in solid tumors; and future development of these assets. We are looking forward to providing additional detail at 2024 ASCO^®. These forward-looking statements are based on management’s current expectations. 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 market volatility; 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-Q for the quarter ended March 31, 2024 filed with the Securities and Exchange Commission, or SEC, on May 8, 2024, 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.

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

CONTACT: Investor and Media Inquiries:  
Sherri Spear 
Merus N.V. 
VP Investor Relations and Corporate Communications 
617-821-3246 
s.spear@merus.nl

Kathleen Farren  
Merus N.V. 
IR/Corp Comms 
617-230-4165 
k.farren@merus.nl