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