Merus Announces Publication of Abstracts on MCLA-129 for Presentation at ESMO Asia Congress 2023 - Seite 2

Observations in the abstract include:  

• As of a May 10, 2023 data cutoff date, 48 patients (pts) with advanced/metastatic EGFRm NSCLC were treated (14/1L, 34/2L+)
  • In the 1L setting, 14 pts were treated, with 10 pts evaluable for response   
    • 2 confirmed partial responses (PRs) and 6 unconfirmed PRs were observed (8/10, 80%; 95% CI 44-98) by Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. per investigator assessment; all responses were ongoing as of the data cutoff date
    • 90% disease control rate (DCR) (95% CI 56-100) 
    • 10 weeks (range 2-26) median duration of exposure with 93% continuing treatment
  • In the 2L+ setting, 34 pts were treated, with 22 pts evaluable for response
    • All received prior osimertinib in 1L/2L setting, 71% as the most recent therapy; 24% received prior chemotherapy
    • 6 confirmed PRs and 5 unconfirmed PRs were observed (11/22, 50%; 95% CI 28-72) by RECIST v1.1. per investigator assessment; 9 responses were ongoing as of the data cutoff date, including 4 of the unconfirmed PRs
    • 82% DCR (95% CI 60-95)
    • 10 weeks (range 2-38) median duration of exposure with 68% continuing treatment 
• Early safety assessment in 48 NSCLC pts treated with MCLA-129 plus osimertinib included
  • Most common adverse events (AEs) regardless of causality were infusion related reactions (IRRs; composite term) in 85% (6% ≥ grade(G) 3)
  • Skin toxicity (composite term) in 75% (4% G3)
  • Treatment related interstitial lung disease (ILD)/pneumonitis in five patients (10%), two were G2, two were G3, and one was G5 and one progressed to G5 after the data cutoff date
  • Venous thromboembolic (VTE) events in 15%; 4% treatment related
    

Presentation Details:
Session: Thoracic Cancer
Date: Sunday, December 3, 2023
Time: 9:40 -9:45 a.m. SGT
Presentation #: 516MO

Poster presentation title: Efficacy and safety of MCLA-129, an anti-EGFR/c-MET bispecific antibody, in head and neck squamous cell cancer (HNSCC) 
Observations in the abstract include:  

• As of a May 10, 2023 data cutoff date, 18 pts with previously treated HNSCC were treated
  • Pts received median of two lines prior therapy, 89% prior chemotherapy, 78% prior anti-PD-(L)1, 28% prior cetuximab
  • 12 pts were evaluable for response   
    • 2 unconfirmed PRs were observed (2/12, 17%) by RECIST v1.1. per investigator assessment; one response was ongoing as of the data cutoff date  
    • 67% DCR (95% CI 35-90%)
    • 8 weeks (range 2-17) median duration of exposure with 50% continuing on treatment
• Early safety assessment in 18 HNSCC pts treated with MCLA-129 monotherapy included
  • Most common AEs regardless of causality were IRRs (composite term) in 72% (28% ≥ G3), all on cycle 1 day 1, that led to treatment discontinuation in two pts
  • Skin toxicity in 61% (11% G3)
  • No ILD or VTE events were reported

Presentation details: