At the 2025 ASCO Annual Meeting, RemeGen presented data from phase 1b/2 clinical trial of RC108 in combination with furmonertinib in patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) who have progressed on EGFR-TKI treatment, and the results showed obvious synergistic effect between RC108 and furmonertinib.

RC108 is a c-mesenchymal-epithelial transition factor (c-MET) targeted ADC developed by RemeGen. It binds to MET with high affinity and precisely delivers cytotoxins into c-MET-expressing tumor cells. Furmonertinib is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) developed by Allist Pharmaceuticals.

Studies have shown that MET-overexpression is the main resistance mechanism for the progression of EGFR-TKI treatment. RC108 has a good killing effect on tumor cells with different MET expression levels. The results of phase 1 study (NCT04617314) showed that the objective response rate (ORR) of RC108 alone in patients with MET-overexpressing (≥ IHC 1+) locally advanced or metastatic NSCLC who have progressed on EGFR-TKI treatment was 33%.

The study presented at 2025 ASCO is an open, single-arm, multicenter phase 1b/2 clinical trial to evaluate the safety, tolerability, efficacy, and pharmacokinetic profile of RC108 in treatment of patients, aiming to provide a reference basis for the development of a rational combination dosing regimen for subsequent studies.

Results of the analysis up to April 11, 2025 showed that RC108 in combination with furmonertinib demonstrated encouraging antitumor activity in patients with MET-overexpressing locally advanced or metastatic NSCLC with a manageable safety profile:

• In patients with ≥1+ tumor cells membrane staining and ≤20% tumor cells with strong (3+) cytoplasmic staining, ORR was 40.5%, and median progression-free survival (PFS) was 7.1 months.

• In patients with ≥3+ tumor cells membrane staining and ≤20% tumor cells with strong (3+) cytoplasmic staining, ORR was 61.1%, and median PFS was 8.2 months.

• Common AEs included: asthenia, nausea, decreased appetite, vomiting, etc.

RemeGen is currently preparing phase 3 clinical study of this combination therapy.