The European Society for Medical Oncology (ESMO) Asia Congress will be held in Singapore.
Lepu Biotech will present new Phase II clinical data on their EGFR-targeting ADC drug, MRG003, in combination with the PD-1 antibody, pitilimab, for the treatment of EGFR-mutated, recurrent, or metastatic nasopharyngeal carcinoma (NPC) at the conference.
The Phase II clinical trial included patients who had progressed after first-line platinum-based chemotherapy. These patients received treatment with 3.0 mg/kg of pitilimab and 2.0 mg/kg of MRG003 (administered every three weeks). As of June 30, 2024, a total of 30 patients had been enrolled, 29 of whom (96.7%) had progressed after PD-(L)1 antibody treatment. Among them, 2 patients achieved a complete response (CR), 18 patients had a partial response (PR), 8 patients had stable disease (SD), with an overall response rate (ORR) of 66.7% and a disease control rate (DCR) of 93.3%. Data on median progression-free survival (mPFS) and duration of response (DoR) are still maturing, but the 6-month PFS rate was 76.2%, and the 6-month DoR rate was 83.3%. Regarding safety, most adverse events were of grade 1-2, with grade 3-4 events occurring in only 23.3% of patients, significantly lower than the chemotherapy rate of 43.8% (Keynote 122).
According to the latest Phase IIa clinical data presented at last year’s ESMO meeting, 61 NPC patients were treated with either 2.0 mg/kg or 2.3 mg/kg of MRG003. As of March 15, 2023, among 57 evaluable NPC patients who had failed prior PD-1/PD-L1 or platinum-based treatments, the ORR was 47.4%, and the DCR was 79.0%. In the 2.3 mg/kg dose group (29 evaluable patients), the ORR was 55.2%, and the DCR was 86.2%.
From the latest clinical data on the combination of pitilimab and MRG003, it is evident that the combination therapy further enhances the efficacy of MRG003 in recurrent or metastatic NPC. There is no doubt that the clinical breakthrough of MRG003 will profoundly change the treatment landscape for recurrent or metastatic NPC.
Summary:
China is a high-incidence country for nasopharyngeal cancer, accounting for half of the global cases, with approximately 60,000 new cases annually. In recent years, immune checkpoint inhibitors combined with chemotherapy have become the standard first-line treatment for recurrent or metastatic NPC. However, with the widespread use of immune checkpoint inhibitors, the issue of resistance is inevitable. Therefore, an optimal treatment option for patients with PD-(L)1-resistant recurrent or metastatic NPC is urgently needed.
MRG003, an EGFR-targeting ADC developed by Lepu Biotech, has shown promising efficacy in later-line NPC patients and is expected to provide new treatment options for NPC patients. The results of the pitilimab + MRG003 combination therapy presented at this ESMO Asia conference demonstrate excellent anti-tumor efficacy and good safety in recurrent or metastatic NPC patients who have failed first-line immunotherapy. This combination therapy is expected to become a new preferred treatment option for PD-(L)1-resistant recurrent or metastatic NPC.
