In phase 1a, 1 patient (5%) achieved a partial response, and 5 (23%) achieved stable disease. In phase 1b, 8 patients (21%) achieved a confirmed partial response, and 12 (31%) achieved stable disease. The objective response rates for SCCHN, NPC, and CRC were 40%, 44%, and 0%, and the disease control rates were 100%, 89%, and 25%, respectively....The findings of this nonrandomized clinical trial suggest that MRG003 showed a manageable safety profile and promising antitumor activity in patients with EGFR-positive NPC and SCCHN.

Among these 9 EGFR positive pts, one with NPC in the 2.5 mg/kg cohort had partial response, four had stable disease (one with H&N in the 1.5 mg/kg, one each with NPC and H&N in the 2.0 mg/kg, and one with EC in the 2.5 mg/kg cohorts). The disease control rate (DCR) at doses ≥1.5 mg/kg was 100% for the EGFR positive pts....The dose escalation study of MRG003 showed manageable safety profiles and encouraging preliminary antitumor activity in pts with EGFR-positive solid tumors. MRG003 is currently being evaluated as a single agent in phase I dose expansion cohorts to further assess safety, PK, and antitumor activity.