Zymeworks’ ZW191 Shows Strong Early Efficacy in Phase I Cancer Trial

Zymeworks’ antibody-drug conjugate ZW191, targeting folate receptor-alpha (FR⍺), demonstrated encouraging Phase I results presented at the AACR-NCI-EORTC Conference in Boston. Among 41 patients with metastatic non-small cell lung, ovarian, and endometrial cancers, ZW191 achieved a 44% overall objective response rate (ORR), rising to 53% at doses between 6.4mg/kg and 9.6mg/kg. In gynaecological cancers, the ORR reached 50%, and 64% at higher doses. The therapy showed a manageable safety profile, with grade 3 or higher adverse events limited to anaemia (10%), thrombocytopenia (5%), and neutropenia (5%), and no treatment-related deaths or discontinuations. Zymeworks identified 11.2mg/kg as the maximum tolerated dose and selected 6.4mg/kg and 9.6mg/kg for further evaluation. These findings validate the company’s ADC platform, combining an engineered antibody with its proprietary payload ZD06519.

28-10-2025