Zymeworks Advances Novel RAS-Targeting ADC Platform with Clinical Data from ZW191 at AACR 2026
核心洞察
Zymeworks will present mature Phase 1 clinical data from ZW191, a folate receptor alpha (搜索)-targeting ADC with proprietary topoisomerase 1 (搜索) inhibitor payload, demonstrating potential as a best-in-class therapy for advanced solid tumors.
The company unveiled a novel pan-RAS (搜索) inhibitor ADC platform featuring multiple candidates (ZW418 (搜索), ZW427 (搜索), ZW439 (搜索)) that demonstrate superior potency compared to clinical benchmark RMC-6236 and strong activity across RAS-mutated cancers.
Preclinical data show ZW191's combination potential with standard-of-care agents including carboplatin, paclitaxel, bevacizumab, and PARP inhibitors, driven by enhanced DNA damage in tumor cells.
Zymeworks Inc. announced acceptance of seven presentations at the American Association for Cancer Research (AACR) Annual Meeting, including mature clinical data from its Phase 1 trial of ZW191 and breakthrough preclinical findings from a novel pan-RAS (搜索) inhibitor antibody-drug conjugate platform targeting RAS-mutated cancers.
Clinical Progress with ZW191 Shows Promise
The company will present updated results from Part 1 dose escalation of the ZWI-ZW191-101 study, a Phase 1 first-in-human multicenter open-label trial evaluating ZW191 in participants with advanced solid tumors. ZW191 is a folate receptor alpha (搜索) (FRα)-targeting ADC incorporating Zymeworks' proprietary topoisomerase 1 (搜索) inhibitor payload ZD06519.
"The more mature results build on the initial data we presented at the AACR-EORTC-NCI conference in October 2025 and further reinforce our confidence in the potential ZW191 to be a well-tolerated and effective agent that is potentially best-in-class for patients with advanced, heavily pretreated cancers," said Dr. Sabeen Mekan, Senior Vice President and Chief Medical Officer of Zymeworks.
ZW191 targets folate receptor alpha (搜索), which is found in approximately 75% of high-grade serous ovarian carcinomas and 70% of lung adenocarcinomas. The ADC is currently under investigation in patients with advanced ovarian, endometrial, and non-small cell lung cancers (NSCLC).
Novel Pan-RAS Inhibitor Platform Addresses Critical Unmet Need
Zymeworks unveiled a comprehensive pan-RAS (搜索) inhibitor ADC platform designed to overcome the efficacy and tolerability limitations of current oral pan-RAS inhibitors. Despite clinical promise, existing oral RAS inhibitors are associated with on-target toxicities in normal tissues.
The platform incorporates newly synthesized pan-RAS (搜索) inhibitor payloads demonstrating higher potency than the clinical benchmark RMC-6236. Optimized drug-linkers showed strong tumor regressions at low doses and no significant toxicity at high doses in preclinical models, establishing a promising platform with potential for improved efficacy and tolerability across multiple RAS-driven cancers, including NSCLC, pancreatic, and colorectal cancer (搜索).
Multiple RAS-Targeting Candidates Show Strong Preclinical Activity
The company will present data on several novel ADC candidates incorporating the pan-RAS (搜索) inhibitor platform:
ZW418 (搜索) is a biparatopic ADC targeting PTK7 (搜索), a protein broadly overexpressed in NSCLC. Preclinical data demonstrate superior internalization and tumor penetration compared to clinical benchmark PTK7-targeted antibodies, alongside potent and targeted tumor cell killing and strong anti-tumor activity across multiple RAS (搜索)-mutated cancer models.
ZW427 (搜索) targets Ly6E (搜索), a protein broadly overexpressed across multiple solid tumors. Preclinical data demonstrate potent and targeted tumor cell killing, strong bystander activity, and anti-tumor activity across multiple RAS (搜索)-mutated cancer models including NSCLC, pancreatic, and colorectal cancers.
ZW439 (搜索) targets Claudin 18.2 (CLDN18.2 (搜索)) and is designed to address the urgent unmet need in pancreatic cancer (搜索). Preclinical data demonstrate potent and targeted tumor cell killing across a range of CLDN18.2 expression levels, strong bystander activity, and highly efficacious anti-tumor activity in multiple cancer models, alongside an encouraging tolerability profile.
Combination Strategies and Novel Payload Mechanisms
New preclinical data demonstrate ZW191's strong anti-tumor activity when combined with standard-of-care agents, including carboplatin, paclitaxel, bevacizumab, and PARP inhibitors, driven by enhanced DNA damage in tumor cells. These findings, combined with encouraging early clinical data highlighting ZW191's single-agent activity and differentiated safety profile, support its potential to deliver meaningful efficacy improvements across multiple cancer types and treatment settings.
Additionally, Zymeworks developed a novel ADC platform incorporating newly synthesized eIF4A (搜索) inhibitor payloads, which block translation of key oncogenic proteins including MYC (搜索) and KRAS (搜索). This approach offers a differentiated mechanism with the potential to address resistance seen with other ADC payload classes, demonstrating potent and targeted tumor cell killing in vitro and promising anti-tumor activity across multiple clinically relevant targets in vivo, including HER2 (搜索), Ly6E (搜索), TROP2 (搜索), and EGFR (搜索).
Strategic Implications for RAS-Driven Cancers
"In addition to new preclinical combination insights from our ADC candidate ZW191, we will present data from our emerging RAS (搜索) inhibitor ADC platform and several novel candidates designed to target treatment of RAS mutated cancers, some of the most prevalent oncogenic-driven human cancer types," said Dr. Paul Moore, Chief Scientific Officer at Zymeworks. "Together, these findings demonstrate our differentiated approach to ADC design and our commitment to developing innovative therapies for patients with difficult-to-treat cancers."
The presentations will take place at the AACR Annual Meeting from April 17-22, 2026, in San Diego, California, with the ZW191 clinical data scheduled for oral presentation on April 21, 2026.