Zymeworks’ FRα-Targeting ADC ZW191 Gets FDA Fast Track Nod To Speed Development For Advanced Or Metastatic PROC Patients

Zymeworks Inc. announced that the U.S. Food and Drug Administration has granted Fast Track designation to ZW191, an investigational antibody-drug conjugate (ADC) being developed for patients with advanced or metastatic platinum-resistant ovarian cancer. This form of ovarian cancer is difficult to treat, and new therapeutic options are urgently needed.

ZW191 is designed to target folate receptor-α (FRα), a protein commonly found on the surface of several tumor types. FRα is present in about 75% of high-grade serous ovarian cancers, more than half of endometrial cancers, and around 70% of lung adenocarcinomas. Because of this high expression, ZW191 has been engineered to enter FRα-positive cancer cells and deliver a novel topoisomerase-1 inhibitor payload called ZD06519. This payload was developed by Zymeworks specifically to destroy tumor cells and has the potential to also impact surrounding cancer cells through a bystander effect.

The FDA’s Fast Track program is intended to accelerate the development and review of promising therapies for serious medical conditions. By receiving this designation, ZW191 may move through certain regulatory processes more quickly, helping to bring the treatment to patients sooner if it continues to show positive results.

According to Dr. Sabeen Mekan, Senior Vice President and Chief Medical Officer at Zymeworks, the Fast Track designation emphasizes the potential of ZW191 to meet the needs of patients who have already undergone treatment but still face cancer progression. She noted that the designation was granted regardless of FRα expression levels, which suggests that ZW191 may benefit a broader range of patients without requiring biomarker-based selection. Dr. Mekan added that this recognition supports the company’s growing expertise in antibody-drug conjugate development.

Zymeworks is currently studying ZW191 in a Phase 1 clinical trial (NCT06555744). This ongoing study is evaluating safety, tolerability, how the drug behaves in the body, and early signs of anti-tumor activity in patients with advanced solid tumors. The results from this first-in-human study will help shape the future development plan for ZW191 as the company continues to explore its potential in treating difficult-to-manage cancers.