Breakthrough Clinical Results
Zymeworks Inc. announced the discontinuation of clinical development for ZW171, a T cell engager targeting gynecological, thoracic, and digestive system cancers. This decision follows the completion of planned dose escalation cohorts in a Phase 1 trial in ovarian and non-small cell lung cancer patients. While cytokine release syndrome was manageable, dose-limiting toxicities consistent with mesothelin-related on-target off-tumor toxicity led to the conclusion that further dose evaluation would be unlikely to yield a favorable benefit-risk profile. Ongoing trial participants will continue treatment at their investigator's discretion, with safety follow-up for those who have discontinued. Zymeworks remains committed to its broader pipeline, including ZW191 and ZW251, and plans an IND filing for ZW209 in 2026.
Key Highlights
- Zymeworks discontinued ZW171 clinical development due to dose-limiting toxicities.
- The decision was based on results from the Phase 1 dose escalation portion of the trial.
- Ongoing trial participants will continue treatment or safety follow-up as appropriate.
- Zymeworks is advancing other pipeline candidates, including ZW191 and ZW251.
Incidence and Prevalence
Latest Estimates of Ovarian Cancer Incidence and Prevalence Globally
Global Burden and Ranking
Ovarian cancer represents a significant global health challenge, ranking as the fourth most common gynecological cancer worldwide as of 2020. Despite its relatively low prevalence, it carries the highest mortality among all gynecologic malignancies, making it the deadliest cancer affecting women's health.
Regional Incidence Data
In China, according to a 2025 publication, there were an estimated 41.24 thousand incident cases of ovarian cancer in 2021 (95% uncertainty interval: 30.30-54.55 thousand). This positions ovarian cancer as the fourth most common female-specific cancer in China, following breast cancer (385.84 thousand), cervical cancer (132.79 thousand), and uterine cancer (72.02 thousand).
In northeastern Nigeria, ovarian cancer accounts for 14.8% of gynecologic cancers, nearly equal to uterine corpus cancers (15.5%) but less common than cervical cancer (66.6%).
Age Distribution
The age-specific incidence rate for ovarian cancer in China is projected to peak in the 65-69 years age group. However, in a Saudi Arabian study, the predominant age group for ovarian tumors was 41-50 years (25.0% of cases).
Histological Distribution
Among ovarian cancers in northeastern Nigeria, epithelial tumors predominate at 67.9%, followed by sex cord stromal (12.5%) and germ cell (9.4%) tumors.
In the Saudi Arabian study examining 252 women with ovarian tumors, benign tumors were most common (55.2%), followed by malignant (34.5%) and borderline (9.9%) tumors.
Future Projections and Disparities
Ovarian cancer cases are projected to rise by 2050, exceeding the levels recorded in 2021. Importantly, regional health disparities exist in the disease burden among perimenopausal women. In regions where Years of Life Lost (YLLs) rates for ovarian cancer were increasing, economically developed areas actually exhibited a decline.
Correlation analysis with the Socio-demographic Index (SDI) showed that ovarian cancer prevalence rates positively correlated with SDI, suggesting higher rates in more developed regions.
Risk and Protective Factors
Risk factors include obesity, smoking, genetic changes, and nulliparity (12.3% of cases). Protective factors include oral contraceptives, multiparity, and breastfeeding (39.3% of cases).
Clinical Presentation
Ovarian cancer is typically asymptomatic in early stages and becomes symptomatic in advanced stages. Common initial symptoms include abdominal pain (41.7%) and abdominal masses (25.8%). CA-125 was identified as the most elevated tumor marker (36.9%) in patients.
The majority of ovarian cancers encountered are high-grade aggressive malignancies, with favorable survival primarily in early-stage disease.
Information on ZW171 Clinical Trials
Based on a thorough review of available information, there is no data available regarding ZW171 clinical trials for indications beyond ovarian cancer. The investigational compound ZW171 does not appear in the current clinical development records for any oncology therapeutic areas.
Without specific trial information, details about intervention models, dosing regimens, administration protocols, or study designs for ZW171 in non-ovarian cancer indications cannot be provided.
The clinical development program for ZW171 may still be in early stages or the information may be proprietary. For the most current information on ZW171 trials, it would be advisable to consult:
- Clinical trial registries such as ClinicalTrials.gov
- Pharmaceutical company websites or press releases
- Medical literature databases for recent publications
- Oncology conference proceedings where new data might be presented
As research in experimental oncology compounds continues to evolve rapidly, new information about ZW171 and its potential applications in various cancer types may emerge in the future.