# Zymeworks Reports 64.5% Confirmed Response Rate for ZW191 in Platinum-Resistant Ovarian Cancer

> Zymeworks presented Phase 1 data showing a 64.5% confirmed objective response rate for ZW191 at 6.4 mg/kg in platinum-resistant ovarian cancer.

- Published: 2026-10-24T07:03:55+00:00
- Section: Research & Clinical Trials
- Author: News Desk
- URL: https://newsforagent.com/news/2026-10-24/zymeworks-zw191-phase-1-esmo-data
- Source: [TradingView](https://www.tradingview.com/news/globenewswire:e74d33df1094b:0-zymeworks-presents-new-phase-1-data-for-folate-receptor-alpha-targeting-antibody-drug-conjugate-zw191-at-esmo-congress-2026/)

## Key takeaways

- Zymeworks reported a confirmed objective response rate of 64.5% at 6.4 mg/kg and 55.3% at 9.6 mg/kg in high-grade serous platinum-resistant ovarian cancer.
- Grade 3 or higher treatment-related adverse events occurred in 22% of patients at 6.4 mg/kg versus 44% at 9.6 mg/kg.
- Zymeworks has engaged MTS Healthcare to evaluate strategic partnering opportunities to fund further development of ZW191.

[Zymeworks](https://akta.pro/company-profiles/0000m2r/zymeworks) presented Phase 1 data for ZW191, a folate receptor alpha-targeting antibody-drug conjugate, at the ESMO Congress 2026 in Madrid, showing a confirmed objective response rate of 64.5% at the 6.4 mg/kg dose in patients with high-grade serous platinum-resistant ovarian cancer. The data were published by [TradingView](https://www.tradingview.com/news/globenewswire:e74d33df1094b:0-zymeworks-presents-new-phase-1-data-for-folate-receptor-alpha-targeting-antibody-drug-conjugate-zw191-at-esmo-congress-2026/).

## ZW191 Phase 1 Results in Ovarian Cancer

The analysis covered 80 patients with platinum-resistant ovarian cancer randomized to ZW191 at 6.4 mg/kg (n=37) or 9.6 mg/kg (n=43) every three weeks, as of a September 10, 2026 data cutoff. Patients had received a median of four prior lines of therapy, and 45% had received five or more. Median follow-up was seven months.

Among response-evaluable patients with high-grade serous disease, the confirmed objective response rate was 64.5% at 6.4 mg/kg and 55.3% at 9.6 mg/kg, with disease control rates of 100% and 92.1%. Confirmed response rates by FRα expression were 69.2% in high, 50.0% in intermediate and 55.0% in low or negative patients. Median duration of response was not yet reached at either dose, and six-month progression-free survival was 61% in both groups.

Grade 3 or higher treatment-related adverse events occurred in 22% of patients at 6.4 mg/kg compared with 44% at 9.6 mg/kg. Dose reductions occurred in 5% and 33% of patients, and discontinuations due to adverse events in 14% and 19%. No deaths due to treatment-emergent adverse events were reported in either group.

"The robust response rates observed at both doses, including meaningful activity in patients with low or negative FRα expression, reinforce the potential of ZW191 to benefit a broader patient population," said Sabeen Mekan, M.D., Senior Vice President and Chief Medical Officer, Zymeworks.

## Zymeworks Funding and Partnership History

Zymeworks is a Vancouver-based royalty-driven biotechnology company developing antibody-based therapeutics for difficult-to-treat cancers, according to akta.pro [company records](https://akta.pro/company-data). The same records show Zymeworks secured $250 million in non-recourse royalty-backed note financing from Royalty Pharma in March 2026, secured by 30% of worldwide tiered royalties on Ziihera, extending its cash runway beyond 2028. The company reported $403.8 million in cash and cash equivalents as of Q1 2026, up from $270.6 million at year-end 2025.

## Earlier Zymeworks Deals and Approvals

Zymeworks licensed its experimental lung cancer drug ZW209 to Roche in a deal worth up to $813 million, including $55 million upfront and $40 million for a dose-optimization study, Reuters reported in October 2026. The company completed its acquisition of Theravance Biopharma in October 2026, adding the COPD drug YUPELRI and its $60 million annualized cash flow, according to American Banking and Market News. In September 2026, Zymeworks reported FDA approval of zanidatamab for first-line HER2-positive gastric and gastroesophageal adenocarcinoma, Investing.com reported.

## Zymeworks Conference Call on October 27

Zymeworks will hold a conference call with management on October 27, 2026, at 8:30 am Eastern Time. The company said the ESMO presentation will be available on its website at [zymeworks.com/publications](http://zymeworks.com).

## Companies in this story

- [Zymeworks company profile](https://akta.pro/company-profiles/0000m2r/zymeworks) · website: http://zymeworks.com

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