Zymeworks Inc. presents new Phase 1 data for folate receptor alpha-targeting antibody-drug conjugate zw191 at ESMO Congress 2026. Published on 10/24/2026 at 03:35 am EDT S&P Capital IQ Zymeworks Inc. presented new clinical data from the randomized dose-optimization portion of its ongoing Phase 1 study evaluating ZW191, a FRa-targeting antibody-drug conjugate (ADC), at the European Society for Medical Oncology (ESMO) Congress 2026 in Madrid, Spain. The presentation highlights compelling anti-tumor activity in heavily pretreated patients with platinum-resistant ovarian cancer (PROC), including patients with high-grade serous disease across all levels of FRa expression. The results demonstrate compelling response rates, durability and a favorable tolerability profile, particularly at the 6.4 mg/kg dose, further supporting the potential of ZW191 to address limitations of currently available FRa-targeted therapies and expand treatment opportunities for patients with ovarian cancer. The analysis included efficacy and safety data from 80 patients with PROC randomized to receive ZW191 at 6.4 mg/kg (n=37) or 9.6 mg/kg (n=43) every three weeks, as of the September 10, 2026 data cutoff date. Patients were heavily pretreated, having received a median of four prior lines of therapy, with 45% receiving five or more prior lines. Median follow-up was seven months. FRa expression was assessed by immunohistochemistry and categorized as low/negative (0%?24%), intermediate (25%?74%) or high (75%?100%) based on the percentage of tumor cells with 2+ or 3+ staining intensity. Among response-evaluable patients with high-grade serous PROC, ZW191 demonstrated a cORR of 64.5% at 6.4 mg/kg and 55.3% at 9.6 mg/kg, with disease control rates of 100% and 92.1%, respectively. These findings demonstrate compelling anti-tumor activity at both doses in a heavily pretreated patient population. ZW191 demonstrated meaningful anti-tumor activity across FRa expression in patients with high-grade serous PROC. Confirmed objective response rates were 69.2% in patients with high FRa expression, 50.0% in patients with intermediate FRa expression and 55.0% in patients with low or negative FRa expression. Responses to ZW191 were deep and durable, with median duration of response not yet reached at either dose. Six-month progression-free survival (PFS) was 61% in both groups, while median PFS was 7.9 months at 6.4 mg/kg and 9.8 months at 9.6 mg/kg in patients with high-grade serous PROC. At the time of data cutoff, 45% of patients remained on treatment, and PFS data continue to mature, especially at 6.4 mg/kg. ZW191 continued to demonstrate a favorable tolerability profile, particularly at 6.4 mg/kg. Grade 3 or higher treatment-related adverse events occurred in 22% of patients receiving 6.4 mg/kg compared with 44% at 9.6 mg/kg. Treatment-emergent adverse events leading to dose reductions occurred in 5% and 33% of patients, respectively, while discontinuations due to adverse events occurred in 14% and 19%. No deaths due to treatment-emergent adverse events were reported in either treatment group. The overall safety profile was manageable and supports continued clinical development. The findings demonstrate encouraging anti-tumor activity across the 6.4 mg/kg and 9.6 mg/kg dose levels, with a more favorable tolerability profile at 6.4 mg/kg. These results will inform optimal dose selection for further clinical development. ZW191's differentiated profile, including its novel FRa-targeting antibody, proprietary topoisomerase I inhibitor payload, ZD06519, and high drug-to-antibody ratio, supports its potential to address key limitations of existing therapies and broaden the applicability of FRa-targeted treatment approaches. ZW191 is an antibody-drug conjugate engineered to target a protein called folate receptor-? found in ~75% of high-grade serous ovarian carcinomas, over 50% of endometrial cancers, and ~70% of lung adenocarcinomas. ZW191?s differentiated design strongly supports its ability to internalize into FR?-expressing cells with the potential to release bystander active topoisomerase-1 inhibitor (ZD06519), a novel proprietary payload developed by Zymeworks to kill tumor cells. (C) S&P Capital IQ - 2026

Roche's $813 million Zymeworks deal adds to $1.08 billion cancer bet. Months before Vancouver-based Zymeworks agreed to license its experimental cancer treatment to Roche, the biotechnology company had already identified two Roche-linked drugs among its potential competitors. The disclosure, contained in Zymeworks' March 2026 annual filing, places Friday's $813 million agreement within a broader Roche investment in treatments targeting DLL3, a protein associated with small-cell lung cancer. One of those investments already carries a potential value exceeding $1 billion. Roche's latest agreement gives the Swiss pharmaceutical company global development and commercialization rights to Zymeworks' ZW209, according to Reuters. Sponsored · Selkirk Copper Mines Zymeworks will receive $55 million upfront and another $40 million if Roche initiates a planned dose-optimization study. The Vancouver company could collect an additional $718 million through development, regulatory, and commercial milestones, plus royalties on future sales. In January 2025, Roche signed a separate agreement with Innovent Biologics for IBI3009, an experimental antibody-drug conjugate also targeting DLL3. The transaction provided Innovent with $80 million upfront and eligibility for up to $1 billion in milestone payments. Together, the two agreements represent $1.893 billion in maximum potential payments, excluding royalties. Only $135 million consists of upfront consideration, with the remaining $1.758 billion tied to future development decisions and milestones. Zymeworks' own annual report identifies Roche/Innovent's IBI3009 as a competing approach to ZW209. The same filing lists Chugai/Roche's ALPS12, another DLL3-targeting T-cell engager, among competing development programs. Sponsored · Silver47 Exploration Inc. The treatments differ technologically. Innovent's IBI3009 uses an antibody-drug conjugate to deliver a cancer-killing payload. ZW209 is designed to engage immune cells through DLL3, CD3, and CD28, with the goal of improving antitumor activity through additional T-cell stimulation. Zymeworks has reported encouraging laboratory and preclinical findings, but these have not established effectiveness in patients. The market is not entirely experimental. Amgen received full FDA approval for its DLL3-targeting treatment Imdelltra in November 2025. The authorization covers certain adults with extensive-stage small-cell lung cancer following platinum-based chemotherapy. In Amgen's Phase 3 DeLLphi-304 study, median overall survival reached 13.6 months with Imdelltra, compared with 8.3 months for patients receiving standard chemotherapy. ZW209 has yet to demonstrate comparable clinical results. Zymeworks CEO Kenneth Galbraith told Reuters that Roche agreed to the partnership before efficacy data were available, citing the platform's technological differentiation. The first patient is expected to enter the study before the end of 2026. Under the agreement, Roche will assume subsequent development responsibility after Zymeworks completes dose escalation. Information for this briefing was found via the sources and the companies mentioned. The author has no securities or affiliations related to this organization. Not a recommendation to buy or sell. Always do additional research and consult a professional before purchasing a security. The author holds no licenses.

Zymeworks has appointed Suzanne Monahan as senior vice president, commercial, and general manager of Theravance Biopharma, effective immediately. She will report to Kenneth Galbraith, chair and chief executive officer. Monahan will lead commercial strategy for YUPELRI (revefenacin), the first and only once-daily nebulised long-acting muscarinic antagonist approved in the US for maintaining treatment of chronic obstructive pulmonary disease. Zymeworks recently acquired Theravance Biopharma. Monahan has more than 20 years of commercial experience in pharmaceuticals and medical devices. She most recently served as senior vice president at Pacira BioSciences, and earlier worked at Shionogi, Circassia Pharmaceuticals, Sanofi-Aventis, and Salix Pharmaceuticals. "Suzanne is a proven commercial leader," Galbraith said.