ZW191 Hits 64.5% Response Rate at 6.4 mg/kg With Half the Severe Toxicity
ZYME sits 78% above its 52-week low of $16.003.
Summary
Zymeworks posted randomized Phase 1 data for ZW191, its FRα ADC, in platinum-resistant ovarian cancer: confirmed objective response rate of 64.5% at 6.4 mg/kg versus 55.3% at 9.6 mg/kg. The lower dose also cut grade ≥3 treatment-related adverse events to 22% from 44%, a clean efficacy-safety case for picking 6.4 mg/kg as the registrational dose. Responses showed up across high, low and negative FRα expression, which if it holds would widen the addressable population well beyond FRα-high therapies. Median PFS was 7.9 months at 6.4 mg/kg versus 9.8 months at 9.6 mg/kg, with duration of response not yet reached and 45% of patients still on treatment at cutoff — so the PFS comparison is immature. This is early-stage dose-optimization data, not registrational, and it lands after a busy stretch: the August Ziihera first-line GEA approval and $250M Jazz milestone, the $929M Theravance close in September, and yesterday's $55M Roche ZW209 license. Next steps are a formal dose selection and larger Phase 2 data, with an Oct 27 webcast scheduled.
At the time of this announcement, ZYME was trading at $28.55 on NASDAQ in the Life Sciences sector, with a market capitalization of approximately $2B. The 52-week trading range was $16.00 to $31.34. This news item was assessed with positive market sentiment and an importance score of 7 out of 10. Source: Wiseek News.