AstraZeneca Falls Today Even as Imfinzi Wins a Landmark Survival Test

This article first appeared on GuruFocus. AstraZeneca (NYSE:AZN), the oncology and biopharmaceutical company, reported a late-stage lung-cancer victory Tuesday, but investors refused to celebrate. Its U.S. shares fell approximately 0.7% to $161.51 even after Imfinzi, combined with Amgen's Imdelltra, significantly extended survival among patients with extensive-stage small-cell lung cancer. The 563-patient DeLLphi-305 trial cleared its primary overall-survival goal while also improving progression-free survival and response rates. No new safety concerns emerged. The catch is that the companies have not released the numerical survival data, leaving investors without the figures needed to judge how strongly the regimen could compete. Amgen sponsored the study, while AstraZeneca provided Imfinzi and partial funding. Imfinzi produced $6.06 billion in 2025, and oncology generated approximately 46% of AstraZeneca's $30.7 billion in first-half 2026 revenue. The chart shows the shares trading 10.72% below their $180.91 GF Value estimate, suggesting the market still wants harder evidence on efficacy, regulatory timing and commercial upside. The trial strengthens Imfinzi's growth case, but AstraZeneca must share the economics with Amgen and prove the added treatment complexity can translate into meaningful new sales. More News