AstraZeneca and Daiichi Sankyo reported mixed results Monday from a final-phase study of their lung cancer treatment, and AZN stock tumbled.
The treatment led to a statistically significant improvement in progression-free survival. That meant patients who received the drug lived longer before their cancer worsened than patients who received a standard drug. But the results weren't yet clear for overall survival. That measures how long patients live before dying of any reason.
Further, some patients died in the study, though the companies didn't say how many. SVB Securities analyst Andrew Berens noted the release didn't state whether the drug was at fault in the patients' death.
"The press release lacked details as well as commentary that the results were clinically relevant, causing speculation that the results may have been less robust than anticipated for this highly anticipated (study)," Berens said in a note to clients.
On today's stock market, AZN stock plunged 8.8% to close at 65.25. Shares dropped below the lower boundary of a flat base with a buy point at 76.56, according to MarketSmith.com. Daiichi Sankyo stock tumbled 15.5% to 26.91.
AZN Stock: Overall Survival Shows 'Early Trend'
The drug, dubbed datopotamab deruxtecan, belongs to the antibody drug conjugate class. These drugs are often compared to smart bombs. They direct toxic chemicals to specific targets on tumor cells, aiming to limit damage to surrounding healthy tissue.
Susan Galbraith, AstraZeneca's executive vice president of oncology research and development, says the new drug challenges "the entrenched standard of care."
But investors hammered AZN stock. They likely wanted a strong enough result in overall survival to allow AstraZeneca and Daiichi Sankyo to stop the study early. The companies said there was an "early trend" in overall survival. But it wasn't enough to show statistical significance at this point.
"The (study) will continue as planned to assess overall survival with greater maturity," the companies said in a news release.
Follow Allison Gatlin on Twitter at @IBD_AGatlin.
