ESMO: AstraZeneca wows with Imfinzi's 11-month survival edge in lung cancer

MADRID, Spain—In May, AstraZeneca stunned the market with news that its PD-L1 med Imfinzi had succeeded in significantly delaying time to cancer progression in the lung-cancer maintenance setting. And now, the company is unveiling just how long that delay was.

In a phase 3 trial pitting it against placebo in surgery-ineligible patients with stage 3 non-small cell lung cancer, Imfinzi kept disease at bay for 16.8 months—11.2 months longer than placebo did, AstraZeneca revealed at the European Society for Medical Oncology (ESMO) annual meeting in Madrid. Leerink Partners analyst Seamus Fernandez called the outcome "striking."

That improvement in progression-free survival held across different subgroups, too—including those whose tumors did and did not express the PD-L1 tumor, AZ said.

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The data are “really exciting,” considering that “typically these patients, the plan is for them to watch and wait,” Andrew Coop, AZ’s VP of U.S. Medical Affairs, Oncology, said. “ ... And what happens, we know in almost 90% of cases for these patients, unfortunately, they progress.”

They’re also exciting from an immuno-oncology market-growth standpoint, Bernstein analyst Tim Anderson said after the top-line data dropped in May. The trial, dubbed Pacific, “shows that I-O has a place in nonmetastatic disease,” he wrote, adding that it’s “the kind of breakthrough that promises to pull upward on the I-O market size.”

And AstraZeneca—which will be alone in the market for a good two to three year, Anderson predicts—is in prime position to benefit. The opportunity in the G7 markets tallies about 47,000 patients, he estimates.

The way Fernandez sees it, that benefit should be coming soon. "We believe the Pacific data should result in a relatively rapid uptake of Imfinzi in this setting," he wrote in a note to clients. He's currently forecasting peak sales of about $1 billion worldwide in stage 3 non-small cell lung cancer, though the "impressive progression-free survival data could produce upside to these estimates." 

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AstraZenenca can certainly use the boost Pacific will provide, especially in light of its recent immuno-oncology combo flop in first-line lung cancer. And it’ll have it sooner rather than later; in July, it snagged the FDA’s breakthrough designation, which promises to speed it down the regulatory pathway.