AstraZeneca has come up short in another lung cancer trial of its immuno-oncology combo, this time in patients who've failed on two prior treatments.
But investors shouldn’t use the outcome to predict the forthcoming results of a closely watched first-line study, analysts say.
Tuesday, the British drugmaker said its PD-L1 med Imfinzi and candidate tremelimumab had failed to improve survival in third-line patients whose tumors didn’t express PD-L1. There was a bright spot, though: A substudy that pitted solo Imfinzi against chemo in PD-L1-positive patients showed a “clinically meaningful” difference for the AZ drug in the risk of death.
The results weren’t terribly surprising to analysts; Bernstein’s Tim Anderson, for one, said in a note to clients that he thought the trial, dubbed Arctic, “was likely to yield mixed results (and it did).”
And the way he sees it, that’s not such a bad thing. Overall, “the field has moved on,” he said, calling Arctic “basically the hangover from a now abandoned hypothesis” that PD-L1/CTLA4 pairings such as AZ’s will extend benefits to the PD-L1 negative population.
ODDO BHF’s Pierre Corby wrote in his own note to clients that removing the combination from models would have “minimum impact.”
And while investors may be tempted to take the outcome as a sign that the Imfinzi-tremelimumab combo is destined for failure in first-line, PD-L1-positive patients—the all-important population in the I-O market—they shouldn’t, Anderson said.
“That outcome is certainly not foreshadowed” by the miss in PD-L1 negative patients, he wrote.
If there’s any readthrough to Mystic, AstraZeneca’s first-line trial, it’s that Imfinzi still holds promise as a monotherapy, Anderson figures.
“We continue to believe that Imfinzi is likely is show an OS benefit in 1L PD-L1(+) patients, and obtain a (modest) foothold in the market,” he wrote.
Of course, it’ll still be a while before industry watchers have that data, which is slated to arrive in the second half of the year. And in the meantime, there will be plenty of other key I-O news from companies including Merck and Roche that should keep investors busy.