Roche's Tecentriq hits a lung cancer slowdown in its bid to challenge Merck

Roche has been chomping at the bit to challenge Merck & Co. in the previously untreated non-small cell lung cancer space, but it’s going to have to wait a little longer.

Wednesday, the Swiss drugmaker’s Genentech unit said the agency had extended its review of a cocktail anchored by immuno-oncology drug Tecentriq by three months. It now expects to hand down a verdict by Dec. 5.

The reason for the delay? It’ll allow “the FDA time to review additional information requested in support” of Roche’s filing, the company said. But it’ll also largely negate a priority review boost that Roche had hoped would quickly usher it into the firstline setting.

RELATED: Roche's Tecentriq cocktail hops into the FDA fast lane for another Merck showdown

Regulators are reviewing data from the Impower150 study that showed a combo of Tecentriq, older Roche blockbuster Avastin and chemo could top an Avastin-chemo pairing when it came to extending patients’ lives. That benefit showed up across various subgroups, and it was seen regardless of patients’ levels of PD-L1, the biomarker targeted by the class of meds that includes Tecentriq and Merck's Keytruda.

For now, though, Roche will have to wait to challenge current lung cancer king Merck, whose Keytruda is running the frontline table. Keytruda is the only member of the PD-1/PD-L1 class to bear an approval for previously untreated lung cancer patients—considered the most lucrative field because of its size—and it’s got two of them, both in combination with chemo and as a monotherapy.

RELATED: With FDA's new 'real-time' review, Merck's Keytruda scores paramount nod in lung cancer

And recently, the FDA cemented Keytruda’s lead. Late last month, it approved a label update for the drug, clearing Merck to tout data showing Keytruda-plus-chemo could slash patients’ risk of death by half versus solo chemo.

Even if Roche can pick up a green light for its Tecentriq regimen, analysts don't think it’ll measure up favorably against Merck’s leader.

“My conclusion: Roche’s I-O-chemo trends WORSE than Merck's I-O-chemo on [progression-free survival]. On [overall survival], Roche and Merck look roughly comparable,” Evercore ISI analyst Umer Raffat wrote in December, with analyst Tim Anderson, formerly of Bernstein, adding that Merck’s chemo combo trial, “on its face ... undeniably looks better.”

Credit Suisse's Vamil Divan followed up Thursday, writing to his own clients that the FDA Tecentriq stall "illustrates the challenges we believe competitors will have in displacing Merck."