AstraZeneca's Imfinzi gets FDA green light to challenge Roche in small cell lung cancer

Move over, Roche. There’s a new small cell lung cancer therapy on the scene, and it belongs to AstraZeneca.

Monday, the FDA cleared the British drugmaker’s Imfinzi—in tandem with standard-of-care chemo—for use in previously untreated patients with extensive-stage small cell lung cancer. About 15% of all lung cancer cases are small cell, a fast-growing form of the disease.

The agency based its decision on results from the phase 3 Caspian trial, which showed last year that the Imfinzi-chemo combo could slash patients’ risk of death by 27% compared with solo chemo. Later in the year, the FDA doled out its priority review status to hasten the regulatory process.

RELATED: AstraZeneca wins speedy FDA review for Imfinzi to challenge Roche in small cell lung cancer

SVB Leerink analyst Andrew Berens has estimated that SCLC could pad Imfinzi’s sales by $413 million in the U.S. and about $828 million worldwide. Those revenues would add to the lung cancer sales the drug is generating in previously treated, stage 3 disease, where competitors are far behind.

Unfortunately for AstraZeneca, it’s not alone in its new field, where it’ll need to play catch-up to Roche. The Swiss pharma giant’s Tecentriq has already spent a year on the market after becoming the first in its class of PD-1/PD-L1 drugs to snag an FDA green light.

AZ, though, has a couple differentiators it was quick to tout in its approval announcement. For starters, Imfinzi can be used alongside etoposide and a choice of either carboplatin or cisplatin chemo, giving patients more flexibility than they have with Tecentriq, which isn’t cleared for use with cisplatin chemo.

Key opinion leaders surveyed by SVB Leerink "believed that Imfinzi could have an advantage over Tecentriq, given the dosing flexibility," Berens wrote in a Monday note to clients. 

The cisplatin option is particularly important outside the U.S., where it's more commonly used. Still, "in the U.S., there are some physicians for whom the ability to use cisplatin is important," Dave Fredrickson, EVP and global head of AstraZeneca’s oncology business unit, said. And Imfinzi is also the only immuno-oncology drug that has shown both a significant survival benefit and a significant improved response rate in the population, he pointed out—a fact AZ's sales reps will be highlighting alongside the flexibility feature.

"Within U.S. context of the launch, it's really both of those elements that we're going to be looking to differentiate in the eyes of physicians," Fredrickson said.

RELATED: AstraZeneca's tremelimumab records another miss as Imfinzi combo strikes out in small cell lung cancer

Of course, the company was looking for an even bigger leg up when it trialed Imfinzi with CTLA4 candidate tremelimumab, going for a chemo-free option for patients. But that study recently came up short, with the immuno-oncology duo failing to show it could extend the lives of newly diagnosed patients.

Meanwhile, Fredrickson applauded AstraZeneca's regulatory and commercial teams for notching an approval while working from home amid the novel coronavirus pandemic.

"We did not allow the constraints of people working remotely to get in the way of making sure we brought this option … as quickly as would in any other situation," he said.