WCLC: AstraZeneca heads for Roche battle with Imfinzi small-cell survival win

Right now, Roche’s Tecentriq is the only immuno-oncology therapy approved in small cell lung cancer. But it may soon have to make some room for AstraZeneca’s Imfinzi.

Adding Imfinzi to standard-of-care chemo reduced newly diagnosed extensive-stage patients’ risk of death by 27% in a phase 3 study, the drugmaker said Monday at the World Conference on Lung Cancer in Barcelona. Patients lived a median 13 months on the Imfinzi combo, versus 10.3 months on chemo.

At the 18-month mark, 33.9% of Imfinzi patients were still alive, compared with 24.7% of those who received solo chemo.

With those results in hand, AstraZeneca will go after regulatory green lights around the world. But if it can snag one in the U.S., it’ll have Roche to contend with.

The Swiss drugmaker in March won an FDA OK for Tecentriq in tandem with chemo in the same patient population after showing it could extend patients’ lives by a median of 12.3 months. While the number of small cell patients is much smaller than the non-small cell lung cancer (NSCLC) group—which Merck currently dominates with its own contender, Keytruda—analysts have predicted Roche could rack up $1.5 billion in the indication.

RELATED: AstraZeneca's Imfinzi tees up small cell lung cancer fight with Roche

AstraZeneca is hoping to score a piece of the pie, though—and it thinks a couple key factors will help set Imfinzi apart from its Roche rival. Unlike Tecentriq, which can only be used alongside carboplatin-based chemo, Imfinzi can be used with carboplatin- or cisplatin-based regimens. And that flexibility could help spur adoption around the world, Dave Fredrickson, executive vice president and global head of AstraZeneca’s oncology business unit, said in an email interview.

“Standards of care in terms of preferred chemotherapy vary across the globe,” he said. “We know cisplatin is a preferred chemotherapy backbone in Europe and other parts of the world, while on the other hand carboplatin is preferred in the U.S.”

RELATED: In another I-O first for Roche, Tecentriq nabs blockbuster small cell lung cancer nod

The Imfinzi study, called Caspian, also allowed up to six cycles of chemo, “which is the first time that's been allowed in an I-O-chemo study—so we really compared against a robust, real-world, control arm,” Fredrickson added.

A small cell lung cancer nod would be the second for AstraZeneca in the broader lung cancer sphere. It also bears a go-ahead in stage 3 NSCLC that can’t be surgically removed, and it’s without in-class competition in that arena.