- AstraZeneca's cancer immunotherapy Imfinzi helped patients with locally advanced lung cancer live longer versus placebo, according to topline results from a Phase 3 study announced by the drugmaker Friday.
- Treatment with the PD-L1 inhibitor led to a statistically significant and, according to AstraZeneca, clinically meaningful overall survival benefit in Stage 3 unresectable non-small cell lung cancer (NSCLC).
- The Food and Drug Administration had approved Imfinzi for that indication in February on the basis of progression-free survival results released last fall. The survival benefit should help drive uptake of the medicine, which has yet to break into the later, metastatic NSCLC setting.
In cancer immunotherapy, attention has largely focused on the large market for metastatic lung cancer, where Merck & Co. leads rivals Bristol-Myers Squibb and Roche. A clinical setback last year stymied AstraZeneca's plans to jump into that field, damaging the company's chances of catching up.
But success in a study called PACIFIC has positioned the British drugmaker well ahead of its competitors in the smaller market for Stage 3 NSCLC, where tumors have only advanced locally.
According to estimates from AstraZeneca, Stage 3 NSCLC represents about one-third of the broader incidence of NSCLC, with 105,000 patients across the top eight countries. For most of those patients, their tumors are unresectable, or not removable by surgery, and are typically treated with chemoradiation therapy (CRT) followed by active surveillance.
In an initial analysis, PACIFIC showed giving patients Imfinzi after CRT extended median progression-free survival by 11.2 months versus placebo.
Now, a planned review by the study's Data Monitoring Committee found the drug also helps patients live longer, too. Only topline results are available currently. Detailed results are expected to be presented at an upcoming medical meeting, AstraZeneca said.
Imfinzi's success should help boost the drug's commercial momentum. In the first quarter, sales of Imfinzi totaled $62 million, with an "overwhelming majority" coming from the new lung cancer indication, according to comments by David Fredrickson, head of AstraZeneca's oncology business unit, on a recent call with investors.
In January, about 3,000 patients in the U.S. were infused with Imfinzi, which is also approved in bladder cancer. In April, by comparison, about 7,000 patients had been infused with the drug — reflecting uptake following the OK for Stage 3 NSCLC in February.
AstraZeneca estimates it has between an 18 month and 24 month lead over rivals in the indication. Given the company's struggles in metastatic lung cancer, that edge will be an important factor in the drug's commercial success.
Shares in AstraZeneca were little moved in Friday morning trading.