DURVALUMAB APPROVED BY FDA FOR UNRESECTABLE NSCLC AFTER CHEMORADIATION

The US Food and Drug Administration (FDA) today approved durvalumab (Imfinzi, AstraZeneca) for the treatment of patients with stage III non–small cell lung cancer (NSCLC) whose tumors are unresectable and whose cancer has not progressed after chemoradiation.

The immunotherapy becomes the first treatment approved to reduce the risk of the cancer progressing in this setting.

"For patients with stage III lung cancer that cannot be removed surgically, the current approach to prevent progression is chemoradiation. Although a small number of patients may be cured with the chemoradiation, the cancer may eventually progress. Patients now have an approved therapy that has been shown to keep the cancer from progressing for a longer time after chemoradiation," Richard Pazdur, MD, acting director of the Office of Hematology and Oncology Products in the FDA's Center for Drug Evaluation and Research commented in a news release.

Durvalumab is an anti-programmed death ligand 1 (PD-L1) inhibitor and has one previous FDA approval, for certain patients with locally advanced or metastatic bladder cancer.

The new approval is based on results from the 731-patient PACIFIC trial, in which all of the patients had nonprogressive cancer after chemoradiation. In the randomized study, durvalumab significantly improved progression-free survival (PFS) compared with placebo; the median PFS was 16.8 months with durvalumab vs 5.6 months with placebo (hazard ratio, 0.52; P < .0001).

The objective response rate was significantly higher with durvalumab than with placebo, at 28.4% vs 16.0% (P < .001).

The findings were presented last year at the European Society for Medical Oncology annual meeting and were simultaneously published online in the New England Journal of Medicine.

Scott J. Antonia, MD, PhD, chair of the Department of Thoracic Oncology at the H. Lee Moffitt Cancer Center and Research Institute, Tampa, Flordia, who was investigator in the PACIFIC trial, said in a statement: "Until now, treatment guidelines have recommended that patients with unresectable stage III lung cancer undergo a period of active surveillance following chemoradiation therapy until disease progression. Given that up to 89% of patients will progress to metastatic disease, it is important that there is now a new option that can give patients more time without disease progression. The PACIFIC trial data supporting today's approval of Imfinzi will change how we treat these patients."

Various lung cancer experts have commented that these results change the treatment paradigm because they show — for the first time — that an immunotherapy is beneficial at an earlier stage of lung cancer (ie, locally advanced unresectable stage III NSCLC). All the previous trials with immunotherapy in lung cancer have been in later-stage disease: advanced and metastatic NSCLC.

In the pivotal trial, grade 3/4 adverse events were slightly more common with durvalumab than with placebo, seen in 29.9% vs 26.1% of patients, with adverse events leading to discontinuation experienced by 15.4% of durvalumab patients and 9.8% of placebo patients.

Grade 3/4 immune-related adverse events were recorded in 3.4% of durvalumab patients vs 2.6% of patients given placebo. In contrast, any grade immune-related events were seen in 24.2% and 8.1% of the respective patient groups.

"This is an important advance," commented Michael Boyer, MD, clinical professor of medicine at the University of Sydney, Australia, last year at the World Conference on Lung Cancer, as reported by Medscape Medical News, where he acted as a meeting discussant of trial quality-of-life data. Numerous previous trials have attempted to improve outcomes in this patient population, and all have failed, he observed.

David Fredrickson, executive vice president and head of the Oncology Business Unit at AstraZeneca, said: "The approval of Imfinzi in this earlier stage of non–small cell lung cancer is a truly meaningful milestone for patients who, until now, had no FDA-approved treatment options following chemoradiation therapy. Globally, approximately 30% of patients with NSCLC present with stage III disease, and we are excited to launch the first immunotherapy into this setting."

Follow Medscape senior journalist Nick Mulcahy on Twitter: @MulcahyNick