Immunotherapy improved DFS versus placebo in patients regardless of PD-L1 expression

The FDA has approved pembrolizumab (Keytruda) as an adjuvant therapy following surgical resection and platinum-based chemotherapy for patients with stage IB, II, or IIIA non-small cell lung cancer (NSCLC), Merck announcedopens in a new tab or window.

The approval makes pembrolizumab the only immunotherapy to be approved for NSCLC regardless of PD-L1 expression in both the adjuvant and metastatic settings, the company noted.

“While there have been many advances for patients with metastatic disease, surgery remains the typical treatment for people with stage IB, II, and IIIA non-small cell lung cancer. Unfortunately, many of these patients who undergo surgery still see their disease return,” said Roy S. Herbst, MD, PhD, deputy director and chief of medical oncology at Yale Cancer Center and Smilow Cancer Hospital in New Haven, Connecticut, in a company press release.

“Today’s approval for Keytruda offers a new, important immunotherapy treatment option for stage IB (T2a ≥4 cm), II, or IIIA patients with non-small cell lung cancer following surgery and adjuvant chemotherapy,” he continued.

Approval was based on data from the multicenter phase III KEYNOTE-091 trialopens in a new tab or window, also known as PEARLS, which involved 1,177 patients randomized 1:1 to intravenous pembrolizumab 200 mg or placebo every 3 weeks. Of these patients, 86% had received platinum-based chemotherapy following resection. The median duration of exposure to pembrolizumab was 11.7 months.

Median disease-free survival (DFS) was 58.7 months with pembrolizumab compared with 34.9 months with placebo among patients who received adjuvant platinum-based chemotherapy following surgical resection (HR 0.73, 95% CI 0.60-0.89), meeting the trial’s primary endpoint.

In an exploratory subgroup analysis of 167 patients who did not receive adjuvant chemotherapy, the HR for DFS was 1.25 (95% CI 0.76-2.05).

Overall survival results were immature at the time of analysis.

Regarding safety, Merck said adverse reactions observed in KEYNOTE-091 were largely similar to those occurring in other patients with NSCLC receiving pembrolizumab as a single agent, with the exception of hypothyroidism (22%), hyperthyroidism (11%), and pneumonitis (7%).

There were two deaths due to myocarditis.