A study of cancer patients enrolled in trials of the programmed cell death-1 inhibiting medicine nivolumab found that among a minority who developed pneumonitis during treatment, distinct radiographic patterns were significantly associated with the level of pneumonitis severity.

Investigators found that cryptic organizing pneumonia pattern (COP) was the most common, though not the most severe. Led by Mizuki Nishino, MD, of Brigham and Women’s Hospital, Boston, the researchers looked at the 20 patients out of a cohort of 170 (11.8%) who had developed pneumonitis, and found that radiologic patterns indicating acute interstitial pneumonia/acute respiratory distress syndrome (n = 2) had the highest severity grade on a scale of 1-5 (median 3), followed by those with COP pattern (n = 13, median grade 2), hypersensitivity pneumonitis (n = 2, median grade 1), and nonspecific interstitial pneumonia (n = 3, median grade 1). The pattern was significantly associated with severity (P = .0006).

The study cohort included patients being treated with nivolumab for lung cancer, melanoma, and lymphoma; the COP patten was the most common across tumor types and observed in patients receiving monotherapy and combination therapy alike. Therapy with nivolumab was suspended for all 20 pneumonitis patients, and most (n = 17) received treatment for pneumonitis with corticosteroids with or without infliximab, for a median treatment time of 6 weeks. Seven patients were able to restart nivolumab, though pneumonitis recurred in two, the investigators reported ( Clin Cancer Res. 2016 Aug 17. doi: 10.1158/1078-0432.CCR-16-1320 ).

“Time from initiation of therapy to the development of pneumonitis had a wide range (0.5-11.5 months), indicating an importance of careful observation and follow-up for signs and symptoms of pneumonitis throughout treatment,” Dr. Nishino and colleagues wrote in their analysis, adding that shorter times were observed for lung cancer patients, possibly because of their higher pulmonary burden, a lower threshold for performing chest scans in these patients, or both. “In most patients, clinical and radiographic improvements were noted after treatment, indicating that [PD-1 inhibitor-related pneumonitis], although potentially serious, is treatable if diagnosed and managed appropriately. The observation emphasizes the importance of timely recognition, accurate diagnosis, and early intervention.”

The lead author and several coauthors disclosed funding from Bristol-Myers Squibb, which sponsored the trial, as well as from other manufacturers.