CIP incidence was also higher among patients with squamous NSCLC compared with other histologies.
“One possibility is that different tumors elicit migration of different inflammatory cells into the lung, thus changing the risk for [the] development of pneumonitis,” Dr Suresh suggested. “Since there are known demographic and other [associations] between tumor histology types, another possibility is that tumor histology is simply a marker for some other patient characteristic that increases risk for pneumonitis.”
Overall CIP incidence was higher in their patient cohort than among other, previously reported in clinical trial patient populations — 19% compared with 3% to 5%.
There are several possible reasons for higher CIP incidence, Dr Suresh said.
“First, our cohort included both patients enrolled in clinical trials and patients treated in ‘real-world’ settings, outside of clinical trials,” he said. “Patient inclusion criteria for clinical trials are more stringent, so it is possible that in a more pragmatic setting, more cases of pneumonitis are seen.”
“Also, the criteria for diagnosing pneumonitis in our cohort involved discussion of the relevant data within a multidisciplinary team of pulmonologists, radiologists, and oncologists, which may have increased our ability to detect new cases,” Dr Suresh added.
Working with Jarushka Naidoo, MBChB, of the Sidney Kimmel Cancer Center at Johns Hopkins University and the Johns Hopkins Bloomberg Institute for Cancer Immunotherapy, Baltimore, Maryland, Dr Suresh’s team also found a seasonal pattern to CIP in their cohort, with increased caseloads in the winter time, suggesting a possible relationship between ICI, seasonal viral lung infection, and CIP risk.1
Dr Suresh and colleagues are now exploring CIP correlations with other immune-related adverse events.
“I think this study highlights the need for close pharmacovigilance,” Dr Suresh emphasized. “Pneumonitis may be more common than previously thought, and given our time to onset and risk factor data, close attention to respiratory symptoms may be warranted in the first 4 to 6 months after initiation of ICI therapy in NSCLC patients.”
Disclosure: The authors of the original study report receiving fees from the pharmaceutical industry. For a full list of disclosures, please refer to the original study.
- Suresh K, Voong KR, Shankar B, et al. Pneumonitis in non-small cell lung cancer patients receiving immune checkpoint immunotherapy: incidence and risk factors [published online September 26, 2018]. J Thorac Oncol. 2018;S1556-0864(18):33118-6. doi: 10.1016/j.jtho.2018.08.2035