Transient asymptomatic pulmonary opacity frequently seen in osimertinib-related pneumonitis

A recent study has found a considerably increased frequency of drug-related pneumonitis (DRP) among patients treated with osimertinib in first-line settings, with nearly half of the patients who experience DRP exhibiting transient asymptomatic pulmonary opacity features.

The study included 452 patients who received osimertinib as a first-line treatment for advanced EGFR mutated nonsmall cell lung cancer (NSCLC). Researchers looked at the patients’ chest computed tomography (CT) scans and clinical information during osimertinib exposure.

The primary endpoint of DRP of any grade occurred in 80 patients (18 percent), with 21 (4.6 percent) having grade ≥3 DRP.

In the DRP group, 46 percent of patients showed transient asymptomatic pulmonary opacity. With regard to CT patterns, 30 patients (38 percent) had organizing pneumonia, 21 (26 percent) had simple pulmonary eosinophilia, 18 (23 percent) had hypersensitivity pneumonia, nine (11 percent) had diffuse alveolar damage, and two (3 percent) had nonspecific interstitial pneumonia.

Multivariate Cox proportional hazards analysis revealed that smoking history was independently associated with an increased risk of DRP (hazard ratio, 1.72, 95 percent confidence interval, 1.01–2.89; p=0.046).

In the 3-month landmark analysis, patients who developed DRP showed poor treatment response. On the other hand, the presence of TAPO had a null effect on treatment efficacy.