Noninfectious pneumonitis after everolimus therapy for advanced renal cell carcinoma

Noninfectious pneumonitis is a known class effect of mammalian target of rapamycin (mTOR) inhibitors.

To assess the incidence, radiographic patterns, management, and outcome of pneumonitis in patients with advanced renal cell carcinoma receiving everolimus.

Clinical study data from 416 patients, randomized to receive everolimus versus placebo, were analyzed for adverse events of pneumonitis. Radiographic studies performed every 8 weeks were subject to a prospective, independent, blinded central review for the presence of findings indicative of pneumonitis.

Of 274 patients receiving everolimus, clinical pneumonitis was suspected for 37 patients (13.5%) (none with placebo). Nine cases (3.3%) were grade 1 (asymptomatic), 18 (6.6%) were grade 2 (not interfering with daily living), and 10 (3.6%) were grade 3 (interfering with daily living or oxygen indicated). No grade 4 (life-threatening) pneumonitis was observed. Of the 10 patients with grade 3 pneumonitis, 5 had baseline radiological evidence of pneumonitis before everolimus therapy. Twenty of the 37 cases (54.0%) were reversible within the follow-up period; resolution followed dose reduction for 20 patients and treatment discontinuation in 10 patients. Corticosteroid therapy was initiated in 16 cases. Dedicated radiological review of available serial radiographic studies (245 patients receiving everolimus and 132 receiving placebo) found a higher percentage of new radiographic findings even in patients without a diagnosis of clinical pneumonitis who were receiving everolimus versus placebo (38.9 vs. 15.2%).

Early recognition, prompt intervention, and a conservative approach are important in managing the risk associated with noninfectious pneumonitis in association with everolimus. Clinical trial registered with www.clinicaltrials.gov (NCT 00410124).