Pulmonary adverse events related to idelalisib therapy: A single centre experience

Abstract

Idelalisib is a potent and selective inhibitor of the PI3Kδ approved since September 2014 for the treatment of several types of B cell malignancies. Pulmonary adverse events related to idelalisib are an emerging serious adverse event. We report here a single centre cohort of 16 patients who initiated idelalisib as routine treatment. Five of them experienced severe pulmonary adverse events related to idelalisib therapy. Comparison of the 5 patients with severe pulmonary events versus the 11 patients without identified no predisposing factors. Severe pulmonary adverse events were related to infectious pneumonia and/or to a drug-induced pneumonitis. The mechanisms of idelalisib-associated pneumonitis are unknown but consistent with the drug-induced pneumonitis described with mTOR inhibitors. Indeed, by inhibiting PI3Kδ, idelalisib also inhibits the mTOR pathway. Clinicians should be aware that any idelalisib-treated patient who presents with pulmonary symptoms should be evaluated for pneumonitis. Corticosteroids should be considered in addition to anti-infective therapy in case of severe pneumonitis or persistent pulmonary symptoms despite adequate antibiotic therapy.

Keywords:

• Idelalisib-related pneumonitis
• idelalisib
• idelalisib-associated pneumonitis

Acknowledgements

The authors thank Fiona Ecarnot (EA3920, University Hospital Besancon, France) for editing the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Author contributions

All authors cared for the patients. CM, AD and FBS conceived and designed the study. CM and FBS wrote the manuscript. All authors critically reviewed the manuscript and gave final approval.