Pulmonary toxicity induced by carfilzomib: a case report and review of the literature.

BACKGROUND: Carfilzomib (Kyprolis™) is a second-generation proteasome inhibitor registered for the management of relapsed or refractory multiple myeloma. Drug safety profile includes hypertension, heart failure, and acute kidney failure. There are only scarce data on carfilzomib pulmonary toxicity. CASE DESCRIPTION: In this report, we present a case of a Caucasian man in his 50s diagnosed with multiple myeloma and treated with daratumumab-carfilzomib-dexamethasone as second-line therapy. After 5 months of treatment, the patient developed noninfectious interstitial pneumonitis with respiratory failure. After a thorough differential diagnosis, we identified the patient's symptoms as a direct result of drug administration. Carfilzomib withdrawal alone led to clinical and radiologic improvement, whereas reintroducing the therapy worsened the condition. Daratumumab as monotherapy was continued without adverse events. The precise cause of carfilzomib pulmonary toxicity remains unknown. CONCLUSION: Given the rarity of the reported syndrome, our case highlights the need to monitor pulmonary function on carfilzomib treatment, as well as the possibility of symptom cessation on early drug withdrawal without additional interventions.