Safety-Related Postmarketing Modifications of Drugs for Hematological Malignancies

The prevalence of safety-related postmarketing label modifications of medications for hematological malignancies is unknown. We identified 35 new drugs indicated for hematological malignancies approved by the US Food and Drug Administration between January 1999 and December 2014. Characteristics of supporting trials and safety-related label modifications from approval to December 2017 were collected from drug labels. Regulatory review and approval pathways were also collected. New drug approvals were supported by trials with a median of 167 patients (interquartile range 115-316). All drugs were approved based on surrogate endpoints. Twenty-seven drug approvals (77%) were not supported by randomized controlled trials. All drugs received orphan drug designation, and most were granted fast track designation, priority review, and accelerated approval (83, 74, and 60%, respectively). A total of 28 drugs (80%) had postmarketing safety-related label modifications. Additions to black box warnings, contraindications, warnings and precautions, and common adverse reactions were identified in 31, 11, 77, and 46% of drugs, respectively. Five drugs (14%) were permanently or temporarily withdrawn from the US market. Drugs for hematological malignancies are often approved based on limited evidence through expedited regulatory pathways with incomplete safety profiles. Hematologists should be vigilant for unrecognized side effects when prescribing newly approved drugs.