Ethical and Practical Considerations in Removing Black Box Warnings from Drug Labels

Rosiglitazone and trametinib exhibit potent anti-tumor activity in a mouse model of muscle invasive bladder cancer

Muscle invasive bladder cancers (BCs) can be divided into 2 major subgroups-basal/squamous (BASQ) tumors and luminal tumors. Since Pparg has low or undetectable expression in BASQ tumors, we tested the effects of rosiglitazone, Pparg agonist, in a mouse model of BASQ BC. We find that rosiglitazone reduces proliferation while treatment with rosiglitazone plus trametinib, a MEK inhibitor, induces apoptosis and reduces tumor volume by 91% after 1 month. Rosiglitazone and trametinib also induce a shift from BASQ to luminal differentiation in tumors, which our analysis suggests is mediated by retinoid signaling, a pathway known to drive the luminal differentiation program. Our data suggest that rosiglitazone, trametinib, and retinoids, which are all FDA approved, may be clinically active in BASQ tumors in patients.

A Longitudinal Analysis of Black Box Warnings: Trends and Implications for Drug Safety

A black box warning, signaling potential life-threatening adverse effects of medications or medical devices, is crucial for public and healthcare professional awareness. Comprehending and adhering to these warnings can prevent serious harm. This review aims to elucidate their significance. Data on drugs with black box warnings were collected from the Food and Drug Administration's (FDA's) official website using the search term 'Boxed warnings' from January 1, 2015, to January 31, 2024. A Microsoft Excel spreadsheet (Microsoft Corporation, Redmond, WA, USA) containing black box warnings for this period was downloaded from the FDA's website. Additional parameters, such as drug class and whether the warnings were new or existing, were added to the downloaded spreadsheet. The collected data were organized by year, categorizing new and existing warnings, along with details on the evidence source, system-wise classification, and black box warnings for commonly used drugs, including their clinical significance. Results show that in the past decade, 40% of black box warnings were issued in 2023, followed by 12% in 2022. Most warnings (67%) comprised existing ones with minor revisions while 29% were new. Nine existing warnings were removed during the period. Post-marketing studies predominantly provided evidence for these warnings. Neuropsychiatric concerns like addiction potential (31%), suicidal tendency (7%), and hypersensitivity reactions (12%) were the frequently encountered black box warnings. Black box warnings play a crucial role in highlighting the serious adverse effects of medications. Neuropsychiatric warnings have been frequent over the past decade. Awareness of these warnings is essential to prevent adverse effects and enhance patient care, especially concerning drugs like guaifenesin/hydrocodone bitartrate, zolpidem, and montelukast commonly encountered in clinical practice.

Information shocks and pharmaceutical firms' marketing efforts: Evidence from the Chantix black box warning removal

We study how pharmaceutical firm marketing responds to a regulatory decision that represents a positive information shock about drug safety. In the context of the smoking cessation drug Chantix, we estimate the effects of a Food and Drug Administration (FDA) decision to remove the drug's black box warning on two forms of marketing: monetary and in-kind payments to physicians (detailing) and direct-to-consumer advertising. Using identification strategies that leverage geographic variation in latent demand for smoking cessation therapy and the targeted nature of the information shock, we find that the removal of the warning significantly increased Chantix-related detailing payments and increased expenditures on national television advertising of Chantix. Understanding these firm-level strategic promotion responses is important, as they have implications for the dissemination of new drug information and the behaviors of physicians and consumers.

Implications of Removing Rosiglitazone's Black Box Warning and Restricted Access Program on the Uptake of Thiazolidinediones and Dipeptidyl Peptidase-4 Inhibitors Among Patients with Type 2 Diabetes

BACKGROUND

Medications are increasingly being approved with limited, short-term evidence regarding safety. Regulatory safety concerns may emerge for these drugs but later may be reversed if additional evidence suggests no warning is indicated.

OBJECTIVE

To describe trends over time in the initiation of rosiglitazone and pioglitazone-both in the thiazolidinedione (TZD) class-and medications from the dipeptidyl peptidase-4 (DPP-4) inhibitor class before and after the FDA removed a black box warning and restricted access program for rosiglitazone regarding an increased risk of myocardial infarction.

METHODS

This retrospective study evaluated initiation of TZDs and DPP-4 inhibitors using 2001-2015 administrative claims data from a U.S. commercially insured population. Patients were aged 18-64 years and were new users of either a TZD or DPP-4 inhibitor. Among all patients who were new users of either a TZD or a DPP-4 inhibitor during each quarter-year (Q), the percentage of patients who initiated rosiglitazone, pioglitazone, and DPP-4 inhibitors were calculated.

RESULTS

There were 630,977 patients eligible for the study. During 2007, rosiglitazone initiators decreased from 39.1% to 8.0% in 2007 Q4 when the black box warning was implemented. During 2010, rosiglitazone initiators decreased from 7.6% to 1.0%, as safety evidence accumulated and the restricted access program requirement was announced. Rosiglitazone initiation remained below 1.0%, even after regulatory restrictions were removed in November 2013. Pioglitazone initiation decreased from 46.4% in 2010 Q1 to 14.8% in 2011 Q4 and remained relatively constant between 14.5% and 17.8% after regulatory restrictions for rosiglitazone were removed. After DPP-4 inhibitors first became available in 2006 Q3, initiation of this medication class increased rapidly, stayed relatively constant between 42.8% and 45.5% in 2009, and then quickly rose and remained above 80% from 2012 through 2015.

CONCLUSIONS

This case study provides some evidence that adding and later reversing drug safety warnings-particularly those with restricted access requirements-may affect the uptake of the targeted product into the population when multiple clinically relevant treatment alternatives are available (such as type 2 diabetes). Once a treatment falls out of favor, removal of safety warnings and/or restricted access programs may not lead to increased use.

DISCLOSURES

This project was not directly supported by any funding. Hickson was supported by the National Heart, Lung, and Blood Institute through a National Research Service Award (NRSA) training grant (4T32HL007055-41) as a postdoctoral research fellow with the Cardiovascular Disease Epidemiology Program at The University of North Carolina at Chapel Hill (UNC-CH). Cole was supported by a NRSA Predoctoral Traineeship from the Agency for Healthcare Research and Quality sponsored by The Cecil G. Sheps Center for Health Services Research, UNC-CH (grant no. T32-HS000032) and a predoctoral fellowship from the American Foundation for Pharmaceutical Education. Unrelated to this project, Cole was a part-time employee of Truven Health Analytics/IBM Watson Health. Dusetzina has nothing to disclose.