Regulatory and clinical consequences of negative confirmatory trials of accelerated approval cancer drugs: retrospective observational study.

OBJECTIVES: To investigate the regulatory handling of cancer drugs that were granted accelerated approval by the US Food and Drug Administration (FDA) but failed to improve the primary endpoint in post-approval trials and to evaluate the extent to which negative post-approval trials changed the recommendations in treatment guidelines. DESIGN: Retrospective observational study. SETTING: FDA and National Comprehensive Cancer Network (NCCN) reports. INCLUDED DRUGS: Cancer drugs that received accelerated approval from the FDA and had negative post-approval trials. MAIN OUTCOME MEASURES: Regulatory outcomes, including withdrawal, conversion to regular approval, and no action. RESULTS: 18 indications for 10 cancer drugs that received accelerated approval but failed to improve the primary endpoint in post-approval trials were identified. Of these, 11 (61%) were voluntarily withdrawn by the manufacturer and one (bevacizumab for breast cancer) was revoked by the FDA. Of the 11 withdrawals, six occurred in 2021 alone. The remaining six (33%) indications remain on the label. The NCCN guidelines provide a high level of endorsement (category 1 endorsement for one and category 2A endorsement for seven) for accelerated approval drugs that have failed post-approval trials, sometimes even after the approval has been withdrawn or revoked. CONCLUSION: Cancer drug indications that received accelerated approval often remained on formal FDA approved drug labelling and continued to be recommended in clinical guidelines several years after statutorily required post-approval trials showed no improvement in the primary efficacy endpoint. Clinical guidelines should better align with the results of post-approval trials of cancer drugs that received accelerated approval.

Toward a broader view of mechanisms of drug cardiotoxicity.

Cardiotoxicity, defined as toxicity that affects the heart, is one of the most common adverse drug effects. Numerous drugs have been shown to have the potential to induce lethal arrhythmias by affecting cardiac electrophysiology, which is the focus of current preclinical testing. However, a substantial number of drugs can also affect cardiac function beyond electrophysiology. Within this broader sense of cardiotoxicity, this review discusses the key drug-protein interactions known to be involved in cardiotoxic drug response. We cover adverse effects of anticancer, central nervous system, genitourinary system, gastrointestinal, antihistaminic, anti-inflammatory, and anti-infective agents, illustrating that many share mechanisms of cardiotoxicity, including contractility, mitochondrial function, and cellular signaling.

Suspension of ulipristal acetate for uterine fibroids during ongoing EMA's review of liver injury risk: Unfortunate timing during the Covid-19 pandemic!

OBJECTIVE: EMA decided that with ulipristal acetate (UPA) treatment for uterine fibroids, should be discontinued due to the associated risk of hepatic failure, We analyzed whether the risk of recurrent symptoms due to fibroids may lead to an increased risk of Covid -19 infection and death, that would exceed the former risk of hepatic failure and transplantation. STUDY DESIGN, SIZE, DURATION: We used a Markov model to generate probabilities. PARTICIPANTS/MATERIALS, SETTING, METHODS: There are currently about 36,250 treated patients in Europe. We estimated bleeding probabilities, while using or discontinuing UPA, which may induce a need of medical or surgical management in symptomatic patients, and increase the risk of acquiring a Covid-19 infection, and die from it. We also estimated the risk of suffering a hepatic failure and hepatic transplantation. MAIN RESULTS AND THE ROLE OF CHANCE: Based on our assumptions, ceasing UPA during a Covid 19 pandemic may be associated with a fatality ratio between 4 and 18, due to the Pandemic, whereas pursuing UPA would be associated with a fatality rate due to the pandemic between 1-2, and an added fatality rate due to hepatic impairment of 1. The added risk of stopping UPA may range between 2 and 15 additional deaths. Our calculations suggest that the decision to stop UPA in the middle of the Covid- 19 pandemic may be untimely, since it may result in an increased risk of Covid-19 infection, due to the recurrence of symptoms and the need for medical and surgical treatment. WIDER IMPLICATIONS OF THE FINDINGS: A decision, like the one EMA took need to be taken in a wider health context of a population, than simply analyzing its role as regulating agent for medications.

Response to Propoxyphene Market Withdrawal: Analgesic Substitutes, Doses, and Adverse Events.

OBJECTIVE: Experts cautioned that patients affected by the November 2010 withdrawal of the opioid analgesic propoxyphene might receive riskier prescriptions. To explore this, we compared drug receipts and outcomes among propoxyphene users before and aftermarket withdrawal. STUDY DESIGN: Using OptumLabs data, we studied 3 populations: commercial, Medicare Advantage (MA) aged (age 65+ y) and MA disabled (age below 65 y) enrollees. The exposed enrollees received propoxyphene in the 3 months before market withdrawal (n=13,622); historical controls (unexposed) received propoxyphene 1 year earlier (n=9971). Regression models estimated daily milligrams morphine equivalent (MME), daily prescription acetaminophen dose, potentially toxic acetaminophen doses, nonopioid prescription analgesics receipt, emergency room visits, and diagnosed falls, motor vehicle accidents, and hip fractures. PRINCIPAL FINDINGS: Aged MA enrollees illustrate the experience of all 3 populations examined. Following the market withdrawal, propoxyphene users in the exposed cohort experienced an abrupt decline of 69% in average daily MME, compared with a 14% decline in the unexposed. Opioids were discontinued by 34% of the exposed cohort and 18% of the unexposed. Tramadol and hydrocodone were the most common opioids substituted for propoxyphene. The proportion of each group receiving ≥4 g of prescription acetaminophen per day decreased from 12% to 2% in the exposed group but increased from 6% to 8% among the unexposed. Adverse events were rare and not significantly different in exposed versus unexposed groups. CONCLUSIONS: After propoxyphene market withdrawal, many individuals experienced abrupt discontinuation of opioids. Policymakers might consider supporting appropriate treatment transitions and monitoring responses following drug withdrawals.

Drug Withdrawal Due to Safety: A Review of the Data Supporting Withdrawal Decision.

INTRODUCTION: Several drugs were withdrawn from the market due to safety. OBJECTIVE: The aim of this study was to describe data supporting drug withdrawal from the market due to safety reasons in countries belonging to the World Health Organization. METHODS: We analyzed drugs withdrawn from the market between 1990 and 2010. All medicine agencies of the countries belonging to the Program for International Drug Monitoring of the World Health Organization were contacted. To complete data, Medline, reference books and available drug databases were also searched. Information sources on which authorities based their withdrawal were categorized and the average time between the first date of exposure and withdrawal was calculated and stratified. RESULTS: A total of 133 drugs that met the inclusion/exclusion criteria were withdrawn from the market due to safety reasons in the period reviewed (1990 - 2010). Hepatotoxicity (n=36, 27.1%), cardiac disorders (n=25, 18.8%), hypersensitivity (n=17, 12.8%) and nephrotoxicity (n=14, 9.8%) were the major reasons responsible for 69.2% of all drugs withdrawn. In most cases, Information Sources for drug withdrawal were spontaneous reports and/or case reports (n=86, 64.7%), followed by clinical trials (n=24, 18.0%). The average time between the introduction of a drug and its withdrawal due to safety reasons was 20.3 years (SD±13.8). CONCLUSION: According to available and published evidence, there is no gold standard to identify risks associated with drug exposure. These findings strengthen the role of different information sources within the drug safety review process.

Secret safety warnings on medicines: A case study of information access requests.

PURPOSE: There has been less attention to the transparency of postmarket evidence of harmful effects of medicines than of premarket clinical trial data. This is a case study of requests for Australian "direct health professional communications" (DHPCs). These letters are used by regulators and manufacturers to inform clinicians of emergent evidence of harm. DHPCs are not made public by Australia's Therapeutic Goods Administration (TGA). METHODS: We requested all DHPCs sent out in Australia from 2007 to 2016 inclusive for 207 drugs that were subject to safety advisories over this decade in Canada, the United Kingdom, and/or the United States. We contacted 39 manufacturers (February to May 2018), with repeat requests to nonrespondents, and a follow-up freedom-of-information (FOI) request to the TGA. RESULTS: Fifteen companies provided information, either sending DHPCs (n = 4, on five drugs) or affirming none were sent out (n = 11). The remaining 24 of 39 (62%) companies did not provide DHPCs: nine (23%) refused the request, often citing commercial confidentiality; the rest provided no answer despite repeat requests. In total, we had no information for 170 of 207 (82%) of the drugs. Our FOI request to the TGA was unsuccessful. CONCLUSIONS: Our experience highlights unacceptable secrecy concerning safety warnings previously sent to thousands of Australian clinicians. In the absence of explicit regulatory policy supporting disclosure, companies differed in their response. These letters warn of serious and often life-threatening harm and guide safer care; full ongoing public access is needed, ideally in searchable online databases.

Analysis of factors related to the occurrence of important drug-specific postmarketing safety-related regulatory actions: A cohort study focused on first-in-class drugs.

PURPOSE: First-in-class (FIC) drugs with novel modes of action pose concerns regarding important postmarketing safety issues. The purpose of this study was to analyze the factors related to the occurrence of postmarketing safety-related regulatory actions (PSRAs) for drugs approved in the United States (US), with a focus on FIC drugs. METHODS: New molecular entities and new therapeutic biologics approved in the United States between 1 January 2003 and 31 December 2013 were included in the analysis. Important drug-specific PSRAs were defined as market withdrawal or the addition of new black box warnings or warnings due to adverse drug reactions. The relationship between baseline characteristics and the occurrence of important drug-specific PSRAs was investigated using a multivariate logistic regression model. We also defined the event as the first important PSRA and estimated the time-to-event for each factor. RESULTS: ATC category L (antineoplastic and immunomodulating agents) and FIC drug classification were shown to be statistically significant factors, with odds ratios of 2.15 (95% CI: 1.12-4.11; P = 0.0203) and 1.87 (95% CI: 1.06-3.31; P = 0.0309), respectively. ATC category L and FIC drugs were also significant factors for time to occurrence of the first event. CONCLUSION: FIC designation and ATC category L were identified as factors related to important drug-specific PSRAs. These factors were also associated with the time to occurrence of the first important drug-specific PSRAs.

Serious Adverse Drug Events Reported to the FDA: Analysis of the FDA Adverse Event Reporting System 2006-2014 Database.

BACKGROUND: Data on adverse drug events (ADEs) observed at the population level provide important evidence regarding the safety of a pharmaceutical product in real-world settings. Recent patterns in serious and fatal ADE reporting have not been documented. OBJECTIVE: To assess recent patterns in serious and fatal ADE reports in the United States. METHODS: We conducted a retrospective analysis of the publicly available 2006-2014 FDA Adverse Event Reporting System database. Non-U.S. reports, reports from clinical trials, and reports with missing outcome data were excluded. The annual numbers of ADEs with reported outcome of death, disability, and other serious outcomes were determined. Types (direct, manufacturer expedited, or manufacturer periodic) and sources (consumer, health professional, or other) of these serious ADE reports were also identified. The distribution of serious ADE reports by patient age groups (< 18, 18-44, 45-64, and ≥ 65 years) was determined. Drugs listed as primary suspects in serious ADEs (death, disability, and other serious outcomes) were identified and ranked. Descriptive statistics were used to characterize the patterns in serious or fatal ADE reporting. RESULTS: From 2006 to 2014, the number of serious ADEs reported to the FDA increased 2-fold. A total of 902,323 serious outcomes were reported over the 9-year study period: 244,408 deaths, 72,141 disabilities, and 585,774 other serious outcomes. The relative percentage of reports of deaths was highest during 2012 (32.4%). The percentage of reports of disability was highest during 2006 (12.1%). Overall, the "other serious outcomes" category accounted for almost 65% of serious ADEs reports. Expedited reports from drug manufacturers were most common (about 72%) of the serious ADEs with available data on report type. Health professionals (47.3%) were the most common source of report followed by consumers (36.1%) and other sources (16.6%). A disproportionately high number of reported ADEs was among patients aged 45-64 years (40%) and ≥ 65 years (32.6%). Antineoplastic drugs were more frequently reported with deaths. Three antidepressant drugs were among the top 10 drugs reported with disability. During 2006-2014, there were 38 drugs with more than 1,000 reports of serious ADEs in a given year: 2 drugs currently withdrawn from the market (rofecoxib and parecoxib), 10 drugs with an FDA risk evaluation and mitigation strategies (REMS) program, 13 biologic or specialty drugs, and 14 others. CONCLUSIONS: An overall increase in the trend of the number of serious ADE reports was observed from 2006 to 2014. Drugs with a REMS program and biologic and specialty drugs were involved in a significant number of reported serious ADEs. Data on reporting patterns can guide surveillance and pharmacoepidemiological studies to understand the public health burden of serious ADEs. DISCLOSURES: No outside funding supported this study. Hansen has received consulting fees from and has provided expert testimony for Daichii Sankyo and Takeda. The other authors have nothing to disclose.

Moulds associated with contaminated ocular and injectable drugs: FDA recalls, epidemiology considerations, drug shortages, and aseptic processing.

Recent (2012) grave but rare outbreaks of fungal meningitis and endophthalmitis associated with drugs contaminated with select environmental moulds (Exserohilum and Fusarium, respectively) have exacerbated mycology concerns for formulation, good laboratory practices (GLP), and use of the final drug product. Intensified investigations (2013-2015) by the Food and Drug Administration (FDA) that included added responsibilities for specialty compounding laboratories have prompted at least nine voluntary mould-related drug recalls during 2014-2015. Both primary manufactures (five recalls, two companies) and secondary-processing compound laboratories (at least eight recalls, six companies) and near 0.8 million units were involved. These constituted minor fractions of recalled drug products in an estimated 2500 recalls among other causes during this time period. Recalls of similar drugs in 2016 were indirectly related to fungi. None of the mould-related- drug-recall episodes during 2014-2016 have been identified with fungal disease outbreaks. The recalls included drugs in short supply worldwide such as injectable sodium chloride- and related saline solutions as well as ocular formulations. Insufficient environmental monitoring and GLP compliance, particularly for aseptic processing of non-preserved formulations, appeared to be underlying factors in the fungal contaminations. Observations of mould growth in drugs during their processing should be accurately recorded and investigated; cryptic listings under "particulate" designations should be avoided. Confirmed identifications for chronic contaminants are recommended. Heat-tolerant moulds with resistant morphotypes are prime concerns.

Investigation assessing the publicly available evidence supporting postmarketing withdrawals, revocations and suspensions of marketing authorisations in the EU since 2012.

OBJECTIVES: To assess the sources of publicly available evidence supporting withdrawal, revocation or suspension of marketing authorisations ('regulatory actions') due to safety reasons in the EU since 2012 and to investigate the time taken since initial marketing authorisation to reach these regulatory decisions. SETTING: This investigation examined the sources of evidence supporting 18 identified prescription medicinal products which underwent regulatory action due to safety reasons within the EU in the period 1 July 2012 to 31 December 2016. RESULTS: Eighteen single or combined active substances ('medicinal products') withdrawn, revoked or suspended within the EU for safety reasons between 2012 and 2016 met the inclusion criteria. Case reports were most commonly cited, supporting 94.4% of regulatory actions (n=17), followed by randomised controlled trial, meta-analyses, animal and in vitro, ex vivo or in silico study designs, each cited in 72.2% of regulatory actions (n=13). Epidemiological study designs were least commonly cited (n=8, 44.4%). Multiple sources of evidence contributed to 94.4% of regulatory decisions (n=17). Death was the most common adverse drug reaction leading to regulatory action (n=5; 27.8%), with four of these related to medication error or overdose. Median (IQR) time taken to reach a decision from the start of regulatory review was found to be 204.5 days (143, 535 days) and decreased across the study period. Duration of marketing prior to regulatory action, from the medicinal product's authorisation date, increased across the period 2012-2016. CONCLUSIONS: The sources of evidence supporting pharmacovigilance regulatory activities appear to have changed since implementation of Directive 2010/84/EU and Regulation (EU) No. 1235/2010. This, together with a small improvement in regulatory efficiency, suggests progress towards more rapid regulatory decisions based on more robust evidence. Future research should continue to monitor sources of evidence supporting regulatory decisions and the time taken to reach these decisions over time.

Guía metodológica para la evaluación de la eficacia y la seguridad de nuevos fármacos: implementación de las recomendaciones de EUnetHTA / Methodological guideline for the efficacy and safety assessment of new pharmaceuticals: implementation of EUnetHTA's recommendations

La colaboración European Network for Health Technology Assessment (EUnetHTA) es la red colaborativa de agencias y organismos públicos de evaluación de tecnologías sanitarias de la Unión Europea. En este marco se han elaborado guías metodológicas y procedimientos comunes que han dado lugar al denominado HTA Core Model®. La Agencia de Evaluación de Tecnologías Sanitarias de Andalucía (AETSA), miembro de la Red Española de Agencias de Evaluación de Tecnologías Sanitarias y Prestaciones del Sistema Nacional de Salud, y de la colaboración EUnetHTA, participa en la recién iniciada Tercera Acción Conjunta (Joint Action 3) de EUnetHTA (2016-2019). Adicionalmente, la AETSA cuenta con una línea de evaluación de medicamentos. Parte del trabajo se integra en la elaboración de informes de posicionamiento terapéutico (IPT) sobre fármacos que han recibido recientemente la autorización de comercialización, que coordina la Agencia Española de Medicamentos y Productos Sanitarios. Como apoyo a este trabajo, la AETSA elabora «Informes de síntesis de evidencia: medicamentos», en los que se realiza una evaluación comparada de la eficacia y la seguridad de los fármacos de los que va a elaborarse un IPT. La AETSA ha diseñado un proceso para la elaboración de dichos informes, basado en el HTA Core Model® y en las guías metodológicas de EUnetHTA. En este trabajo se describe la metodología empleada en la elaboración de la guía realizada por la AETSA para la elaboración de estos informes y se presentan los distintos apartados en los que esta se estructura (AU)

The European network for Health Technology Assessment (EUnetHTA) is the network of public health technology assessment (HTA) agencies and entities from across the EU. In this context, the HTA Core Model®, has been developed. The Andalusian Agency for Health Technology Assessment (AETSA) is a member of the Spanish HTA Network and EUnetHTA collaboration In addition, AETSA participates in the new EUnetHTA Joint Action 3 (JA, 2016–2019). Furthermore, AETSA works on pharmaceutical assessments. Part of this work involves drafting therapeutic positioning reports (TPRs) on drugs that have recently been granted marketing authorisation, which is overseen by the Spanish Agency of Medicines and Medical Devices (AEMPS). AETSA contributes by drafting ‘Evidence synthesis reports: pharmaceuticals’ in which a rapid comparative efficacy and safety assessment is performed for drugs for which a TPR will be created. To create this type of report, AETSA follows its own methodological guideline based on EUnetHTA guidelines and the HTA Core Model®. In this paper, the methodology that AETSA has developed to create the guideline for ‘Evidence synthesis reports: pharmaceuticals’ is described. The structure of the report itself is also presented (AU)

Postmarketing withdrawal of human medicinal products because of adverse reactions in animals: a systematic review and analysis.

PURPOSE: We have identified human medicinal products for which animal data were used as evidence for withdrawal, determined whether the adverse reactions were reported in humans, established whether confirmatory human studies were conducted, and explored the withdrawal patterns over time. METHODS: We searched the World Health Organization's Consolidated List of [Medicinal] Products, drug regulatory authorities' websites, PubMed, Google Scholar, and selected textbooks to identify medicinal products withdrawn from 1950 to June 2016. We included medicinal products for which animal data were specifically reported as a reason for withdrawal. We used a checklist adapted from the International Agency for Research on Cancer criteria to rate the evidence. RESULTS: In 37 cases, evidence from animals was the reason given for withdrawal between 1963 and 2000. Evidence of carcinogenicity was cited in 23 cases (62%). Limited evidence for harms occasioned withdrawal in over 80% of cases. In 11 cases (30%), the adverse drug reactions were subsequently reported in humans. In 5 instances (14%), formal studies were conducted in humans. The median interval to withdrawal following reports of adverse reactions was 2 years (IQR = 1-9 y). CONCLUSIONS: Regulatory authorities and drug manufacturers are likely to withdraw medicinal products quickly from the market when animal experiments suggest increased risks of cancers or congenital malformations. Human studies are seldom conducted when harms are suspected in animals. Future research should explore better methods of extrapolating harms data from animal research to humans.

Impact of Medicine Withdrawal on Reporting of Adverse Events Involving Therapeutic Alternatives: A Study from the French Spontaneous Reporting Database.

INTRODUCTION: The consequences of the withdrawal of marketing authorisation of drugs have mostly been studied considering drug prescription patterns for the therapeutic alternatives of the withdrawn drugs. The potential concomitant changes in the reporting of adverse reactions concerning these alternatives have been studied less often. OBJECTIVE: The objective of this study was to analyse the changes in the reporting of adverse events (AEs) for therapeutic alternatives after the withdrawal of three medicines (dextropropoxyphene, pioglitazone and tetrazepam) from the market for safety reasons. METHODS: This study was performed using both the French pharmacovigilance database and the Echantillon Généraliste des Bénéficiaires (a random sample of French health insurance affiliates). For dextropropoxyphene, pioglitazone and tetrazepam alternatives, the number and types of case reports were studied for both the year preceding the first official safety warning and the year following the withdrawal. Reporting rates expressed per 10,000 reimbursements (RRReimb) and per 10,000 treated patients (RRPat) were also compared for the two periods. RESULTS: After dextropropoxyphene withdrawal, case reports and reimbursements increased for tramadol (case reports: +23%, reimbursements: +13%) and codeine (case reports: +74%, reimbursements: +47%), RRPat being significantly increased for tramadol (0.92 vs. 1.06, p = 0.02). After pioglitazone withdrawal, case reports increased for dipeptidyl peptidase-4 (DPP-4) inhibitors, glinides, and glucagon-like peptide 1 (GLP-1) analogues (+84%, +22% and +5%, respectively) and reimbursements (+55, +11 and +50%, respectively); both decreased for sulfonylureas (case reports: -6%, reimbursements: -2%). RRPat increased for DPP-4 inhibitors (1.63 vs. 2.26, p = 0.008). After tetrazepam withdrawal, case reports increased for diazepam, methocarbamol and thiocolchicoside (+110, +86 and +157%, respectively), as lesser did reimbursements. RRPat increased for diazepam (1.78 vs. 2.41, p = 0.054) and thiocolchicoside (0.14 vs. 0.24, p = 0.013). CONCLUSION: For the three drug withdrawals investigated, the number of case reports involving alternatives increased to a larger extent than the numbers of prescriptions. This could relate to a higher occurrence of AEs in new users of alternatives who switched from the withdrawn medicines or to an increased awareness of possible AEs.

Post-marketing drug withdrawals: Pharmacovigilance success, regulatory problems.

Modern pharmacovigilance began in the 1960s, since when the subject has grown markedly, interest having particularly increased since 2010. One index of its success is the increasing speed with which serious adverse drug reactions are discovered after marketing of a medicinal product. However, the speed with which products have subsequently been withdrawn as a result of the discovery of serious adverse reactions has not consistently changed. This highlights problems that regulators and manufacturers face when serious reactions are discovered, with difficulties in deciding which of several consequent actions to take: to add specific warnings (cautions) or contraindications to the product label; to issue a Direct Healthcare Professional Communication; to allow informed patients to decide whether they will take the drug; or, in the most serious cases, to withdraw the product or revoke the licence. Conflicts of interest may inhibit decision-making. Recommendations that arise from these observations are that: health professionals and patients should be more vigorously encouraged to report suspected adverse drug reactions; regulatory authorities and drug manufacturers should take quicker confirmatory action when serious suspected adverse drug reactions are reported, even anecdotally, with formal studies to test for causality conducted sooner rather than later, applying lower than usual thresholds for suspicion; temporary suspensions or restrictions could be considered during such assessments; universal guidelines are needed for determining when a drug should be withdrawn if serious adverse drug reactions are suspected; there should be more rigorous monitoring and verification of deaths and reporting of reasons for drop-outs during clinical trials, with more transparency in reporting adverse events and ready access to premarketing clinical study reports; post-marketing drug monitoring systems and medicines regulation in low-to-middle income economies, especially in Africa, where withdrawals are fewer than elsewhere, should be strengthened.

Classification of nervous system withdrawn and approved drugs with ToxPrint features via machine learning strategies.

BACKGROUND AND OBJECTIVES: Early-phase virtual screening of candidate drug molecules plays a key role in pharmaceutical industry from data mining and machine learning to prevent adverse effects of the drugs. Computational classification methods can distinguish approved drugs from withdrawn ones. We focused on 6 data sets including maximum 110 approved and 110 withdrawn drugs for all and nervous system diseases to distinguish approved drugs from withdrawn ones. METHODS: In this study, we used support vector machines (SVMs) and ensemble methods (EMs) such as boosted and bagged trees to classify drugs into approved and withdrawn categories. Also, we used CORINA Symphony program to identify Toxprint chemotypes including over 700 predefined chemotypes for determination of risk and safety assesment of candidate drug molecules. In addition, we studied nervous system withdrawn drugs to determine the key fragments with The ParMol package including gSpan algorithm. RESULTS: According to our results, the descriptors named as the number of total chemotypes and bond CN_amine_aliphatic_generic were more significant descriptors. The developed Medium Gaussian SVM model reached 78% prediction accuracy on test set for drug data set including all disease. Here, bagged tree and linear SVM models showed 89% of accuracies for phycholeptics and psychoanaleptics drugs. A set of discriminative fragments in nervous system withdrawn drug (NSWD) data sets was obtained. These fragments responsible for the drugs removed from market were benzene, toluene, N,N-dimethylethylamine, crotylamine, 5-methyl-2,4-heptadiene, octatriene and carbonyl group. CONCLUSION: This paper covers the development of computational classification methods to distinguish approved drugs from withdrawn ones. In addition, the results of this study indicated the identification of discriminative fragments is of significance to design a new nervous system approved drugs with interpretation of the structures of the NSWDs.

Post-Marketing Regulation of Medicines Withdrawn from the Market Because of Drug-Attributed Deaths: An Analysis of Justification.

INTRODUCTION: Several medicinal products have been withdrawn from the market because of drug-attributed deaths. However, there has been no investigation of whether such withdrawals were justified, and the extent to which confirmatory studies are used to investigate drug-adverse event relationships when deaths are reported is uncertain. We documented medicinal products withdrawn from the market because of drug-attributed deaths, identified confirmatory studies investigating the drug-adverse event relationships, examined whether withdrawals of medicinal products because of drug-attributed deaths after marketing were justified based on a mechanistic analysis, and examined the trends over time. METHODS: We searched electronic and non-electronic sources to identify medicinal products that were withdrawn because of drug-attributed deaths. We used a previously published algorithm to examine whether the withdrawals of products were justified. We then searched PubMed and Google Scholar to identify studies investigating the drug-adverse event relationships, used the Oxford Centre for Evidence-Based Medicine criteria to document the levels of evidence, and assessed whether the evidence of an association was confirmed. RESULTS: We included 83 medicinal products. The reasons for withdrawal appeared to have been justified in 80 cases (96%). The median interval between the first reported adverse reaction that was related to the cause of death and the first reported death was 1 year (interquartile range = 1-3); products were withdrawn sooner when the interval between the first reported relevant adverse reaction and the first death was shorter. Confirmatory studies were conducted in 57 instances (69%), and there was evidence of an association in 52 cases (63%). Four products (5%) were re-introduced after initial withdrawal. CONCLUSION: Regulatory authorities have been justified in making withdrawal decisions when deaths have been attributed to medicinal products, using the precautionary principle when alternative decisions could have been made. Medicinal products are likely to be quickly withdrawn from the market when there is a short interval to the first reported deaths. The use of an algorithm such as we have used in this study could help to expedite the process of decision making.

Post-marketing withdrawal of anti-obesity medicinal products because of adverse drug reactions: a systematic review.

BACKGROUND: We identified anti-obesity medications withdrawn since 1950 because of adverse drug reactions after regulatory approval, and examined the evidence used to support such withdrawals, investigated the mechanisms of the adverse reactions, and explored the trends over time. METHODS: We conducted searches in PubMed, the World Health Organization database of drugs, the websites of drug regulatory authorities, and selected full texts, and we hand searched references in retrieved documents. We included anti-obesity medications that were withdrawn between 1950 and December 2015 and assessed the levels of evidence used for making withdrawal decisions using the Oxford Centre for Evidence-Based Medicine criteria. RESULTS: We identified 25 anti-obesity medications withdrawn between 1964 and 2009; 23 of these were centrally acting, via monoamine neurotransmitters. Case reports were cited as evidence for withdrawal in 80% of instances. Psychiatric disturbances, cardiotoxicity (mainly attributable to re-uptake inhibitors), and drug abuse or dependence (mainly attributable to neurotransmitter releasing agents) together accounted for 83% of withdrawals. Deaths were reportedly associated with seven products (28%). In almost half of the cases, the withdrawals occurred within 2 years of the first report of an adverse reaction. CONCLUSIONS: Most of the drugs that affect monoamine neurotransmitters licensed for the treatment of obesity over the past 65 years have been withdrawn because of adverse reactions. The reasons for withdrawal raise concerns about the wisdom of using pharmacological agents that target monoamine neurotransmitters in managing obesity. Greater transparency in the assessment of harms from anti-obesity medications is therefore warranted.

Testing the usefulness of the number needed to treat to be harmed (NNTH) in benefit-risk evaluations: case study with medicines withdrawn from the European market due to safety reasons.

OBJECTIVE: To explore the usefulness of number needed to treat to be harmed (NNTH), in benefit-risk assessments, by studying the agreement between NNTH values and withdrawals of medicines from European market due to safety reasons. METHODS: Medicines with data from longitudinal studies were included. Studies were identified from European Medicines Agency's Reports. Meta-analyses were performed to pool odds ratios (OR) with 95% confidence-intervals (CI). Published control event rates were applied to ORs to calculate NNTHs (95%CI) for selected adverse events. RESULTS: NNTH (95%CI) decreased from pre- to post-marketing for the eight medicines included: peripheral neuropathy (∞ vs. 12[non-significant; NS] with almitrine; heart valve disease with benfluorex (∞ vs. NNTH ranging from 7[4-13] to 7[5-9]); myopathy (-4096[NS] vs. 797[421-1690]), new-onset diabetes (113[NS] vs. 390[425-778]), bleeding (∞ vs. 517[317-1153]), and infection (∞ vs. 253[164-463]) with niacin-laropiprant; psychiatric disorders (12[7-34] vs. 9[5-24]) with rimonabant; myocardial infarction (MI) [-1305 vs. 270[89-4362]) with rofecoxib; MI (-510 vs. NNTH ranging from 152[55-4003] to 568[344-1350]) with rosiglitazone; cardiovascular events (∞ vs. 245[129-1318]) with sibutramine; and liver injury (∞ vs. 5957[NS]) with ximelagatran. CONCLUSION: NNTH have potential of use as a supportive tool in benefit-risk re-evaluations of medicines and may help regulators to making decisions on drug safety.

Benefit-risk reassessment of medicines: a retrospective analysis of all safety-related referral procedures in Europe during 2001-2012.

PURPOSE: The aim of this study was to determine the outcomes and timing within the product life cycle of all benefit-risk reassessment procedures for marketed products that were completed by the committee for medicinal product for human use during 2001-2012. METHODS: A cohort of all referral procedures for benefit-risk reassessment (Article 20, Article 31, Article 36, Article 107 procedures) for which committee for medicinal product for human use issued an opinion between 1 January 2001 and 31 December 2012 was created. The European Medicines Agency website and the Dutch Medicines Evaluation Board website were used to collect all data. RESULTS: There were a total of 73 benefit-risk reassessments during the study period; 61 reassessments for a single product and 12 reassessments for multiple products or an entire product class. Nineteen reassessments resulted in the recommendation to remove the product from the market. On average, a benefit-risk reassessment was performed 18.7 years after the product was first marketed. Seventeen products were marketed 5 years or less when the reassessment procedure was completed; six of these products were subsequently removed from the market. CONCLUSIONS: The majority of all benefit-risk reassessments that were performed during the study period did not result in removing the product from the market, but rather, in confirming the positive benefit-risk of the product, conditional to changes to the product's marketing authorisation. About half of all products that were removed from the market during the 2000s had been marketed for more than 20 years. Copyright © 2016 John Wiley & Sons, Ltd.