Sabine M. J. M. Straus

Safety-Related Regulatory Actions for Biologicals Approved in the United States and the European Union

CONTEXT Biologicals are a relatively new class of medicines that carry specific risks (eg, immunogenicity). However, limited information is available on the nature and timing of safety problems with their use that were identified after approval. OBJECTIVE To determine the nature, frequency, and timing of safety-related regulatory actions for biologicals following approval in the United States and/or the European Union. DESIGN AND SETTING Follow-up of a group of biologicals approved in the United States and/or European Union between January 1995 and June 2007. Vaccines, allergenic products, and products for further manufacture and transfusion purposes were excluded. MAIN OUTCOME MEASURES Nature, frequency, and timing of safety-related regulatory actions defined as (1) dear healthcare professional letters (United States) and direct healthcare professional communications (European Union), (2) black box warnings (United States), and (3) safety-related marketing withdrawals (United States and European Union) issued between January 1995 and June 2008. RESULTS A total of 174 biologicals were approved (136 in the United States and 105 in the European Union, of which 67 were approved in both regions). Eighty-two safety-related regulatory actions (46 dear healthcare professional letters, 17 direct healthcare professional communications, 19 black box warnings, and no withdrawals) were issued for 41 of the 174 different biologicals (23.6%). The probability of a first safety-related regulatory action, derived from Kaplan-Meier analyses, was 14% (95% confidence interval [CI], 9%-19%) 3 years after approval and 29% (95% CI, 20%-37%) 10 years after approval. Biologicals first in class to obtain approval had a higher risk for a first safety-related regulatory action compared with later approved products in that class (12.0/1000 vs 2.9/1000 months, respectively; hazard ratio, 3.7 [95% CI, 1.5-9.5]). Warnings mostly concerned the classes general disorders and administration site conditions, infections and infestations, immune system disorders and neoplasms benign, malignant, and unspecified. CONCLUSIONS The nature of safety problems identified after approval for biologicals is often related to the immunomodulatory effect (infections). Because the biologicals first to be approved in a class were more likely to be subjected to regulatory action, close monitoring is recommended.

Lower Risk of Cancer in Patients on Metformin in Comparison With Those on Sulfonylurea Derivatives Results from a large population-based follow-up study

OBJECTIVE Numerous studies have suggested a decreased risk of cancer in patients with diabetes on metformin. Because different comparison groups were used, the effect magnitude is difficult to estimate. Therefore, the objective of this study was to further analyze whether, and to what extent, use of metformin is associated with a decreased risk of cancer in a cohort of incident users of metformin compared with users of sulfonylurea derivatives. RESEARCH DESIGN AND METHODS Data for this study were obtained from dispensing records from community pharmacies individually linked to hospital discharge records from 2.5 million individuals in the Netherlands. The association between the risk of cancer in those using metformin compared with those using sulfonylurea derivatives was analyzed using Cox proportional hazard models with cumulative duration of drug use as a time-varying determinant. RESULTS Use of metformin was associated with a lower risk of cancer in general (hazard ratio 0.90 [95% CI 0.88–0.91]) compared with use of sulfonylurea derivatives. When specific cancers were used as end points, similar estimates were found. Dosage-response relations were identified for users of metformin but not for users of sulfonylurea derivatives. CONCLUSIONS In our study, cumulative exposure to metformin was associated with a lower risk of specific cancers and cancer in general, compared with cumulative exposure to sulfonylurea derivatives. However, whether this should indeed be seen as a decreased risk of cancer for the use of metformin or as an increased risk of cancer for the use sulfonylurea derivatives remains to be elucidated.

Common NOS1AP Variants Are Associated With a Prolonged QTc Interval in the Rotterdam Study

Background— QT prolongation is an important risk factor for sudden cardiac death. About 35% of QT-interval variation is heritable. In a recent genome-wide association study, a common variant (rs10494366) in the nitric oxide synthase 1 adaptor protein (NOS1AP) gene was found to be associated with QT-interval variation. We tested for association of 2 NOS1AP variants with QT duration and sudden cardiac death. Methods and Results— The Rotterdam Study is a population-based, prospective cohort study of individuals ≥55 years of age. The NOS1AP variants rs10494366 T>G and rs10918594 C>G were genotyped in 6571 individuals. Heart rate–corrected QT interval (QTc) was determined with ECG analysis software on up to 3 digital ECGs per individual (total, 11108 ECGs from 5374 individuals). The association with QTc duration was estimated with repeated-measures analyses, and the association with sudden cardiac death was estimated by Cox proportional-hazards analyses. The rs10494366 G allele (36% frequency) was associated with a 3.8-ms (95% confidence interval, 3.0 to 4.6; P=7.8×10−20) increase in QTc interval duration for each additional allele copy, and the rs10918594 G allele (31% frequency) was associated with a 3.6-ms (95% confidence interval, 2.7 to 4.4; P=6.9×10−17) increase per additional allele copy. None of the inferred NOS1AP haplotypes showed a stronger effect than the individual single-nucleotide polymorphisms. There were 233 sudden cardiac deaths over 11.9 median years of follow-up. No significant association was observed with sudden cardiac death risk. Conclusions— Common variants in NOS1AP are strongly associated with QT-interval duration in an elderly population. Larger sample sizes are needed to confirm or exclude an effect on sudden cardiac death risk.

The incidence of sudden cardiac death in the general population

BACKGROUND AND OBJECTIVES To determine the incidence of sudden cardiac death in a general (Dutch) population. METHODS Cohort study in the Integrated Primary Care Information (IPCI) project, a database with all medical data from 150 general practices in The Netherlands. The study population comprised 249,126 subjects with a mean follow-up of 2.54 years. RESULTS In this period 4,892 deaths were identified, 582 of which were classified as (probable) sudden cardiac death. The overall incidence of sudden cardiac death in this population was 0.92 cases per 1,000 person-years (95%CI: 0.85-0.99). The risk was 2.3-fold higher in men than in women, and increased with age. The incidence of sudden cardiac death peaked in October and was lowest in August. CONCLUSIONS The incidence of sudden cardiac death in the general Dutch population was almost 1 per 1,000 person-years per year during the period 1 January, 1995 to 1 April, 2001. Most of the cases occurred at home.

Psychotropic drugs associated with corrected QT interval prolongation

Aims: To study whether listed putative corrected QT (QTc)-prolonging psychotropic drugs indeed prolong the QTc interval under everyday circumstances and to evaluate whether this is a class effect or an individual drug effect, we conducted a prospective population-based cohort study. Methods: This study was conducted as part of the Rotterdam Study and included 3377 men and 4845 women (≥55 years) who had triennial electrocardiograms (ECGs). The primary end points of the study were the length of the QTc interval at each ECG, the difference in QTc interval between consecutive ECGs within one person, and the risk of an abnormally prolonged QTc interval. Drug use at the index date was obtained from automated dispensing records. The associations were examined by means of a repeated measurement analysis, adjusted for age, sex, diabetes mellitus, hypertension, myocardial infarction, heart failure, and use of class 1 QTc-prolonging drugs. Results: Of the 8222 participants, 813 participants (9.9%) developed QTc prolongation during follow-up and 492 participants (74.4% women) used psychotropic drugs at the time of an ECG. Starting tricyclic antidepressants increased the QTc interval significantly with 6.9 milliseconds (95% confidence interval [CI], 3.1-10.7 milliseconds) between consecutive ECGs in comparison with consecutive ECGs of participants not using tricyclic antidepressants, in particular starting amitriptyline (8.5 milliseconds; 95% CI, 2.8-14.2 milliseconds), maprotiline (13.9 milliseconds; 95% CI, 3.6-24.3 milliseconds), and nortriptyline (35.3 milliseconds; 95% CI, 8.0-62.6 milliseconds). Starting lithium also increased the QTc interval significantly (18.6 milliseconds; 95% CI, 4.8-32.4 milliseconds). Conclusions: In this population-based prospective cohort study, we confirmed the importance of antidepressants and antipsychotics as potential contributors to QTc prolongation. Especially, starting tricyclic antidepressant drugs (as a class) is associated with a significant intraindividual increase in the QTc interval in comparison to the change in nonusers. The tricyclic antidepressants seem to prolong the QTc interval as a class effect.

Use of Dipeptidyl Peptidase-4 Inhibitors and the Reporting of Infections: A Disproportionality Analysis in the World Health Organization VigiBase

OBJECTIVE Dipeptidyl peptidase-4 (DPP-4) inhibitors are a new class of antidiabetic drugs. They inactivate incretin hormones but also have many other effects throughout the body, among which are effects on the immune system. This might result in an increased infection risk. This study assessed the association between use of DPP-4 inhibitors and the reporting of infections. RESEARCH DESIGN AND METHODS A nested case-control was conducted using VigiBase, the World Health Organization-Adverse Drug Reactions (WHO-ADR) database. The base cohort consisted of ADRs for antidiabetic drugs (Anatomical Therapeutic Chemical code A10). Cases were defined as ADRs of infection according to the Medical Dictionary for Regulatory Activities (MedDRA) classification system. All other ADRs were considered controls. Reporting odds ratios (RORs) were calculated to estimate the strength of the association between different classes of antidiabetic drugs and the reporting of infections. RESULTS We identified 305,415 suspected ADRs involving antidiabetic drugs in 106,469 case reports, of which 8,083 involved DPP-4 inhibitors monotherapy. Overall, the reporting of infections was higher for patients using DPP-4 inhibitors compared with users of biguanides (ROR 2.3 [95% CI 1.9–2.7]). Reporting of upper respiratory tract infections (ROR 12.3 [95% CI 8.6–17.5]) was significantly associated with use of DPP-4 inhibitors. CONCLUSIONS This study indicates an increased reporting of infections, in particular upper respiratory tract infections, for users of DPP-4 inhibitors compared with users of other antidiabetic drugs. However, the limitations of spontaneous reporting systems (e.g., underreporting, the Weber-effect, reporting bias) should be taken into account. Therefore, further research is needed to evaluate this suspicion and the underlying mechanism.

Impact of Safety-Related Regulatory Action on Clinical Practice A Systematic Review

AbstractBackground: After market approval, new serious safety issues are regularly identified for drugs that lead to regulatory action to inform healthcare professionals. However, the effectiveness of these safety-related regulatory actions is under question. We currently lack a comprehensive overview of the effects of these drug safety warnings on clinical practice to resolve the debate about their effectiveness. Objective: The aim of this systematic review is to provide an overview of studies that assessed the impact of safety warnings. Study Selection: A systematic search was performed for articles assessing the impact of Direct Healthcare Professional Communications or ‘Dear Doctor’ letters, Black Box Warnings and Public Health Advisories on clinical behaviour published between January 1996 and January 2010. The following variables were extracted: publication year, country, name of the drug, safety issue, specific safety warning (Direct Healthcare Professional Communication/Black Box Warning/Public Health Advisory), effect (intended/unintended) of the safety warning, outcome measure and study design. Papers were checked for several quality aspects. Study data were summarized using descriptive analyses. Results: A total of 50 articles were identified. Two articles assessed two different drugs and were therefore counted twice (n = 52). Thirty-three articles described the impact of safety warnings issued for three drugs and drug groups, i.e. third-generation oral contraceptives, cisapride and selective serotonin reuptake inhibitors. The remaining 19 articles described a broad variety of 14 drugs and drug groups. Twenty-five studies applied an interrupted time series design, 23 a controlled or uncontrolled before/after design, and four articles applied both. None of the articles could rule out the influence of confounding factors. The intended effects were reported in 18 (72%) of the 25 before/after analyses, whereas only 11 (41%) of the 27 interrupted time series analyses reported an impact. Only two (8%) of the before/after analyses against 11 (41%) of the interrupted time series analyses reported mixed impacts. When unintended effects were assessed in case of selective serotonin reuptake inhibitors and third-generation oral contraceptives, these were almost always present: in 19 of 22 and 4 of 5 articles, respectively. Our review shows that safety-related regulatory action can have some impact on clinical practice but firm conclusions are difficult to draw. Evidence is primarily based on three drugs and drug groups. Almost half of the studies had inadequate before/after designs and the heterogeneity in analyses and outcome measures hampered the reporting of overall effect sizes. Studies with adequate interrupted time series design reported a more mixed impact of safety warnings than before/after studies. Furthermore, this review shows the relevance of considering not only the intended but also the unintended effects of safety warnings. Conclusions: There is a clear need for further research with appropriate study designs and statistical analyses, with more attention to confounding factors such as media coverage, to understand the impact of safety-related regulatory action.

Evaluation of post-authorization safety studies in the first cohort of EU Risk Management Plans at time of regulatory approval.

AbstractBackgound: Since November 2005, an EU Risk Management Plan (EU-RMP) has had to be submitted as part of a marketing application for all new chemical entities in the EU. In the EU-RMP, the safety profile of the medicine has to be described and pharmacovigilance activities should be proposed to study further safety concerns during use of the drug in the real-world setting. These activities include, for example, collection of spontaneously reported adverse events and post-authorization safety studies (PASS). Since the submission of an EU-RMP is a relatively new requirement, there is limited knowledge on the quality and completeness of the study protocols of PASS at the time of approval and there are no data on the influence of certain drug characteristics on the proposed pharmacovigilance activities. Objective: To examine the types of proposed pharmacovigilance activities in a sample of EU-RMPs, describe and evaluate the methodology of PASS, identify problems and propose remedies, and compare characteristics between biologicals and small molecules. Methods: Eighteen EU-RMPs (nine for biologicals, nine for small molecules) given a positive decision regarding the marketing application by the Committee for Medicinal Products for Human Use between November 2005 and May 2007 were included in this descriptive cohort study. The EU-RMPs were selected over time and different therapeutic areas. Classification of the safety concerns (‘important identified risks’, ‘important potential risks’, ‘important missing information’ within the EU-RMP was studied. For PASS, data source (registry, population-based database, sponsor-owned clinical trial database), source of study population to be included in PASS and comprehensiveness of study protocol (full protocol, limited protocol, study synopsis, short description, commitment without further information) were studied. Results: Compared to small molecules, safety concerns for biologicals were less frequently classified as important identified risks (relative risk [RR] 0.6; 95% CI 0.3, 1.0) and more frequently as important missing information (RR 1.6; 95% CI 1.0, 2.7).Forty-seven PASS were proposed; 31 for biologicals and 16 for small molecules. Compared with studies proposed in population-based databases (4 for biologicals, 8 for small molecules), studies in registries (18 for biologicals, 4 for small molecules) were more frequently proposed for biologicals than for small molecules (RR 2.5; 95% CI 1.1, 5.7). About 60% of the proposed PASS will include EU inhabitants. No full study protocols were submitted; 26% involved a limited study protocol, 33% a study synopsis, 37% a short description and 4% a commitment without further information. Conclusion: Approximately 40% of the study proposals for PASS were classified as a short description or a commitment to perform a study without further information, precluding an adequate scientific assessment. Study ing non-EU populations may give rise to difficulties with generalizability of the results to the EU due to differences in patient characteristics, differences in the indication for the medicine and different healthcare systems. This study emphasizes the need for more complete study proposals to be submitted earlier on in the evaluation period and for the inclusion of EU inhabitants in PASS. In addition, differences in the characteristics between biologicals and small molecules, e.g. in the data source proposed, support the need for individualized tailored PASS depending on the type of drug.

A Decade of Safety-Related Regulatory Action in the Netherlands A Retrospective Analysis of Direct Healthcare Professional Communications from 1999 to 2009

Background: As pre-approval trials are inherently limited in assessing the complete benefit-risk profile of a new drug, serious safety issues may emerge once a drug gains widespread use after approval. Regulators face the dilemma of balancing timely market access with the need for complete data on risks. This challenge has led to a life-cycle approach but, so far, few data are available on post-approval safety issues requiring regulatory action.Objective: The aim of this study is to determine the frequency, timing and nature of safety issues that necessitated safety-related regulatory action in the form of a Direct Healthcare Professional Communication (DHPC) issued by pharmaceutical companies in collaboration with the Dutch Medicines Evaluation Board during the past decade.Methods: All DHPCs issued in the Netherlands from 1 January 1999 to 1 January 2009 were retrospectively collected from the national regulatory authorities. Elapsed time between the approval date and the issue of the DHPC was determined. Characteristics of the action including the nature of the safety issue (according to Medical Dictionary for Regulatory Activities [MedDRA®] terminology), type of drug and procedural aspects of the regulatory action taken were reviewed. DHPC characteristics were tabulated and explorative non-parametric tests were performed to study the effect of safety issue, drug class, drug type, orphan drug and first-in-class status on elapsed time from approval to the DHPC.Results: 157 DHPCs were issued concerning 112 different active substances, approximately 9% (112/1200) of active substances available in the Netherlands in 2007. The number of DHPCs issued increased by 2.1 (95% CI 1.2, 3.1; p< 0.001) DHPCs per year over the past decade, reaching a total of 25 in 2008. The median time between approval and DHPC was 5.3 years (range 0.13-48 years). No significant trend in elapsed time to DHPC was observed in relation to the studied years (p = 0.06). One-third of all DHPCs were issued in the first 3 years after approval, but 27% (n=43/157) of the DHPCs were issued 10 or more years after approval. Timing of DHPCs differed depending on safety issue, drug class, drug type and orphan drug status. DHPCs mostly concerned adverse events in the system organ class of ‘cardiac disorders’ (15%), ‘injury, poisoning and procedural complications’ (13%) and ‘general disorders and administration site conditions’ (10%). In ten cases the drug was eventually withdrawn. Withdrawal occurred a median duration of 2.4 years after registration (range of 1.5–48 years) and was most frequently due to cardiac disorders (including QT interval prolongation; four occasions) and hepatobiliary disorders (two occasions).Conclusions: In the past decade, the number of DHPCs has increased over time. This is likely caused by a multitude of factors: increased risk awareness by the public, media, regulators and other stakeholders; the type of drugs approved, such as orphan drugs and biologicals; and the regulatory process, including conditional approvals. The number of DHPCs may in the future increase further with the possibility of screening large epidemiological databases proactively for adverse drug events. Nine percent of all marketed drugs required a safety-related action. Regulatory action is taken shortly (<3 years) after market approval nearly as often as after intermediate (3–10 years) and long-term (>10 years) market exposure. These findings underline the need for risk management during the whole life cycle of a drug.

Compliance with pregnancy prevention programmes of isotretinoin in Europe: a systematic review

Most of the publications on isotretinoin, pregnancy and compliance with the pregnancy prevention programme (PPP) originate from North America. Information specific for the European situation is very limited. The aim of this study was to identify publications describing the use of isotretinoin in humans and the compliance with the PPP in Europe, a systematic search in Medline and Embase was conducted using the terms ‘isotretinoin, pregnancy (and Europe)’. Furthermore, a manual search in publications was performed. A total of 17 publications were identified. Publications consisted of case reports of exposed pregnancies, surveys among dermatologists or pharmacists and database studies evaluating compliance with the PPP. The studies and surveys dealt with groups of patients exposed to isotretinoin before or during pregnancy and/or compliance with the isotretinoin PPP. Where the information was provided, in 6–26% of cases isotretinoin was prescribed in full accordance with the PPP. Pregnancy incidence was seen in 0·2–1·0 per 1000 women of childbearing age using isotretinoin. Between 65% and 87% of these pregnancies were terminated. This review of studies in Europe performed to date shows failures in the implementation of the PPP. Therefore, the isotretinoin PPP must be scrutinized to identify whether new measures should be taken or whether the failures in the implementation need to be corrected. New measures should take into account the definition of the ultimate goal of a PPP and the acceptable burden. In the meantime, stakeholders could make a start with adjustments in the implementation of the PPP by taking responsibility and enhancing the performance by explicit instructions, monitoring the performance and adjusting, if necessary.