EMA Recommendation for the Pediatric Indications of Plerixafor (Mozobil) to Enhance Mobilization of Hematopoietic Stem Cells for Collection and Subsequent Autologous Transplantation in Children with Lymphoma or Malignant Solid Tumors.

On March 28, 2019, the Committee for Medicinal Products for Human Use adopted a positive opinion recommending the marketing authorization for the medicinal product plerixafor. The marketing authorization holder for this medicinal product is Genzyme Europe B.Th. The adoption was for an extension of the existing adult indication in combination with granulocyte colony-stimulating factor (G-CSF) to pediatric patients (aged 1 year to <18 years) to enhance mobilization of hematopoietic stem cells to the peripheral blood for collection and subsequent autologous transplantation in children with lymphoma or solid malignant tumors. This treatment is indicated either preemptively, when circulating stem cell count on the predicted day of collection after adequate mobilization with G-CSF (with or without chemotherapy) is expected to be insufficient with regard to desired hematopoietic stem cells yield, or in children who previously failed to collect sufficient hematopoietic stem cells. The efficacy and safety of plerixafor were evaluated in an open label, multicenter, phase I/II, dose-ranging, and randomized controlled study (DFI12860) in pediatric patients with solid tumors, including neuroblastoma, sarcoma, Ewing sarcoma, or lymphoma, who were eligible for autologous hematopoietic stem cell transplantation. Forty-five patients (aged 1 year to <18 years) were randomized, 2:1, using 0.24 mg/kg of plerixafor plus standard mobilization (G-CSF with or without chemotherapy) versus control (standard mobilization alone). The primary analysis showed that 80% of patients in the plerixafor arm experienced at least a doubling of the peripheral blood (PB) CD34+ count, observed from the morning of the day preceding the first planned apheresis to the morning prior to apheresis, versus 28.6% of patients in the control arm (p = .0019). The median increase in PB CD34+ cell counts from baseline to the day of apheresis was 3.2-fold in the plerixafor arm versus by 1.4-fold in the control arm. The observed safety profile in the pediatric population was consistent with that in adults, with adverse events mainly related to injection site reactions, hypokalemia, and increased blood bicarbonate. Importantly, plerixafor exposure did not seem to negatively affect transplant efficiency. This article summarizes the scientific review of the application leading to regulatory approval in the European Union. IMPLICATIONS FOR PRACTICE: This review of the marketing authorization of plerixafor will raise awareness of pediatric indication granted for this medicinal product.

Navigating stormy waters: 10 years of operation of the European Union Regulatory Network Incident Management Plan for Medicines for Human Use.

PURPOSE: The article provides an overview of the European Union Incident Management plan (EU-IMP) and reviews its first 10 years of operation. It outlines its scope, objectives, triggers, principles, and components. METHODS: Records were extracted from the European Pharmacovigilance Issues Tracking Tool and a separate tracking system for the period August 20, 2009 to August 19, 2019. RESULTS: During the 10 years of observation, 78 incidents were reviewed by the Incident Review Network and addressed through routine measures. Their number has varied throughout the years with a significant decrease after 2012. Incidents mainly covered safety (56%) and quality (34%) issues or a combination thereof (5%). The majority (70%) were notified by EU regulators and involved centrally and nationally authorized product in similar proportions. A referral was recommended as the assessment pathway for 47% of the issues while lines-to-take were the most frequent communication measure (the sole measure in 65% cases). Forty-six per cent of the issues resulted in a variation, whereas 22% resulted in maintenance of the marketing authorization. CONCLUSION: The EU-IMP is underpinned by a robust regulatory framework with defined processes and clear roles and responsibilities and offers a platform to coordinate actions and communication at EU level, rapidly pool expertise, minimize duplications, and address public health incidents.

Is patient exposure preapproval and postapproval a determinant of the timing and frequency of occurrence of safety issues?

BACKGROUND: The amount of drug exposure, pre and post approval, is considered to be a direct determinant of knowledge about the safety of a drug. A larger pre-approval exposed population is supposed to reduce the risk of unanticipated safety issues post-approval. The amount of use in the postapproval population is also expected to influence the occurrence and timing of safety issues. We investigated how the amount of pre and post approval exposure influences the detection of post-approval safety issues. METHODS: A cohort of innovative drugs approved in Europe was followed for the period of 2012-2016. The main outcome of interest was a new safety issue in the period. Post-approval exposure was collected at 6 month intervals, and pre-approval exposure was collected at the moment of authorisation. Other characteristics collected for the included drugs were anatomical therapeutical chemical (ATC) class, biological status, orphan status and type of approval. We used Cox proportional hazards regression to investigate the association between exposure and the hazard of having a first safety issue. RESULTS: The pre-approval exposure was not associated with the risk of safety issues after adjusting for ATC class, biological status, and treatment duration. Higher post-approval exposure was associated with more new safety issues identified (HR = 2.44 (95% CI = 1.12-5.31)) for drugs with more than 1,000 patient-years of cumulative exposure compared to drugs with less than 1,000 patient years of exposure. CONCLUSION: Our results suggest that postapproval exposure influences the detection of safety issues.

Latest clinical recommendations on valproate use for migraine prophylaxis in women of childbearing age: overview from European Medicines Agency and European Headache Federation.

Migraine is a common and burdensome neurological condition which affects mainly female patients during their childbearing years. Valproate has been widely used for the prophylaxis of migraine attacks and is also included in the main European Guidelines. Previous (2014) European recommendations on limiting the use of valproate in women of childbearing age did not achieve their objective in terms of limiting the use of valproate in women of childbearing age and raising awareness regarding the hazardous effect of valproate to children exposed in utero. The teratogenic and foetotoxic effects of valproate are well documented, and more recent studies show that there is an even greater neurodevelopmental risk to children exposed to valproate in the womb. The latest 2018 European review from the European Medicines Agency, with the active participation of the European Headache Federation, concluded that not enough has been done to mitigate the risks associated with in utero exposure to valproate. The review called for more extensive restrictions to the conditions for prescribing, better public awareness, and a more effective education campaign in migrainous women.

Decision making in drug safety-a literature review of criteria used to prioritize newly detected safety issues.

PURPOSE: In drug safety, there is a lack of guidance on how prioritization of safety issues should be performed. The aim of this literature review is to provide an overview of criteria used for signal prioritization and of the associated decision support frameworks. METHODS: A search strategy was constructed to identify relevant articles in Medline/Embase databases from the period from 1 January 1995 to 31 August 2015. The prioritization criteria were extracted and classified in relevant categories. RESULTS: From an initial set of 63 articles, 11 were retained for full review. The articles mentioned 48 criteria used in the prioritization process, with a median of six criteria per study [range: 1-16]. More than half of the criteria (63%), referred to strength of evidence while 19% related to public health impact, 14% to general public and media attention and 4% to novelty of the drug event association. Fifteen criteria were tested for predictive value with 11 showing positive results, most of them from the strength of evidence category. Six decision-making frameworks are presented, which incorporate criteria from various categories. Five of these frameworks were tested against expert decisions or by other means, but only in one database each and for a limited set of products. CONCLUSIONS: There is a wide range of prioritization criteria described in the literature; however, few of them demonstrated predictive value. Many criteria with predictive value were related to strength of evidence category and to novelty. There were few attempts at integrating different criteria in decision support frameworks. Five of the frameworks were tested for validity and showed usefulness, while at least three are already in use for prioritization. Copyright © 2016 John Wiley & Sons, Ltd.

Baseline incidence of intussusception in early childhood before rotavirus vaccine introduction, the Netherlands, January 2008 to December 2012.

Intussusception is a rare, potentially life-threatening condition in early childhood. It gained attention due to an unexpected association with the first rotavirus vaccine, RotaShield, which was subsequently withdrawn from the market. Across Europe, broad variations in intussusception incidence rates have been reported. This study provides a first estimate of intussusception incidence in young children in the Netherlands from 1 January 2008 to 31 December 2012, which could be used for future rotavirus safety monitoring. Our estimates are based on two different sources: electronic medical records from the primary healthcare database (IPCI), as well as administrative data from the Dutch hospital register (LBZ). The results from our study indicate a low rate of intussusception. Overall incidence rate in children < 36 months of age was 21.2 per 100,000 person-years (95% confidence interval (CI): 12.5-34.3) based on primary healthcare data and 22.6 per 100,000 person-years (95% CI: 20.9-24.4) based on hospital administrative data. The estimates suggest the upper and lower bound of the expected number of cases.

The effect of exposure misclassification in spontaneous ADR reports on the time to detection of product-specific risks for biologicals: a simulation study.

BACKGROUND AND OBJECTIVE: The availability of accurate product-specific exposure information is essential in the pharmacovigilance of biologicals, because differences in the safety profile may emerge between products containing the same active substance. In spontaneous adverse drug reaction (ADR) reports, drug exposure may, however, be misclassified, that is, attributed to the incorrect product. The aim of this study was to explore the effect of exposure misclassification on the time to detection of product-specific risks in spontaneous reporting systems. METHODS: We used data simulations to explore the effect of exposure misclassification. We simulated an active substance-specific subset of a spontaneous reporting system and used the proportional reporting ratio for signal detection. The effect of exposure misclassification was evaluated in three test cases representing product-specific ADRs that may occur for biologicals and studied in relative terms by varying the model parameters (market share and relative risk). RESULTS: We found that exposure misclassification results in the largest delay in identification of risks that have a weak association (relative risk < 2 or 3) with the product of interest and in situations where the product associated with the unique risk has a large (>50%) market share. The absolute public health impact of exposure misclassification, in terms of cases/time to detection, varied considerably across the test cases. CONCLUSION: Exposure misclassification in ADR reports may result in a delayed detection of product-specific risks, particularly in the detection of weak drug-event associations. Our findings can help inform the future implementation and refinement of product-specific and batch-specific signal detection procedures.

Understanding drug preferences, different perspectives.

AIMS: To compare the values regulators attach to different drug effects of oral antidiabetic drugs with those of doctors and patients. METHODS: We administered a 'discrete choice' survey to regulators, doctors and patients with type 2 diabetes in The Netherlands. Eighteen choice sets comparing two hypothetical oral antidiabetic drugs were constructed with varying drug effects on glycated haemoglobin, cardiovascular risk, bodyweight, duration of gastrointestinal complaints, frequency of hypoglycaemia and risk of bladder cancer. Responders were asked each time which drug they preferred. RESULTS: Fifty-two regulators, 175 doctors and 226 patients returned the survey. Multinomial conditional logit analyses showed that cardiovascular risk reduction was valued by regulators positively (odds ratio 1.98, 95% confidence interval 1.11-3.53), whereas drug choices were negatively affected by persistent gastrointestinal problems (odds ratio 0.24, 95% confidence interval 0.14-0.41) and cardiovascular risk increase (odds ratio 0.49, 95% confidence interval 0.27-0.87). Doctors and patients valued these effects in a similar manner to regulators. The values that doctors attached to large changes in glycated haemoglobin and that both doctors and patients attached to hypoglycaemia and weight gain also reached statistical significance. No group's drug choice was affected by a small absolute change in risk of bladder cancer when presented in the context of other drug effects. When comparing the groups, the value attached by regulators to less frequent hypoglycaemic episodes was significantly smaller than by patients (P = 0.044). CONCLUSIONS: Regulators may value major benefits and risks of drugs for an individual diabetes patient mostly in the same way as doctors and patients, but differences may exist regarding the value of minor or short-term drug effects.

The role of electronic healthcare record databases in paediatric drug safety surveillance: a retrospective cohort study.

AIM: Electronic healthcare record (EHR)-based surveillance systems are increasingly being developed to support early detection of safety signals. It is unknown what the power of such a system is for surveillance among children and adolescents. In this paper we provide estimates of the number and classes of drugs, and incidence rates (IRs) of events, that can be monitored in children and adolescents (0-18 years). METHODS: Data were obtained from seven population-based EHR databases in Denmark, Italy, and the Netherlands during the period 1996-2010. We estimated the number of drugs for which specific adverse events can be monitored as a function of actual drug use, minimally detectable relative risk (RR) and IRs for 10 events. RESULTS: The population comprised 4 838 146 individuals (25 575 132 person years (PYs)), who were prescribed 2170 drugs (1 610 631 PYs drug-exposure). Half of the total drug-exposure in PYs was covered by only 18 drugs (0.8%). For a relatively frequent event like upper gastrointestinal bleeding there were 39 drugs for which an association with a RR ≥4, if present, could be investigated. The corresponding number of drugs was eight for a rare event like anaphylactic shock. CONCLUSION: Drug use in children is rare and shows little variation. The number of drugs with enough exposure to detect rare adverse events in children and adolescents within an EHR-based surveillance system such as EU-ADR is limited. Use of additional sources of paediatric drug exposure information and global collaboration are imperative in order to optimize EHR data for paediatric safety surveillance.

Long-term use of 5α-reductase inhibitors and the risk of male breast cancer.

BACKGROUND: The 5α-reductase inhibitors (5-ARI) finasteride and dutasteride are indicated for the treatment of lower urinary tract symptoms caused by benign prostatic hyperplasia. Case reports have suggested that 5-ARIs increase the risk for male breast cancer, with no conclusive evidence. The objective of this study was to quantify the association between use of 5-ARIs and the risk for male breast cancer. METHODS: A case-control study was conducted with data from the United Kingdom Clinical Practice Research Datalink database among all men aged 45 years and older in the period 1 January 1992 to 31 December 2011. Cases of men diagnosed with breast cancer were matched to up 10 controls on age and general practice. Crude and adjusted odds ratios were estimated for the risk of breast cancer associated with the use of 5-ARIs. RESULTS: Three hundred and ninety-eight cases were identified and matched to 3,930 controls. Ever use of 5-ARIs was associated with an adjusted odds ratio for breast cancer of 1.08 (95 % CI 0.62-1.87) compared to non-users. Increasing cumulative duration of treatment showed no increasing risks: adjusted odds ratios for use for less than 280, for 280 to 1,036 and for more than 1,036 days were 1.21 (95 % CI 0.47-3.10), 0.94 (95 % CI 0.36-2.41) and 1.29 (95 % CI 0.54-3.08), respectively. CONCLUSIONS: In this study, there was no evidence of an association between short- or long-term treatment with 5-ARIs and the risk for breast cancer in older men.

COVID-19 Vaccines and Heavy Menstrual Bleeding: The Impact of Media Attention on Reporting to EudraVigilance.

BACKGROUND AND OBJECTIVE: During the COVID-19 vaccination campaign, over 34,000 reports of heavy menstrual bleeding following the administration of COVID-19 vaccines originating in the Economic European Area were submitted to EudraVigilance, the European Union database of suspected adverse drug reactions. More than 90% of these reports were sent by consumers while the remaining by healthcare professionals. Public concerns regarding menstruation disorders in COVID-19 vaccinees were also covered by the media. We investigated the impact of media attention on the reporting trends of heavy menstrual bleeding to EudraVigilance. METHODS: We used media outlets published in the Economic European Area on menstrual disorders and COVID-19 vaccines from the beginning of the vaccination campaign in the Economic European Area (1 January, 2021) until December 2022 (i.e., after the regulatory request to add the adverse event to the product information) and spontaneous reports from EudraVigilance. RESULTS: We found that the publication of safety updates from regulatory authorities and subsequent coverage in media outlets preceded increased reporting to EudraVigilance. Furthermore, the heavy menstrual bleeding reported in the cases occurred several weeks or months earlier and were not submitted to the respective date. The analysis suggests that the spikes in reporting of heavy menstrual bleeding were to some extent influenced by media coverage in some countries. CONCLUSIONS: Consumer reporting to the European Union spontaneous data collection system, EudraVigilance, was of high value for regulatory safety reviews, albeit the reporting behaviours were not free of the influence of the media. These sources of information can be investigated to understand the context of safety concerns of public health interest.

The Role of the European Medicines Agency in the Safety Monitoring of COVID-19 Vaccines and Future Directions in Enhancing Vaccine Safety Globally.

The European Union (EU) regulatory network was at the forefront of the safety monitoring of COVID-19 vaccines during the pandemic. An unprecedented number of case reports of suspected adverse reactions after vaccination called for huge efforts for the assessment of this safety information, to ensure that any possible risks were detected and managed as early as possible, while ruling out coincidental but temporally related adverse health outcomes. We describe the role of the European Medicines Agency alongside the EU regulatory network in the safety monitoring of the COVID-19 vaccines, and provide an insight into challenges, particularities and outcomes of the scientific assessment and regulatory decisions in the complex, dynamic international environment of the pandemic. We discuss the flexible procedural tools that were used to ensure an expedited scientific assessment of safety issues, and subsequent updates of the product information (i.e., labelling) when available evidence (e.g., spontaneous reports, findings from observational studies and/or scientific literature) suggested that causal association is at least a reasonable possibility. The safety monitoring was accompanied by enhanced transparency measures, proactive communication, and easy access to information, which played a key role in public reassurance. The pandemic has been a powerful booster for worldwide collaboration, exchange of information and work-sharing. The safety monitoring of COVID-19 vaccines continues, and the lessons learned will be applied in future safety reviews, as well as future health emergencies.

Real-World Evidence to Support EU Regulatory Decision Making-Results From a Pilot of Regulatory Use Cases.

Studies using real-world data (RWD) can complement evidence from clinical trials and fill evidence gaps during different stages of a medicine's lifecycle. This review presents the experience resulting from the European Medicines Agency (EMA) pilot to generate RWE to support evaluations by EU regulators and down-stream decision makers from September 2021 to February 2023. A total of 61 research topics were identified for RWE generation during this period, covering a wide range of research questions, primarily generating evidence on medicines safety (22, 36%), followed by questions on the design and feasibility of clinical trials (11, 18%), drug utilization (10, 16%), clinical management (10, 16%), and disease epidemiology. A significant number of questions were related to the pediatric population and/or rare diseases. A total of 27 regulatory-led RWD studies have been conducted. Most studies were descriptive and aimed at estimating incidence and prevalence rates of clinical outcomes including adverse events or to evaluate medicines utilization. The review highlights key learnings to guide further efforts to enable the use and establish the value of real-world evidence (RWE) for regulatory decisions. For instance, there is a need to access additional fit-for-purpose and representative data, and to explore further means to provide timely evidence that meets regulatory timelines. The need for early interactions and close collaboration with study requesters, e.g., from the Agency's scientific Committees, to better understand the research question is equally important. Finally, the review provides our perspective on the way forward to maximize the potential of regulatory-led RWE generation.

Number of patients studied prior to approval of new medicines: a database analysis.

BACKGROUND: At the time of approval of a new medicine, there are few long-term data on the medicine's benefit-risk balance. Clinical trials are designed to demonstrate efficacy, but have major limitations with regard to safety in terms of patient exposure and length of follow-up. This study of the number of patients who had been administered medicines at the time of medicine approval by the European Medicines Agency aimed to determine the total number of patients studied, as well as the number of patients studied long term for chronic medication use, compared with the International Conference on Harmonisation's E1 guideline recommendations. METHODS AND FINDINGS: All medicines containing new molecular entities approved between 2000 and 2010 were included in the study, including orphan medicines as a separate category. The total number of patients studied before approval was extracted (main outcome). In addition, the number of patients with long-term use (6 or 12 mo) was determined for chronic medication. 200 unique new medicines were identified: 161 standard and 39 orphan medicines. The median total number of patients studied before approval was 1,708 (interquartile range [IQR] 968-3,195) for standard medicines and 438 (IQR 132-915) for orphan medicines. On average, chronic medication was studied in a larger number of patients (median 2,338, IQR 1,462-4,135) than medication for intermediate (878, IQR 513-1,559) or short-term use (1,315, IQR 609-2,420). Safety and efficacy of chronic use was studied in fewer than 1,000 patients for at least 6 and 12 mo in 46.4% and 58.3% of new medicines, respectively. Among the 84 medicines intended for chronic use, 68 (82.1%) met the guideline recommendations for 6-mo use (at least 300 participants studied for 6 mo and at least 1,000 participants studied for any length of time), whereas 67 (79.8%) of the medicines met the criteria for 12-mo patient exposure (at least 100 participants studied for 12 mo). CONCLUSIONS: For medicines intended for chronic use, the number of patients studied before marketing is insufficient to evaluate safety and long-term efficacy. Both safety and efficacy require continued study after approval. New epidemiologic tools and legislative actions necessitate a review of the requirements for the number of patients studied prior to approval, particularly for chronic use, and adequate use of post-marketing studies. Please see later in the article for the Editors' Summary.

Additional risk minimisation measures in the EU - are they eligible for assessment?

PURPOSE: "Additional" risk minimisation measures (aRMMs) can be necessary to optimise the benefit-risk balance of a drug. Evaluation of effectiveness of these measures has become mandatory with the new European Union (EU) pharmacovigilance legislation in force since July 2012. The aim of this study was to classify the aRMMs in the EU with a special emphasis on the possibilities to analyse the effectiveness of these aRMMs in existing electronic healthcare databases (EHDs). METHODS: European Public Assessment Reports were reviewed to identify key elements of the aRMMs. Researchers categorised the key elements based on the objectives, i.e. knowledge change or behavioural change and sub-categorised the behavioural changes. They assessed for each key element if it would be eligible for analysis in existing EHDs. RESULTS: 68 drugs with aRMMs contained 801 key elements of which 57% aimed at behavioural changes. 22% of all key elements, all aimed behavioural changes, were assessed eligible for analysis in existing EHDs. These mainly concerned recommendations targeted at healthcare professionals regarding drug prescription, e.g. dose recommendations, contraindications or the need to perform laboratory tests for patient monitoring. CONCLUSIONS: Only a limited proportion of key elements of the aRMMs could potentially be monitored in existing EHDs as these data sources cannot capture all the required data. Due to difference between existing EHDs, not necessarily all available EHDs are appropriate for every drug or aRMM. To facilitate rapid evaluation of aRMM implementation and timely adjustments, industry and regulatory authorities should agree well-defined key elements of aRMMs leading to unambiguous actions of the target group.

Duration of Effectiveness Evaluation of Additional Risk Minimisation Measures for Centrally Authorised Medicinal Products in the EU Between 2012 and 2021.

INTRODUCTION: In studies evaluating the effectiveness of additional risk minimisation measures (aRMMs), the need for speed must be properly balanced with the quality of the study. We assessed the duration of aRMM effectiveness evaluations, using additional pharmacovigilance activities, for centrally authorised medicinal products in the European Union. METHODS: We established a cohort of medicinal products with aRMMs at marketing authorisation (MA) that were centrally authorised from July 2012-December 2021 using the European Public Assessment Reports. Evaluation studies were identified from the Risk Management Plans at the time of MA. Subsequently, we retrieved protocols, final study reports, Pharmacovigilance Risk Assessment Committee (PRAC) assessment reports, and PRAC minutes. We calculated the probability of completing an effectiveness evaluation within 60 months after MA using time-to-event analyses. Besides, we compared the planned final report with the actual final report date. RESULTS: We identified 134 medicinal products authorised with aRMMs, of which almost half (n = 63, 47.0%) had an effectiveness evaluation study. The probability of an evaluation for a medicinal product being completed within 60 months after MA was 20.7% (95% CI 6.8-32.6). Regarding study design, the probability of completing a study was higher for cross-sectional studies when compared to cohort studies (p = 0.002). Moreover, 81.0% of studies were delayed when compared to their planned final report date. CONCLUSION: The probability of completing an aRMM effectiveness evaluation at time for renewal of the MA was only one in five. Furthermore, estimates of the duration of studies around MA are too optimistic, with the majority being delayed.

An Exploratory Study of the Impact of COVID-19 Vaccine Spontaneous Reporting on Masking Signal Detection in EudraVigilance.

INTRODUCTION: During the signal detection process, statistical methods are used to identify drug-event combinations (DECs) which are disproportionately reported when compared with other drugs and events in the entire database. We hypothesise that the high volume of COVID-19 vaccine adverse drug reaction (ADR) reports transmitted to EudraVigilance may have affected the performance of disproportionality statistics used in routine signal detection, potentially resulting in signals either being masked, or false associations being flagged as potential signals. OBJECTIVE: Our aim was to study the impact of COVID-19 vaccine spontaneous reporting on statistical signal detection in EudraVigilance. METHODS: We recalculated the reporting odds ratio (ROR) for signals that were previously discussed at the level of the Pharmacovigilance Risk Assessment Committee, or signals that were retrieved from EudraVigilance, by omitting COVID-19 vaccine reports from the standard ROR calculation and then comparing the lower confidence interval (LCI) of the recalculated ROR to the LCI of the actual ROR in EudraVigilance. RESULTS: In total, 52 signals for 38 active substances were reviewed. For 35 signals, the LCI of the recalculated ROR value was lower than the LCI of the actual ROR (suggesting that COVID-19 vaccine ADR reporting had a positive effect on the strength of the signal) while for 15 signals the LCI of the recalculated ROR value was higher than the LCI of the actual ROR (suggesting that COVID-19 vaccine ADR reporting had an attenuating effect on the strength of the signal). For two signals, no change in the ROR was observed. In our analysis, six significant results were found. Five DECs were found to be masked: bleomycin and immune thrombocytopenia (actual ROR LCI = 0.94, recalculated ROR LCI = 1.02), vortioxetine and heavy menstrual bleeding (actual ROR LCI = 0.3, recalculated ROR LCI = 1.06), caplacizumab and heavy menstrual bleeding (actual ROR LCI = 0.98, recalculated ROR LCI = 3.47), ziprasidone and amenorrhoea (actual ROR LCI = 0.84, recalculated ROR LCI = 1.67), and azacitidine and pericarditis (actual ROR LCI = 0.81, recalculated ROR LCI = 2.01). For the DEC of adalimumab and immune reconstitution inflammatory syndrome, the LCI of the actual ROR value was 1.14 and removing COVID-19 vaccine reporting resulted in an LCI of the recalculated ROR value of 0.94 (below threshold). CONCLUSIONS: We demonstrated five cases of masking and one case of false-positive association due to the influence of COVID-19 vaccine spontaneous reporting on the ROR. This suggests that the high number of adverse drug reaction reports for COVID-19 vaccines in EudraVigilance has the potential to affect routine statistical signal detection activities. The impact of COVID-19 vaccine ADR reports on current signal detection practices requires further evaluation and solutions to tackle masking issues in EudraVigilance may need to be developed.

Rituximab-induced thrombocytopenia: a cohort study.

The combined information of drug exposure and laboratory test results on an individual patient level obtained in daily clinical practice can add important information about the safety of a drug. Thrombocytopenia is a known adverse drug reaction of rituximab, which has already been identified during the preregistration trials, but knowledge on incidence and risk factors in clinical practice is limited. We, therefore, aimed to estimate the incidence and explore the risk factors for the development of rituximab-induced thrombocytopenia (a platelet count, <100 × 10(9) platelets/L) in clinical practice. Ninety patients were eligible for inclusion of which 27 developed thrombocytopenia (cumulative incidence, 30%) within 30 days after administration of rituximab and 18 patients developed grade 3/4 thrombocytopenia (cumulative incidence, 20%). Patients with and without thrombocytopenia were compared to explore risk factors. Patients with a relatively low platelet count (217 vs. 324 × 10(9) /L, P = 0.011) before administration of rituximab had a higher risk for the development of thrombocytopenia, and although not statistically significant, patients treated with rituximab within the oncology setting (OR, 4.7; 95% CI, 1.0-23.3), independent of concomitant use of cytostatics, as compared to the autoimmune diseases and patients with a high platelet distribution width (PDW) (16.1 vs. 15.8, P = 0.051). In conclusion, the incidence of rituximab-induced thrombocytopenia was higher than that identified during the clinical trials. Healthcare professionals should consider thrombocytopenia as a relevant reaction during treatment with rituximab. More frequent monitoring of the platelet count is especially advised in patients treated in the oncology indication and/or with a low platelet count and high PDW.

Prescriptive contraceptive use among isotretinoin users in the Netherlands in comparison with non-users: a drug utilisation study.

PURPOSE: To assess the compliance with the isotretinoin Pregnancy Prevention Programme (PPP) by evaluating the use of prescribed contraceptives among isotretinoin users. The PPP contains a requirement for the use of contraceptive methods for women of childbearing potential. METHODS: A drug utilisation study was performed using data from a drug prescription database (containing Dutch community pharmacy data) covering a population of 500 000 patients. Contraceptive use in female isotretinoin users and in a reference group of female non-isotretinoin users (aged 15-49 years) was compared using data from 1999 until 2006 in 2-year periods. Descriptive statistics were used. RESULTS: Of the female isotretinoin users (n = 651), 52%-54% filled prescriptions on contraceptives in strict accordance to the PPP, used before, during, and after discontinuation of isotretinoin, compared with 39%-46% in the reference group. A more liberal approach of a minimum of one prescription for a contraceptive method showed 61%-64% use of contraceptives among isotretinoin users. Similar patterns were seen when data were broken down in age groups. Furthermore, a higher proportion of female patients using isotretinoin prescribed by general practitioners used prescribed contraceptives compared with those receiving isotretinoin by specialists. CONCLUSION: Compliance with the contraceptive use according to a PPP for a teratogenic drug such as isotretinoin is 52%-64%, which is lower than anticipated. Reasons for the low compliance will need to be clarified before further measures can be taken.