Steven M. Belknap

Rituximab-associated hepatitis B virus (HBV) reactivation in lymphoproliferative diseases: meta-analysis and examination of FDA safety reports

BACKGROUND Rituximab has been associated with hepatitis B virus reactivation (HBV-R). However, the characteristics and scope of this association remain largely undefined. METHODS We completed a comprehensive literature search of all published rituximab-associated HBV-R cases and from the Food and Drug Administration (FDA) Adverse Event Reporting System (AERS) MedWatch database. Literature and FDA cases were compared for completeness, and a meta-analysis was completed. RESULTS One hundred and eighty-three unique cases of rituximab-associated HBV-R were identified from the literature (n = 27 case reports, n = 156 case series). The time from last rituximab to reactivation was 3 months (range 0-12), although 29% occurred >6 months after last rituximab. Within FDA data (n = 118 cases), there was a strong signal for rituximab-associated HBV-R [proportional reporting ratio = 28.5, 95% confidence interval (CI) 23.9-34.1; Empiric Bayes Geometric Mean = 26.4, 95% CI 21.4-31.1]. However, the completeness of data in FDA reports was significantly inferior compared with literature cases (P < 0.0001). Among HBV core antibody (HBcAb(+)) series, the pooled effect of rituximab-based therapy showed a significantly increased risk of HBV-R compared with nonrituximab-treated patients (odds ratio 5.73, 95% CI 2.01-16.33; Z = 3.33, P = 0.0009) without heterogeneity (χ(2) = 2.12, P = 0.5473). CONCLUSIONS The FDA AERS provided strong HBV-R safety signals; however, literature-based cases provided a significantly more complete description. Furthermore, meta-analysis of HBcAb(+) series identified a more than fivefold increased rate of rituximab-associated HBV-R.

A Randomized Controlled Trial of Filgrastim as an Adjunct to Antibiotics for Treatment of Hospitalized Patients with Community-Acquired Pneumonia

Because of the critical role of neutrophils in host defenses, it was hypothesized that stimulation of neutrophil production and function with Filgrastim would improve the outcome of hospitalized patients with community-acquired pneumonia. To test this hypothesis, a randomized, placebo-controlled, multicenter trial of Filgrastim (300 micrograms/day up to 10 days) as an adjunct to antibiotics was conducted for these patients. Outcome measures included time to resolution of morbidity (TRM, a composite measure of temperature, respiratory rate, blood oxygenation, and chest radiograph), 28-day mortality, length of stay, and adverse events. Filgrastim increased blood neutrophils 3-fold, but TRM, mortality, and length of hospitalization were not affected. Treatment, however, accelerated radiologic improvement and appeared to reduce serious complications (e.g., empyema, adult respiratory distress syndrome, and disseminated intravascular coagulation). Filgrastim administration was safe and well tolerated in these patients. Additional trials are needed to establish the value of this approach to treatment of infectious diseases.

Serious Adverse Cutaneous and Hepatic Toxicities Associated with Nevirapine Use by Non-HIV-Infected Individuals

BackgroundNevirapine is a nonnucleoside reverse transcriptase antiretroviral agent. Among HIV-infected individuals, rare instances (<1%) of serious cutaneous and hepatic toxicity have been reported. Because of its favorable pharmacokinetic profile, non–HIV-infected individuals have received nevirapine-containing postexposure prophylaxis (PEP). ObjectiveTo describe the clinical features of cutaneous and hepatic toxicity that occurred when nevirapine was administered to non–HIV-infected individuals. MethodsReports of nevirapine-associated cutaneous or hepatic toxicity occurring among non–HIV-infected individuals were obtained from the US Food and Drug Administrations adverse event reporting system, the pharmaceutic manufacturer, occupational health programs in Chicago, physicians, and case reports. The Eastern Cooperative Oncology Group (ECOG) scoring system was used to grade toxicity. ResultsTwelve non–HIV-infected individuals developed severe cutaneous toxicity, including 3 with Stevens-Johnson syndrome, after 7 to 12 days of nevirapine-containing PEP regimens. Thirty non–HIV-infected individuals developed hepatotoxicity after 8 to 35 days of single-agent nevirapine (n = 8) or a nevirapine-containing PEP regimen (n = 22). Findings included ECOG grade 3 or 4 hepatotoxicity (n = 14), fevers (n = 11), skin rashes (n = 8), eosinophilia (n = 6), and fulminant hepatic necrosis requiring an orthotopic liver transplant (n = 1). Rates of severe hepatotoxicity (grade 3 or 4) in non–HIV-infected individuals ranged from 10% (4/41) to 62% (5/8). Liver biopsy material from 2 individuals was consistent with a hypersensitivity syndrome. ConclusionsSerious hepatic and cutaneous toxicities can occur in non–HIV-infected individuals who receive short-term nevirapine therapy. The rate of severe hepatotoxicity appears to be greater in non–HIV-infected individuals than in HIV-infected persons and may be associated with higher CD4 counts. The use of PEP regimens containing nevirapine should be discouraged.

Acute tolerance to cocaine in humans

There is controversy as to whether acute tolerance develops to the principal effects of cocaine in humans. The studies described here demonstrate the phenomenon of acute tolerance to cocaine chronotropic and subjective effects and the rate and extent of tolerance development. Stable plasma cocaine concentrations were produced and then maintained in volunteer cocaine users by administering an intravenous cocaine injection followed by a cocaine infusion designed to compensate for the plasma clearance of cocaine. The euphoric effect (high) intensified to a peak at about 1 hour and then declined toward baseline at 4 hours despite the presence of constant plasma cocaine levels. The chronotropic effect reached a peak within 10 minutes and then declined, with a half‐life of 31 ± 13 (mean ± SD) minutes toward a plateau at 33% ± 21% of its peak intensity. Tolerance development was quantified as an exponential process, with a rate constant (tolerance factor) accounting for the progressive alteration of the cocaine concentration‐effect relationship.

Bisphosphonates and nonhealing femoral fractures: analysis of the FDA Adverse Event Reporting System (FAERS) and international safety efforts: a systematic review from the Research on Adverse Drug Events And Reports (RADAR) project.

BACKGROUND In the United States, hip fracture rates have declined by 30% coincident with bisphosphonate use. However, bisphosphonates are associated with sporadic cases of atypical femoral fracture. Atypical femoral fractures are usually atraumatic, may be bilateral, are occasionally preceded by prodromal thigh pain, and may have delayed fracture-healing. This study assessed the occurrence of bisphosphonate-associated nonhealing femoral fractures through a review of data from the U.S. FDA (Food and Drug Administration) Adverse Event Reporting System (FAERS) (1996 to 2011), published case reports, and international safety efforts. METHODS We analyzed the FAERS database with use of the proportional reporting ratio (PRR) and empiric Bayesian geometric mean (EBGM) techniques to assess whether a safety signal existed. Additionally, we conducted a systematic literature review (1990 to February 2012). RESULTS The analysis of the FAERS database indicated a PRR of 4.51 (95% confidence interval [CI], 3.44 to 5.92) for bisphosphonate use and nonhealing femoral fractures. Most cases (n = 317) were attributed to use of alendronate (PRR = 3.32; 95% CI, 2.71 to 4.17). In 2008, international safety agencies issued warnings and required label changes. In 2010, the FDA issued a safety notification, and the American Society for Bone and Mineral Research (ASBMR) issued recommendations about bisphosphonate-associated atypical femoral fractures. CONCLUSIONS Nonhealing femoral fractures are unusual adverse drug reactions associated with bisphosphonate use, as up to 26% of published cases of atypical femoral fractures exhibited delayed healing or nonhealing.

Dissemination of Information on Potentially Fatal Adverse Drug Reactions for Cancer Drugs From 2000 to 2002: First Results From the Research on Adverse Drug Events and Reports Project

PURPOSE To describe the clinical findings, occurrence rates, causality evidence, and dissemination media for serious cancer drug-associated adverse drug reactions (ADRs) reported in the postmarketing setting. METHODS ADRs were termed serious if they resulted in death or severe organ failure. ADR information for oncology drugs from package insert (PI) revisions, so-called Dear Doctor letters, and journal articles was evaluated to identify serious ADRs reported from 2000 to 2002. Timing and content of information disseminated was assessed. RESULTS Twenty-five serious ADRs associated with 22 oncology drugs were identified after approval. Approximately half of these serious ADRs are associated with drugs approved before 1995. ADRs were described in articles in medical journals (17 ADRs), PI revisions (18 ADRs), and Dear Doctor letters (12 ADRs). PI revisions occurred less than 1 year after peer-reviewed publication for four ADRs. These revisions often differed for similar ADRs that occurred with drugs of the same class. Five of the seven ADRs lacking PI changes occurred with off-label use, for which PI change is not recommended by US Food and Drug Administration (FDA) policy. No cancer drug was withdrawn from the market during the observation period. CONCLUSION Our findings demonstrate that serious ADRs may be discovered as long as 36 years after a drug receives FDA approval. This suggests a need for continued vigilance and efficient strategies for dissemination of information about ADRs associated with cancer drugs.

Amiodarone-associated Optic Neuropathy: A Critical Review

Although amiodarone is the most commonly prescribed anti-arrhythmic drug, its use is limited by serious toxicities, including optic neuropathy. Current reports of amiodarone-associated optic neuropathy identified from the Food and Drug Administrations Adverse Event Reporting System and published case reports were reviewed. A total of 296 reports were identified: 214 from the Adverse Event Reporting System, 59 from published case reports, and 23 from adverse events reports for patients enrolled in clinical trials. Mean duration of amiodarone therapy before vision loss was 9 months (range 1-84 months). Insidious onset of amiodarone-associated optic neuropathy (44%) was the most common presentation, and nearly one third were asymptomatic. Optic disk edema was present in 85% of cases. Following drug cessation, 58% had improved visual acuity, 21% were unchanged, and 21% had further decreased visual acuity. Legal blindness (<20/200) was noted in at least one eye in 20% of cases. Close ophthalmologic surveillance of patients during the tenure of amiodarone administration is warranted.

Adverse Event Reporting in Clinical Trials of Finasteride for Androgenic Alopecia A Meta-analysis

IMPORTANCE Two meta-analyses conclude that finasteride treatment of androgenic alopecia (AGA) is safe but do not assess quality of safety reporting. OBJECTIVE To assess safety reporting for clinical trial reports of finasteride for AGA. DATA SOURCES MEDLINE, ClinicalTrials.gov, and a clinical data repository for an academic medical center. STUDY SELECTION Published clinical trial reports for finasteride treatment of AGA. DATA EXTRACTION AND SYNTHESIS For each trial, we assessed quality of adverse event reporting, extracted the number and type of adverse events in treatment and placebo groups, and assessed duration of safety evaluation and adequacy of blinding. Two observers independently extracted the data; differences were resolved by consensus. We assessed generalizability in a large cohort of men prescribed finasteride, 1.25 mg/d or less, by assessing for eligibility in the finasteride-AGA pivotal trials. MAIN OUTCOMES AND MEASURES Quality was assessed as adequate, partially adequate, inadequate, or no events reported. We used funnel plots of the hazard ratio to assess bias. RESULTS Of 34 clinical trials, none had adequate safety reporting, 19 were partially adequate, 12 were inadequate, and 3 reported no adverse events. Funnel plots were asymmetric with a bias toward lower odds ratio for sexual adverse effects, suggesting systematic underdetection. No reports assessed adequacy of blinding, 18 (53%) disclosed conflicts of interest, and 19 (56%) received funding from the manufacturer. Duration of drug safety evaluation was 1 year or less for 26 of 34 trials (76%). Of 5704 men in the clinical data repository who were treated for AGA with finasteride, 1.25 mg/d or less, for AGA, only 31% met inclusion criteria for the pivotal trials referenced in the manufacturers full prescribing information and 33% took finasteride for more than 1 year. CONCLUSIONS AND RELEVANCE Available toxicity information from clinical trials of finasteride in men with AGA is very limited, is of poor quality, and seems to be systematically biased. In a cohort of men prescribed finasteride for routine treatment of AGA, most would have been excluded from the pivotal studies that supported US Food and Drug Administration approval for AGA. Published reports of clinical trials provide insufficient information to establish the safety profile for finasteride in the treatment of AGA.

Pediatric nephrogenic systemic fibrosis is rarely reported: a RADAR report

BackgroundNephrogenic systemic fibrosis is a fibrosing disorder associated with exposure to gadolinium-based contrast agents in people with severely compromised renal function.ObjectiveThe purpose of this study was to determine the reported number of cases of nephrogenic systemic fibrosis in children using three distinct publicly available data sources.Materials and methodsWe conducted systematic searches of the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS), the International Center for Nephrogenic Systemic Fibrosis Research (ICNSFR) registry and published literature from January 1997 through September 2012. We contacted authors of individual published cases to obtain follow-up data. Data sets were cross-referenced to eliminate duplicate reporting.ResultsWe identified 23 children with nephrogenic systemic fibrosis. Seventeen had documented exposure to gadolinium-based contrast agents. Six children had been reported in both the FAERS and the literature, four in the FAERS and the ICNSFR registry and five in all three data sources.ConclusionNephrogenic systemic fibrosis has been rarely reported in children. Although rules related to confidentiality limit the ability to reconcile reports, active pharmaco-vigilance using RADAR (Research on Adverse Drug events And Reports) methodology helped in establishing the number of individual pediatric cases within the three major data sources.

Quality of reporting of serious adverse drug events to an institutional review board: A case study with the novel cancer agent, imatinib mesylate

Purpose: Serious adverse drug event (sADE) reporting to Institutional Review Boards (IRB) is essential to ensure pharmaceutical safety. However, the quality of these reports has not been studied. Safety reports are especially important for cancer drugs that receive accelerated Food and Drug Administration approval, like imatinib, as preapproval experience with these drugs is limited. We evaluated the quality, accuracy, and completeness of sADE reports submitted to an IRB. Experimental Design: sADE reports submitted to an IRB from 14 clinical trials with imatinib were reviewed. Structured case report forms, containing detailed clinical data fields and a validated causality assessment instrument, were developed. Two forms were generated for each ADE, the first populated with data abstracted from the IRB reports, and the second populated with data from the corresponding clinical record. Completeness and causality assessments were evaluated for each of the two sources, and then compared. Accuracy (concordance between sources) was also assessed. Results: Of 115 sADEs reported for 177 cancer patients to the IRB, overall completeness of adverse event descriptions was 2.4-fold greater for structured case report forms populated with information from the clinical record versus the corresponding forms from IRB reports (95.0% versus 40.3%, P < 0.05). Information supporting causality assessments was recorded 3.5-fold more often in primary data sources versus IRB adverse event descriptions (93% versus 26%, P < 0.05). Some key clinical information was discrepant between the two sources. Conclusions: The use of structured syndrome-specific case report forms could enhance the quality of reporting to IRBs, thereby improving the safety of pharmaceuticals administered to cancer patients.