Machine Learning To Stratify Methicillin-Resistant Staphylococcus aureus Risk among Hospitalized Patients with Community-Acquired Pneumonia.

Methicillin-resistant Staphylococcus aureus (MRSA) is an uncommon but serious cause of community-acquired pneumonia (CAP). A lack of validated MRSA CAP risk factors can result in overuse of empirical broad-spectrum antibiotics. We sought to develop robust models predicting the risk of MRSA CAP using machine learning using a population-based sample of hospitalized patients with CAP admitted to either a tertiary academic center or a community teaching hospital. Data were evaluated using a machine learning approach. Cases were CAP patients with MRSA isolated from blood or respiratory cultures within 72 h of admission; controls did not have MRSA CAP. The Classification Tree Analysis algorithm was used for model development. Model predictions were evaluated in sensitivity analyses. A total of 21 of 1,823 patients (1.2%) developed MRSA within 72 h of admission. MRSA risk was higher among patients admitted to the intensive care unit (ICU) in the first 24 h who required mechanical ventilation than among ICU patients who did not require ventilatory support (odds ratio [OR], 8.3; 95% confidence interval [CI], 2.4 to 32). MRSA risk was lower among patients admitted to ward units than among those admitted to the ICU (OR, 0.21; 95% CI, 0.07 to 0.56) and lower among ICU patients without a history of antibiotic use in the last 90 days than among ICU patients with antibiotic use in the last 90 days (OR, 0.03; 95% CI, 0.002 to 0.59). The final machine learning model was highly accurate (receiver operating characteristic [ROC] area = 0.775) in training and jackknife validity analyses. We identified a relatively simple machine learning model that predicted MRSA risk in hospitalized patients with CAP within 72 h postadmission.

Individual meropenem epithelial lining fluid and plasma PK/PD target attainment.

It is unclear whether plasma is a reliable surrogate for target attainment in the epithelial lining fluid (ELF). The objective of this study was to characterize meropenem target attainment in plasma and ELF using prospective samples. The first 24-hour T>MIC was evaluated vs 1xMIC and 4xMIC targets at the patient (i.e., fixed MIC of 2 mg/L) and population [i.e., cumulative fraction of response (CFR) according to EUCAST MIC distributions] levels for both plasma and ELF. Among 65 patients receiving ≥24 hours of treatment, 40% of patients failed to achieve >50% T>4xMIC in plasma and ELF, and 30% of patients who achieved >50% T>4xMIC in plasma had <50% T>4xMIC in ELF. At 1xMIC and 4xMIC targets, 3% and 25% of patients with >95% T>MIC in plasma had <50% T>MIC in ELF, respectively. Those with a CRCL >115 mL/min were less likely to achieve >50%T>4xMIC in ELF (P < 0.025). In the population, CFR for Escherichia coli at 1xMIC and 4xMIC was >97%. For Pseudomonas aeruginosa, CFR was ≥90% in plasma and ranged 80%-85% in ELF at 1xMIC when a loading dose was applied. CFR was reduced in plasma (range: 75%-81%) and ELF (range: 44%-60%) in the absence of a loading dose at 1xMIC. At 4xMIC, CFR for P. aeruginosa was 60%-86% with a loading dose and 18%-62% without a loading dose. We found that plasma overestimated ELF target attainment inup to 30% of meropenem-treated patients, CRCL >115 mL/min decreased target attainment in ELF, and loading doses increased CFR in the population.

Characterizing Risk Factors for Clostridioides difficile Infection among Hospitalized Patients with Community-Acquired Pneumonia.

Hospitalized patients with community-acquired pneumonia (CAP) are at risk of developing Clostridioides difficile infection (CDI). We developed and tested clinical decision rules for identifying CDI risk in this patient population. The study was a single-center retrospective, case-control analysis of hospitalized adult patients empirically treated for CAP between 1 January 2014 and 3 March 2018. Differences between cases (CDI diagnosed within 180 days following admission) and controls (no test result indicating CDI during the study period) with respect to prehospitalization variables were modeled to generate propensity scores. Postadmission variables were used to predict case status on each postadmission day where (i) ≥1 additional case was identified and (ii) each model stratum contained ≥15 subjects. Models were developed and tested using optimal discriminant analysis and classification tree analysis. Forty-four cases and 181 controls were included. The median time to diagnosis was 50 days postadmission. After weighting, three models were identified (20, 117, and 165 days postadmission). The day 20 model yielded the greatest (weighted [w]) accuracy (weighted area under the receiver operating characteristic curve [wROC area] = 0.826) and the highest chance-corrected accuracy (weighted effect strength for sensitivity [wESS] = 65.3). Having a positive culture (odds, 1:4; P = 0.001), receipt of ceftriaxone plus azithromycin for a defined infection (odds, 3:5; P = 0.006), and continuation of empirical broad-spectrum antibiotics with activity against P. aeruginosa when no pathogen was identified (odds, 1:8; P = 0.013) were associated with CDI on day 20. Three models were identified that accurately predicted CDI in hospitalized patients treated for CAP. Antibiotic use increased the risk of CDI in all models, underscoring the importance of antibiotic stewardship.

The First 2 Years of Biosimilar Epoetin for Cancer and Chemotherapy-Induced Anemia in the U.S.: A Review from the Southern Network on Adverse Reactions.

Biosimilars are biologic drug products that are highly similar to reference products in analytic features, pharmacokinetics and pharmacodynamics, immunogenicity, safety, and efficacy. Biosimilar epoetin received Food and Drug Administration (FDA) approval in 2018. The manufacturer received an FDA nonapproval letter in 2017, despite receiving a favorable review by FDA's Oncologic Drugs Advisory Committee (ODAC) and an FDA nonapproval letter in 2015 for an earlier formulation. We discuss the 2018 FDA approval, the 2017 FDA ODAC Committee review, and the FDA complete response letters in 2015 and 2017; review concepts of litigation, naming, labeling, substitution, interchangeability, and pharmacovigilance; review European and U.S. oncology experiences with biosimilar epoetin; and review the safety of erythropoiesis-stimulating agents. In 2020, policy statements from AETNA, United Health Care, and Humana indicated that new epoetin oncology starts must be for biosimilar epoetin unless medical need for other epoetins is documented. Empirical studies report that as of 2012, reference epoetin use decreased from 40%-60% of all patients with cancer with chemotherapy-induced anemia to <5% of such patients because of safety concerns. Between 2018 and 2020, biosimilar epoetin use varied, increasing to 81% among one private insurer's patients covered by Medicare whose cancer care is administered with Oncology Analytics and to 41% with the same private insurer's patients with cancer covered by commercial health insurance and administered by the private insurer, to 0% in several Veterans Administration Hospitals, increasing to 100% in one large county hospital in California, and with yet-to-be-reported data from most oncology settings. We conclude that biosimilar epoetin appears to have overcome some barriers since 2015, although current uptake in the U.S. is variable. Pricing and safety considerations for all erythropoiesis-stimulating agents are primary determinants of biosimilar epoetin oncology uptake. IMPLICATIONS FOR PRACTICE: Few oncologists understand substitution and interchangeability of biosimilars with reference drugs. Epoetin biosimilar is new to the market, and physician and patient understanding is limited. The development of epoetin biosimilar is not familiar to oncologists.

Improving oncology biosimilar launches in the EU, the USA, and Japan: an updated Policy Review from the Southern Network on Adverse Reactions.

The EU, the USA, and Japan account for the majority of biological pharmacotherapy use worldwide. Biosimilar regulatory approval pathways were authorised in the EU (2006), in Japan (2009), and in the USA (2015), to facilitate approval of biological drugs that are highly similar to reference products and to encourage market competition. Between 2007 and 2020, 33 biosimilars for oncology were approved by the European Medicines Agency (EMA), 16 by the US Food and Drug Administration (FDA), and ten by the Japan Pharmaceuticals and Medical Devices Agency (PMDA). Some of these approved applications were initially rejected because of manufacturing concerns (four of 36 [11%] with the EMA, seven of 16 [44%] with the FDA, none of ten for the PMDA). Median times from initial regulatory submission before approval of oncology biosimilars were 1·5 years (EMA), 1·3 years (FDA), and 0·9 years (PMDA). Pharmacists can substitute biosimilars for reference biologics in some EU countries, but not in the USA or Japan. US regulation prohibits substitution, unless the biosimilar has been approved as interchangeable, a designation not yet achieved for any biosimilar in the USA. Japan does not permit biosimilar substitution, as prescribers must include the product name on each prescription and that specific product must be given to the patient. Policy Reviews published in 2014 and 2016 in The Lancet Oncology focused on premarket and postmarket policies for oncology biosimilars before most of these drugs received regulatory approval. In this Policy Review from the Southern Network on Adverse Reactions, we identify factors preventing the effective launch of oncology biosimilars. Introduction to the market has been more challenging with therapeutic than for supportive care oncology biosimilars. Addressing region-specific competition barriers and educational needs would improve the regulatory approval process and market launches for these biologics, therefore expanding patient access to these products in the EU, the USA, and Japan.

End of an era for erythropoiesis-stimulating agents in oncology.

Erythropoiesis-stimulating agents (ESAs) are available to treat chemotherapy-induced anemia (CIA). In 2007-2008, regulatory notifications advised of venous thromboembolism and mortality risks while the Center for Medicare and Medicaid Services' restricted ESA initiation to patients with hemoglobin <10 g/dl. In 2010, a Risk Evaluation and Mitigation Strategies required consent prior to administration. We evaluated ESA utilization from 2003 to 2012 and obtained private health insurer claims data for persons with lung, colorectal, or breast cancer from 2001 to 2012. ESA use for CIA was determined by an ESA claim after chemotherapy, up to 6 months after treatment. We identified 839,948 commercially insured patients, including 24,785 patients with ESA-treated CIA (3.2%). Darbepoetin use increased 3.9-fold from 2003 to 2007 (12.3% to 48.7%) and then decreased 95% to 2.6% by 2012. Epoetin use decreased 90% from 2003 to 2012 (30.3% to 3.1%). Between 2003 and 2012, mean epoetin dosing decreased 0.8-fold (244,979 in 2003 vs. 196,216 units in 2012), but increased 1.8-fold for darbepoetin-treated CIA (262 in 2003 to 467 µg in 2012). Among CIA patients, transfusions were low (4.5%) in 2002-2007, then increased 2.2-fold between 2008 and 2012. Safety initiatives between 2007 and 2010 facilitated reductions in ESA use combined with changes in coverage. These data show the efficacy of regulatory efforts, publication of adverse events and changes in reimbursement in reducing use of ESAs. Future studies are warranted to optimize deimplementation strategies to improve patient safety.

Regulatory and Clinical Experiences with Biosimilar Filgrastim in the U.S., the European Union, Japan, and Canada.

Biosimilar filgrastims are primarily indicated for chemotherapy-induced neutropenia prevention. They are less expensive formulations of branded filgrastim, and biosimilar filgrastim was the first biosimilar oncology drug administered in European Union (EU) countries, Japan, and the U.S. Fourteen biosimilar filgrastims have been marketed in EU countries, Japan, the U.S., and Canada since 2008, 2012, 2015, and 2016, respectively. We reviewed experiences and policies for biosimilar filgrastim markets in EU countries and Japan, where uptake has been rapid, and in the U.S. and Canada, where experience is rapidly emerging. U.S. regulations for designating biosimilar interchangeability are under development, and such regulations have not been developed in most other countries. Pharmaceutical substitution is allowed for new filgrastim starts in some EU countries and in Canada, but not Japan and the U.S. In EU countries, biosimilar adoption is facilitated with favorable hospital tender offers. U.S. adoption is reportedly 24%, while the second filgrastim biosimilar is priced 30% lower than branded filgrastim and 20% lower than the first biosimilar filgrastim approved by the U.S. Food and Drug Administration. Utilization is about 60% in EU countries, where biosimilar filgrastim is marketed at a 30%-40% discount. In Japan, biosimilar filgrastim utilization is 45%, primarily because of 35% discounts negotiated by Central Insurance and hospital-only markets. Overall, biosimilar filgrastim adoption barriers are small in many EU countries and Japan and are diminishing in Canada in the U.S. Policies facilitating improved U.S. adoption of biosimilar filgrastim, based on positive experiences in EU countries and Japan, including favorable insurance coverage; larger price discount relative to reference filgrastim pricing; closing of the "rebate trap" with transparent pricing information; formal educational efforts of patients, physicians, caregivers, and providers; and allowance of pharmaceutical substitution of biosimilar versus reference filgrastim, should be considered. IMPLICATIONS FOR PRACTICE: We reviewed experiences and policies for biosimilar filgrastims in Europe, Japan, Canada, and the U.S. Postmarketing harmonization of regulatory policies for biosimilar filgrastims has not occurred. Acceptance of biosimilar filgrastims for branded filgrastim, increasing in the U.S. and in Canada, is commonplace in Japan and Europe. In the U.S., some factors, accepted in Europe or Japan, could improve uptake, including acceptance of biosimilars as safe and effective; larger cost savings, decreasing "rebate traps" where pharmaceutical benefit managers support branded filgrastim, decreased use of patent litigation/challenges, and allowing pharmacists to routinely substitute biosimilar for branded filgrastim.

Iohexol-measured glomerular filtration rate and urinary biomarker changes between vancomycin and vancomycin plus piperacillin-tazobactam in a translational rat model.

Recent clinical studies have reported additive nephrotoxicity with the combination of vancomycin and piperacillin-tazobactam. However, preclinical models have failed to replicate this finding. This study assessed differences in iohexol-measured glomerular filtration rate (GFR) and urinary injury biomarkers among rats receiving this antibiotic combination. Male Sprague-Dawley rats received either intravenous vancomycin, intraperitoneal piperacillin-tazobactam, or both for 96 hours. Iohexol-measured GFR was used to quantify real-time kidney function changes. Kidney injury was evaluated via the urinary biomarkers: kidney injury molecule-1 (KIM-1), clusterin, and osteopontin. Compared to the control, rats that received vancomycin had numerically lower GFR after drug dosing on day 3. Rats in this group also had elevations in urinary KIM-1 on experimental days 2 and 4. Increasing urinary KIM-1 was found to correlate with decreasing GFR on experimental days 1 and 3. Rats that received vancomycin+piperacillin-tazobactam did not exhibit worse kidney function or injury biomarkers compared to vancomycin alone. The combination of vancomycin+piperacillin-tazobactam does not cause additive nephrotoxicity in a translational rat model. Future clinical studies investigating this antibiotic combination should employ more sensitive biomarkers of kidney function and injury, similar to those utilized in this study.

Antimicrobial never events: Objective application of a framework to assess vancomycin appropriateness.

To address appropriateness of antibiotic use, we implemented an electronic framework to evaluate antibiotic "never events" (NEs) at 2 medical centers. Patient-level vancomycin administration records were classified as NEs or non-NEs. The objective framework allowed capture of true-positive vancomycin NEs in one-third of patients identified by the electronic strategy.

Consequences to patients, clinicians, and manufacturers when very serious adverse drug reactions are identified (1997-2019): A qualitative analysis from the Southern Network on Adverse Reactions (SONAR).

BACKGROUND: Adverse drug/device reactions (ADRs) can result in severe patient harm. We define very serious ADRs as being associated with severe toxicity, as measured on the Common Toxicity Criteria Adverse Events (CTCAE)) scale, following use of drugs or devices with large sales, large financial settlements, and large numbers of injured persons. We report on impacts on patients, clinicians, and manufacturers following very serious ADR reporting. METHODS: We reviewed clinician identified very serious ADRs published between 1997 and 2019. Drugs and devices associated with reports of very serious ADRs were identified. Included drugs or devices had market removal discussed at Food and Drug Advisory (FDA) Advisory Committee meetings, were published by clinicians, had sales > $1 billion, were associated with CTCAE Grade 4 or 5 toxicity effects, and had either >$1 billion in settlements or >1,000 injured patients. Data sources included journals, Congressional transcripts, and news reports. We reviewed data on: 1) timing of ADR reports, Boxed warnings, and product withdrawals, and 2) patient, clinician, and manufacturer impacts. Binomial analysis was used to compare sales pre- and post-FDA Advisory Committee meetings. FINDINGS: Twenty very serious ADRs involved fifteen drugs and one device. Legal settlements totaled $38.4 billion for 753,900 injured persons. Eleven of 18 clinicians (61%) reported harms, including verbal threats from manufacturer (five) and loss of a faculty position (one). Annual sales decreased 94% from $29.1 billion pre-FDA meeting to $4.9 billion afterwards (p<0.0018). Manufacturers of four drugs paid $1.7 billion total in criminal fines for failing to inform the FDA and physicians about very serious ADRs. Following FDA approval, the median time to ADR reporting was 7.5 years (Interquartile range 3,13 years). Twelve drugs received Box warnings and one drug received a warning (median, 7.5 years following ADR reporting (IQR 5,11 years). Six drugs and 1 device were withdrawn from marketing (median, 5 years after ADR reporting (IQR 4,6 years)). INTERPRETATION: Because very serious ADRs impacts are so large, policy makers should consider developing independently funded pharmacovigilance centers of excellence to assist with clinician investigations. FUNDING: This work received support from the National Cancer Institute (1R01 CA102713 (CLB), https://www.nih.gov/about-nih/what-we-do/nih-almanac/national-cancer-institute-nci; and two Pilot Project grants from the American Cancer Society's Institutional Grant Award to the University of South Carolina (IRG-13-043-01) https://www.cancer.org/ (SH; BS).

Evaluation of a potential clinical interaction between ceftriaxone and calcium.

In April 2009, the FDA retracted a warning asserting that ceftriaxone and intravenous calcium products should not be coadministered to any patient to prevent precipitation events leading to end-organ damage. Following that announcement, we sought to evaluate if the retraction was justified. A search of the FDA Adverse Event Reporting System was conducted to identify any ceftriaxone-calcium interactions that resulted in serious adverse drug events. Ceftazidime-calcium was used as a comparator agent. One hundred four events with ceftriaxone-calcium and 99 events with ceftazidime-calcium were identified. Adverse drug events were recorded according to the listed description of drug involvement (primary or secondary suspect) and were interpreted as probable, possible, unlikely, or unrelated. For ceftriaxone-calcium-related adverse events, 7.7% and 20.2% of the events were classified as probable and possible for embolism, respectively. Ceftazidime-calcium resulted in fewer probable embolic events (4%) but more possible embolic events (30.3%). Among cases that considered ceftriaxone or ceftazidime and calcium as the primary or secondary drug, one case was classified as a probable embolic event. That patient received ceftriaxone-calcium and died, although an attribution of causality was not possible. Our analysis suggests a lack of support for the occurrence of ceftriaxone-calcium precipitation events in adults. The results of the current analysis reinforce the revised FDA recommendations suggesting that patients >28 days old may receive ceftriaxone and calcium sequentially and provide a transparent and reproducible methodology for such evaluations.

End of an era of administering erythropoiesis stimulating agents among Veterans Administration cancer patients with chemotherapy-induced anemia.

Erythropoisis stimulating agent (ESA) use was addressed in Food and Drug Administration (FDA) Oncology Drug Advisory Committee (ODAC) meetings between 2004 and 2008. FDA safety-focused regulatory actions occurred in 2007 and 2008. In 2007, black box warnings advised of early death and venous thromboembolism (VTE) risks with ESAs in oncology. In 2010, a Risk Evaluation Strategies (REMS) was initiated, with cancer patient consent that mortality and VTE risks were noted with ESAs. We report warnings and REMS impacts on ESA utilization among Veterans Administration (VA) cancer patients with chemotherapy-induced anemia (CIA). Data were from Veterans Affairs database (2003-2012). Epoetin and darbepoetin use were primary outcomes. Segmented linear regression was used to estimate changes in ESA use levels and trends, clinical appropriateness, and adverse events (VTEs) among chemotherapy-treated cancer patients. To estimate changes in level of drug prescription rate after policy actions, model-specific indicator variables as covariates based on specific actions were included. ESA use fell by 95% and 90% from 2005, for epoetin and darbepoetin, from 22% and 11%, respectively, to 1% and 1%, respectively, among cancer patients with CIA, respectively (p<0.01). Following REMS in 2010, mean hematocrit levels at ESA initiation decreased from 30% to 21% (p<0.01). Black box warnings preceded decreased ESA use among VA cancer patients with CIA. REMS was followed by reduced hematocrit levels at ESA initiation. Our findings contrast with privately- insured and Medicaid insured cancer patient data on chemotherapy-induced anemia where ESA use decreased to 3% to 7% by 2010-2012. By 2012, the era of ESA administration to VA to cancer patients had ended but the warnings remain relevant and significant. In 2019, oncology/hematology national guidelines (ASCO/ASH) recommend that cancer patients with chemotherapy-induced anemia should receive ESAs or red blood cell transfusions after risk-benefit evaluation.

Serial plasma voriconazole concentrations after allogeneic hematopoietic stem cell transplantation.

Plasma voriconazole concentrations vary considerably between patients receiving standard dosing, and trough voriconazole concentrations are known to affect efficacy and toxicity. Temporal variations in serial plasma voriconazole concentrations through the course of therapy in hematopoietic stem cell transplantation patients has not been carefully described. Paired voriconazole concentrations in 64 patients were studied to determine the predictability of the second concentration based on the first. The difference between the two values was < or = 5% in six patients. In 25 patients, the second concentration was higher by a median of 40%. In 33 patients, the subsequent concentration was lower by a median of 59%. For patients with an initial concentration of < 2 microg/ml, the correlation between the two values was poor (r = 0.24; P < 0.17). For those with an initial concentration of > or = 2 microg/ml, the correlation was good (r = 0.72; P < 0.0001). There was no relationship between the magnitude of the change and the time elapsing between the two measurements. Among the 43 patients who had an initial concentration of > or = 1 microg/ml, the two voriconazole measurements were strongly correlated (r = 0.66, P < 0.0001), but only 67% had a voriconazole serum concentration of > or = 1 microg/ml on the second measurement. No studied variables were reliable predictors in identifying concentrations above or below 1 or 2 microg/ml. Our data suggest that variations in voriconazole concentrations are unpredictable despite standard dosing, and the acceptability of a concentration on one occasion cannot be extrapolated to future concentrations in the same patient. This suggests that ongoing therapeutic drug monitoring and dose adjustment may be beneficial in patients requiring prolonged voriconazole therapy.

Ticlopidine- and clopidogrel-associated thrombotic thrombocytopenic purpura (TTP): review of clinical, laboratory, epidemiological, and pharmacovigilance findings (1989-2008).

Thrombotic thrombocytopenic purpura (TTP) is a fulminant disease characterized by platelet aggregates, thrombocytopenia, renal insufficiency, neurologic changes, and mechanical injury to erythrocytes. Most idiopathic cases of TTP are characterized by a deficiency of ADAMTS13 (a disintegrin and metalloprotease, with thrombospondin-1-like domains) metalloprotease activity. Ironically, use of anti-platelet agents, the thienopyridine derivates clopidogrel and ticlopidine, is associated with drug induced TTP. Data were abstracted from a systematic review of English-language literature for thienopyridine-associated TTP identified in MEDLINE, EMBASE, the public website of the Food and Drug Administration, and abstracts from national scientific conferences from 1991 to April 2008. Ticlopidine and clopidogrel are the two most common drugs associated with TTP in FDA safety databases. Epidemiological studies identify recent initiation of anti-platelet agents as the most common risk factor associated with risks of developing TTP. Laboratory studies indicate that most cases of thienopyridine-associated TTP involve an antibody to ADAMTS13 metalloprotease, present with severe thrombocytopenia, and respond to therapeutic plasma exchange (TPE); a minority of thienopyridine-associated TTP presents with severe renal insufficiency, involves direct endothelial cell damage, and is less responsive to TPE. The evaluation of this potentially fatal drug toxicity can serve as a template for future efforts to comprehensively characterize other severe adverse drug reactions.

Hepatotoxicity associated with long- versus short-course HIV-prophylactic nevirapine use: a systematic review and meta-analysis from the Research on Adverse Drug events And Reports (RADAR) project.

BACKGROUND AND OBJECTIVE: The antiretroviral nevirapine can cause severe hepatotoxicity when used 'off-label' for preventing mother-to-child HIV transmission (PMTCT), newborn post-exposure prophylaxis and for pre- and post-exposure prophylaxis among non-HIV-infected individuals. We describe the incidence of hepatotoxicity with short- versus long-course nevirapine-containing regimens in these groups. METHODS: We reviewed hepatotoxicity cases among non-HIV-infected individuals and HIV-infected pregnant women and their offspring receiving short- (or=5 days) nevirapine prophylaxis. Sources included adverse event reports from pharmaceutical manufacturers and the US FDA, reports from peer-reviewed journals/scientific meetings and the Research on Adverse Drug events And Reports (RADAR) project. Hepatotoxicity was scored using the AIDS Clinical Trial Group criteria. RESULTS: Toxicity data for 8216 patients treated with nevirapine-containing regimens were reviewed. Among 402 non-HIV-infected individuals receiving short- (n=251) or long-course (n=151) nevirapine, rates of grade 1-2 hepatotoxicity were 1.99% versus 5.30%, respectively, and rates of grade 3-4 hepatotoxicity were 0.00% versus 13.25%, respectively (p<0.001 for both comparisons). Among 4740 HIV-infected pregnant women receiving short- (n=3031) versus long-course (n=1709) nevirapine, rates of grade 1-2 hepatotoxicity were 0.62% and 7.04%, respectively, and rates of grade 3-4 hepatotoxicity were 0.23% versus 4.39%, respectively (p<0.001 for both comparisons). The rates of grade 3-4 hepatotoxicity among 3074 neonates of nevirapine-exposed HIV-infected pregnant women were 0.8% for those receiving short-course (n=2801) versus 1.1% for those receiving long-course (n=273) therapy (p<0.72). CONCLUSIONS: Therapy duration appears to significantly predict nevirapine hepatotoxicity. Short-course nevirapine for HIV prophylaxis is associated with fewer hepatotoxic reactions for non-HIV-infected individuals or pregnant HIV-infected women and their offspring, but administration of prophylactic nevirapine for >or=2 weeks appears to be associated with high rates of hepatotoxicity among non-HIV-infected individuals and HIV-infected pregnant mothers. When full highly active antiretroviral therapy (HAART) regimens are not available, single-dose nevirapine plus short-course nucleoside reverse transcriptase inhibitors to decrease the development of HIV viral resistance is an essential therapeutic option for PMTCT and these data support the safety of single-dose nevirapine in this setting.

Caveat Medicus: Clinician experiences in publishing reports of serious oncology-associated adverse drug reactions.

Oncology-associated adverse drug/device reactions can be fatal. Some clinicians who treat single patients with severe oncology-associated toxicities have researched case series and published this information. We investigated motivations and experiences of select individuals leading such efforts. Clinicians treating individual patients who developed oncology-associated serious adverse drug events were asked to participate. Inclusion criteria included having index patient information, reporting case series, and being collaborative with investigators from two National Institutes of Health funded pharmacovigilance networks. Thirty-minute interviews addressed investigational motivation, feedback from pharmaceutical manufacturers, FDA personnel, and academic leadership, and recommendations for improving pharmacovigilance. Responses were analyzed using constant comparative methods of qualitative analysis. Overall, 18 clinicians met inclusion criteria and 14 interviewees are included. Primary motivations were scientific curiosity, expressed by six clinicians. A less common theme was public health related (three clinicians). Six clinicians received feedback characterized as supportive from academic leaders, while four clinicians received feedback characterized as negative. Three clinicians reported that following the case series publication they were invited to speak at academic institutions worldwide. Responses from pharmaceutical manufacturers were characterized as negative by 12 clinicians. One clinician's wife called the post-reporting time the "Maalox month," while another clinician reported that the manufacturer collaboratively offered to identify additional cases of the toxicity. Responses from FDA employees were characterized as collaborative for two clinicians, neutral for five clinicians, unresponsive for negative by six clinicians. Three clinicians endorsed developing improved reporting mechanisms for individual physicians, while 11 clinicians endorsed safety activities that should be undertaken by persons other than a motivated clinician who personally treats a patient with a severe adverse drug/device reaction. Our study provides some of the first reports of clinician motivations and experiences with reporting serious or potentially fatal oncology-associated adverse drug or device reactions. Overall, it appears that negative feedback from pharmaceutical manufacturers and mixed feedback from the academic community and/or the FDA were reported. Big data, registries, Data Safety Monitoring Boards, and pharmacogenetic studies may facilitate improved pharmacovigilance efforts for oncology-associated adverse drug reactions. These initiatives overcome concerns related to complacency, indifference, ignorance, and system-level problems as barriers to documenting and reporting adverse drug events- barriers that have been previously reported for clinician reporting of serious adverse drug reactions.

Evaluation of serious adverse drug reactions: a proactive pharmacovigilance program (RADAR) vs safety activities conducted by the Food and Drug Administration and pharmaceutical manufacturers.

BACKGROUND: The Food and Drug Administration (FDA) and pharmaceutical manufacturers conduct most postmarketing pharmaceutical safety investigations. These efforts are frequently based on data mining of databases. In 1998, investigators initiated the Research on Adverse Drug events And Reports (RADAR) project to investigate reports of serious adverse drug reactions (ADRs) and prospectively obtain information on these cases. We compare safety efforts for evaluating serious ADRs conducted by the FDA and pharmaceutical manufacturers vs the RADAR project. METHODS: We evaluated the completeness of serious ADR descriptions in the FDA and RADAR databases and the comprehensiveness of notifications disseminated by pharmaceutical manufacturers and the RADAR investigators. A serious ADR was defined as an event that led to death or required intensive therapies to reverse. RESULTS: The RADAR investigators evaluated 16 serious ADRs. Compared with descriptions of these ADRs in FDA databases (2296 reports), reports in RADAR databases (472 reports) had a 2-fold higher rate of including information on history and physical examination (92% vs 45%; P<.001) and a 9-fold higher rate of including basic science findings (34% vs 4%; P = .08). Safety notifications were disseminated earlier by pharmaceutical suppliers (2 vs 4 years after approval, respectively), although notifications were less likely to include information on incidence (46% vs 93%; P = .02), outcomes (8% vs 100%; P<.001), treatment or prophylaxis (25% vs 93%; P<.001), or references (8% vs 80%; P<.001). CONCLUSION: Proactive safety efforts conducted by the RADAR investigators are more comprehensive than those conducted by the FDA and pharmaceutical manufacturers, but dissemination of related safety notifications is less timely.

Predicting outcome after emergent cerclage using classification tree analysis.

We sought to develop a predictive model for gestational age at delivery after placement of an emergent cerclage in the second trimester. Data were obtained for women undergoing emergent cerclage in response to documented cervical change on physical examination at a university hospital between 1980 and 2000. Hierarchically optimal classification tree analysis (CTA) was used to predict delivery prior to 24 weeks, between 24 and 27 6/7 weeks, or after 27 6/7 weeks. One hundred sixteen women were available for analysis. Delivery prior to 24 weeks was best predicted by presence of prolapsed membranes and gestational age at cerclage placement; delivery between 24 and 27 6/7 weeks was best predicted by parity alone; delivery of at least 28 weeks was best predicted by cervical dilation and length, presence of prolapsed membranes, and parity. When choosing a single model to predict delivery at the three different gestational age periods, the last model yielded the most accurate results. CTA can be used to construct a predictive model for outcome after emergent cerclage that may be informative for both patients and physicians.

Venous thromboembolism and mortality associated with recombinant erythropoietin and darbepoetin administration for the treatment of cancer-associated anemia.

CONTEXT: The erythropoiesis-stimulating agents (ESAs) erythropoietin and darbepoetin are licensed to treat chemotherapy-associated anemia in patients with nonmyeloid malignancies. Although systematic overviews of trials have identified venous thromboembolism (VTE) risks, none have identified mortality risks with ESAs. OBJECTIVE: To evaluate VTE and mortality rates associated with ESA administration for the treatment of anemia among patients with cancer. DATA SOURCES: A published overview from the Cochrane Collaboration (search dates: January 1, 1985-April 1, 2005) and MEDLINE and EMBASE databases (key words: clinical trial, erythropoietin, darbepoetin, and oncology), the public Web site of the US Food and Drug Administration and ESA manufacturers, and safety advisories (search dates: April 1, 2005-January 17, 2008). STUDY SELECTION: Phase 3 trials comparing ESAs with placebo or standard of care for the treatment of anemia among patients with cancer. DATA EXTRACTION: Mortality rates, VTE rates, and 95% confidence intervals (CIs) were extracted by 3 reviewers from 51 clinical trials with 13 611 patients that included survival information and 38 clinical trials with 8172 patients that included information on VTE. DATA SYNTHESIS: Patients with cancer who received ESAs had increased VTE risks (334 VTE events among 4610 patients treated with ESA vs 173 VTE events among 3562 control patients; 7.5% vs 4.9%; relative risk, 1.57; 95% CI, 1.31-1.87) and increased mortality risks (hazard ratio, 1.10; 95% CI, 1.01-1.20). CONCLUSIONS: Erythropoiesis-stimulating agent administration to patients with cancer is associated with increased risks of VTE and mortality. Our findings, in conjunction with basic science studies on erythropoietin and erythropoietin receptors in solid cancers, raise concern about the safety of ESA administration to patients with cancer.

Estimating causal effects for survival (time-to-event) outcomes by combining classification tree analysis and propensity score weighting.

RATIONALE, AIMS AND OBJECTIVES: A common approach to assessing treatment effects in nonrandomized studies with time-to-event outcomes is to estimate propensity scores and compute weights using logistic regression, test for covariate balance, and then estimate treatment effects using Cox regression. A machine-learning alternative-classification tree analysis (CTA)-used to generate propensity scores and to estimate treatment effects in time-to-event data may identify complex relationships between covariates not found using conventional regression-based approaches. METHOD: Using empirical data, we identify all statistically valid CTA propensity score models and then use them to compute strata-specific, observation-level propensity score weights that are subsequently applied in outcomes analyses. We compare findings obtained using this framework to the conventional method, by evaluating covariate balance and treatment effect estimates obtained using Cox regression and a weighted CTA outcomes model. RESULTS: All models had some imbalanced covariates. Nevertheless, treatment effect estimates were generally consistent across all weighted models. CONCLUSIONS: In the study sample, given that all approaches elicited similar results, using CTA increased confidence that bias could not be reduced any further. Because the CTA algorithm identifies all statistically valid propensity score models for a sample, it is most likely to identify a correctly specified propensity score model-and therefore should be used either to confirm results using traditional methods, or to reveal biases that may be missed by traditional methods. Moreover, given that the true treatment effect is never known in observational data, CTA should be considered for estimating outcomes because no statistical assumptions are required.