Survival Outcomes by Race and Ethnicity in Veterans With Nonmetastatic Castration-Resistant Prostate Cancer.

Importance: Racial and ethnic disparities in prostate cancer are poorly understood. A given disparity-related factor may affect outcomes differently at each point along the highly variable trajectory of the disease. Objective: To examine clinical outcomes by race and ethnicity in patients with nonmetastatic castration-resistant prostate cancer (nmCRPC) within the US Veterans Health Administration. Design, Setting, and Participants: A retrospective, observational cohort study using electronic health care records (January 1, 2006, to December 31, 2021) in a nationwide equal-access health care system was conducted. Mean (SD) follow-up time was 4.3 (3.3) years. Patients included in the analysis were diagnosed with prostate cancer from January 1, 2006, to December 30, 2020, that progressed to nmCRPC defined by (1) increasing prostate-specific antigen levels, (2) ongoing androgen deprivation, and (3) no evidence of metastatic disease. Patients with metastatic disease or death within the landmark period (3 months after the first nmCRPC evidence) were excluded. Main Outcomes and Measures: The primary outcome was time from the landmark period to death or metastasis; the secondary outcome was overall survival. A multivariate Cox proportional hazards model, Kaplan-Meier estimates, and adjusted survival curves were used to evaluate outcome differences by race and ethnicity. Results: Of 12 992 patients in the cohort, 826 patients identified as Hispanic (6%), 3671 as non-Hispanic Black (28%; henceforth Black), 7323 as non-Hispanic White (56%; henceforth White), and 1172 of other race and ethnicity (9%; henceforth other, including American Indian or Alaska Native, Asian, Native Hawaiian or Other Pacific Islander, unknown by patient, and patient declined to answer). Median time elapsed from nmCRPC to metastasis or death was 5.96 (95% CI, 5.58-6.34) years for Black patients, 5.62 (95% CI, 5.11-6.67) years for Hispanic patients, 4.11 (95% CI, 3.96-4.25) years for White patients, and 3.59 (95% CI, 3.23-3.97) years for other patients. Median unadjusted overall survival was 6.26 (95% CI, 6.03-6.46) years among all patients, 8.36 (95% CI, 8.0-8.8) years for Black patients, 8.56 (95% CI, 7.3-9.7) years for Hispanic patients, 5.48 (95% CI, 5.2-5.7) years for White patients, and 4.48 (95% CI, 4.1-5.0) years for other patients. Conclusions and Relevance: The findings of this cohort study of patients with nmCRPC suggest that differences in outcomes by race and ethnicity exist; in addition, Black and Hispanic men may have considerably improved outcomes when treated in an equal-access setting.

Use of a Medication Safety Audit and Feedback Tool in the Emergency Department Is Affected by Prescribing Characteristics.

BACKGROUND: The Enhancing Quality of Prescribing Practices for Older Veterans Discharged from the Emergency Department (EQUIPPED) program developed an audit and feedback health information technology (IT) solution with the intent to replace the in-person academic detailing service provided by the program. The EQUIPPED dashboard provides emergency department (ED) providers with a personalized view of their prescribing performance. OBJECTIVES: Here, we analyze the association between ED provider characteristics and viewership of the EQUIPPED dashboard, adding insight into strategies for addressing barriers to initial use. METHODS: We performed a retrospective analysis of EQUIPPED dashboard viewership among four Veterans Affairs (VA) EDs. We extracted quantitative data from user interaction logs to determine evidence of dashboard use. Provider characteristics and baseline potentially inappropriate medication (PIM) prescribing rate were extracted from the VA's Corporate Data Warehouse. Logistic regression was used to examine the association between dashboard use and provider characteristics. RESULTS: A total of 82 providers were invited to receive audit and feedback via the EQUIPPED dashboard. Among invited providers, 40 (48.7%) had evidence of at least 1 dashboard view during the 1-year feedback period. Adjusted analyses suggest that providers with a higher baseline PIM prescribing rate were more likely to use the dashboard (odds ratio [OR]: 1.22; 95% confidence interval [CI]: 1.01-1.47). Furthermore, providers at ED site D were more likely to use the dashboard in comparison to the other sites (OR: 9.99; 95% CI: 1.72-58.04) and reportedly had the highest site-level baseline PIM rate. CONCLUSION: Providers with lower PIM prescribing rates (i.e., <5%) receive communication from an integrated dashboard reminder system that they are "optimal prescribers" which may have discouraged initial attempts to view the dashboard. Site D had the highest baseline PIM rate, but further qualitative investigation is warranted to better understand why site D had the greatest users of the dashboard.

A comprehensive SEER registry analysis of elderly patients with classical Hodgkin lymphoma based on treatment era and race.

We conducted a Surveillance, Epidemiology, and End Results Program (SEER-18) registry analysis of classical Hodgkin lymphoma (cHL) patients more than 60 years old and compared outcomes of those diagnosed between 2006 and 2010 (cohort 1) to those identified between 2011 and 2015 (cohort 2) based on treatment era and race. Cohort 1 had a median overall survival (OS) of 4 years and cohort 2 had a median OS of 4.75 years [hazard ratio (HR): 0.92 (0.85-1.00); p = 0.052]. Non-Hispanic blacks (NHBs) had a similar 5-year OS compared to non-Hispanic whites (NHWs) of 48.6% vs. 50.2% (HR: 0.95 [0.79-1.15]; p > 0.99); on the contrary, Hispanics had worse 5-year OS of 41.8% vs. 48.6% (HR: 1.24 [1.09-1.41]; p < 0.001). NHW was the only race that had improvement in 5-year OS in 2011-2015 compared to 2006-2010 (51% vs. 46.5%, p = 0.002). In the multivariable analysis, older age, male gender, stage III-IV, unmarried status, Hispanic race, lack of chemotherapy, and diagnosis in 2006-2010 were associated with worse OS. Lymphoma was the most common cause of death in 60% of patients. In conclusion, elderly cHL patients diagnosed after 2010 had improved OS by nine months that was most prevalent in NHWs, and disparity in OS existed between NHWs and Hispanics throughout the study period.

Developing the VA Geriatric Scholars Programs' Clinical Dashboards Using the PDSA Framework for Quality Improvement.

BACKGROUND: Involving clinician end users in the development process of clinical dashboards is important to ensure that user needs are adequately met prior to releasing the dashboard for use. The challenge with following this approach is that clinician end users can undergo periodic turnover, meaning, the clinicians that played a role in the initial development process may not be the same individuals that use the dashboard in future. OBJECTIVES: Here, we summarize our Plan, Do, Study, Act (PDSA)-guided clinical dashboard development process for the VA Geriatric Scholars Program (GSP) and the value of continuous, iterative development. We summarize dashboard adaptations that resulted from two PDSA cycles of improvement for the potentially inappropriate medication dashboard (PIMD), one of many Geriatric Scholars clinical dashboards. We also present the evaluative performance of the PIMD. METHODS: Evaluation of the PIMD was performed using the system usability scale (SUS) and through review of user interaction logs. Routine end users that were Geriatric Scholars and had evidence of 5 or more dashboard views were invited to complete an electronic form that contained the 10-item SUS. RESULTS: The proportion of Geriatric Scholars that utilized the PIMD increased for each iterative dashboard version that was produced as a byproduct from feedback (31.0% in 2017 to 60.2% in 2019). The overall usability of the PIMD among routine users was found to be above average (SUS score: 75.2 [95% CI 70.5-79.8]) in comparison to the recommended standard of acceptability (SUS score: 68) CONCLUSION: The solicitation of feedback during dashboard orientations led to iterative adaptations of the PIMD that broadened its intended use. The presented PDSA-guided process to clinical dashboard development for the VA GSP can serve as a valuable framework for development teams seeking to produce well-adopted and usable health information technology (IT) innovations.

Improved overall survival over time in advanced stage mycosis fungoides: a cross-sectional study.

Mycosis Fungoides (MF) is a rare T-cell lymphoma and evidence on treatment practices, and outcomes are limited. We evaluated changes in practice patterns and corresponding effects on overall survival (OS) in MF using a cross-sectional study of patients diagnosed with MF from 2004 to 2016 in the National Cancer Database. Outcomes evaluated included patterns of care and OS across treatment eras. We found factors associated with chemotherapy use included male gender, treatment from 2004 to 2010 and stage III-IV disease. Factors associated with radiotherapy receipt included stage I-II disease, nonacademic treatment centers, male gender, non-black race, and Medicare status. Immunotherapy use was associated with treatment from 2004 to 2010 and stage III-IV disease. After propensity score matching, there was no OS difference among patients with stage I-II disease between 2004-2010 and 2011-2016. However, amongst patients with stage III-IV disease, OS was significantly improved in those treated from 2011 to 2016.

Integration of Patient-Reported Outcome Measures in the Electronic Health Record: The Veterans Affairs Experience.

PURPOSE: There are growing efforts to integrate patient-reported outcome (PRO) data into electronic health records (EHRs) to bring together disparate sources of patient information and improve medical care. PRO measures can be used to assess cancer symptom presence and severity. Integrating PRO tools in EHRs can alert providers to address symptoms, which is an essential component of comprehensive oncology care. METHODS: We modified a PRO used to measure cancer and end-of-life symptoms, the Edmonton Symptom Assessment System to create the Veteran Symptom Assessment System (VSAS). VSAS was implemented as an integrated PRO as part of the Veterans Administration EHR system and was used at hematology-oncology clinics in Veteran Administration (VA) medical centers in the Southeast. RESULTS: From 2013 to 2014, VSAS was introduced, underwent usability testing and modifications, and was finally implemented in the EHR. Between 2015 and 2019, VSAS was administered 43,883 times in 9,058 patients. Eighty-nine percent of Veterans were male, 11% were female, 52% identified as non-Hispanic White, and 43% identified as African American. Fatigue, shortness of breath with exertion, and pain were most frequently reported initially (68%, 48%, and 45%, respectively) and were most frequently rated as severe (27%, 16%, and 17%, respectively). In patients diagnosed with stage IV cancer, higher symptom burden was significantly associated with shorter overall survival. The majority of Veterans with longitudinal measurements experienced improvement in symptoms, most frequently in severe symptoms. CONCLUSION: To our knowledge, this is the first large-scale implementation of a PRO system, integrated in the VA EHR, in ambulatory patients with cancer and blood disorders. The integration of VSAS within the VA EHR is a significant demonstration and a necessary requirement for current and future systemic initiatives in cancer symptom management.

Phase 1/2 study of intratumoral G100 (TLR4 agonist) with or without pembrolizumab in follicular lymphoma.

Intratumoral injection of G100, a toll-like receptor 4 (TLR4) agonist, was shown pre-clinically to stimulate anti-tumor immune responses and tumor regression. This open-label, multicenter, phase 1/2 trial evaluated the safety, tolerability, and preliminary efficacy of intratumoral G100 injections following localized low-dose radiation in patients with follicular lymphoma (ClinicalTrials.gov #NCT02501473). The study was comprised of a G100 dose escalation (5 or 10 µg/dose, or 20 µg/dose for large tumors); a randomized component comparing G100 to G100 plus pembrolizumab; and G100 20 µg/dose expansion. Adverse events grade ≥3 were uncommon in patients treated with G100, and no unexpected toxicities were observed when combined with pembrolizumab. G100 20 µg (n = 18) resulted in an overall response rate of 33.3% and abscopal tumor regression in 72.2% of patients. This early-phase study provides a foundation for combining an intratumoral TLR4 agonist with agents to produce immune-mediated responses in follicular lymphoma with limited added toxicity.

Treatment Patterns and Outcomes in a Nationwide Cohort of Older and Younger Veterans with Waldenström Macroglobulinemia, 2006-2019.

Little is known about real-world treatment patterns and outcomes in Waldenström macroglobulinemia (WM) following the recent introduction of newer treatments, especially among older adults. We describe patterns of first-line (1 L) WM treatment in early (2006-2012) and modern (2013-2019) eras and report outcomes (overall response rate (ORR), overall survival (OS), progression-free survival (PFS), and adverse event (AE)-related discontinuation) in younger (≤70 years) and older (>70 years) populations. We followed 166 younger and 152 older WM patients who received 1 L treatment between January 2006 and April 2019 in the Veterans Health Administration. Median follow-up was 43.5 months (range: 0.6-147.2 months). Compared to the early era, older patients in the modern era achieved improved ORRs (early: 63.8%, modern: 72.3%) and 41% lower risk of death/progression (hazard ratio (HR) for PFS: 0.59, 95% CI (confidence interval): 0.36-0.95), with little change in AE-related discontinuation between eras (HR: 0.82, 95% CI: 0.4-1.7). In younger patients, the AE-related discontinuation risk increased almost fourfold (HR: 3.9, 95% CI: 1.1-14), whereas treatment effects did not change between eras (HR for OS: 1.4, 95% CI: 0.66-2.8; HR for PFS: 1.1, 95% CI: 0.67-1.7). Marked improvements in survival among older adults accompanied a profound shift in 1 L treatment patterns for WM.

Predicting Survival in Veterans with Follicular Lymphoma Using Structured Electronic Health Record Information and Machine Learning.

The most accurate prognostic approach for follicular lymphoma (FL), progression of disease at 24 months (POD24), requires two years' observation after initiating first-line therapy (L1) to predict outcomes. We applied machine learning to structured electronic health record (EHR) data to predict individual survival at L1 initiation. We grouped 523 observations and 1933 variables from a nationwide cohort of FL patients diagnosed 2006-2014 in the Veterans Health Administration into traditionally used prognostic variables ("curated"), commonly measured labs ("labs"), and International Classification of Diseases diagnostic codes ("ICD") sets. We compared performance of random survival forests (RSF) vs. traditional Cox model using four datasets: curated, curated + labs, curated + ICD, and curated + ICD + labs, also using Cox on curated + POD24. We evaluated variable importance and partial dependence plots with area under the receiver operating characteristic curve (AUC). RSF with curated + labs performed best, with mean AUC 0.73 (95% CI: 0.71-0.75). It approximated, but did not surpass, Cox with POD24 (mean AUC 0.74 [95% CI: 0.71-0.77]). RSF using EHR data achieved better performance than traditional prognostic variables, setting the foundation for the incorporation of our algorithm into the EHR. It also provides for possible future scenarios in which clinicians could be provided an EHR-based tool which approximates the predictive ability of the most accurate known indicator, using information available 24 months earlier.

Real-world practice patterns and outcomes in Veterans with relapsed/refractory diffuse large B-cell lymphoma.

Aim: To describe practices and outcomes in veterans with relapsed/refractory diffuse large B-cell lymphoma. Patients & methods: Using Veteran Affairs Cancer Registry System and electronic health record data, we identified relapsed/refractory diffuse large B-cell lymphoma patients completing second-line treatment (2L) in 2000-2016. Treatments were classified as aggressive/nonaggressive. Analyses included descriptive statistics and the Kaplan-Meier estimation of progression-free survival and overall survival. Results: Two hundred and seventy patients received 2L. During median 9.7-month follow-up starting from 2L, 470 regimens were observed, averaging 2.7 regimens/patient: 219 aggressive, 251 nonaggressive. One hundred and twenty-one patients proceeded to third-line, 50 to fourth-line and 18 to fifth-line treatment. Median progression-free survival in 2L was 5.2 months. Median overall survival was 9.5 months. Forty-four patients (16.3%) proceeded to bone marrow transplant. Conclusion: More effective, less toxic treatments are needed and should be initiated earlier in treatment trajectory.

Atrial Fibrillation and Bleeding in Patients With Chronic Lymphocytic Leukemia Treated with Ibrutinib in the Veterans Health Administration.

BACKGROUND: Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in adults. The introduction of novel oral agents, starting with ibrutinib in 2013, has revolutionized the therapeutic landscape; however, clinical trials have suggested an association between ibrutinib and the risk of bleeding-related adverse events and atrial fibrillation (Afib) in patients with CLL. METHODS: Patients diagnosed and treated for CLL at the Veterans Health Administration (VHA) from 2010 to 2014 were followed until December 31, 2016, death, or lack of utilization of hematology/oncology services for ≥ 18 months; or until incidence of another cancer. Treatments dispensed, evidence of VHA system use, bleeding events, and Afib were determined from the administrative records, laboratory records, pharmacy dispensation records, and clinical notes in the electronic healthcare record. RESULTS: From 2010 to 2014, 2,796 patients were diagnosed and received care for CLL within the VHA, of whom 172 patients received ibrutinib and 291 received bendamustine + rituximab (BR). The use of anticoagulants following induction therapy did not differ between BR and ibrutinib patients (9% vs 8%, respectively), nor did the use of antiplatelets agents (6% vs 2%, respectively). Of the 291 patients that received BR, 12 (4%) developed a bleeding event compared with 20 (12%) who received ibrutinib. Additionally, 13 (8%) ibrutinib patients developed Afib compared with 9 (3%) BR patients. CONCLUSIONS: Real-world evidence from a nationwide cohort of patients with CLL suggests that while ibrutinib is associated with increased bleeding-related adverse events and Afib, the risk is comparable to those reported in previous clinical trials. These findings suggest that patients in real-world clinical care settings with higher levels of comorbidities may be at an increased risk for bleeding events and Afib.

Usability Testing a Potentially Inappropriate Medication Dashboard: A Core Component of the Dashboard Development Process.

BACKGROUND: With the increased usage of dashboard reporting systems to monitor and track patient panels by clinical users, developers must ensure that the information displays they produce are accurate and intuitive. When evaluating usability of a clinical dashboard among potential end users, developers oftentimes rely on methods such as questionnaires as opposed to other, more time-intensive strategies that incorporate direct observation. OBJECTIVES: Prior to release of the potentially inappropriate medication (PIM) clinical dashboard, designed to facilitate completion of a quality improvement project by clinician scholars enrolled in the Veterans Affairs (VA) workforce development Geriatric Scholars Program (GSP), we evaluated the usability of the system. This article describes the process of usability testing a dashboard reporting system with clinicians using direct observation and think-aloud moderating techniques. METHODS: We developed a structured interview protocol that combines virtual observation, think-aloud moderating techniques, and retrospective questioning of the overall user experience, including use of the System Usability Scale (SUS). Thematic analysis was used to analyze field notes from the interviews of three GSP alumni. RESULTS: Our structured approach to usability testing identified specific functional problems with the dashboard reporting system that were missed by results from the SUS. Usability testing lead to overall improvements in the intuitive use of the system, increased data transparency, and clarification of the dashboard's purpose. CONCLUSION: Reliance solely on questionnaires and surveys at the end stages of dashboard development can mask potential functional problems that will impede proper usage and lead to misinterpretation of results. A structured approach to usability testing in the developmental phase is an important tool for developers of clinician friendly systems for displaying easily digested information and tracking outcomes for the purpose of quality improvement.

Maintenance rituximab in Veterans with follicular lymphoma.

Real-world practice patterns and clinical outcomes in patients with follicular lymphoma (FL), including the adoption of maintenance rituximab (MR) therapy in the United States (US), have been reported in few studies since the release of the National LymphoCare Study almost a decade ago. We analyzed data from the largest integrated healthcare system in the United States, the Veterans Health Administration (VHA), to identify rates of adoption and effectiveness of MR in FL patients after first-line (1L) treatment. We identified previously untreated patients with FL in the VHA between 2006 and 2014 who achieved at least stable disease after chemoimmunotherapy or immunotherapy. Among these patients, those who initiated MR within 238 days of 1L composed the MR group, whereas those who did not were classified as the non-MR group. We examined the effect of MR on progression-free survival (PFS) and overall survival (OS). A total of 676 patients met our inclusion criteria, of whom 300 received MR. MR was associated with significant PFS (hazard ratio [HR]=0.55, P < .001) and OS (HR = 0.53, P = .005) compared to the non-MR group, after adjusting by age, sex, ethnicity, geographic region, diagnosis period, stage, grade at diagnosis, hemoglobin, lactate dehydrogenase (LDH), Charlson comorbidity index (CCI), 1L treatment regimen, and response to 1L treatment. These results suggest that in FL patients who do not experience disease progression after 1L treatment in real-world settings, MR is associated with a significant improvement in both PFS and OS. Maintenance therapy should be considered in FL patients who successfully complete and respond to 1L therapy.

Real-world practice patterns in veterans with metastatic castration-resistant prostate cancer.

BACKGROUND: Metastatic castration-resistant prostate cancer (mCRPC) is incurable, with most patients surviving less than 3 years. However, many treatments that extend survival have been approved in the past decade. OBJECTIVE: To describe the patient demographics, disease characteristics, treatment patterns, and outcomes in a cohort of Veterans diagnosed with mCRPC in the Veterans Health Administration. DESIGN: We identified 3,637 Veterans diagnosed with prostate cancer between January 2006 and August 2015 with evidence of mCRPC through December 2016. We described the most commonly used systemic mCRPC treatments according to mCRPC diagnosis era: Epoch 1 (2006-2010) or Epoch 2 (2011-2016). Patient demographics, disease characteristics, and treatment patterns were examined using descriptive statistics. An unadjusted Kaplan-Meier method was used to estimate the median time to biochemical progression and overall survival (OS) with 95% confidence intervals. RESULTS: The median age at initial prostate cancer diagnosis was 68 years. Approximately 67% of patients were non-Hispanic white, 29% were black, and 4% were other/unknown. A high-risk Gleason score (8-10) was reported in 748 (67%) of patients in Epoch 1 and 1578 (63%) of patients in Epoch 2, and the median prostate-specific antigen level at initial prostate cancer diagnosis was higher in Epoch 1 patients than in Epoch 2 patients (68 vs. 35 ng/ml). Following mCRPC diagnosis, the most common first-line therapies in Epoch 1 patients were docetaxel (83%) and abiraterone (9%), whereas Epoch 2 patients mainly received abiraterone (47%), docetaxel (36%), and enzalutamide (15%). In Epoch 1 and Epoch 2 patients, the median time to biochemical progression (unadjusted) was 9 and 13 months, respectively, and the median OS (unadjusted) was 15 and 23 months, respectively. CONCLUSIONS: The introduction of new therapies has resulted in increased use of the noncytotoxic agents abiraterone and enzalutamide as first-line treatment in lieu of docetaxel. Our results suggest that more recently diagnosed patients (Epoch 2) have a delayed time to biochemical progression and longer OS (unadjusted) compared with patients diagnosed earlier (Epoch 1).

Safety and efficacy of allogeneic hematopoietic stem cell transplant after PD-1 blockade in relapsed/refractory lymphoma.

Anti-programmed cell death protein 1 (PD-1) monoclonal antibodies are being increasingly tested in patients with advanced lymphoma. Following treatment, many of those patients are likely to be candidates for allogeneic hematopoietic stem cell transplant (HSCT). However, the safety and efficacy of HSCT may be affected by prior PD-1 blockade. We conducted an international retrospective analysis of 39 patients with lymphoma who received prior treatment with a PD-1 inhibitor, at a median time of 62 days (7-260) before HSCT. After a median follow-up of 12 months, the 1-year cumulative incidences of grade 2-4 and grade 3-4 acute graft-versus-host disease (GVHD) were 44% and 23%, respectively, whereas the 1-year incidence of chronic GVHD was 41%. There were 4 treatment-related deaths (1 from hepatic sinusoidal obstruction syndrome, 3 from early acute GVHD). In addition, 7 patients developed a noninfectious febrile syndrome shortly after transplant requiring prolonged courses of steroids. One-year overall and progression-free survival rates were 89% (95% confidence interval [CI], 74-96) and 76% (95% CI, 56-87), respectively. One-year cumulative incidences of relapse and nonrelapse mortality were 14% (95% CI, 4-29) and 11% (95% CI, 3-23), respectively. Circulating lymphocyte subsets were analyzed in 17 patients. Compared with controls, patients previously treated with PD-1 blockade had significantly decreased PD-1+ T cells and decreased ratios of T-regulatory cells to conventional CD4 and CD8 T cells. In conclusion, HSCT after PD-1 blockade appears feasible with a low rate of relapse. However, there may be an increased risk of early immune toxicity, which could reflect long-lasting immune alterations triggered by prior PD-1 blockade.

Pralatrexate Monitoring Using a Commercially Available Methotrexate Assay to Avoid Potential Drug Interactions.

Pralatrexate (PDX) is a folate antagonist structurally similar to methotrexate (MTX). Unlike MTX, it is currently not known whether PDX exhibits delayed clearance and heightened toxicity in the setting of fluid overload. A specific serum assay for PDX is not commercially available. To our knowledge, we report the first case using an MTX serum assay as a surrogate for PDX concentrations to avoid a potential drug-drug interaction with pralatrexate. We describe a 76-year-old man with refractory cutaneous T-cell lymphoma who began therapy with weekly PDX 15 mg/m(2) intravenous infusions on days 1, 8, and 15 of a 28-day cycle. He subsequently developed mucositis, a moderate right-sided pleural effusion, and peripheral edema over the next 5 weeks. Aggressive diuresis with furosemide was initiated, which was then withheld the day before his next PDX dose to avoid a potential drug-drug interaction between PDX and furosemide. His baseline MTX/PDX concentration (measured prior to administration of the cycle 2, week 2 PDX dose) was less than 0.20 µmol/L (i.e., undetectable). After PDX administration, his 1-hour peak MTX/PDX concentration increased to 0.58 µmol/L. Aggressive diuresis was withheld until his MTX/PDX concentration was undetectable, 43.5 hours later. PDX is more potent than MTX and displays similar pharmacokinetic properties. PDX concentrations using the serum MTX assay reflect lower values than those reported from PDX-specific assays in clinical studies. Because PDX is approved by the U.S. Food and Drug Administration for the treatment of uncommon malignancies, it is unlikely that a specific assay will be commercially developed. We propose that the MTX serum assay has merit for use in determining when to reinstate possible interacting drug therapies such as loop diuretics.

Chemotherapy and antibody combinations for relapsed/refractory non-Hodgkin's lymphoma.

Monoclonal antibodies are commonly used in combination with chemotherapy when treating non-Hodgkin's lymphoma. Superior clinical benefits of chemotherapy-antibody combinations have been convincingly demonstrated in the setting of initial therapy in large randomized trials for many of the most common lymphoma subtypes. Clinicians have extrapolated from data in the initial treatment setting to justify chemotherapy-antibody combinations in the treatment of relapsed lymphoma. Many Phase II studies of chemotherapy-antibody combinations in relapsed lymphoma reviewed herein demonstrate clinical activity, and several randomized Phase III trials demonstrate superior clinical results when antibody is added to chemotherapy regimens in relapsed patients who have not previously been exposed to antibodies. Less clear is whether antibodies add to the clinical benefit of chemotherapy when patients have previously been exposed to antibodies, much less in the setting of patients who did not have a good result to a previous antibody-containing treatment plan.