Bruce D Cheson

Georgetown University, Washington, Washington, D.C., United States

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Publications (495)

  • [Show abstract] [Hide abstract] ABSTRACT: B Cell receptor (BCR) kinase inhibitor (KI) therapy represents a paradigm shift in Chronic Lymphocytic Leukemia (CLL) management, but data on practice patterns after KI discontinuation and optimal sequencing are limited. We conducted a multicenter, retrospective, comprehensive analysis on 178 CLL patients (ibrutinib=143; idelalisib=35) who discontinued KI therapy. We examined responses, toxicity, post-KI therapies, and overall survival (OS). Patients had a median of 3 prior therapies (range 0-11); del17p (34%), p53 mutation (27%), del11q (33%), and complex karyotype (29%). Overall response rate (ORR) to first KI was 62% (complete response (CR) 14%). The most common reasons for KI discontinuation were toxicity (51%), CLL progression (29%), and Richter's transformation (RT) (8%). Median progression free survival (PFS) and OS from KI initiation were 10.5 and 29 months, respectively. Notably, initial KI choice did not impact PFS or OS, however, RT portended significantly inferior OS (P=0.0007). 114 patients received subsequent salvage therapy following KI discontinuation with an ORR to subsequent KI at 50% and a median PFS of 11.9 months. Median PFS in KI intolerant patients treated with an alternate KI was not reached (NR) versus 7 months for patients with CLL progression. In summary, these data demonstrate that toxicity was the most common reason for KI discontinuation, and that patients who discontinue KI due to toxicity can respond to an alternate KI, and these responses may be durable.
    Article · Sep 2016 · Blood
  • Ranjana H Advani · Daniel Lebovic · Andy Chen · [...] · Bruce D Cheson
    [Show abstract] [Hide abstract] ABSTRACT: Purpose: Pinatuzumab vedotin is an antibody-drug conjugate with the potent antimicrotubule agent monomethyl auristatin E (MMAE) conjugated to an anti-CD22 antibody via a protease-cleavable linker. This Phase I study determined its recommended Phase II dose (RP2D) and evaluated its safety, tolerability, and anti-tumor activity alone and with rituximab in relapsed/refractory (r/r) non-Hodgkin's lymphoma (NHL) and chronic lymphocytic leukemia (CLL). Experimental design: Patients received escalating doses of pinatuzumab vedotin every 21 days. Clinical activity at the RP2D alone or with rituximab was evaluated in r/r diffuse large B-cell lymphoma (DLBCL) and r/r indolent NHL (iNHL) patients. Results: Seventy-five patients received single-agent pinatuzumab vedotin. The RP2D was 2.4 mg/kg, based on dose-limiting toxicities (DLT) of Grade 4 neutropenia >7 days in 1/3 patients and Grade 4 neutropenia <7 days in 2/3 patients treated at 3.2 mg/kg (maximum assessed dose). No DLTs occurred at 2.4 mg/kg. At the RP2D, neutropenia was the most common Grade {greater than or equal to}3 adverse event. Peripheral neuropathy-related Grade {greater than or equal to}2 adverse events most frequently resulted in treatment discontinuation. Rituximab co-treatment did not impact safety, tolerability, or pharmacokinetics of pinatuzumab vedotin. Unconjugated MMAE exposure was much lower than antibody-conjugated MMAE exposure without accumulation with repeat dosing. At the RP2D, objective responses were observed in DLBCL (9/25) and iNHL (7/14) patients; 2/8 patients treated with pinatuzumab vedotin (RP2D) and rituximab had complete responses. CLL patients showed no objective responses. Conclusions: The RP2D of pinatuzumab vedotin alone and with rituximab was 2.4 mg/kg, which was well tolerated, with encouraging clinical activity in r/r NHL.
    Article · Sep 2016 · Clinical Cancer Research
  • Bruce D Cheson · Stephen Ansell · Larry Schwartz · [...] · Philippe Armand
    [Show abstract] [Hide abstract] ABSTRACT: Uniformly adopted response criteria are essential for assessment of therapies incorporating conventional chemotherapy and chemoimmunotherapy regimens. Recently, immunomodulatory agents, such as immune checkpoint inhibitors, have demonstrated impressive activity in a broad range of lymphoma histologies. However, these agents may be associated with clinical and imaging findings during treatment suggestive of progressive disease (PD) despite evidence of clinical benefit (e.g., tumor flare or pseudo-progression). Considering this finding as PD could lead to patients being prematurely removed from a treatment from which they actually stand to benefit. This phenomenon has been well described with checkpoint blockade therapy in solid tumors, and anecdotally seen in lymphoma as well. To address this issue in the context of lymphoma immunomodulatory therapy, a workshop was convened to provide provisional recommendations to modify current response criteria in patients receiving these and future agents in clinical trials. The term "Indeterminate Response" (IR) was introduced in order to identify such lesions until confirmed as flare/pseudo-progression or true PD by either biopsy or subsequent imaging.
    Article · Aug 2016 · Blood
  • Chaitra S Ujjani · Bruce D Cheson
    Article · Jul 2016 · British Journal of Haematology
  • Laurie H Sehn · Neil Chua · Jiri Mayer · [...] · Bruce D Cheson
    [Show abstract] [Hide abstract] ABSTRACT: Patients with indolent non-Hodgkin lymphoma who fail to achieve adequate disease control with rituximab-based treatment have few treatment options and a poor prognosis. We aimed to assess a combination of obinutuzumab (GA101), a novel glyco-engineered type II anti-CD20 monoclonal antibody, and bendamustine in this patient population.
    Article · Jun 2016 · The Lancet Oncology
  • Bruce D Cheson
    [Show abstract] [Hide abstract] ABSTRACT: With the increasing number of targeted agents for the treatment of patients with lymphoid malignancies comes the promise of safe and effective chemotherapy-free treatment strategies. A number of single agents, such as ibrutinib and idelalisib, have demonstrated impressive efficacy with a favorable toxicity profile. The observations that most responses are, however, partial and treatment duration is indefinite, have stimulated interest in combinations of these agents with chemotherapy as well as with each other. Despite the promise of this approach, several recent trials of combinations of agents have been terminated as the result of life-threatening and fatal complications. Such outcomes have generated a cautionary note of the potential for unforeseen adverse effects that challenge drug development and mitigate against the empiric combination of such drugs outside of a clinical trial setting.
    Article · May 2016 · Blood
  • Chaitra S Ujjani · Elizabeth M Hill · Hongkun Wang · [...] · Bruce D Cheson
    [Show abstract] [Hide abstract] ABSTRACT: The ability of positron emission tomography-computerized tomography (PET-CT) to accurately detect bone marrow involvement (BMI) has been suggested in Hodgkin lymphoma (HL) and diffuse large B-cell lymphoma (DLBCL), but its abilities in other histologies is less established. The aim of this retrospective study was to confirm the role of PET-CT in detecting BMI in DLBCL and HL, and to explore its usefulness in other subtypes. Of the 149 newly diagnosed patients, common subtypes included DLBCL, follicular lymphoma (FL) and HL. In DLBCL, the sensitivity and specificity of PET-CT at diagnosis were 75% and 92%. In FL, the sensitivity and specificity of PET-CT were 67% and 85% at diagnosis, and 73% and 89% at relapse. In HL, the sensitivity and specificity were 100% and 74%. PET-CT was able to detect BMI in patients with negative biopsies. Most of the patients in which PET-CT failed to identify BMI were already advanced stage by imaging. In this analysis, PET-CT was highly accurate for detecting BMI at diagnosis in DLBCL and HL and highly specific in FL at diagnosis and relapse. Results also suggested the diagnostic advantage of PET-CT over bone marrow biopsy in detecting BMI. Prospective evaluation is necessary and may eliminate biopsies in future patients.
    Article · Apr 2016 · British Journal of Haematology
  • [Show abstract] [Hide abstract] ABSTRACT: Purpose: Four US National Clinical Trials Network components (Southwest Oncology Group, Cancer and Leukemia Group B/Alliance, Eastern Cooperative Oncology Group, and the AIDS Malignancy Consortium) conducted a phase II Intergroup clinical trial that used early interim fluorodeoxyglucose positron emission tomography (FDG-PET) imaging to determine the utility of response-adapted therapy for stage III to IV classic Hodgkin lymphoma. Patients and methods: The Southwest Oncology Group S0816 (Fludeoxyglucose F 18-PET/CT Imaging and Combination Chemotherapy With or Without Additional Chemotherapy and G-CSF in Treating Patients With Stage III or Stage IV Hodgkin Lymphoma) trial enrolled 358 HIV-negative patients between July 1, 2009, and December 2, 2012. A PET scan was performed after two initial cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) and was labeled PET2. PET2-negative patients (Deauville score 1 to 3) received an additional four cycles of ABVD, whereas PET2-positive patients (Deauville score 4 to 5) were switched to escalated bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (eBEACOPP) for six cycles. Among 336 eligible and evaluable patients, the median age was 32 years (range, 18 to 60 years), with 52% stage III, 48% stage IV, 49% International Prognostic Score 0 to 2, and 51% score 3 to 7. Results: Three hundred thirty-six of the enrolled patients were evaluable. Central review of the interim PET2 scan was performed in 331 evaluable patients, with 271 (82%) PET2-negative and 60 (18%) PET2-positive. Of 60 eligible PET2-positive patients, 49 switched to eBEACOPP as planned and 11 declined. With a median follow-up of 39.7 months, the Kaplan-Meier estimate for 2-year overall survival was 98% (95% CI, 95% to 99%), and the 2-year estimate for progression-free survival (PFS) was 79% (95% CI, 74% to 83%). The 2-year estimate for PFS in the subset of patients who were PET2-positive after two cycles of ABVD was 64% (95% CI, 50% to 75%). Both nonhematologic and hematologic toxicities were greater in the eBEACOPP arm than in the continued ABVD arm. Conclusion: Response-adapted therapy based on interim PET imaging after two cycles of ABVD seems promising with a 2-year PFS of 64% for PET2-positive patients, which is much higher than the expected 2-year PFS of 15% to 30%.
    Article · Apr 2016 · Journal of Clinical Oncology
  • [Show abstract] [Hide abstract] ABSTRACT: Although agents targeting B-cell receptor signaling have provided practice-changing results in relapsed chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphoma, they require prolonged administration and provide incomplete responses. Given synergistic preclinical activity with phosphatidylinositol 3-kinase delta and spleen tyrosine kinase inhibition, this phase 2 study evaluated the safety and efficacy of the combination of idelalisib and entospletinib. Eligible patients with relapsed or refractory CLL or non-Hodgkin lymphoma underwent intrapatient dose escalation with each agent. With a median treatment exposure of 10 weeks, 60% and 36% of patients with CLL or follicular lymphoma, respectively, achieved objective responses. However, the study was terminated early due to treatment-emergent pneumonitis in 18% of patients (severe in 11 of 12 cases). Although most patients recovered with supportive measures and systemic steroids, 2 fatalities occurred and were attributed to treatment-emergent pneumonitis. Increases of interferon γ and interleukins 6, 7, and 8 occurred over time in patients who developed pneumonitis. Future studies of novel combinations should employ conservative designs that incorporate pharmacodynamics/biomarker monitoring. These investigations should also prospectively evaluate plasma cytokine/chemokine levels in an attempt to validate biomarkers predictive of response and toxicity. This trial was registered at www.clinicaltrials.gov as #NCT01796470.
    Article · Mar 2016 · Blood
  • Kruti Sheth Nair · Bruce Cheson
    [Show abstract] [Hide abstract] ABSTRACT: Idelalisib is a first in class, delta isoform specific, PI3-kinase inhibitor. Based on its high level of efficacy and acceptable safety profile, this oral drug has been approved by the US Food and Drug Administration as a single agent for the treatment of relapsed or refractory small lymphocytic lymphoma, and follicular non-Hodgkin lymphoma, and in combination with rituximab for patients with chronic lymphocytic leukemia. Adverse effects of particular concern include diarrhea, pneumonitis, and transient elevations of hepatic transaminase levels. Efforts to improve on the activity of this drug have included combinations with standard chemotherapy agents, such as bendamustine, and other targeted therapies, including checkpoint inhibitors. However, other combinations have been associated with life-threatening and fatal toxicities. Thus, the development of such regimens should be conducted carefully in the context of a clinical research study. Idelalisib has a vital role as second-line therapy for chronic lymphocytic leukemia, especially for patients with high-risk disease and multiple comorbidities, and studies are exploring the use of this agent as front-line therapy to improve the outcome of patients with indolent B-cell malignancies.
    Article · Feb 2016
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    Bruce D. Cheson · Wolfram Brugger · Gandhi Damaj · [...] · Pier Luigi Zinzani
    [Show abstract] [Hide abstract] ABSTRACT: Bendamustine has achieved widespread international regulatory approval and is a standard agent for the treatment for chronic lymphocytic leukemia (CLL), indolent non-Hodgkin lymphoma and multiple myeloma. Since approval, the number of indications for bendamustine has expanded to include aggressive non-Hodgkin lymphoma and Hodgkin lymphoma and novel targeted therapies, based on new bendamustine regimens/combinations, are being developed against CLL and lymphomas. In 2010, an international panel of bendamustine experts met and published a set of recommendations on the safe and effective use of bendamustine in patients suffering from hematologic disorders. In 2014, this panel met again to update these recommendations since the clarification of issues including optimal dosing and management of bendamustine-related toxicities. The aim of this report is to communicate the latest consensus on the use of bendamustine, permitting the expansion of its safe and effective administration, particularly in new combination therapies.
    Full-text Article · Nov 2015 · Leukemia and Lymphoma
  • Maria Chaudhry · Bruce D Cheson
    [Show abstract] [Hide abstract] ABSTRACT: Chronic lymphocytic leukemia/small lymphocytic lymphoma is the most prevalent form of adult leukemia in western countries. Chemotherapy has been the mainstay of treatment for the last several decades. The introduction of biological, targeted agents (e.g., monoclonal antibodies) has dramatically improved treatment options. The addition of rituximab to fludarabine and cyclophosphamide has improved patient outcomes, as compared to fludarabine and cyclophosphamide. Nevertheless, chronic lymphocytic leukemia remains incurable, leaving considerable room for improvement. One approach would be to enhance the activity of the CD20 antibody. The next-generation monoclonal antibody ofatumumab has not demonstrated superiority over rituximab, whereas obinutuzumab-chlorambucil is superior to rituximab-chlorambucil. Recent efforts to combine anti-CD20 antibodies with new targeted therapies offer the potential to move toward alternative non-chemotherapy-based treatment approaches.
    Article · Sep 2015 · Expert Review of Hematology
  • [Show abstract] [Hide abstract] ABSTRACT: The International Prognostic Score (IPS-7) is the most commonly used risk stratification tool for advanced Hodgkin lymphoma (HL), however recent studies suggest the IPS-7 is less discriminating due to improved outcomes with contemporary therapy. We evaluated the seven variables for IPS-7 recorded at study entry for 854 patients enrolled on Eastern Cooperative Oncology Group 2496 trial. Univariate and multivariate Cox models were used to assess their prognostic ability for freedom from progression (FFP) and overall survival (OS). The IPS-7 remained prognostic however its prognostic range has narrowed. On multivariate analysis, two factors (age, stage) remained significant for FFP and three factors (age, stage, haemoglobin level) for OS. An alternative prognostic index, the IPS-3, was constructed using age, stage and haemoglobin level, which provided four distinct risk groups [FFP (P = 0·0001) and OS (P < 0·0001)]. IPS-3 outperformed the IPS-7 on risk prediction for both FFP and OS by model fit and discrimination criteria. Using reclassification calibration, 18% of IPS-7 low risk patients were re-classified as intermediate risk and 13% of IPS-7 intermediate risk patients as low risk. For patients with advanced HL, the IPS-3 may provide a simpler and more accurate framework for risk assessment in the modern era. Validation of these findings in other large data sets is planned.
    Article · Sep 2015 · British Journal of Haematology
  • John P Leonard · Sin-Ho Jung · Jeffrey Johnson · [...] · Bruce D Cheson
    [Show abstract] [Hide abstract] ABSTRACT: Lenalidomide and rituximab (LR) are active agents in follicular lymphoma (FL). Combination regimens have not been previously assessed in randomized studies. The Cancer and Leukemia Group B (Alliance) 50401 trial is a randomized phase II trial studying rituximab (375 mg/m(2) weekly for 4 weeks), lenalidomide (15 mg per day on days 1 to 21, followed by 7 days of rest, in cycle 1 and then 20 mg per day on days 1 to 21, followed by 7 days of rest, in cycles 2 to 12), or LR. The rituximab-alone arm was discontinued as a result of poor accrual. Eligibility included recurrent FL and prior rituximab with time to progression of ≥ 6 months from last dose. Aspirin or heparin was recommended for patients at high thrombosis risk. Ninety-one patients (lenalidomide, n = 45; LR, n = 46) received treatment; median age was 63 years (range, 34 to 89 years), and 58% were intermediate or high risk according to the Follicular Lymphoma International Prognostic Index. In the lenalidomide and LR arms, grade 3 to 4 adverse events occurred in 58% and 53% of patients, with 9% and 11% of patients experiencing grade 4 toxicity, respectively; grade 3 to 4 adverse events included neutropenia (16% v 20%, respectively), fatigue (9% v 13%, respectively), and thrombosis (16% [n = 7] v 4% [n = 2], respectively; P = .157). Thirty-six percent of lenalidomide patients and 63% of LR patients completed 12 cycles. Lenalidomide alone was associated with more treatment failures, with 22% of patients discontinuing treatment as a result of adverse events. Dose-intensity exceeded 80% in both arms. Overall response rate was 53% (20% complete response) and 76% (39% complete response) for lenalidomide alone and LR, respectively (P = .029). At the median follow-up of 2.5 years, median time to progression was 1.1 year for lenalidomide alone and 2 years for LR (P = .0023). LR is more active than lenalidomide alone in recurrent FL with similar toxicity, warranting further study in B-cell non-Hodgkin lymphoma as a platform for addition of novel agents. © 2015 by American Society of Clinical Oncology.
    Article · Aug 2015 · Journal of Clinical Oncology
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    Sally F Barrington · N George Mikhaeel · Lale Kostakoglu · [...] · Bruce D Cheson
    Full-text Article · Aug 2015 · Journal of Clinical Oncology
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    Full-text Article · Jul 2015 · Mayo Clinic Proceedings
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    [Show abstract] [Hide abstract] ABSTRACT: Aurora A kinase (AAK) is upregulated in highly proliferative lymphomas, suggesting its potential as a therapeutic target. Alisertib is a novel oral AAK inhibitor without adverse safety signals in early-phase studies that demonstrated preliminary activity in T-cell lymphoma. This phase II study was conducted to further investigate the efficacy of alisertib in relapsed or refractory peripheral T-cell non-Hodgkin lymphoma (PTCL). Eligible patients with histologically confirmed relapsed/refractory PTCL or transformed Mycosis fungoides (tMF) received alisertib 50 mg twice a day for 7 days on 21-day cycles. Of 37 eligible patients, the histologic subtypes enrolled included PTCL not otherwise specified (n = 13), angioimmunoblastic T-cell lymphoma (n = 9), tMF (n = 7), adult T-cell lymphoma/leukemia (n = 4), anaplastic large-cell lymphoma (n = 2), and extranodal natural killer/T-cell lymphoma (n = 2). Grade 3 and 4 adverse events in ≥ 5% of patients included neutropenia (32%), anemia (30%), thrombocytopenia (24%), febrile neutropenia (14%), mucositis (11%), and rash (5%). Treatment was discontinued most commonly for disease progression. Among the PTCL subtypes, the overall response rate was 30%, whereas no responses were observed in tMF. Aurora B kinase was more commonly overexpressed than AAK in tumor specimens. Analysis of AAK, Aurora B kinase, MYC, BCL-2, phosphatidylinositol 3-kinase γ, and Notch1 expression revealed no association with response. Alisertib has antitumor activity in PTCL, including heavily pretreated patients. These promising results are being further investigated in an ongoing international, randomized phase III trial comparing alisertib with investigator's choice in PTCL. © 2015 by American Society of Clinical Oncology.
    Full-text Article · Jun 2015 · Journal of Clinical Oncology
  • Bruce D Cheson
    [Show abstract] [Hide abstract] ABSTRACT: Standardized response criteria for lymphoma are critical for the evaluation of new therapies. Widely adopted recommendations, most recently the Lugano classification, have been developed primarily for assessment of conventional chemotherapeutic regimens. More recently, several classes of drugs, including immunomodulatory agents, B cell receptor pathway targeting kinases, and checkpoint (PD-1, PDL-1) inhibitors have demonstrated impressive activity in a broad range of histologies. However, they may be associated with features during treatment suggestive of progressive disease despite clinical benefit. Immune response criteria have been proposed for solid tumors, and a modification is needed to be more applicable to lymphomas. Following treatment, conservative use of imaging is recommended based on clinical indications. As newer targeted agents with unique mechanisms of action are developed, current response and follow-up criteria must be made sufficiently flexible for optimal evaluation.
    Article · Jun 2015 · Current Oncology Reports
  • [Show abstract] [Hide abstract] ABSTRACT: The phase III North American Intergroup E2496 Trial (Combination Chemotherapy With or Without Radiation Therapy in Treating Patients With Hodgkin's Lymphoma) compared doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) with mechlorethamine, doxorubicin, vincristine, bleomycin, vinblastine, etoposide, and prednisone (Stanford V). We report results of a planned subgroup analysis in patients with stage I or II bulky mediastinal Hodgkin lymphoma (HL). Patients were randomly assigned to six to eight cycles of ABVD every 28 days or Stanford V once per week for 12 weeks. Two to 3 weeks after completion of chemotherapy, all patients received 36 Gy of modified involved field radiotherapy (IFRT) to the mediastinum, hila, and supraclavicular regions. Patients on the Stanford V arm received IFRT to additional sites ≥ 5 cm at diagnosis. Primary end points were failure-free survival (FFS) and overall survival (OS). Of 794 eligible patients, 264 had stage I or II bulky disease, 135 received ABVD, and 129 received Stanford V. Patient characteristics were matched. The overall response rate was 83% with ABVD and 88% with Stanford V. At a median follow-up of 6.5 years, the study excluded a difference of more than 21% in 5-year FFS and more than 16% in 5-year OS between ABVD and Stanford V (5-year FFS: 85% v 79%; HR, 0.68; 95% CI, 0.37 to 1.25; P = .22; 5-year OS: 96% v 92%; HR, 0.49; 95% CI, 0.16 to 1.47; P = .19). In-field relapses occurred in < 10% of the patients in each arm. For patients with stage I or II bulky mediastinal HL, no substantial statistically significant differences were detected between the two regimens, although power was limited. To the best of our knowledge, this is the first prospective trial reporting outcomes specific to this subgroup, and it sets a benchmark for comparison of ongoing and future studies. © 2015 by American Society of Clinical Oncology.
    Article · Apr 2015 · Journal of Clinical Oncology
  • Bruce D Cheson
    [Show abstract] [Hide abstract] ABSTRACT: With each passing year, chemotherapy is less and less a focus of interest. Instead, the focus is on the abundance of exciting new biologic and targeted agents that are bulldozing the therapeutic landscape in the lymphomas and chronic lymphocytic leukemia. Recently, my medical students requested a lecture on the topic of “chemotherapy in hematologic malignancies.” I explained that I was unable to comply because the subject was archaic: with each passing year, chemotherapy is less and less a focus of interest. Instead, the focus is on the abundance of exciting new biologic and targeted agents that are bulldozing the therapeutic landscape in the lymphomas and chronic lymphocytic leukemia, with many of these new agents in oral form and most well-tolerated. In this issue of ONCOLOGY, Drs. Siddiqi and Rosen provide a glimpse of where we are with a number of these new agents in the management of chronic lymphocytic leukemia and non-Hodgkin lymphoma. © 2015, UBM Medica Healthcare Publications. All rights reserved.
    Article · Apr 2015 · Oncology (Williston Park, N.Y.)

Publication Stats

25k Citations

Institutions

  • 2003-2015
    • Georgetown University
      • Division of Hematology and Oncology
      Washington, Washington, D.C., United States
  • 2011
    • Washington Hospital Center
      Washington, Washington, D.C., United States
  • 2008-2010
    • The Harvard Drug Group
      Ливония, Michigan, United States
    • University of Rochester
      • James P. Wilmot Cancer Center
      Rochester, NY, United States
  • 2005-2007
    • University of Cologne
      Köln, North Rhine-Westphalia, Germany
    • University of Nebraska at Omaha
      Omaha, Nebraska, United States
  • 1995-2007
    • National Cancer Institute (USA)
      Maryland, United States
  • 2005-2006
    • University of Iowa
      • Department of Radiology
      Iowa City, IA, United States
  • 2004
    • Universität Ulm
      Ulm, Baden-Württemberg, Germany
  • 2002
    • The Nebraska Medical Center
      Omaha, Nebraska, United States
  • 1998-2002
    • NCI-Frederick
      Фредерик, Maryland, United States
  • 1993
    • The EMMES Corporation
      Роквилл, Maryland, United States
  • 1987
    • University of Utah
      • Department of Biology
      Salt Lake City, UT, United States