Kieron Dunleavy

Navitoclax, a targeted high-affinity inhibitor of BCL-2, in lymphoid malignancies: a phase 1 dose-escalation study of safety, pharmacokinetics, pharmacodynamics, and antitumour activity.

BACKGROUND Proteins of the BCL-2 family regulate clonal selection and survival of lymphocytes, and are frequently overexpressed in lymphomas. Navitoclax is a targeted high-affinity small molecule that inhibits the anti-apoptotic activity of BCL-2 and BCL-XL. We aimed to assess the safety and antitumour activity of navitoclax in patients with lymphoid tumours, and establish the drugs pharmacokinetic and pharmacodynamic profiles. METHODS In this phase 1 dose-escalation study, patients (aged ≥18 years) with relapsed or refractory lymphoid malignancies were enrolled and treated at seven sites in the USA between November, 2006, and November, 2009. A modified Fibonacci 3+3 design was used to assign patients to receive oral navitoclax once daily by one of two dosing schedules: intermittently for the first 14 days of a 21-day cycle (14/21) at doses of 10, 20, 40, 80, 110, 160, 225, 315, or 440 mg/day; or continuously for 21 days of a 21-day cycle (21/21) at doses of 200, 275, 325, or 425 mg/day. Study endpoints were safety, maximum tolerated dose, pharmacokinetic profile, pharmacodynamic effects on platelets and T cells, and antitumour activity. This trial is registered with ClinicalTrials.gov, number NCT00406809. FINDINGS 55 patients were enrolled (median age 59 years, IQR 51-67), 38 to receive the 14/21 dosing schedule, and 17 to receive the 21/21 dosing schedule. Common toxic effects included grade 1 or 2 anaemia (41 patients), infection (39), diarrhoea (31), nausea (29), and fatigue (21); and grade 3 or 4 thrombocytopenia (29), lymphocytopenia (18), and neutropenia (18). On the intermittent 14/21 schedule, dose-limiting toxic effects were hospital admissions for bronchitis (one) and pleural effusion (one), grade 3 increase in aminotransferases (one), grade 4 thrombocytopenia (one), and grade 3 cardiac arrhythmia (one). To reduce platelet nadir associated with intermittent 14/21 dosing, we assessed a 150 mg/day lead-in dose followed by a continuous 21/21 dosing schedule. On the 21/21 dosing schedule, two patients did not complete the first cycle and were excluded from assessment of dose-limiting toxic effects; dose-limiting toxic effects were grade 4 thrombocytopenia (one), grade 3 increase in aminotransferases (one), and grade 3 gastrointestinal bleeding (one). Navitoclax showed a pharmacodynamic effect on circulating platelets and T cells. Clinical responses occurred across the range of doses and in several tumour types. Ten of 46 patients with assessable disease had a partial response, and these responders had median progression-free survival of 455 days (IQR 40-218). INTERPRETATION Navitoclax has a novel mechanism of peripheral thrombocytopenia and T-cell lymphopenia, attributable to high-affinity inhibition of BCL-XL and BCL-2, respectively. On the basis of these findings, a 150 mg 7-day lead-in dose followed by a 325 mg dose administered on a continuous 21/21 dosing schedule was selected for phase 2 study. FUNDING Abbott Laboratories, Genentech, and National Cancer Institute, National Institutes of Health.

Differential efficacy of bortezomib plus chemotherapy within molecular subtypes of diffuse large B-cell lymphoma

Gene expression profiling of diffuse large B-cell lymphoma (DLBCL) has revealed distinct molecular subtypes that include germinal center B cell-like (GCB) and activated B cell-like (ABC) DLBCL. ABC DLBCL has a worse survival after upfront chemotherapy and is characterized by constitutive activation of the antiapoptotic nuclear factor-kappa B (NF-kappaB) pathway, which can inhibit chemotherapy. We hypothesized that inhibition of NF-kappaB might sensitize ABC but not GCB DLBCL to chemotherapy and improve outcome. As the proteasome inhibitor bortezomib can inhibit NF-kappaB through blocking IkappaBalpha degradation, we investigated bortezomib alone followed by bortezomib and doxorubicin-based chemotherapy in recurrent DLBCL. Tumor tissue was analyzed by gene expression profiling and/or immunohistochemistry to identify molecular DLBCL subtypes. As a control, we showed that relapsed/refractory ABC and GCB DLBCL have equally poor survivals after upfront chemotherapy. Bortezomib alone had no activity in DLBCL, but when combined with chemotherapy, it demonstrated a significantly higher response (83% vs 13%; P < .001) and median overall survival (10.8 vs 3.4 months; P = .003) in ABC compared with GCB DLBCL, respectively. These results suggest bortezomib enhances the activity of chemotherapy in ABC but not GCB DLBCL, and provide a rational therapeutic approach based on genetically distinct DLBCL subtypes. This trial is registered with http://www.ClinicalTrials.gov under identifier NCT00057902.

Dose-adjusted EPOCH-rituximab therapy in primary mediastinal B-cell lymphoma.

BACKGROUND Primary mediastinal B-cell lymphoma is a distinct subtype of diffuse large-B-cell lymphoma that is closely related to nodular sclerosing Hodgkins lymphoma. Patients are usually young and present with large mediastinal masses. There is no standard treatment, but the inadequacy of immunochemotherapy alone has resulted in routine consolidation with mediastinal radiotherapy, which has potentially serious late effects. We aimed to develop a strategy that improves the rate of cure and obviates the need for radiotherapy. METHODS We conducted a single-group, phase 2, prospective study of infusional dose-adjusted etoposide, doxorubicin, and cyclophosphamide with vincristine, prednisone, and rituximab (DA-EPOCH-R) and filgrastim without radiotherapy in 51 patients with untreated primary mediastinal B-cell lymphoma. We used results from a retrospective study of DA-EPOCH-R from another center to independently verify the outcomes. RESULTS The patients had a median age of 30 years (range, 19 to 52) and a median tumor diameter of 11 cm; 59% were women. During a median of 5 years of follow-up, the event-free survival rate was 93%, and the overall survival rate was 97%. Among the 16 patients who were involved in the retrospective analysis at another center, over a median of 3 years of follow-up, the event-free survival rate was 100%, and no patients received radiotherapy. No late morbidity or cardiac toxic effects were found in any patients. After follow-up ranging from 10 months to 14 years, all but 2 of the 51 patients (4%) who received DA-EPOCH-R alone were in complete remission. The 2 remaining patients received radiotherapy and were disease-free at follow-up. CONCLUSIONS Therapy with DA-EPOCH-R obviated the need for radiotherapy in patients with primary mediastinal B-cell lymphoma. (Funded by the National Cancer Institute; ClinicalTrials.gov number, NCT00001337.).

Phase II Study of Dose-Adjusted EPOCH and Rituximab in Untreated Diffuse Large B-Cell Lymphoma With Analysis of Germinal Center and Post-Germinal Center Biomarkers

PURPOSE To assess the clinical outcome and the influence of biomarkers associated with apoptosis inhibition (Bcl-2), tumor proliferation (MIB-1), and cellular differentiation on the outcome with dose-adjusted (DA) EPOCH (etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin) plus rituximab (R) infusional therapy in diffuse large B-cell lymphoma (DLBCL) with analysis of germinal center B-cell (GCB) and post-GCB subtypes by immunohistochemistry. PATIENTS AND METHODS Phase II study of 72 patients with untreated de novo DLBCL who were at least 18 years of age and stage II or higher. Radiation consolidation was not permitted. RESULTS Patients had a median age of 50 years (range, 19 to 85) and 40% had a high-intermediate or high International Prognostic Index (IPI). At 5 years, progression-free survival (PFS) and overall survival (OS) were 79% and 80%, respectively, with a median potential follow-up of 54 months. PFS was 91%, 90%, 67%, and 47%, and OS was 100%, 90%, 74%, and 37%, for 0 to 1, 2, 3, and 4 to 5 IPI factors, respectively, at 5 years. The Bcl-2 and MIB-1 biomarkers were not associated with PFS or OS. Based on DA-EPOCH historical controls, rituximab only benefited Bcl-2 positive tumors. Bcl-6 expression was associated with higher PFS whereas GCB exhibited a marginally significant higher PFS compared with post-GCB DLBCL. CONCLUSION DA-EPOCH-R outcome was not affected by tumor proliferation and rituximab appeared to overcome the adverse effect of Bcl-2. Bcl-6 may identify a biologic program associated with a superior outcome. Overall, DA-EPOCH-R shows promising outcome in low and intermediate IPI groups. A molecular model of treatment outcome with rituximab and chemotherapy is presented.

Low-Intensity Therapy in Adults with Burkitt’s Lymphoma

BACKGROUND Burkitts lymphoma is an aggressive B-cell lymphoma that occurs in children and adults and is largely curable with the use of intensive and toxic chemotherapy. Current treatments are less effective and have more severe side effects in adults and patients with immunodeficiency than in children. METHODS We studied low-intensity treatment consisting of infused etoposide, doxorubicin, and cyclophosphamide with vincristine, prednisone, and rituximab (EPOCH-R) in patients with untreated Burkitts lymphoma. Two EPOCH-R regimens were tested: a standard dose-adjusted combination in human immunodeficiency virus (HIV)-negative patients (DA-EPOCH-R group) and a lower-dose short-course combination with a double dose of rituximab in HIV-positive patients (SC-EPOCH-RR group). RESULTS A total of 30 consecutive patients were treated; 19 patients were in the DA-EPOCH-R group, and 11 in the SC-EPOCH-RR group. The overall median age of the patients was 33 years, and 40% were 40 years of age or older; 73% of the patients had intermediate-risk disease, and 10% had high-risk disease. The principal toxic events, fever and neutropenia, were observed during 22% of the DA-EPOCH-R treatment cycles and 10% of the SC-EPOCH-RR treatment cycles. The tumor lysis syndrome developed in 1 patient; no treatment-related deaths occurred. The median cumulative doses of doxorubicin-etoposide and cyclophosphamide administered in the SC-EPOCH-RR group were 47% and 57% lower, respectively, than those administered in the DA-EPOCH-R group. With median follow-up times of 86 months in the DA-EPOCH-R group and 73 months in the SC-EPOCH-RR group, the rates of freedom from progression of disease and overall survival were, respectively, 95% and 100% with DA-EPOCH-R and 100% and 90% with SC-EPOCH-RR. None of the patients died from Burkitts lymphoma. CONCLUSIONS In this uncontrolled prospective study, low-intensity EPOCH-R-based treatment was highly effective in adults with sporadic or immunodeficiency-associated Burkitts lymphoma. (Funded by the National Cancer Institute; ClinicalTrials.gov numbers, NCT00001337 and NCT00006436.).

Circulating tumour DNA and CT monitoring in patients with untreated diffuse large B-cell lymphoma: a correlative biomarker study

BACKGROUND Diffuse large-B-cell lymphoma is curable, but when treatment fails, outcome is poor. Although imaging can help to identify patients at risk of treatment failure, they are often imprecise, and radiation exposure is a potential health risk. We aimed to assess whether circulating tumour DNA encoding the clonal immunoglobulin gene sequence could be detected in the serum of patients with diffuse large-B-cell lymphoma and used to predict clinical disease recurrence after frontline treatment. METHODS We used next-generation DNA sequencing to retrospectively analyse cell-free circulating tumour DNA in patients assigned to one of three treatment protocols between May 8, 1993, and June 6, 2013. Eligible patients had diffuse large-B-cell lymphoma, no evidence of indolent lymphoma, and were previously untreated. We obtained serial serum samples and concurrent CT scans at specified times during most treatment cycles and up to 5 years of follow-up. VDJ gene segments of the rearranged immunoglobulin receptor genes were amplified and sequenced from pretreatment specimens and serum circulating tumour DNA encoding the VDJ rearrangements was quantitated. FINDINGS Tumour clonotypes were identified in pretreatment specimens from 126 patients who were followed up for a median of 11 years (IQR 6·8-14·2). Interim monitoring of circulating tumour DNA at the end of two treatment cycles in 108 patients showed a 5-year time to progression of 41·7% (95% CI 22·2-60·1) in patients with detectable circulating tumour DNA and 80·2% (69·6-87·3) in those without detectable circulating tumour DNA (p<0·0001). Detectable interim circulating tumour DNA had a positive predictive value of 62·5% (95% CI 40·6-81·2) and a negative predictive value of 79·8% (69·6-87·8). Surveillance monitoring of circulating tumour DNA was done in 107 patients who achieved complete remission. A Cox proportional hazards model showed that the hazard ratio for clinical disease progression was 228 (95% CI 51-1022) for patients who developed detectable circulating tumour DNA during surveillance compared with patients with undetectable circulating tumour DNA (p<0·0001). Surveillance circulating tumour DNA had a positive predictive value of 88·2% (95% CI 63·6-98·5) and a negative predictive value of 97·8% (92·2-99·7) and identified risk of recurrence at a median of 3·5 months (range 0-200) before evidence of clinical disease. INTERPRETATION Surveillance circulating tumour DNA identifies patients at risk of recurrence before clinical evidence of disease in most patients and results in a reduced disease burden at relapse. Interim circulating tumour DNA is a promising biomarker to identify patients at high risk of treatment failure. FUNDING National Cancer Institute and Adaptive Biotechnologies.

The role of tumor histogenesis, FDG-PET, and short course EPOCH with dose-dense rituximab (SC-EPOCH-RR) in HIV-associated diffuse large B-cell lymphoma

This is a phase 2 study to assess the role of tumor histogenesis (subtype), fluorodeoxyglucose positron emission tomography (FDG-PET), and short-course etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin with dose-dense rituximab (SC-EPOCH-RR) in newly diagnosed HIV-associated CD20(+) diffuse large B-cell lymphoma. Patients received a minimum of 3 and a maximum of 6 cycles with 1 cycle beyond stable radiographic and FDG-PET scans. Overall, 79% of patients received 3 cycles. Combination antiretroviral therapy was suspended before and resumed after therapy. Thirty-three enrolled patients had a median age of 42 years (range, 9-61 years), and 76% had a high-intermediate or high age-adjusted international prognostic index. At 5 years median follow-up, progression-free and overall survival were 84% and 68%, respectively. There were no treatment-related deaths or new opportunistic infections during treatment, and patients had sustained CD4 cell count recovery and HIV viral control after treatment. FDG-PET after 2 cycles had an excellent negative but poor positive predictive value. Tumor histogenesis was the only characteristic associated with lymphoma-specific outcome with 95% of germinal center B-cell (GCB) versus 44% of non-GCB diffuse large B-cell lymphoma (DLBCL) progression-free at 5 years. SC-EPOCH-RR is highly effective and less immunosuppressive with shorter duration therapy compared with standard strategies. However, new therapeutic advances are needed for non-GCB DLBCL, which remains the important cause of lymphoma-specific death. This trial was registered at www.clinicaltrials.gov as NCT000019253.

A cancer and Leukemia Group B multi-center study of DA-EPOCH-rituximab in untreated diffuse large B-cell lymphoma with analysis of outcome by molecular subtype

Background A phase II trial of dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin and rituximab (DA-EPOCH-R) from the National Cancer Institute showed promising activity in untreated diffuse large B-cell lymphoma. The Cancer and Leukemia Group B conducted a study to determine if these results could be reproduced in a multi-institutional setting. Design and Methods The study included 69 patients with untreated diffuse large B-cell lymphoma at least 18 years of age and at least stage II. Radiaton therapy was not permitted on study. Median age was 58 years (range 23–83) and 40% had high-intermediate or high International Prognostic Index risk. Immunohistochemical biomarkers for cell of origin and proliferation were performed. Results With a median follow up of 62 months, time to progression and overall survival were 81% and 84%, respectively, and time to progression was 87%, 92% and 54% for low/low-intermediate, high-intermediate and high International Prognostic Index risk groups, respectively, at 5-years and beyond. The time to progression and event-free survival of germinal center B-cell lymphoma were 100% and 94%, respectively, and non-germinal center B-cell GCB diffuse large B-cell lymphoma were 67% and 58%, respectively, at 62 months (germinal center vs. non-germinal center B cell P=0.008). DA-EPOCH-R was tolerated without significant grade 4 non-hematologic toxicities. Conclusions These results provide the first confirmation by a multi-institutional group that DA-EPOCH-R provides high durable remissions in diffuse large B-cell lymphoma and is effective in both germinal center and non-germinal center B-cell subtypes. The trial was registered at ClinicalTrials.Gov (NCT00032019).

Vaccine-induced tumor-specific immunity despite severe B-cell depletion in mantle cell lymphoma

The role of B cells in T-cell priming is unclear, and the effects of B-cell depletion on immune responses to cancer vaccines are unknown. Although results from some mouse models suggest that B cells may inhibit induction of T cell–dependent immunity by competing with antigen-presenting cells for antigens, skewing T helper response toward a T helper 2 profile and/or inducing T-cell tolerance, results from others suggest that B cells are necessary for priming as well as generation of T-cell memory. We assessed immune responses to a well-characterized idiotype vaccine in individuals with severe B-cell depletion but normal T cells after CD20-specific antibody–based chemotherapy of mantle cell lymphoma in first remission. Humoral antigen- and tumor-specific responses were detectable but delayed, and they correlated with peripheral blood B-cell recovery. In contrast, vigorous CD4+ and CD8+ antitumor type I T-cell cytokine responses were induced in most individuals in the absence of circulating B cells. Analysis of relapsing tumors showed no mutations or change in expression of target antigen to explain escape from therapy. These results show that severe B-cell depletion does not impair T-cell priming in humans. Based on these results, it is justifiable to administer vaccines in the setting of B-cell depletion; however, vaccine boosts after B-cell recovery may be necessary for optimal humoral responses.

Angioimmunoblastic T cell lymphoma: pathobiological insights and clinical implications.

Purpose of reviewAngioimmunoblastic T cell lymphoma is a complex lymphoproliferative disorder. While recent evidence suggests that the Epstein–Barr virus and B cell disregulation are implicated in the diseases pathogenesis, their mechanistic roles remain largely unknown. The prognosis with traditional chemotherapy has been poor, but improved understanding of the diseases pathobiology has led to several promising novel therapeutic strategies. Recent findingsThe recent finding of overexpression of the chemokine CXCL13 by the neoplastic cells of angioimmunoblastic T cell lymphoma suggests that it is derived from follicular helper T cells. In addition, gene-expression profiling has demonstrated overexpression of several genes characteristic of follicular helper T cells. Vascular endothelial growth factor-A is also highly expressed. Novel therapeutic strategies including immunomodulation with agents like cyclosporine and angiogenesis inhibition with drugs such as bevacizumab are being investigated, and show early promise in this disease. SummaryDiseases such as angioimmunoblastic T cell lymphoma can help illuminate the biology of the normal immune system. Significant progress has been made in understanding the biology of angioimmunoblastic T cell lymphoma. This has paved the way for the development of new therapeutic strategies and these have shown interesting results.