Felipe Samaniego

Phase II Study of Proteasome Inhibitor Bortezomib in Relapsed or Refractory B-Cell Non-Hodgkin's Lymphoma

PURPOSE Evaluate efficacy and toxicity of bortezomib in patients with relapsed or refractory B-cell non-Hodgkins lymphoma. PATIENTS AND METHODS Patients were stratified, based on preclinical data, into arm A (mantle-cell lymphoma) or arm B (other B-cell lymphomas) without limitation in number of prior therapies. Bortezomib was administered as an intravenous push (1.5 mg/m2) on days 1, 4, 8, and 11 every 21 days for a maximum of six cycles. RESULTS Sixty patients with a median number of prior therapies of 3.5 (range, one to 12 therapies) were enrolled; 33 patients were in arm A and 27 were in arm B, including 12 diffuse large B-cell lymphomas, five follicular lymphomas (FL), three transformed FLs, four small lymphocytic lymphomas (SLL), two Waldenstroms macroglobulinemias (WM), and one marginal zone lymphoma. In arm A, 12 of 29 assessable patients responded (six complete responses [CR] and six partial responses [PR]) for an overall response rate (ORR) of 41% (95% CI, 24% to 61%), and a median time to progression not reached yet, with a median follow-up of 9.3 months (range, 1.7 to 24 months). In arm B, four of 21 assessable patients responded (one SLL patient had a CR, one FL patient had a CR unconfirmed, one diffuse large B-cell lymphoma patient had a PR, and one WM patient had a PR) for an ORR of 19% (95% CI, 5% to 42%). Grade 3 toxicity included thrombocytopenia (47%), gastrointestinal (20%), fatigue (13%), neutropenia (10%), and peripheral neuropathy (5%). Grade 4 toxicity occurred in nine patients (15%), and three deaths from progression of disease occurred within 30 days of withdrawal from study. CONCLUSION Bortezomib showed promising activity in relapsed mantle-cell lymphoma and encouraging results in other B-cell lymphomas. Future studies will explore bortezomib in combination with other cytotoxic or biologic agents.

High Rate of Durable Remissions After Treatment of Newly Diagnosed Aggressive Mantle-Cell Lymphoma With Rituximab Plus Hyper-CVAD Alternating With Rituximab Plus High-Dose Methotrexate and Cytarabine

PURPOSE To determine the response, failure-free survival (FFS), and overall survival rates and toxicity of rituximab plus an intense chemotherapy regimen in patients with previously untreated aggressive mantle-cell lymphoma (MCL). PATIENTS AND METHODS This was a prospective phase II trial of rituximab plus fractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (hyper-CVAD; considered one cycle) alternating every 21 days with rituximab plus high-dose methotrexate-cytarabine (considered one cycle) for a total of six to eight cycles. RESULTS Of 97 assessable patients, 97% responded, and 87% achieved a complete response (CR) or unconfirmed CR. With a median follow-up time of 40 months, the 3-year FFS and overall survival rates were 64% and 82%, respectively, without a plateau in the curves. For the subgroup of patients < or = 65 years of age, the 3-year FFS rate was 73%. The principal toxicity was hematologic. Five patients died from acute toxicity. Four patients developed treatment-related myelodysplasia/acute myelogenous leukemia, and three patients died while in remission from MCL. A total of eight treatment-related deaths (8%) occurred. CONCLUSION Rituximab plus hyper-CVAD alternating with rituximab plus high-dose methotrexate and cytarabine is effective in untreated aggressive MCL. Toxicity is significant but expected. Because of the shorter FFS concurrent with significant toxicity in patients more than 65 years of age, this regimen is not recommended as standard therapy for this age subgroup. Larger prospective randomized studies are needed to define the role of this regimen in the treatment of MCL patients compared with existing and new treatment modalities.

HIV-1 Tat protein exits from cells via a leaderless secretory pathway and binds to extracellular matrix-associated heparan sulfate proteoglycans through its basic region.

Objective:To analyze the mechanisms of release and the extracellular fate of the HIV-1 Tat protein and to determine the Tat domain binding to the extracellular matrix. Design and methods:Release of Tat was studied by pulse-chase experiments with Tat-transfected COS-1 cells in the presence or absence of different serum concentrations, temperatures and drugs inhibiting the classical secretion pathway or endo-exocytosis, such as brefeldin A and methylamine. The binding of extracellular Tat to heparan sulfate proteoglycans (HSPG) was determined by using trypsin, heparin or heparinase in pulse-chase experiments, by gel shift and competition assays with radiolabeled heparin, and by heparin-affinity chromatography. The mapping of the Tat binding site to heparin was defined by functional assays of rescue of Tat-defective HIV-1 proviruses. Results:Tat is released in the absence of cell death or permeability changes. Tat release is dependent upon the temperature and serum concentration, and it is not blocked by brefeldin A or methylamine. After release, a portion of the protein remains in a soluble form whereas the other binds to extracellular matrix (ECM)- associated HSPG. The HSPG-bound Tat can be retrieved into a soluble form by heparin, heparinase or trypsin. Binding to heparin is competed out by heparin-binding factors such as basic fibroblast growth factor (bFGF), and it is mediated by the Tat basic region which forms a specific complex with heparin which blocks HIV-1 rescue by exogenous Tat and allows purification of a highly biologically active protein. Conclusions:These results demonstrate that Tat exits from intact cells through a leaderless secretion pathway which shares several features with that of acid FGF or bFGF. The released Tat binds to HSPG through its basic region and this determines its storage into the ECM, as occurs for bFGF.

Safety and Activity of PD1 Blockade by Pidilizumab in Combination with Rituximab in Patients with Relapsed Follicular Lymphoma: a Single Group, Open-label, Phase 2 Trial

BACKGROUND Endogenous or iatrogenic antitumour immune responses can improve the course of follicular lymphoma, but might be diminished by immune checkpoints in the tumour microenvironment. These checkpoints might include effects of programmed cell death 1 (PD1), a co-inhibitory receptor that impairs T-cell function and is highly expressed on intratumoral T cells. We did this phase 2 trial to investigate the activity of pidilizumab, a humanised anti-PD1 monoclonal antibody, with rituximab in patients with relapsed follicular lymphoma. METHODS We did this open-label, non-randomised trial at the University of Texas MD Anderson Cancer Center (Houston, TX, USA). Adult (≥18 years) patients with rituximab-sensitive follicular lymphoma relapsing after one to four previous therapies were eligible. Pidilizumab was administered at 3 mg/kg intravenously every 4 weeks for four infusions, plus eight optional infusions every 4 weeks for patients with stable disease or better. Starting 17 days after the first infusion of pidilizumab, rituximab was given at 375 mg/m(2) intravenously weekly for 4 weeks. The primary endpoint was the proportion of patients who achieved an objective response (complete response plus partial response according to Revised Response Criteria for Malignant Lymphoma). Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00904722. FINDINGS We enrolled 32 patients between Jan 13, 2010, and Jan 20, 2012. Median follow-up was 15.4 months (IQR 10.1-21.0). The combination of pidilizumab and rituximab was well tolerated, with no autoimmune or treatment-related adverse events of grade 3 or 4. The most common adverse events of grade 1 were anaemia (14 patients) and fatigue (13 patients), and the most common adverse event of grade 2 was respiratory infection (five patients). Of the 29 patients evaluable for activity, 19 (66%) achieved an objective response: complete responses were noted in 15 (52%) patients and partial responses in four (14%). INTERPRETATION The combination of pidilizumab plus rituximab is well tolerated and active in patients with relapsed follicular lymphoma. Our results suggest that immune checkpoint blockade is worthy of further study in follicular lymphoma. FUNDING National Institutes of Health, Leukemia and Lymphoma Society, Cure Tech, and University of Texas MD Anderson Cancer Center.

Eight-year experience with allogeneic stem cell transplantation for relapsed follicular lymphoma after nonmyeloablative conditioning with fludarabine, cyclophosphamide, and rituximab

Nonmyeloablative stem cell transplantation in patients with follicular lymphoma has been designed to exploit the graft-versus-lymphoma immunity. The long-term effectiveness and toxicity of this strategy, however, is unknown. In this prospective study, we analyzed our 8-year experience. Patients received a conditioning regimen of fludarabine (30 mg/m(2) daily for 3 days), cyclophosphamide (750 mg/m(2) daily for 3 days), and rituximab (375 mg/m(2) for 1 day plus 1000 mg/m(2) for 3 days). They were then given an infusion of human leukocyte antigen-matched hematopoietic cells from related (n = 45) or unrelated donors (n = 2). Tacrolimus and methotrexate were used for graft-versus-host disease (GVHD) prophylaxis. Forty-seven patients were included. All patients experienced complete remission, with only 2 relapses. With a median follow-up time of 60 months (range, 19-94), the estimated survival and progression-free survival rates were 85% and 83%, respectively. All 18 patients who were tested and had evidence of JH/bcl-2 fusion transcripts in the bone marrow at study entry experienced continuous molecular remission. The incidence of grade 2-IV acute GVHD was 11%. Only 5 patients were still undergoing immunosuppressive therapy at the time of last follow-up. We believe that the described results are a step forward toward developing a curative strategy for recurrent follicular lymphoma.

Lenalidomide in combination with rituximab for patients with relapsed or refractory mantle-cell lymphoma: a phase 1/2 clinical trial

BACKGROUND The combination of rituximab and lenalidomide has shown promise for the treatment of mantle-cell lymphoma (MCL) in preclinical studies. We aimed to identify the maximum tolerated dose (MTD) of lenalidomide when combined with rituximab in a phase 1 trial and to assess the efficacy and safety of this combination in a phase 2 trial in patients with relapsed or refractory MCL. METHODS Patients with relapsed or refractory MCL who had received one to four previous lines of treatment were enrolled in this single-arm, open-label, phase 1/2 trial at MD Anderson Cancer Center. In phase 1, to identify the MTD of lenalidomide, four patient cohorts received escalating doses (10, 15, 20, and 25 mg) of daily oral lenalidomide on days 1-21 of each 28-day cycle. 375 mg/m(2) intravenous rituximab was also administered in four weekly doses during cycle 1 only. In phase 2, patients received rituximab plus the MTD of lenalidomide, following the same cycles as for phase 1. Treatment in both phases continued until disease progression, stem-cell transplantation, or severe toxicity. The primary efficacy endpoint was overall response (complete or partial response). The secondary efficacy endpoint was survival. We used the Kaplan-Meier method to estimate response duration, progression-free survival, and overall survival. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00294632. FINDINGS 52 patients were enrolled between Feb 10, 2006 and July 30, 2009, 14 in phase 1 and 44 (including six patients who received the MTD of lenalidomide in the phase 1 portion) in phase 2. The MTD was 20 mg lenalidomide. One patient who was treated with 25 mg lenalidomide developed a grade 4 non-neutropenic infection and died. In the phase 2 portion of the study, grade 3-4 haematological toxicities included neutropenia (29 patients), lymphopenia (16 patients), leucopenia (13 patients), and thrombocytopenia (ten patients). There were only two episodes of febrile neutropenia. Among 44 patients in phase 2, 25 (57%) had an overall response: 16 (36%) had a complete response and nine (20%) had a partial response. The median response duration was 18·9 months (95% CI 17·0 months to not reached [NR]). The median progression-free survival was 11·1 months (95% CI 8·3 to 24·9 months), and the median overall survival was 24·3 months (19·8 months to NR). Five of 14 patients who had received bortezomib treatment before enrolment achieved an overall response. INTERPRETATION Oral lenalidomide plus rituximab is well tolerated and effective for patients with relapsed or refractory MCL. FUNDING Celgene.

Ten-year follow-up after intense chemoimmunotherapy with Rituximab-HyperCVAD alternating with Rituximab-high dose methotrexate/cytarabine (R-MA) and without stem cell transplantation in patients with untreated aggressive mantle cell lymphoma

Mantle cell lymphoma (MCL) has a poor overall survival after treatment with conventional chemotherapy. Intense chemoimmunotherapy without consolidation stem cell transplantation is a potential therapeutic option. We report on a prospective Phase II study with rituximab in combination with fractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone (R‐Hyper‐CVAD) alternating with rituximab in combination with high‐dose methotrexate‐cytarabine (R‐MA) in untreated patients with diffuse and nodular MCL and their blastoid variants. Ninety‐seven patients were treated, of whom 97% responded and 87% achieved a complete remission. At 10 years of follow up (median 8 years), the median overall survival (OS) for all patients had not been reached and the median time to failure (TTF) for all patients was 4.6 years, without a plateau in the curves. For the group of patients aged 65 years or younger, the median OS had not been reached and the median TTF was 5.9 years. Multivariate analysis revealed pre‐treatment serum levels of β2 microglobulin, International Prognostic Index (IPI) score and mantle cell IPI (MIPI) score, as predictive of both OS and TTF. We conclude that intense chemoimmunotherapy without stem cell transplantation is effective for untreated aggressive MCL.

Double hit lymphoma: The MD Anderson Cancer Center clinical experience

We report our experience with 129 cases of double hit lymphoma (DHL), defined as B‐cell lymphoma with translocations and/or extra signals involving MYC plus BCL2 and/or BCL6. All cases were reviewed for histopathological classification. Median age was 62 years (range, 18–85), 84% of patients had advanced‐stage disease, and 87% had an International Prognostic Index score ≥2. Fourteen patients (11%) had a history of low‐grade follicular lymphoma. MYC translocation was present in 81%, and extra signals of MYC in 25% of patients. IGH‐BCL2 translocation was present in 84% and extra signals of BCL2 in 12% of patients. Two‐year event‐free survival (EFS) rates in all patients and patients who received R‐CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone), R‐EPOCH (rituximab, etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin), and R‐HyperCVAD/MA (rituximab, hyperfractionated cyclophosphamide, vincristine, doxorubicin, dexamethasone, alternating with cytarabine plus methotrexate) were 33%, 25%, 67% and 32%, respectively. In patients achieving complete response with initial therapy (n = 71), 2‐year EFS rates in patients who did (n = 23) or did not (n = 48) receive frontline stem cell transplantation were 68% and 53%, respectively (P = 0·155). The cumulative incidence of central nervous system involvement was 13% at 3 years. Multivariate analysis identified performance status ≥2 and bone marrow involvement as independent adverse prognostic factors for EFS and OS. Further research is needed to identify predictive and/or targetable biological markers and novel therapeutic approaches for DHL patients.

Safety and activity of lenalidomide and rituximab in untreated indolent lymphoma: an open-label, phase 2 trial

BACKGROUND Standard treatments for indolent non-Hodgkin lymphomas are often toxic, and most patients ultimately relapse. Lenalidomide, an immunomodulatory agent, is effective as monotherapy for relapsed indolent non-Hodgkin lymphoma. We assessed the efficacy and safety of lenalidomide plus rituximab in patients with untreated, advanced stage indolent non-Hodgkin lymphoma. METHODS In this phase 2 trial, undertaken at one instution, patients with follicular lymphoma and marginal zone lymphoma were given lenalidomide, orally, at 20 mg/day on days 1-21 of each 28-day cycle. For patients with small lymphocytic lymphoma, dosing began at 10 mg/day to avoid tumour flare, with an escalation of 5 mg/month to 20 mg/day. Rituximab was given at 375 mg/m(2) as an intravenous infusion on day 1 of each cycle. Patients responding after six cycles could continue therapy for up to 12 cycles. The primary endpoint was overall response, defined as the proportion of patients who achieved a partial or complete response; patients were assessed for response if they had any post-baseline tumour assessment. This trial is registered with ClinicalTrials.gov, number NCT00695786. FINDINGS 110 patients with follicular lymphoma (n=50), marginal zone lymphoma (n=30), and small lymphocytic lymphoma (n=30) were enrolled from June 30, 2008, until Aug 12, 2011. 93 of 103 evaluable patients had an overall response (90%, 95% CI 83-95). Complete responses occurred in 65 (63%, 95% CI 53-72) and partial responses in 28 patients (27%, 19-37). Of 46 evaluable patients with follicular lymphoma, 40 (87%) patients had a complete response and five (11%) had a partial response. Of 27 evaluable patients with marginal zone lymphoma, 18 (67%) had a complete response and six (22%) had a partial response. Of 30 evaluable patients with small lymphocytic lymphoma, seven (23%) had a complete response and 17 (57%) had a partial response. The most common grade 3 or 4 adverse events were neutropenia (38 [35%] of 110 patients), muscle pain (ten [9%]), rash (eight [7%]), cough, dyspnoea, or other pulmonary symptoms (five [5%]), fatigue (five [5%]), thrombosis (five [5%]), and thrombocytopenia (four [4%]). INTERPRETATION Lenalidomide plus rituximab is well tolerated and highly active as initial treatment for indolent non-Hodgkin lymphoma. An international phase 3 study (NCT01476787) to compare this regimen with chemotherapy in patients with untreated follicular lymphoma is in progress. FUNDING Celgene Corporation and Richard Spencer Lewis Memorial Foundation and Cancer Center Support Grant.

Phase II trial of denileukin diftitox for relapsed/refractory T-cell non-Hodgkin lymphoma

This phase II study evaluated the safety and efficacy of denileukin diftitox, an interleukin‐2–diphtheria toxin fusion protein, in relapsed/refractory T‐cell non‐Hodgkin lymphoma (T‐NHL), excluding cutaneous T‐cell lymphoma. Eligible patients received denileukin diftitox 18 μg/kg/d × 5 d every 3 weeks for up to eight cycles. Tumour staging was performed every two cycles and the primary endpoint was the objective response rate [complete response (CR) + partial response (PR)]. For 27 patients enrolled, median age: 55 years (range 26–80 years), 70·4% male, and mean prior therapies: 2·5 (range 1–6). Objective responses (six CRs, seven PRs) were achieved in 13 patients (48·1%), stable disease in eight (29·6%) and six (22·2%) had progressive disease. An objective response was achieved in eight of 13 patients (61·5%) with CD25+ tumours (four CR/four PR) and five of 11 patients (45·5%) with CD25− tumours (two CR/three PR). Median progression‐free survival was 6 months (range, 1–38+ months). Most adverse reactions were grade 1/2 and transient. No grade 4–5 toxicities were reported. Denileukin diftitox had significant activity and was well tolerated in relapsed/refractory T‐NHL, with responses observed in both CD25+ and CD25− tumours. Further studies of denileukin diftitox in combination with other agents are warranted in previously untreated and relapsed/refractory T‐NHL.