Anne W. Beaven

Venetoclax plus rituximab in relapsed or refractory chronic lymphocytic leukaemia: a phase 1b study.

BACKGROUND Selective BCL2 inhibition with venetoclax has substantial activity in patients with relapsed or refractory chronic lymphocytic leukaemia. Combination therapy with rituximab enhanced activity in preclinical models. The aim of this study was to assess the safety, pharmacokinetics, and activity of venetoclax in combination with rituximab. METHODS Adult patients with relapsed or refractory chronic lymphocytic leukaemia (according to the 2008 Modified International Workshop on CLL guidelines) or small lymphocytic lymphoma were eligible for this phase 1b, dose-escalation trial. The primary outcomes were to assess the safety profile, to determine the maximum tolerated dose, and to establish the recommended phase 2 dose of venetoclax when given in combination with rituximab. Secondary outcomes were to assess the pharmacokinetic profile and analyse efficacy, including overall response, duration of response, and time to tumour progression. Minimal residual disease was a protocol-specified exploratory objective. Central review of the endpoints was not done. Venetoclax was dosed daily using a stepwise escalation to target doses (200-600 mg) and then monthly rituximab commenced (375 mg/m2 in month 1 and 500 mg/m2 in months 2-6). Adverse events were graded according to the National Cancer Institute Common Terminology Criteria for adverse events version 4.0. Protocol-guided drug cessation was allowed for patients who achieved complete response (including complete response with incomplete marrow recovery) or negative bone marrow minimal residual disease. Analyses were done per protocol for all patients who commenced drug and included all patients who received at least one dose of venetoclax. Data were pooled across dose cohorts. Patients are still receiving therapy and follow-up is ongoing. The trial is registered at ClinicalTrials.gov, number NCT01682616. FINDINGS Between Aug 6, 2012, and May 28, 2014, we enrolled 49 patients. Common grade 1-2 toxicities included upper respiratory tract infections (in 28 [57%] of 49 patients), diarrhoea (27 [55%]), and nausea (25 [51%]). Grade 3-4 adverse events occurred in 37 (76%) of 49 patients; most common were neutropenia (26 [53%]), thrombocytopenia (eight [16%]), anaemia (seven [14%]), febrile neutropenia (six [12%]), and leucopenia (six [12%]). The most common serious adverse events were pyrexia (six [12%]), febrile neutropenia (five [10%]), lower respiratory tract infection, and pneumonia (each three [6%]). Clinical tumour lysis syndrome occurred in two patients (resulting in one death) who initiated venetoclax at 50 mg. After enhancing tumour lysis syndrome prophylaxis measures and commencing venetoclax at 20 mg, clinical tumour lysis syndrome did not occur. The maximum tolerated dose was not identified; the recommended phase 2 dose of venetoclax in combination with rituximab was 400 mg. Overall, 42 (86%) of 49 patients achieved a response, including a complete response in 25 (51%) of 49 patients. 2 year estimates for progression-free survival and ongoing response were 82% (95% CI 66-91) and 89% (95% CI 72-96), respectively. Negative marrow minimal residual disease was attained in 20 (80%) of 25 complete responders and 28 (57%) of 49 patients overall. 13 responders ceased all therapy; among these all 11 minimal residual disease-negative responders remain progression-free off therapy. Two with minimal residual disease-positive complete response progressed after 24 months off therapy and re-attained response after re-initiation of venetoclax. INTERPRETATION A substantial proportion of patients achieved an overall response with the combination of venetoclax and rituximab including 25 (51%) of 49 patients who achieved a complete response and 28 (57%) of 49 patients who achieved negative marrow minimal residual disease with acceptable safety. The depth and durability of responses observed with the combination offers an attractive potential treatment option for patients with relapsed or refractory chronic lymphocytic leukaemia and could allow some patients to maintain response after discontinuing therapy, a strategy that warrants further investigation in randomised studies. FUNDING AbbVie Inc and Genentech Inc.

Impact of consolidation radiation therapy in stage III-IV diffuse large B-cell lymphoma with negative post-chemotherapy radiologic imaging.

PURPOSE While consolidation radiation therapy (i.e., RT administered after chemotherapy) is routine treatment for patients with early-stage diffuse large B-cell lymphoma (DLBCL), the role of consolidation RT in stage III-IV DLBCL is controversial. METHODS AND MATERIALS Cases of patients with stage III-IV DLBCL treated from 1991 to 2009 at Duke University, who achieved a complete response to chemotherapy were reviewed. Clinical outcomes were calculated using the Kaplan-Meier method and were compared between patients who did and did not receive RT, using the log-rank test. A multivariate analysis was performed using Cox proportional hazards model. RESULTS Seventy-nine patients were identified. Chemotherapy (median, 6 cycles) consisted of anti-CD20 antibody rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP; 65%); cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP; 22%); or other (13%). Post-chemotherapy imaging consisted of positron emission tomography (PET)/computed tomography (CT) (73%); gallium with CT (14%); or CT only (13%). Consolidation RT (median, 25 Gy) was given to involved sites of disease in 38 (48%) patients. Receipt of consolidation RT was associated with improved in-field control (92% vs. 69%, respectively, p = 0.028) and event-free survival (85% vs. 65%, respectively, p = 0.014) but no difference in overall survival (85% vs. 78%, respectively, p = 0.15) when compared to patients who did not receive consolidation RT. On multivariate analysis, no RT was predictive of increased risk of in-field failure (hazard ratio [HR], 8.01, p = 0.014) and worse event-free survival (HR, 4.3, p = 0.014). CONCLUSIONS Patients with stage III-IV DLBCL who achieve negative post-chemotherapy imaging have improved in-field control and event-free survival with low-dose consolidation RT.

Ofatumumab‐based chemoimmunotherapy is effective and well tolerated in patients with previously untreated chronic lymphocytic leukemia (CLL)

Although rituximab‐based chemoimmunotherapy (CIT) has substantially improved clinical outcomes in chronic lymphocytic leukemia (CLL), only 40% to 50% of patients achieve a complete remission (CR). There remains interest in identifying new approaches to improve the effectiveness of CIT. Ofatumumab is a fully human anti‐CD20 monoclonal antibody with greater apparent single‐agent activity than rituximab in CLL patients.

PAK1 Mediates Resistance to PI3K Inhibition in Lymphomas

Purpose: The phosphoinositide 3-kinase (PI3K) pathway is known to play an active role in many malignancies. The role of PI3K inhibition in the treatment of lymphomas has not been fully delineated. We sought to identify a role for therapeutic PI3K inhibition across a range of B-cell lymphomas. Experimental Design: We selected three small molecule inhibitors to test in a panel of 60 cell lines that comprised diverse lymphoma types. We tested the selective PI3K inhibitor BKM120 and the dual PI3K/mTOR inhibitors BEZ235 and BGT226 in these cell lines. We applied gene expression profiling to better understand the molecular mechanisms associated with responsiveness to these drugs. Results: We found that higher expression of the PAK1 gene was significantly associated with resistance to all three PI3K inhibitors. Through RNA–interference-mediated knockdown of the PAK1 gene, we showed a dramatic increase in the sensitivity to PI3K inhibition. We further tested a small-molecule inhibitor of PAK1 and found significant synergy between PI3K and PAK1 inhibition. Conclusion: Thus, we show that PI3K inhibition is broadly effective in lymphomas and PAK1 is a key modulator of resistance to PI3K inhibition. Clin Cancer Res; 19(5); 1106–15. ©2012 AACR.

Pilot study of dacetuzumab in combination with rituximab and gemcitabine for relapsed or refractory diffuse large B-cell lymphoma

Abstract Dacetuzumab, a CD40-targeted, humanized antibody, mediates antitumor activity through effector cell functions and direct apoptotic signal transduction. Preclinical studies demonstrated synergistic activity between dacetuzumab, gemcitabine and rituximab against non-Hodgkin lymphoma in vivo. A phase 1b safety/efficacy study of dacetuzumab in combination with rituximab and gemcitabine was conducted in relapsed/refractory diffuse large B-cell lymphoma (DLBCL). Patients received dacetuzumab at doses of 8 or 12 mg/kg IV weekly with rituximab (375 mg/m2 IV weekly in cycle 1, then every 28 days) and gemcitabine (1000 mg/m2 IV, days 1, 8 and 15, or days 1 and 15). Thirty-three patients with a median age of 67 years were enrolled. Common adverse events (≥15%) were grade 1/2 cytokine release syndrome, nausea, fatigue, thrombocytopenia, headache, decreased appetite, dyspnea, neutropenia, pyrexia, anemia, diarrhea, edema, constipation and cough. Dacetuzumab-related grade 3/4 adverse events occurred infrequently. Six of 30 evaluable patients achieved a complete response (CR) and eight a partial response (PR) per investigator assessment for an overall response rate (ORR) of 47%.

A phase I study evaluating ibritumomab tiuxetan (Zevalin®) in combination with bortezomib (Velcade®) in relapsed/refractory mantle cell and low grade B-cell non-Hodgkin lymphoma

Abstract Proteasome inhibitors may inhibit DNA repair of radiation-induced strand breaks and adducts thereby making the combination of radioimmunotherapy and bortezomib a promising approach. Preclinical models demonstrate additive/synergistic effects from combining DNA damaging agents with proteasome inhibitors. This phase I trial combines ibritumomab tiuxetan with bortezomib. Twelve patients with relapsed/refractory mantle cell and low grade B-cell non-Hodgkin lymphoma were enrolled. Patients with prior radioimmunotherapy were prohibited. The maximum tolerated dose (MTD) was not reached. No dose limiting toxicities (DLTs) occurred in cohort 1 or 2. One of six patients on cohort 3 had DLTs of asthenia, dizziness and neuropathy. Grade 3/4 thrombocytopenia occurred in two patients (16%) and grade 3/4 neutropenia in three patients (25%). Five subjects (41.7%) had complete responses (CRs) and one patient had a partial response (8.3%) for an overall response rate (ORR) of 50%. The combination of standard dose ibritumomab tiuxetan and bortezomib at 1.5 mg/m2 is well tolerated with a promising response rate.

The impact of radiation therapy in patients with diffuse large B-cell lymphoma with positive post-chemotherapy FDG–PET or gallium-67 scans

BACKGROUND 2-[fluorine-18]fluoro-2-deoxy-D-glucose-positron emission tomography (PET) and gallium-67 citrate (gallium) response after chemotherapy are powerful prognostic factors in diffuse large B-cell lymphoma (DLBCL). However, clinical outcomes when consolidation radiation therapy (RT) is administered are less defined. PATIENTS AND METHODS We reviewed 99 patients diagnosed with DLBCL from 1996 to 2007 at Duke University who had a post-chemotherapy response assessment with either PET or gallium and who subsequently received consolidation RT. Clinical outcomes were estimated using the Kaplan-Meier method and compared using the log-rank test. RESULTS Median follow-up was 4.4 years. Stage distribution was I-II in 70% and III-IV in 30%. Chemotherapy was R-CHOP or CHOP in 88%. Median RT dose was 30 Gy. Post-chemotherapy PET (n = 79) or gallium (n = 20) was positive in 21 of 99 patients and negative in 78 of 99 patients. Five-year in-field control was 95% with a negative PET/gallium scan versus 71% with a positive scan (P < 0.01). Five-year event-free survival (EFS; 83% versus 65%, P = 0.04) and overall survival (89% versus 73%, P = 0.04) were also significantly better when the post-chemotherapy PET/gallium was negative. CONCLUSIONS A positive PET/gallium scan after chemotherapy is associated with an increased risk of local failure and death. Consolidation RT, however, still results in long-term EFS in 65% of patients.

A phase II study of cyclophosphamide, etoposide, vincristine and prednisone (CEOP) Alternating with Pralatrexate (P) as front line therapy for patients with peripheral T-cell lymphoma (PTCL): Final results from the T- cell consortium trial

Peripheral T‐cell lymphomas (PTCL) have suboptimal outcomes using conventional CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy. The anti‐folate pralatrexate, the first drug approved for patients with relapsed/refractory PTCL, provided a rationale to incorporate it into the front‐line setting. This phase 2 study evaluated a novel front‐line combination whereby cyclophosphamide, etoposide, vincristine and prednisone (CEOP) alternated with pralatrexate (CEOP‐P) in PTCL. Patients achieving a complete or partial remission (CR/PR) were eligible for consolidative stem cell transplantation (SCT) after 4 cycles. Thirty‐three stage II‐IV PTCL patients were treated: 21 PTCL‐not otherwise specified (64%), 8 angioimmunoblastic T cell lymphoma (24%) and 4 anaplastic large cell lymphoma (12%). The majority (61%) had stage IV disease and 46% were International Prognostic Index high/intermediate or high risk. Grade 3–4 toxicities included anaemia (27%), thrombocytopenia (12%), febrile neutropenia (18%), mucositis (18%), sepsis (15%), increased creatinine (12%) and liver transaminases (12%). Seventeen patients (52%) achieved a CR. The 2‐year progression‐free survival and overall survial, were 39% (95% confidence interval 21–57) and 60% (95% confidence interval 39–76), respectively. Fifteen patients (45%) (12 CR) received SCT and all remained in CR at a median follow‐up of 21·5 months. CEOP‐P did not improve outcomes compared to historical data using CHOP. Defining optimal front line therapy in PTCL continues to be a challenge and an unmet need.

Addition of lenalidomide to rituximab, ifosfamide, carboplatin, etoposide (RICER) in first-relapse/primary refractory diffuse large B-cell lymphoma

Relapsed/refractory diffuse large B‐cell lymphoma (DLBCL) is associated with a poor prognosis. Outcomes are particularly poor following immunochemotherapy failure or relapse within 12 months of induction. We conducted a Phase I/II trial of lenalidomide plus RICE (rituximab, ifosfamide, carboplatin, and etoposide) (RICER) as a salvage regimen for first‐relapse or primary refractory DLBCL. Dose‐escalated lenalidomide was combined with RICE every 14 d. After three cycles of RICER, patients with chemosensitive disease underwent stem cell collection and consolidation with BEAM [BCNU (carmustine), etoposide, cytarabine, melphalan] followed by autologous stem cell transplantation (autoSCT). Patients who recovered from autoSCT toxicities within 90 d initiated maintenance treatment with lenalidomide 25 mg daily for 21 d every 28 d for 12 months. No dose‐limiting or unexpected toxicities occurred with lenalidomide 25 mg plus RICE. Grade 3/4 haematological toxicities resolved appropriately, and planned dose density and dose intensity of RICER were preserved. No lenalidomide or RICE dose reductions were required in any of the three cycles. After two cycles of RICER, nine of 15 patients (60%) achieved a complete response, and two achieved a partial response (13%). Combining lenalidomide with RICE is feasible, and results in promising response rates (particularly complete response rates) in high‐risk DLBCL patients.

The genetic basis of hepatosplenic T-cell lymphoma

Hepatosplenic T-cell lymphoma (HSTL) is a rare and lethal lymphoma; the genetic drivers of this disease are unknown. Through whole-exome sequencing of 68 HSTLs, we define recurrently mutated driver genes and copy-number alterations in the disease. Chromatin-modifying genes, including SETD2, INO80, and ARID1B, were commonly mutated in HSTL, affecting 62% of cases. HSTLs manifest frequent mutations in STAT5B (31%), STAT3 (9%), and PIK3CD (9%), for which there currently exist potential targeted therapies. In addition, we noted less frequent events in EZH2, KRAS, and TP53SETD2 was the most frequently silenced gene in HSTL. We experimentally demonstrated that SETD2 acts as a tumor suppressor gene. In addition, we found that mutations in STAT5B and PIK3CD activate critical signaling pathways important to cell survival in HSTL. Our work thus defines the genetic landscape of HSTL and implicates gene mutations linked to HSTL pathogenesis and potential treatment targets.Significance: We report the first systematic application of whole-exome sequencing to define the genetic basis of HSTL, a rare but lethal disease. Our work defines SETD2 as a tumor suppressor gene in HSTL and implicates genes including INO80 and PIK3CD in the disease. Cancer Discov; 7(4); 369-79. ©2017 AACR.See related commentary by Yoshida and Weinstock, p. 352This article is highlighted in the In This Issue feature, p. 339.