Measurable Residual Disease Testing Following Nonintensive Chemoimmunotherapy is Predictive of Need for Maintenance Therapy in Previously Untreated Mantle Cell Lymphoma: A Wisconsin Oncology Network Study.

INTRODUCTION: Obinutuzumab is hypothesized to improve progression-free survival (PFS) combined with bendamustine induction in mantle cell lymphoma (MCL). Measurable-residual disease (MRD) testing may predict benefit from maintenance therapy. METHODS: Adults (≥ 18 years) with untreated MCL ineligible for intensive therapies received 4 to 6 cycles of bendamustine + obinutuzumab (BO) followed by consolidation obinutuzumab (CO). Restaging after CO included MRD assessment by next-generation sequencing of bone marrow aspirate (BMA) and peripheral blood (PB). Maintenance obinutuzumab (MO) was omitted for patients with imaging complete response (CR) and MRD-negativity in PB/BMA. All other patients received 8 cycles MO. Primary endpoint is PFS; secondary endpoints are response rates, overall survival, and estimation of MRD status. RESULTS: Twenty-one patients enrolled, with median age 70 years and stage IV disease in 95%. Twenty patients completed BO; 10 patients received MO per protocol. Six patients did not complete MO due to progression (n = 4), infection (n = 1) and carcinoma (n = 1). Overall response is 95% (75% CR, 20% partial response). Concordance rate between post-consolidation MRD testing in PB and BMA was 70%. After a median follow-up of 43.9 months, median PFS is 46.5 months. The observed difference between 2-year PFS in groups receiving MO versus observation was not statistically significant (HR 0.45, 95% CI, 0.10-1.91). Most common grade 3/4 toxicities were neutropenia, leukopenia, and infections. CONCLUSIONS: BO is a tolerable induction regimen with higher rates of CR compared with historical rates with bendamustine + rituximab. Omission of MO did not worsen outcomes in patients achieving MRD-negative status after nonintensive induction/consolidation therapy.

High-grade B-cell lymphoma, not otherwise specified: CNS involvement and outcomes in a multi-institutional series.

ABSTRACT: Little is known about the central nervous system (CNS) risk in high-grade B-cell lymphoma, not otherwise specified (HGBL NOS). Hence, we sought to describe the rates of baseline CNS involvement, risk of CNS recurrence after primary therapy, and management strategies in HGBL NOS. In this multicenter retrospective study, we included 160 adults with newly diagnosed HGBL NOS treated between 2016 and 2021 at 20 US institutions. Eleven patients (7%) had baseline CNS involvement at diagnosis (leptomeningeal = 6, parenchymal = 4, and both = 1). Baseline CNS involvement was significantly associated only with MYC rearrangement (OR = 3.5) and testicular (in men) or female pelvic (in women) involvement (OR = 8.1). There was no significant difference in survival outcomes between patients with HGBL NOS with (median PFS = 4 years) or without (median PFS = 2.4 years) baseline CNS involvement (P = 0.45). The cumulative incidence of CNS recurrence at 3 years was 11%. Patients with baseline CNS involvement were at the highest risk (48.5% vs 8% for those without baseline CNS involvement) and were excluded from the risk factors analysis for CNS recurrence. The risk for CNS recurrence was significantly associated with blood or bone marrow involvement, CD5 expression, non-germinal center B-cell subtype, and "dual-expresser lymphoma" phenotype, however, high CNS IPI was not. The prognosis of relapsed HGBL NOS was poor, regardless of whether recurrence was systemic or limited to the CNS, and with currently available salvage strategies, including autologous transplantation and chimeric antigen receptor T-cell modalities, almost all patients with CNS recurrence ultimately succumbed to their disease.

Maintenance low-dose fixed duration lenalidomide and rituximab following bendamustine and rituximab induction in previously untreated chronic lymphocytic leukemia and small lymphocytic lymphoma.

Lenalidomide (LEN) and rituximab (RTX) have independently improved progression-free survival (PFS) in CLL, leading to interest in use of LEN + RTX (R2) following induction chemoimmunotherapy. Patients with previously untreated CLL received bendamustine + RTX (BR) for 6 cycles, then 24 cycles of R2. LEN dosing was 5-10 mg daily; RTX was given odd cycles (12 doses). The primary endpoint is PFS; secondary endpoints are response and overall survival. Thirty-six patients enrolled, median age 64.5 years. Twenty-nine received R2; 12 completed a full course R2 (33.3%), 5 completed R2 with premature discontinuation of LEN. Dose reductions/holds were most often for neutropenia. Complete response was achieved in 33.3%. After median >4 years follow-up, 2-year and 3-year PFS were 86.1% and 69.4%. Five-year overall survival was 92.3%. R2 maintenance may improve PFS after BR induction, and a lower dose of 5 mg/day and ≤1 year of R2 may be most tolerable (NCT00974233).

NCCN Guidelines® Insights: B-Cell Lymphomas, Version 6.2023.

Novel targeted therapies (small molecule inhibitors, antibody-drug conjugates, and CD19-directed therapies) have changed the treatment landscape of relapsed/refractory B-cell lymphomas. Bruton's tyrosine kinase (BTK) inhibitors continue to evolve in the management of mantle cell lymphoma (MCL), in both the relapsed/refractory and the frontline setting. Anti-CD19 CAR T-cell therapies are now effective and approved treatment options for relapsed/refractory follicular lymphoma (FL), diffuse large B-cell lymphoma (DLBCL), and MCL. Bispecific T-cell engagers represent a novel immunotherapeutic approach for relapsed FL and DLBCL after multiple lines of therapies, including prior CAR T-cell therapy. These NCCN Guideline Insights highlight the significant updates to the NCCN Guidelines for B-Cell Lymphomas for the treatment of FL, DLBCL, and MCL.

Outcomes of limited stage primary bone diffuse large B-cell lymphoma in the rituximab era: a multicenter, retrospective study.

Primary bone diffuse large B cell lymphoma (DLBCL) is a rare variant of extranodal non-Hodgkin lymphoma (NHL) historically treated with induction chemotherapy followed by consolidative radiation therapy (RT). It remains unknown whether RT confers additional benefit following rituximab-based chemoimmunotherapy (CIT) induction in patients with limited-stage disease. We conducted a multicenter retrospective analysis of patients treated between 2005 and 2019 using rituximab-based CIT regimens with or without consolidative RT to discern whether consolidative RT adds benefit in patients with stage I-II disease that could be encompassed in one radiation field. A total of 112 patients were included: 78 received CIT and radiation (RT group), and 34 received CIT alone (no RT group). The OS at 10 years was 77.9% in the RT group and 89.0% in the no RT group (p = 0.42). The RFS at 10 years was 73.5% in the RT group and 80.3% in the no RT group (p = 0.88). Neither improved OS nor RFS was associated with the addition of consolidative RT. Subgroup analysis of patients only achieving a partial response after CIT suggests that these patients may benefit from consolidative RT.

High-grade B-cell lymphoma, not otherwise specified: a multi-institutional retrospective study.

In this multi-institutional retrospective study, we examined the characteristics and outcomes of 160 patients with high-grade B-cell lymphoma, not otherwise specified (HGBL-NOS)-a rare category defined by high-grade morphologic features and lack of MYC rearrangements with BCL2 and/or BCL6 rearrangements ("double hit"). Our results show that HGBL-NOS tumors are heterogeneous: 83% of patients had a germinal center B-cell immunophenotype, 37% a dual-expressor immunophenotype (MYC and BCL2 expression), 28% MYC rearrangement, 13% BCL2 rearrangement, and 11% BCL6 rearrangement. Most patients presented with stage IV disease, a high serum lactate dehydrogenase, and other high-risk clinical factors. Most frequent first-line regimens included dose-adjusted cyclophosphamide, doxorubicin, vincristine, and etoposide, with rituximab and prednisone (DA-EPOCH-R; 43%); rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP; 33%); or other intensive chemotherapy programs. We found no significant differences in the rates of complete response (CR), progression-free survival (PFS), or overall survival (OS) between these chemotherapy regimens. CR was attained by 69% of patients. PFS at 2 years was 55.2% and OS was 68.1%. In a multivariable model, the main prognostic factors for PFS and OS were poor performance status, lactate dehydrogenase >3 × upper limit of normal, and a dual-expressor immunophenotype. Age >60 years or presence of MYC rearrangement were not prognostic, but patients with TP53 alterations had a dismal PFS. Presence of MYC rearrangement was not predictive of better PFS in patients treated with DA-EPOCH-R vs R-CHOP. Improvements in the diagnostic criteria and therapeutic approaches beyond dose-intense chemotherapy are needed to overcome the unfavorable prognosis of patients with HGBL-NOS.

NCCN Guidelines® Insights: B-Cell Lymphomas, Version 5.2021.

In the last decade, a better understanding of the molecular pathogenesis of B-cell non-Hodgkin lymphomas has resulted in the development of novel targeted therapies, such as small molecule inhibitors of select kinases in the B-cell receptor pathway, antibody-drug conjugates, and small molecules that target a variety of proteins (eg, CD-19, EZH2, and XPO-1-mediated nuclear export). Anti-CD19 CAR T-cell therapy, first approved for relapsed/refractory (R/R) diffuse large B-cell lymphoma, has also emerged as a novel treatment option for R/R follicular lymphoma and mantle cell lymphoma. These NCCN Guideline Insights highlight the new targeted therapy options included in the NCCN Guidelines for B-Cell Lymphomas for the treatment of R/R disease.

A Three-Arm Randomized Phase II Study of Bendamustine/Rituximab with Bortezomib Induction or Lenalidomide Continuation in Untreated Follicular Lymphoma: ECOG-ACRIN E2408.

PURPOSE: We sought to improve upon frontline bendamustine/rituximab (BR) induction therapy followed by rituximab maintenance in untreated high-risk follicular lymphoma (FL). PATIENTS AND METHODS: Patients were randomized to BR induction followed by 2-year rituximab maintenance (BR-R), BR with bortezomib and rituximab maintenance (BVR-R), or BR followed by lenalidomide (1 year) with rituximab maintenance (BR-LR). Dual primary objectives were complete remission (CR) rate and 1-year disease-free survival (DFS); 289 patients enrolled (NCT01216683). RESULTS: For induction, 92%, 87%, and 86% of patients randomized to BR-R, BVR-R, or BR-LR received six cycles, respectively. CR rate with BR versus BVR induction was 62% versus 75%, respectively (P = 0.04). One-year DFS rates with BR-R versus BR-LR were 85% versus 67%, respectively (P = 0.0009). This was due to an imbalance in CR rates post-BR induction and discontinuation due to adverse events (AEs). The most common grade 3-4 AEs for BVR versus BR were neutropenia and sensory neuropathy (12% vs <1%); 83% of the latter occurred with intravenous bortezomib. The most common grade 3-4 AEs related to LR versus rituximab maintenance were neutropenia 66% versus 21%, respectively (P < 0.0001), and febrile neutropenia 10% versus 2%, respectively (P = 0.05). The overall treatment-related mortality was 1.4%. With 5-year median follow-up, 3-year PFS rates for BR-R, BVR-R, and BR-LR were 77%, 82%, and 76%, respectively (P = 0.36) with OS rates of 87%, 90%, and 84%, respectively (P = 0.79). For prognostication, CR rate and POD-24 were associated with survival. CONCLUSIONS: Altogether, neither bortezomib added to BR induction nor lenalidomide added to rituximab maintenance immediately post-BR induction is recommended in untreated FL.

NCCN Guidelines Insights: B-Cell Lymphomas, Version 3.2019.

Diffuse large B-cell lymphomas (DLBCLs) and follicular lymphoma (FL) are the most common subtypes of B-cell non-Hodgkin's lymphomas in adults. Histologic transformation of FL to DLBCL (TFL) occurs in approximately 15% of patients and is generally associated with a poor clinical outcome. Phosphatidylinositol 3-kinase (PI3K) inhibitors have shown promising results in the treatment of relapsed/refractory FL. CAR T-cell therapy (axicabtagene ciloleucel and tisagenlecleucel) has emerged as a novel treatment option for relapsed/refractory DLBCL and TFL. These NCCN Guidelines Insights highlight important updates to the NCCN Guidelines for B-Cell Lymphomas regarding the treatment of TFL and relapsed/refractory FL and DLBCL.

Dose-Adjusted EPOCH-R Compared With R-CHOP as Frontline Therapy for Diffuse Large B-Cell Lymphoma: Clinical Outcomes of the Phase III Intergroup Trial Alliance/CALGB 50303.

PURPOSE: Alliance/CALGB 50303 (NCT00118209), an intergroup, phase III study, compared dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab (DA-EPOCH-R) with standard rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) as frontline therapy for diffuse large B-cell lymphoma. PATIENTS AND METHODS: Patients received six cycles of DA-EPOCH-R or R-CHOP. The primary objective was progression-free survival (PFS); secondary clinical objectives included response rate, overall survival (OS), and safety. RESULTS: Between 2005 and 2013, 524 patients were registered; 491 eligible patients were included in the final analysis. Most patients (74%) had stage III or IV disease; International Prognostic Index (IPI) risk groups included 26% IPI 0 to 1, 37% IPI 2, 25% IPI 3, and 12% IPI 4 to 5. At a median follow-up of 5 years, PFS was not statistically different between the arms (hazard ratio, 0.93; 95% CI, 0.68 to 1.27; P = .65), with a 2-year PFS rate of 78.9% (95% CI, 73.8% to 84.2%) for DA-EPOCH-R and 75.5% (95% CI, 70.2% to 81.1%) for R-CHOP. OS was not different (hazard ratio, 1.09; 95% CI, 0.75 to 1.59; P = .64), with a 2-year OS rate of 86.5% (95% CI, 82.3% to 91%) for DA-EPOCH-R and 85.7% (95% CI, 81.4% to 90.2%) for R-CHOP. Grade 3 and 4 adverse events were more common (P < .001) in the DA-EPOCH-R arm than the R-CHOP arm, including infection (16.9% v 10.7%, respectively), febrile neutropenia (35.0% v 17.7%, respectively), mucositis (8.4% v 2.1%, respectively), and neuropathy (18.6% v 3.3%, respectively). Five treatment-related deaths (2.1%) occurred in each arm. CONCLUSION: In the 50303 study population, the more intensive, infusional DA-EPOCH-R was more toxic and did not improve PFS or OS compared with R-CHOP. The more favorable results with R-CHOP compared with historical controls suggest a potential patient selection bias and may preclude generalizability of results to specific risk subgroups.

CALGB 50604: risk-adapted treatment of nonbulky early-stage Hodgkin lymphoma based on interim PET.

A negative interim positron emission tomography/computerized tomography (PET/CT) after 1 to 3 cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) in patients with newly diagnosed, nonbulky stage I or II Hodgkin lymphoma (HL) predicts a low relapse rate. This phase 2 trial was designed to determine if a population of patients with early-stage disease can be treated with short-course ABVD without radiation therapy (RT) on the basis of a negative interim PET/CT, thereby limiting the risks of treatment. Between 15 May 2010 and 21 February 2013, 164 previously untreated patients with nonbulky stage I/II HL were enrolled, and 149 were included in the final analysis. Patients received 2 cycles of ABVD followed by PET. Deauville scores 1 to 3 were negative (≤ liver uptake) based on central review. PET- patients received 2 more cycles of ABVD, and PET+ patients received 2 cycles of dose-intense bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (escalated BEACOPP) plus 3060-cGy involved-field RT. The primary objective was to determine 3-year progression-free survival (PFS) for the PET- group. One hundred thirty-five patients (91%) were interim PET-, and 14 patients (9%) were PET+ With median follow-up time of 3.8 years, the estimated 3-year PFS was 91% for the PET- group and 66% for the PET+ group (hazard ratio, 3.84; 95% confidence interval, 1.50-9.84; P = .011). There was 1 death as a result of suicide. Four cycles of ABVD resulted in durable remissions for a majority of patients with early-stage nonbulky HL and a negative interim PET. This trial was registered at www.clinicaltrials.gov as #NCT01132807.

Lenalidomide consolidation benefits patients with CLL receiving chemoimmunotherapy: results for CALGB 10404 (Alliance).

Prior to novel targeted agents for chronic lymphocytic leukemia (CLL), the best chemoimmunotherapy regimen in patients with non-del(11q) disease was unclear. The role of lenalidomide was also not defined. This phase 2 study randomized 342 untreated patients with non-del(11q) CLL requiring therapy to fludarabine plus rituximab (FR; n = 123), FR plus lenalidomide consolidation (FR+L; n = 109), or FR plus cyclophosphamide (FCR; n = 110) and compared 2-year progression-free survival (PFS) rates of each to the historical control rate with FC (60%). Patients with del(11q) in at least 20% of pretreatment cells continued with FCR (n = 27) or were reassigned to FCR+L (n = 31) and excluded from the primary analysis. Among non-del(11q) patients, 2-year PFS rates were 64% (90% confidence interval [CI], 57-71; FR), 72% (90% CI, 65-79; FR+L), and 74% (90% CI, 66-80; FCR); FR+L and FCR had rates significantly greater than historical control. Median PFS was significantly shorter with FR compared with FR+L (P = .04) and FCR (P < .001): 43 (95% CI, 33-50), 61 (95% CI, 45-71), and 97 (95% CI, 61 to not reached) months, respectively. Median follow-up was 73 months and median overall survival (OS) was only reached with FCR (101 months; 95% CI, 96 to not reached). With FR+L, the risk of death decreased over time and was lower than with FR at later time points (P = .01), but not significantly different from FCR (P = .21). Future studies incorporating short courses of lenalidomide into other novel treatment regimens are justified.

VcR-CVAD Induction Chemotherapy Followed by Maintenance Rituximab Produces Durable Remissions in Mantle Cell Lymphoma: A Wisconsin Oncology Network Study.

INTRODUCTION: VcR-CVAD was developed as an intermediate-intensity induction regimen with maintenance rituximab (MR) to improve remission durations after first-line therapy for mantle cell lymphoma (MCL) in older and younger patients with MCL. PATIENTS AND METHODS: Patients with previously untreated MCL received VcR-CVAD induction chemotherapy for 6 cycles (21-day cycles). Patients achieving at least a partial response received rituximab consolidation (375 mg/m2 × 4 weekly doses) and MR (375 mg/m2 every 12 weeks × 20 doses). The primary endpoints were overall and complete response (CR), and the secondary endpoints were progression-free survival (PFS) and overall survival (OS). Thirty patients were enrolled, with a median age of 61 years. There was an even distribution of patients < 60 years and ≥ 60 years. Mantle cell lymphoma international prognostic index medium- or high-risk disease was present in 60%. The overall response rate observed was 90% (77% CR/unconfirmed CR). After a median follow-up of 7.8 years, the 6-year PFS and OS were 53% and 70%, respectively. There was no difference in 6-year PFS or OS between the younger (age < 60 years) and older (age ≥ 60 years) subgroups. In a univariate analysis, lactate dehydrogenase, when analyzed for interaction with age, had a significant effect on PFS outcomes at 6 years. There were no pretreatment variables determined to have a significant effect on OS outcomes at 6 years. CONCLUSIONS: Long-term outcomes with VcR-CVAD are comparable with more intensive inductions and consolidation approaches. MCL is biologically heterogeneous, and durable remission can be achieved with intermediate intensity therapy. MR appears to contribute to these excellent outcomes.

Phase 1 dose escalation multicenter trial of pracinostat alone and in combination with azacitidine in patients with advanced hematologic malignancies.

BACKGROUND: Pracinostat is a potent histone deacetylase inhibitor with antitumor activity in both solid tumor and acute myeloid leukemia (AML) cell lines. Pracinostat is reported to have modest clinical activity in patients with advanced solid tumors. Given the higher preclinical sensitivity of hematologic malignancies to pracinostat, the authors conducted a phase 1 study to assess the safety, maximum tolerated dose, recommended phase 2 dose, efficacy, pharmacokinetics, and pharmacodynamics of pracinostat in patients with advanced hematological malignancies. METHODS: Pracinostat was administered orally 3 times a week for 3 weeks on a 28-day cycle. Patients were assigned to 7 dose levels using a 3 + 3 dose escalation design. RESULTS: A total of 44 patients were enrolled, 25 of whom had AML and 14 of whom had myelodysplastic syndrome. The maximum tolerated dose was 120 mg and the recommended phase 2 dose was 60 mg. Two patients with AML achieved a response: 1 complete remission (CR) and 1 complete cytogenetic response. Despite a dose-dependent increase in the plasma concentration of pracinostat, a similar increase in histone acetylation was not observed. As an extension, 10 additional patients with myelodysplastic syndrome were enrolled to assess the safety and efficacy of pracinostat in combination with azacitidine. Six patients achieved a CR and 3 achieved a CR without platelet recovery with no added toxicity. CONCLUSIONS: The results of the current study demonstrate that pracinostat is safe, with modest single-agent activity in patients with hematological malignancies. Cancer 2017;123:4851-9. © 2017 American Cancer Society.

Phase I Study of the Anti-CD22 Antibody-Drug Conjugate Pinatuzumab Vedotin with/without Rituximab in Patients with Relapsed/Refractory B-cell Non-Hodgkin Lymphoma.

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 antitumor activity alone and with rituximab in relapsed/refractory (r/r) non-Hodgkin 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 of 3 patients and grade 4 neutropenia <7 days in 2 of 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 ≥3 adverse event. Peripheral neuropathy-related grade ≥2 adverse events most frequently resulted in treatment discontinuation. Rituximab cotreatment 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 of 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. Clin Cancer Res; 23(5); 1167-76. ©2016 AACR.

Bendamustine + rituximab chemoimmunotherapy and maintenance lenalidomide in relapsed, refractory chronic lymphocytic leukaemia and small lymphocytic lymphoma: A Wisconsin Oncology Network Study.

Bendamustine + rituximab (BR) has demonstrated high response rates in relapsed/refractory (R/R) chronic lymphocytic leukaemia (CLL) and small lymphocytic lymphoma (SLL). However, progression-free survival (PFS) after BR is <18 months. This study was designed to determine if maintenance lenalidomide after BR induction could improve PFS in R/R CLL/SLL. Thirty-four patients with R/R CLL/SLL who had received 1-5 prior chemotherapy regimens were treated with 6 cycles of BR induction. Patients achieving at least a minor response received twelve 28-d cycles of lenalidomide 5-10 mg/d. The primary endpoint was PFS. The median age was 67 years, with a median of 2 prior therapies. Eleven patients had confirmed presence of 17p and/or 11q deletions. Twenty-five (74%) completed 6 cycles of induction BR (response rate 56%). Nineteen (56%) patients received maintenance lenalidomide; only 6 patients completed the intended 12 cycles, highlighting the limited feasibility of lenalidomide in this setting, primarily due to haematological and infectious toxicities. The observed median PFS of 18·3 months is not significantly different from that of BR induction in R/R CLL/SLL without maintenance therapy (15·2 months). It is possible that lenalidomide maintenance may be more feasible and effective in the front-line setting, which is being tested in an ongoing trial (NCT01754857).

A phase II randomized trial comparing standard and low dose rituximab combined with alemtuzumab as initial treatment of progressive chronic lymphocytic leukemia in older patients: a trial of the ECOG-ACRIN cancer research group (E1908).

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) patients requiring initial therapy are often older and frailer and unsuitable candidates for standard chemoimmunotherapy regimens. Shorter duration combination monoclonal antibody (mAb) therapy using alemtuzumab and rituximab has been shown to be effective and tolerable treatment for CLL. Standard dose anti-CD20 mAb therapy causes loss of CD20 expression by surviving CLL cells, which can be minimized by decreasing the mAb dose. We report a randomized phase II clinical trial enrolling older (≥ 65 years) patients (median age 76 years, n = 31) with treatment naïve progressive CLL. Patients received 8-12 weeks of standard subcutaneous alemtuzumab with either intravenous standard (375 mg/m(2) weekly)(n = 16) or low dose (20 mg/m(2) 3x week)(n = 15) rituximab. This study was closed before full accrual because the manufacturer withdrew alemtuzumab for treatment of CLL. The overall response rate was 90% with an 45% complete response rate, median progression-free survival of 17.9 months and no significant differences in outcome between the low and standard dose rituximab arms. The major toxicities were cytopenia and infection with one treatment fatality caused by progressive multifocal leukoencephalopathy but no other opportunistic infections. Combination mAb therapy was effective and tolerable treatment for older and frailer patients with progressive CLL, achieving a high rate of complete remissions. These data support the role of mAb in therapy for less fit CLL patients and the further study of low dose higher frequency anti-CD20 mAb therapy as a potentially more effective use of anti-CD20 mAb in the treatment of CLL.

PI3-kinase inhibitors in chronic lymphocytic leukemia.

The phosphatidylinositol 3-kinase (PI3K) pathway is being explored as a target of inhibition for B-cell lymphoproliferative disorders, with agents specific for inhibition of the PI3K-δ subunit showing significant clinical activity in chronic lymphocytic leukemia (CLL). Idelalisib (CAL-101, GS-1101) and IPI-145 (INK-1147) are novel oral PI3K-δ inhibitors in development, with rates of objective response of 40-60 % and nodal responses exceeding 70 % in relapsed and refractory CLL. High rates of response have been seen in high-risk CLL (i.e., 17p and 11q deletions), and may allow for more effective therapy in inherently chemotherapy-resistant disease. Combination chemotherapy regimens with idelalisib have similarly demonstrated favorable tolerability and activity. Like other agents that target the B-cell receptor pathway, peripheral lymphocytosis, due to drug-induced changes in lymphocyte trafficking, is common. Noteworthy toxicities include transaminitis and pneumonia/pneumonitis. Multiple studies are evaluating PI3K-δ inhibitor combination regimens, and the rationale for these ongoing and planned studies is reviewed.

Phase 2 study of VcR-CVAD with maintenance rituximab for untreated mantle cell lymphoma: an Eastern Cooperative Oncology Group study (E1405).

Rituximab, bortezomib, modified hyper-cyclophosphamide, doxorubicin, vincristine, dexamethasone (VcR-CVAD) induction chemoimmunotherapy and maintenance rituximab (MR) were evaluated for efficacy and safety in Eastern Cooperative Oncology Group protocol E1405. Patients with previously untreated mantle cell lymphoma received VcR-CVAD chemotherapy every 21 days for 6 cycles, followed by MR for 2 years. Transplant-eligible patients had the option of autologous stem cell transplantation (ASCT) consolidation instead of MR. The primary end point was the complete response (CR) rate to VcR-CVAD. The secondary end points were overall response rate (ORR), progression-free survival (PFS), overall survival (OS), and toxicities. Seventy-five eligible patients with a median age of 62 (range 40-76) were enrolled. The ORR was 95% and a CR was achieved in 68% of patients. After a median follow-up of 4.5 years, 3-year PFS and OS were 72% and 88%, respectively. No substantial difference in PFS or OS was observed between patients treated with MR (n = 44) vs ASCT (n = 22). There were no unexpected toxicities. VcR-CVAD produced high ORR and CR rates in mantle cell lymphoma. MR after VcR-CVAD induction performed similarly to ASCT and may improve response duration. Randomized clinical trials comparing MR against ASCT should be considered and randomized clinical trials evaluating bortezomib's contribution to conventional therapy are under way. This study was registered at www.clinicaltrials.gov as #NCT00433537.