The Public Repository of Xenografts Enables Discovery and Randomized Phase II-like Trials in Mice

More than 90% of drugs with preclinical activity fail in human trials, largely due to insufficient efficacy. We hypothesized that adequately powered trials of patient-derived xenografts (PDX) in mice could efficiently define therapeutic activity across heterogeneous tumors. To address this hypothesis, we established a large, publicly available repository of well-characterized leukemia and lymphoma PDXs that undergo orthotopic engraftment, called the Public Repository of Xenografts (PRoXe). PRoXe includes all de-identified information relevant to the primary specimens and the PDXs derived from them. Using this repository, we demonstrate that large studies of acute leukemia PDXs that mimic human randomized clinical trials can characterize drug efficacy and generate transcriptional, functional, and proteomic biomarkers in both treatment-naive and relapsed/refractory disease.

Diffuse Large B-Cell Lymphoma Version 1.2016

Diffuse large B-cell lymphomas (DLBCL) are now considered a heterogeneous group of distinct molecular subtypes (germinal center B-cell DLBCL, activated B-cell DLBCL, and primary mediastinal large B-cell lymphoma (PMBL) with varied natural history and response to therapy. In addition, a subset of patients with DLBCL have concurrent MYC and/or BCL2 gene rearrangements (double-hit lymphomas; DHL) and others have a dual expression of both MYC and BCL2 proteins (double-expressing DLBCL; DEL). The standard of care for the treatment of patients with PMBL, DHL, or DEL has not been established. Adequate immunophenotyping and molecular testing (in selected circumstances) are necessary for the accurate diagnosis of different subtypes of DLBCL. The NCCN Guidelines included in this issue, part of the NCCN Guidelines for non-Hodgkin's lymphomas, address the diagnosis and management of DLBCL and its subtypes.

Phase II Investigator-Initiated Study of Brentuximab Vedotin in Mycosis Fungoides and Sézary Syndrome With Variable CD30 Expression Level: A Multi-Institution Collaborative Project

PURPOSE

In contrast to Hodgkin lymphoma and systemic anaplastic large-cell lymphoma, CD30 expression of malignant lymphocytes in mycosis fungoides (MF) and Sézary syndrome (SS) is quite variable. Clinical activity and safety of brentuximab vedotin, a CD30 targeting antibody-drug conjugate, was evaluated in MF and SS. Tissue and blood biomarkers of clinical response were explored.

PATIENTS AND METHODS

In this phase II study, patients with MF or SS with negligible to 100% CD30 expression levels were treated with brentuximab vedotin (1.8 mg/kg) every 3 weeks for a maximum of sixteen doses. The primary end point was overall global response rate. Secondary end points included correlation of tissue CD30 expression level with clinical response, time to response, duration of response, progression-free and event-free survivals, and safety.

RESULTS

Of the 32 patients enrolled and treated, 30 patients had available efficacy evaluations. Objective global response was observed in 21 (70%) of 30 patients (90% CI, 53% to 83%). CD30 expression assessed by immunohistochemistry was highly variable, with a median CD30max of 13% (range, 0% to 100%). Those with <5% CD30 expression had a lower likelihood of global response than did those with 5% or greater CD30 expression (P < .005). CD163 positive tumor-associated macrophages, many of which coexpress CD30, were abundant in tissue. Peripheral neuropathy was the most common adverse event.

CONCLUSION

Brentuximab vedotin demonstrated significant clinical activity in treatment-refractory or advanced MF or SS with a wide range of CD30 expression levels. Additional biomarker studies may help optimize rational design of combination therapies with brentuximab vedotin.

Phase II Intergroup Trial of Alisertib in Relapsed and Refractory Peripheral T-Cell Lymphoma and Transformed Mycosis Fungoides: SWOG 1108

PURPOSE

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).

PATIENTS AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

Chronic lymphocytic leukemia/small lymphocytic lymphoma, version 1.2015

Chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL) are different manifestations of the same disease, which are managed in the same way. The advent of novel monoclonal antibodies (ofatumumab and obinutuzumab) led to the development of effective chemoimmunotherapy regimens. The recently approved small molecule kinase inhibitors (ibrutinib and idelalisib) are effective treatment options for CLL in elderly patients with decreased tolerance for aggressive regimens and in patients with poor prognostic features who do not benefit from conventional chemoimmunotherapy regimens. This portion of the NCCN Guidelines for Non-Hodgkin's Lymphomas describes the recent specific to the incorporation of recently approved targeted therapies for the management of patients with newly diagnosed and relapsed or refractory CLL/SLL.

Brentuximab vedotin in the front-line treatment of patients with CD30+ peripheral T-cell lymphomas: results of a phase I study

PURPOSE

Front-line treatment of peripheral T-cell lymphomas (PTCL) involves regimens such as cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP) and results in a 5-year overall survival (OS) rate of less than 50%. This phase I open-label study evaluated the safety and activity of brentuximab vedotin administered sequentially with CHOP or in combination with CHP (CHOP without vincristine) as front-line treatment in patients with CD30(+) PTCL.

PATIENTS AND METHODS

Patients received sequential treatment (once every 3 weeks) with brentuximab vedotin 1.8 mg/kg (two cycles) followed by CHOP (six cycles) or brentuximab vedotin 1.8 mg/kg plus CHP (BV+CHP) for six cycles (once every 3 weeks). Responders received single-agent brentuximab vedotin for eight to 10 additional cycles (for a total of 16 cycles). The primary objective was assessment of safety; secondary end points included objective response rate, complete remission (CR) rate, progression-free survival rate (PFS), and OS. There were no prespecified comparisons of the two treatment approaches.

RESULTS

After sequential treatment, 11 (85%) of 13 patients achieved an objective response (CR rate, 62%; estimated 1-year PFS rate, 77%). Grade 3/4 adverse events occurred in eight (62%) of 13 patients. At the end of combination treatment, all patients (n = 26) achieved an objective response (CR rate, 88%; estimated 1-year PFS rate, 71%). All seven patients without anaplastic large-cell lymphoma achieved CR. Grade 3/4 adverse events (≥ 10%) in the combination-treatment group were febrile neutropenia (31%), neutropenia (23%), anemia (15%), and pulmonary embolism (12%).

CONCLUSION

Brentuximab vedotin, administered sequentially with CHOP or in combination with CHP, had a manageable safety profile and exhibited substantial antitumor activity in newly diagnosed patients with CD30(+) PTCL. A randomized phase III trial is under way, comparing BV+CHP with CHOP (clinical trial No. NCT01777152).

Non-Hodgkin's lymphomas, version 2.2014

Non-Hodgkin's lymphomas (NHLs) are a heterogeneous group of lymphoproliferative disorders originating in B lymphocytes, T lymphocytes, or natural killer cells. Follicular lymphoma (FL) is the most common subtype of indolent NHL, accounting for approximately 22% of all newly diagnosed cases of NHL. The incorporation of rituximab to chemotherapy regimens has become a widely accepted standard of care for first-line therapy for patients with FL. Maintenance and consolidation therapy with rituximab and radioimmunotherapy have also been associated with improved progression-free survival in patients experiencing response to first-line therapy. Despite therapeutic advances that have improved outcomes, FL is generally considered a chronic disease characterized by multiple recurrences with current therapies. This manuscript discusses the recommendations outlined in the NCCN Guidelines for the diagnosis and management of patients with FL.

How I treat the peripheral T-cell lymphomas

The peripheral T-cell lymphomas (PTCLs) encompass a heterogeneous group of diseases that have generally been associated with poor prognosis. The most common PTCLs, peripheral T-cell lymphoma, not otherwise specified, angioimmunoblastic T-cell lymphoma, and anaplastic lymphoma kinase (ALK)-negative anaplastic large cell lymphoma (ALK-negative), despite their unique presentations and histologies, are currently treated similarly. Here we discuss our general approach to the treatment of the most common PTCLs. Based on the best data currently available, which include retrospective analyses and phase 2 prospective studies, our approach has involved cyclophosphamide, doxorubicin, vincristine, prednisone-based therapy followed by consolidation in first remission with autologous stem cell transplant. This treatment strategy likely improves the outcome for patients compared with historical series; however, progression-free survival rates remain disappointing, ranging from 40% to 50%. This is currently an exciting time in the treatment of PTCL due to the advent of recently approved drugs as well as new targeted agents currently under investigation. In addition, gene expression profiling is allowing for a better understanding of underlying disease biology, improved diagnostic accuracy, and prognostication in PTCL. As a result, over the next few years, we expect a significant shift in our management of these diseases with a move toward more individualized therapy leading to improved outcomes.