Faculty Bibliography

Mantle cell lymphoma (MCL) may be 1 of the few cancers for which multiple chemotherapy and nonchemotherapy regimens are considered as standard. Despite the significant activity of chemotherapy in the first-line setting and beyond, its limitations are reflected in the relatively poor ultimate outcomes of patients with MCL treated in the real world. Patients with highly proliferative MCL and those with TP53 mutations tend to respond poorly despite intensive cytotoxic therapies. Patients with comorbidities and those who are geographically isolated may not have access to the regimens that may appear most promising in clinical trials. Thoughtfully directed, nonchemotherapy agents might overcome some of the factors associated with a poor prognosis, such at TP53 mutation, and might resolve some of the challenges related to the toxicity and deliverability of standard chemotherapy regimens. Several clinical trials have already demonstrated that combinations of nonchemotherapy plus chemotherapy drugs can impact outcomes, whereas data with nonchemotherapy agents alone or in combination have suggested that some patients might be well suited to treatment without chemotherapy at all. However, challenges including chronic or unexpected toxicities, the rational vs practical development of combinations, and the financial acceptability of new strategies abound. The nonchemotherapy era is here: how it unfolds will depend on how we meet these challenges.

Clinical trials enrolling follicular lymphoma (FL) patients typically require bone marrow biopsies (BMBs) at baseline and at a subsequent point if complete response is achieved. These procedures are painful, take time and add cost. We hypothesized that BMBs do not provide information significant for response assessment in most follicular lymphoma patients on clinical trials. We identified 99 patients treated on clinical trials for follicular lymphoma between 2000 and 2016. BMBs resulted in a possible response assessment change in 1·0% of patients (95% confidence interval: 0·0-5·5%). We conclude that mandatory BMBs at baseline and for response assessment are unnecessary in clinical trials for follicular lymphoma.

A major revision of the WHO classification of lymphoid and myeloid neoplasms and acute leukemia was released in 2016. A key motivation for this update was to include new information available since the 2008 version with clinical relevance for the diagnosis, prognosis, and therapy of patients. With > 100 entities described, it is important for the clinician to understand features that may be important in daily practice, whereas researchers need to incorporate the new classification scheme into study development and analysis. In this review, we highlight the key aspects of the 2016 update with particular importance to routine patient care and clinical trial design.

In recent years, the number of approved and investigational agents that can be safely administered for the treatment of lymphoma patients for a prolonged period of time has substantially increased. Many of these novel agents are evaluated in early-phase clinical trials in patients with a wide range of malignancies, including solid tumors and lymphoma. Furthermore, with the advances in genome sequencing, new "basket" clinical trial designs have emerged that select patients based on the presence of specific genetic alterations across different types of solid tumors and lymphoma. The standard response criteria currently in use for lymphoma are the Lugano Criteria which are based on [18F]2-fluoro-2-deoxy-D-glucose positron emission tomography or bidimensional tumor measurements on computerized tomography scans. These differ from the RECIST criteria used in solid tumors, which use unidimensional measurements. The RECIL group hypothesized that single-dimension measurement could be used to assess response to therapy in lymphoma patients, producing results similar to the standard criteria. We tested this hypothesis by analyzing 47 828 imaging measurements from 2983 individual adult and pediatric lymphoma patients enrolled on 10 multicenter clinical trials and developed new lymphoma response criteria (RECIL 2017). We demonstrate that assessment of tumor burden in lymphoma clinical trials can use the sum of longest diameters of a maximum of three target lesions. Furthermore, we introduced a new provisional category of a minor response. We also clarified response assessment in patients receiving novel immune therapy and targeted agents that generate unique imaging situations.

Despite the long history of bendamustine as treatment for indolent non-Hodgkin lymphoma, long-term efficacy and toxicity data are minimal. We reviewed long-term data from three clinical trials to characterize the toxicity and efficacy of patients receiving bendamustine. Data were available for 149 subjects at 21 sites. The median age was 60 years at the start of bendamustine (range 39-84), and patients had received a median of 3 prior therapies. The histologies included grades 1-2 follicular lymphoma (FL; n = 73), grade 3 FL (n = 23), small lymphocytic lymphoma (n = 20), marginal zone lymphoma (n = 15), mantle cell lymphoma (n = 9), transformed lymphomas (n = 5), lymphoplasmacytic lymphoma (n = 2) and not reported (n = 2). The median event-free survival was 14·1 months. Nine of 12 attempted stem cell collections were successful. With a median follow-up of 8·9 years, 23 patients developed 25 cancers, including 8 patients with myelodysplastic syndrome/acute myeloid leukaemia. These data provide important information regarding the long-term toxicity of bendamustine in previously treated patients. A small but meaningful number of patients achieved durable remissions following bendamustine. These rigorously collected, patient-level, long-term follow-up data provide reassurance that bendamustine or bendamustine plus rituximab is associated with efficacy and safety for patients with relapsed or refractory indolent non-Hodgkin lymphoma.

Although the BCL6 transcriptional repressor is frequently expressed in human follicular lymphomas (FL), its biological role in this disease remains unknown. Herein we comprehensively identify the set of gene promoters directly targeted by BCL6 in primary human FLs. We noted that BCL6 binds and represses NOTCH2 and Notch pathway genes. Moreover, BCL6 and NOTCH2 pathway gene expression is inversely correlated in FL. Notably BCL6 up-regulation is associated with repression of Notch2 and its target genes in primary human and murine germinal center cells. Repression of Notch2 is an essential function of BCL6 in FL and GC B-cells since inducible expression of Notch2 abrogated GC formation in mice and kills FL cells. Indeed BCL6-targeting compounds or gene silencing leads to the induction of NOTCH2 activity and compromises survival of FL cells whereas NOTCH2 depletion or pathway antagonists rescue FL cells from such effects. Moreover, BCL6 inhibitors induced NOTCH2 expression and suppressed growth of human FL xenografts in vivo and primary human FL specimens ex vivo. These studies suggest that established FLs are thus dependent on BCL6 through its suppression of NOTCH2.

The National Clinical Trials Network lymphoid malignancies Clinical Trials Planning Meeting (CTPM) occurred in November of 2014. The scope of the CTPM was to prioritize across the lymphoid tumors clinically significant questions and to foster strategies leading to biologically informed and potentially practice changing clinical trials. This review from the Hodgkin lymphoma (HL) subcommittee of the CTPM discusses the ongoing clinical challenges in HL, outlines the current standard of care for HL patients from early to advanced stage, and surveys the current science with respect to biomarkers and the landscape of ongoing clinical trials. Finally, we suggest areas of unmet need in HL and elucidate promising therapeutic strategies to guide future HL clinical trials planning across the NCTN.

Aggressive induction chemotherapy followed by autologous haematopoietic stem cell transplant (auto-HCT) is effective for younger patients with mantle cell lymphoma (MCL). However, the optimal induction regimen is widely debated. The Southwestern Oncology Group S1106 trial was designed to assess rituximab plus hyperCVAD/MTX/ARAC (hyperfractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone, alternating with high dose cytarabine and methotrexate) (RH) versus rituximab plus bendamustine (RB) in a randomized phase II trial to select a pre-transplant induction regimen for future development. Patients had previously untreated stage III, IV, or bulky stage II MCL and received either 4 cycles of RH or 6 cycles of RB, followed by auto-HCT. Fifty-three of a planned 160 patients were accrued; an unacceptably high mobilization failure rate (29%) on the RH arm prompted premature study closure. The estimated 2-year progression-free survival (PFS) was 81% vs. 82% and overall survival (OS) was 87% vs. 88% for RB and RH, respectively. RH is not an ideal platform for future multi-centre transplant trials in MCL. RB achieved a 2-year PFS of 81% and a 78% MRD negative rate. Premature closure of the study limited the sample size and the precision of PFS estimates and MRD rates. However, RB can achieve a deep remission and could be a platform for future trials in MCL.

Peripheral T-cell lymphomas (PTCLs) are uncommon, heterogeneous, and aggressive non-Hodgkin's lymphomas. Despite progress in the last several years resulting in a deeper understanding of PTCL biology and pathogenesis, there is currently no accepted single standard of care for newly diagnosed patients, and for those with relapsed or refractory disease, prognosis is dismal. The National Cancer Institute convened a Clinical Trials Planning Meeting to advance the national clinical trial agenda in lymphoma. The objective was to identify unmet needs specific to five major lymphoma subtypes and develop strategies to address them. This consensus statement reviews recent advances in the molecular and genetic characterization of PTCL that may inform novel treatments, proposes strategies to test novel therapies in the relapsed setting with the hopes of rapid advancement into frontline trials, and underscores the need for the identification and development of active and biologically rational therapies to cure PTCL at higher rates, with iterative biomarker evaluation.

BACKGROUND:The development of more effective and safer treatments, especially non-chemotherapeutics, is needed for patients with Waldenström's macroglobulinaemia. The aim of the study was to assess the safety and clinical activity of intravenous ofatumumab monotherapy for untreated and relapsed Waldenström's macroglobulinaemia. METHODS:We did a phase 2, open-label, single-arm study at six centres (hospitals and cancer clinics) in the USA. Patients aged at least 18 years who were diagnosed with untreated or relapsed Waldenström's macroglobulinaemia and required treatment, received up to three cycles of weekly ofatumumab for 5 weeks. For cycle 1, patients received one of two treatment regimens. Group A received ofatumumab 300 mg during week 1 followed by 1000 mg during weeks 2-4. Because of the acceptable safety of the 1000 mg dose in treatment group A and clinical activity of the 2000 mg dose established in chronic lymphocytic leukaemia, the study was amended on Dec 9, 2009, to change cycle 1 for group B who received ofatumumab 300 mg during week 1 and 2000 mg during weeks 2-5. We followed up patients during weeks 5-16 for treatment group A and during weeks 6-16 for treatment group B (no treatment was given during this follow-up). Patients in both groups with stable disease or a minor response after 16 weeks were eligible to then receive a redosing cycle of ofatumumab 300 mg during week 1 and 2000 mg during weeks 2-5. We followed up patients during weeks 6-16 after the redosing cycle (no treatment was given during this follow-up). Patients responding to cycle 1 or the redosing cycle who developed disease progression within 36 months could receive cycle 2 of ofatumumab 300 mg during week 1 and 2000 mg during weeks 2-5. The primary endpoint for this study was the proportion of patients who achieved an overall response (complete responses plus partial responses plus minor responses) after each treatment cycle in the intent-to-treat population every 4 weeks starting at week 8. This trial is registered at www.ClinicalTrials.gov, NCT00811733, and is now complete. FINDINGS/RESULTS:Between March 17, 2009, and Feb 24, 2011, we enrolled and assigned 37 patients to treatment (15 in treatment group A and 22 in treatment group B). All 37 were included in the efficacy and safety analyses. 19 (51%, 95% CI 34·4-68·1) of 37 patients achieved an overall response after cycle 1 and 22 (59%, 42·1-75·2) of 37 achieved an overall response after the redosing cycle; 15 (41%) with partial responses, seven (19%) with minor responses. 13 patients received treatment cycle 2; ten (77%) of the 13 achieved a response. All 37 patients had at least one adverse event; 16 (43%) patients had events of grade 3 or more (30 grade 3, one grade 4). The most common grade 3 or 4 adverse events were infusion reactions (four [11%] of 37), chest pain (two [5%] of 37), haemolysis (two [5%] of 37), and neutropenia (two [5%] of 37). Two (9%) of 22 patients (both in treatment group B) had an IgM flare. 12 patients reported serious adverse events; haemolysis and pyrexia were the most common (each occurring in two [5%] of 37 patients). INTERPRETATION/CONCLUSIONS:A high proportion of patients achieved an overall response with ofatumumab monotherapy and this treatment was well tolerated, with a low incidence of IgM flare. This therapy might be a non-chemotherapeutic treatment option for patients with Waldenström's macroglobulinaemia, especially those with high IgM concentrations. FUNDING/BACKGROUND:GlaxoSmithKline and Genmab.