End-of-treatment and serial PET imaging in primary mediastinal B-cell lymphoma following dose-adjusted EPOCH-R: a paradigm shift in clinical decision making

Dose-adjusted-EPOCH-R obviates the need for radiotherapy in most patients with primary mediastinal B-cell lymphoma. End-of-treatment PET, however, does not accurately identify patients at risk of treatment failure, thereby confounding clinical decision making. To define the role of PET in primary mediastinal B-cell lymphoma following dose-adjusted-EPOCH-R, we extended enrollment and follow up on our published phase II trial and independent series. Ninety-three patients received dose-adjusted-EPOCH-R without radiotherapy. End-of-treatment PET was performed in 80 patients, of whom 57 received 144 serial scans. One nuclear medicine physician from each institution blindly reviewed all scans from their respective institution. End-of-treatment PET was negative (Deauville 1-3) in 55 (69%) patients with one treatment failure (8-year event-free and overall survival of 96.0% and 97.7%). Among 25 (31%) patients with a positive (Deauville 4-5) end-of-treatment PET, there were 5 (20%) treatment failures (8-year event-free and overall survival of 71.1% and 84.3%). Linear regression analysis of serial scans showed a significant decrease in SUV_max in positive end-of-treatment PET non-progressors compared to an increase in treatment failures. Among 6 treatment failures, the median end-of-treatment SUV_max was 15.4 (range, 1.9-21.3), and 4 achieved long-term remission with salvage therapy. Virtually all patients with a negative end-of-treatment PET following dose-adjusted-EPOCH-R achieved durable remissions and should not receive radiotherapy. Among patients with a positive end-of-treatment PET, only 5/25 (20%) had treatment-failure. Serial PET imaging distinguished end-of-treatment PET positive patients without treatment failure, thereby reducing unnecessary radiotherapy by 80%, and should be considered in all patients with an initial positive PET following dose-adjusted-EPOCH-R (clinicaltrials.gov identifier 00001337).

Targeting the B-cell receptor pathway in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous diagnostic category with different molecular subtypes defined by distinct gene expression patterns and divergent mechanisms of oncogenic activation. Several studies have suggested an inferior survival for patients of the activated B-cell-like (ABC) versus the germinal center B-cell-like (GCB) DLBCL subtype which has led to increasing interest in investigating pharmacological inhibition of signaling pathways which contribute to lymphomagenesis and that are specifically utilized by ABC DLBCL cells. One of these signaling cascades is the B-cell receptor (BCR) pathway and several approaches in clinical trials to target this cascade have demonstrated promising therapeutic activity. This review discusses our current understanding of the role of BCR signaling in different DLBCL subtypes, including primary central nervous system lymphoma (PCNSL), a subgroup of DLBCL that is particularly dependent on BCR signaling. One specific aim of this review is to highlight novel approaches to therapeutically target BCR signaling in DLBCL.

Primary mediastinal B-cell lymphoma: biology and evolving therapeutic strategies

Primary mediastinal B-cell lymphoma (PMBCL) is recognized as a distinct clinicopathologic entity that predominantly affects adolescents and young adults and is more common in female subjects. Although PMBCL is considered to be a subtype of diffuse large B-cell lymphoma, its clinical, morphologic, and biological characteristics overlap significantly with those of nodular sclerosing Hodgkin lymphoma (NSHL). Over the past few years, the shared biology of these 2 entities has been highlighted in several studies, and mediastinal gray zone lymphoma, with features intermediate between PMBCL and NSHL, has been recognized as a unique molecular entity. Although there is a lack of consensus about the optimal therapeutic strategy for adolescent and young adult patients newly diagnosed with PMCBL, highly curative strategies that obviate the need for mediastinal radiation are favored by most. Progress in understanding the biology of PMBCL and its close relationship to NSHL have helped pave the way for the investigation of novel approaches such as immune checkpoint inhibition. Other strategies such as adoptive T-cell therapy and targeting CD30 are also being studied.

Modernizing Clinical Trial Eligibility Criteria: Recommendations of the American Society of Clinical Oncology-Friends of Cancer Research HIV Working Group

Purpose People with HIV are living longer as a result of effective antiretroviral therapy. Cancer has become a leading cause of morbidity and mortality in this patient population. However, studies of novel cancer therapeutics have historically excluded patients with HIV. Critical review of eligibility criteria related to HIV is required to accelerate development of and access to effective therapeutics for HIV-infected patients with cancer and make studies more generalizable to this patient population. Methods From January through April 2016, the HIV Working Group conducted a series of teleconferences; a review of 46 New Drug Applications from registration studies of unique agents studied in adults with cancer that led to the initial US Food and Drug Administration approval of that agent from 2011 to 2015; and a review of HIV-related eligibility criteria from National Cancer Institute-sponsored studies. Results were discussed and refined at a multistakeholder workshop held May 12, 2016. The HIV Working Group developed recommendations for eligibility criteria that focus on pharmacologic and immunologic considerations in this patient population and that balance patient safety, access to appropriate investigational agents, and study integrity. Results Exclusion of patients with HIV remains common in most studies of novel cancer agents. Models for HIV-related eligibility criteria in National Cancer Institute-sponsored studies are instructive. HIV infection itself should no longer be an exclusion criterion for most studies. Eligibility criteria related to HIV infection that address concurrent antiretroviral therapy and immune status should be designed in a manner that is appropriate for a given cancer. Conclusion Expanding clinical trial eligibility to be more inclusive of patients with HIV is justified in most cases and may accelerate the development of effective therapies in this area of unmet clinical need.

Role of the tumor microenvironment in mature B-cell lymphoid malignancies

The tumor microenvironment is the cellular and molecular environment in which the tumor exists and with which it continuously interacts. In B-cell lymphomas, this microenvironment is intriguing in that it plays critical roles in the regulation of tumor cell survival and proliferation, fostering immune escape as well as the development of treatment resistance. The purpose of this review is to summarize the proceedings of the Second Annual Summit on the Immune Microenvironment in Hematologic Malignancies that took place on September 11-12, 2014 in Dublin, Ireland. We provide a timely overview of the composition and biological relevance of the cellular and molecular microenvironment interface and discuss the role of interactions between the microenvironment and neoplastic cells in a variety of B-cell lymphomas. In addition, we focus on various novel therapeutic strategies that target the tumor microenvironment, including agents that modulate B-cell receptor pathways and immune-checkpoints, chimeric antigen receptor T cells and immunomodulatory agents.

Inhibition of B Cell Receptor Signaling by Ibrutinib in Primary CNS Lymphoma

Primary CNS lymphoma (PCNSL) harbors mutations that reinforce B cell receptor (BCR) signaling. Ibrutinib, a Bruton's tyrosine kinase (BTK) inhibitor, targets BCR signaling and is particularly active in lymphomas with mutations altering the BCR subunit CD79B and MYD88. We performed a proof-of-concept phase Ib study of ibrutinib monotherapy followed by ibrutinib plus chemotherapy (DA-TEDDi-R). In 18 PCNSL patients, 94% showed tumor reductions with ibrutinib alone, including patients having PCNSL with CD79B and/or MYD88 mutations, and 86% of evaluable patients achieved complete remission with DA-TEDDi-R. Increased aspergillosis was observed with ibrutinib monotherapy and DA-TEDDi-R. Aspergillosis was linked to BTK-dependent fungal immunity in a murine model. PCNSL is highly dependent on BCR signaling, and ibrutinib appears to enhance the efficacy of chemotherapy.

Update on Burkitt Lymphoma

Because of its rarity and high curability, progress in advancing therapeutics in Burkitt lymphoma (BL) has been difficult. Over recent years, several new mutations that cooperate with MYC have been identified, and this has paved the way for testing novel agents in the disease. One of the challenges of most standard approaches typically used is severe treatment-related toxicity that often leads to discontinuation of therapy. To that point, there has been recent success developing intermediate intensity approaches that are well tolerated in all patient groups and maintain high cure rates in a multicenter setting.

Plasma and cerebrospinal fluid pharmacokinetics of doxil after intravenous administration in adults with primary CNS lymphoma

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Background: Doxil, a pegylated liposomal doxorubicin (PLD) has excellent CNS penetration in rodent brain tumor models and is active in patients with lymphoma. The CNS penetration of doxil in humans is unknown. We evaluated the plasma and cerebrospinal fluid (CSF) pharmacokinetics (PK) of doxil in adults primary CNS lymphoma (PCNSL) as a surrogate for CNS penetration. Methods: Adults with PCNSL enrolled on a NCI phase I study of ibrutinib and multi-agent immune-chemotherapy (NCT02203526) received doxil 50 mg/m2 IV over 1 hour on day 2 of 21-day cycles of chemotherapy. In 4 patients with indwelling Ommaya reservoirs serial blood and CSF samples were obtained prior to infusion and until a median of 345 hours, (range 72-477 hours) after doxil administration. Total doxorubicin concentration (liposome bound + protein bound + free) was quantified with a validated liquid chromatography/tandem mass spectrometry assay (lower limit of quantification plasma=0.29 ng/mL, and CSF=0.06 ng/mL). PK parameters were estimated using non-compartmental methods. CSF penetration was calculated from the AUCCSF:AUCplasma. Results:Total doxorubicin plasma concentration time curves were characterized by sustained drug exposure and a median terminal half-life of 64.5 hours. (range, 61.9-65.1 hours). Doxorubicin was measurable in CSF in all patients, but CSF penetration was low. The terminal half-life of doxorubicin in CSF could not be calculated due to persistently measurable concentrations throughout the sampling times. Conclusions: In patients with PCNSL doxorubicin was measurable in CSF for prolonged time periods after doxil administration, but CSF penetration is low. Clinical trial information: NCT02203526. [Table: see text]

DOCK 8 Deficiency, EBV+ Lymphomatoid Granulomatosis, and Intrafamilial Variation in Presentation

Dedicator of cytokinesis 8 (DOCK8) deficiency is an autosomal recessive, combined immunodeficiency within the spectrum of hyper-IgE syndromes. Epstein-Barr virus-positive lymphomatoid granulomatosis (LYG) (EBV + LYG) is a rare diagnosis and a previously unreported presentation of DOCK8 deficiency. A 10-year-old girl was initially evaluated for mild eczema and recurrent sinopulmonary infections. She had normal immunoglobulins with elevated IgE, poor polysaccharide response with low switched memory B cells, low CD4 count, and normal mitogen and antigen responses. Despite clinical improvement following immunoglobulin replacement, a prolonged cough prompted a CT scan, which showed nodules. Biopsy identified a Grade 2 EBV + LYG. Due to an inadequate response with chemotherapy, further workup for primary immunodeficiency was performed. With her symptoms of eczema and IgE elevation, along with her brother's history of recurrent sinopulmonary infections and warts, targeted sequencing of DOCK8 was performed revealing compound heterozygous mutations for the two siblings. Both patients were successfully transplanted with resolution of the LYG and warts, respectively. This is the first reported case of LYG in DOCK8 deficiency. The EBV-driven lymphoproliferative disease along with the infection history in the brother led to the diagnosis of DOCK8 deficiency and curative hematopoietic stem cell transplants.

Double hit lymphoma: from biology to therapeutic implications

INTRODUCTION

Diffuse large B-cell lymphoma (DLBCL) is a molecularly heterogeneous disease defined by different cellular origins and mechanisms of oncogenic activation. Approximately 10% of DLBCL cases harbor a MYC rearrangement and this has been associated with a more aggressive clinical course following standard therapy.

AREAS COVERED

So-called 'double-hit lymphomas' (DHL) or 'triple hit lymphomas' (THL) occur when MYC is concurrently rearranged with BCL2 and/or BCL6. These tumors are characterized by high proliferation rate and a very poor outcome following standard R-CHOP (rituximab, cyclophosphamide, doxorubicin vincristine and prednisone) therapy, in most (though not all) studies that have looked at this. Though there is a paucity of published experience with other chemotherapy regimens, there is emerging evidence that more intensive approaches may improve outcome. Recently, there has been a lot of focus in the literature on 'double-expresser lymphomas' (DEL) with high MYC, BCL2 and/or BCL6 expression but typically without rearrangements of these genes. These DEL cases, have a poor outcome with R-CHOP and there is little consensus on how they should be approached. Expert commentary: This review will focus on the biology and treatment of DHL and DEL, discuss the outcome of these diseases with current standard as well as promising new approaches and conclude with a section on novel agents that are in development for these diseases.

Female fertility following dose-adjusted EPOCH-R chemotherapy in primary mediastinal B-cell lymphomas

We assessed fertility/gonadal function in premenopausal women treated with dose-adjusted EPOCH-Rituximab for untreated primary mediastinal B-cell lymphoma (PMBL). Eligible patents were ≤ 50 years and premenopausal. Serial reproductive histories were obtained and hormonal assays were performed on serum samples before, at the end of treatment and 4-18 months later. Twenty-eight eligible women had a median age (range) of 31 (21-50) years and were followed a median of 7.3 years. Of 23 patients who completed a questionnaire, 19 (83%) were and four were not menstruating prior to chemotherapy. Amenorrhea developed in 12 patients during chemotherapy. At > 1-year follow-up, 14/19 (74%) patients were menstruating, all < 35 years old, and six (43%) of these patients delivered healthy children. Hormonal assays showed ovarian dysfunction during chemotherapy in all patients with varying recovery at 4-18 months after treatment. Fertility was preserved in most women with ovarian failure confined to patients > 40 years old.

Central nervous system involvement in AIDS-related lymphomas

Central nervous system (CNS) involvement is reportedly more common in acquired immunodeficiency syndrome (AIDS)-related lymphomas (ARL). We describe factors and outcomes associated with CNS involvement at baseline (CNS(B) ) and relapse (CNS(R) ) in 886 patients with newly diagnosed ARL. Of 886 patients, 800 received either intrathecal (IT) therapy for CNS(B) or IT prophylaxis. CNS(B) was found in 13%. CNS(B) was not associated with reduced overall survival (OS). There was no difference in the prevalence of CNS(B) between the pre-combination antiretroviral therapy (cART) and cART eras. 5·3% of patients experienced CNS(R) at a median of 4·2 months after diagnosis (12% if CNS(B) ; 4% if not). Median OS after CNS(R) was 1·6 months. On multivariate analysis, only CNS(B) [hazard ratio (HR) 3·68, P = 0·005] and complete response to initial therapy (HR 0·14, P < 0·0001) were significantly associated with CNS(R) . When restricted to patients without CNS(B) , IT CNS prophylaxis with 3 vs. 1 agent did not significantly impact the risk of CNS(R) . Despite IT CNS prophylaxis, 5% of patients experienced CNS(R) . Our data confirms that CNS(R) in ARL occurs early and has a poor outcome. Complete response to initial therapy was associated with a reduced frequency of CNS(R) . Although CNS(B) conferred an increased risk for CNS(R) , it did not impact OS.