XPO1 Enables Adaptive Regulation of mRNA Export Required for Genotoxic Stress Tolerance in Cancer Cells.

Exportin-1 (XPO1), the main soluble nuclear export receptor in eukaryotic cells, is frequently overexpressed in diffuse large B-cell lymphoma (DLBCL). A selective XPO1 inhibitor, selinexor, received approval as single agent for relapsed or refractory (R/R) DLBCL. Elucidating the mechanisms by which XPO1 overexpression supports cancer cells could facilitate further clinical development of XPO1 inhibitors. We uncovered here that XPO1 overexpression increases tolerance to genotoxic stress, leading to a poor response to chemoimmunotherapy. Upon DNA damage induced by MYC expression or exogenous compounds, XPO1 bound and exported EIF4E and THOC4 carrying DNA damage repair mRNAs, thereby increasing synthesis of DNA damage repair proteins under conditions of increased turnover. Consequently, XPO1 inhibition decreased the capacity of lymphoma cells to repair DNA damage and ultimately resulted in increased cytotoxicity. In a phase I clinical trial conducted in R/R DLBCL, the combination of selinexor with second-line chemoimmunotherapy was tolerated with early indication of efficacy. Overall, this study reveals that XPO1 overexpression plays a critical role in the increased tolerance of cancer cells to DNA damage while providing new insights to optimize the clinical development of XPO1 inhibitors. SIGNIFICANCE: XPO1 regulates the dynamic ribonucleoprotein nuclear export in response to genotoxic stress to support tolerance and can be targeted to enhance the sensitivity of cancer cells to endogenous and exogenous DNA damage. See related commentary by Knittel and Reinhardt, p. 3.

Tafasitamab and lenalidomide in large B-cell lymphoma: real-world outcomes in a multicenter retrospective study.

ABSTRACT: In this real-world evaluation of tafasitamab-lenalidomide (TL) in relapsed or refractory LBCL, patients receiving TL had higher rates of comorbidities and high-risk disease characteristics, and substantially lower progression-free survival and overall survival, compared with the L-MIND registration clinical trial for TL.

Multicenter phase 2 study of oral azacitidine (CC-486) plus CHOP as initial treatment for PTCL.

Peripheral T-cell lymphomas (PTCL) with T-follicular helper phenotype (PTCL-TFH) has recurrent mutations affecting epigenetic regulators, which may contribute to aberrant DNA methylation and chemoresistance. This phase 2 study evaluated oral azacitidine (CC-486) plus cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) as initial treatment for PTCL. CC-486 at 300 mg daily was administered for 7 days before C1 of CHOP, and for 14 days before CHOP C2-6. The primary end point was end-of-treatment complete response (CR). Secondary end points included safety and survival. Correlative studies assessed mutations, gene expression, and methylation in tumor samples. Grade 3 to 4 hematologic toxicities were mostly neutropenia (71%), with febrile neutropenia uncommon (14%). Nonhematologic toxicities included fatigue (14%) and gastrointestinal symptoms (5%). In 20 evaluable patients, CR was 75%, including 88.2% for PTCL-TFH (n = 17). The 2-year progression-free survival (PFS) was 65.8% for all and 69.2% for PTCL-TFH, whereas 2-year overall survival (OS) was 68.4% for all and 76.1% for PTCL-TFH. The frequencies of the TET2, RHOA, DNMT3A, and IDH2 mutations were 76.5%, 41.1%, 23.5%, and 23.5%, respectively, with TET2 mutations significantly associated with CR (P = .007), favorable PFS (P = .004) and OS (P = .015), and DNMT3A mutations associated with adverse PFS (P = .016). CC-486 priming contributed to the reprograming of the tumor microenvironment by upregulation of genes related to apoptosis (P < .01) and inflammation (P < .01). DNA methylation did not show significant shift. This safe and active regimen is being further evaluated in the ALLIANCE randomized study A051902 in CD30-negative PTCL. This trial was registered at www.clinicaltrials.gov as #NCT03542266.

Relevance of Bone Marrow Biopsies for Response Assessment in US National Cancer Institute National Clinical Trials Network Follicular Lymphoma Clinical Trials.

PURPOSE: Bone marrow biopsies (BMB) are performed before/after therapy to confirm complete response (CR) in patients with lymphoma on clinical trials. We sought to establish whether BMB add value in assessing response or predict progression-free survival (PFS) or overall survival (OS) outcomes in follicular lymphoma (FL) subjects in a large, multicenter, multitrial cohort. METHODS: Data were pooled from seven trials of 580 subjects with previously untreated FL through Alliance for Clinical Trials in Oncology (Alliance) and SWOG Cancer Research Network (SWOG) completing enrollment from 2008 to 2016. RESULTS: Only 5/580 (0.9%) had positive baseline BMB, CR on imaging, and subsequent positive BMB (P < .0001). Therefore, BMB were irrelevant to response in 99% of subjects. A sensitivity analysis of 385 FL subjects treated on an Eastern Cooperative Oncology Group study was included. In the Eastern Cooperative Oncology Group cohort, 5/385 (1.3%) had BMB that affected response assessment. Since some subjects do not undergo confirmatory BMB, we performed a landmark survival analysis from first radiologic CR with data from 580 subjects from Alliance and SWOG. Of subjects with CR on imaging (n = 187), PFS and OS were not significantly different among those with negative BMB to confirm CR (n = 47) versus those without repeat BMB (n = 140; PFS: adjusted hazard ratio, 1.10, 95% CI, 0.62 to 1.94, log-rank P = .686; OS: hazard ratio, 0.59, 95% CI, 0.23 to 1.53, log-rank P = .276). CONCLUSION: We conclude that BMB add little value to response assessment in subjects with FL treated on clinical trials and we recommend eliminating BMB from clinical trial requirements. BMB should also be removed from diagnostic guidelines for FL except in scenarios in which it may change management including confirmation of limited stage and assessment of cytopenias. This would reduce cost, patient discomfort, resource utilization, and potentially remove a barrier to trial enrollment.

Unmet mental health needs in patients with advanced B-cell lymphomas.

CONTEXT: Existing research on psychological distress and mental health service utilization has focused on common types of solid tumor cancers, leaving significant gaps in our understanding of patients experiencing rare forms of hematologic cancers. OBJECTIVE: To examine distress, quality of life, and mental health service utilization among patients with aggressive, refractory B-cell lymphomas. METHOD: Patients (n = 26) with B-cell lymphomas that relapsed after first- or second-line treatment completed self-report measures of distress (Hospital Anxiety and Depression Scale) and quality of life (Short-Form Health Survey, SF-12). Patients also reported whether they had utilized mental health treatment since their cancer diagnosis. RESULTS: Approximately 42% (n = 11) of patients reported elevated levels of psychological distress. Of patients with elevated distress, only one quarter (27.2%; n = 3) received mental health treatment, while more than half did not receive mental health treatment (54.5%; n = 6), and 18.1% (n = 2) did not want treatment. Patients with elevated distress reported lower mental quality of life than patients without elevated distress [F (1, 25) = 15.32, p = 0.001]. SIGNIFICANCE OF THE RESULTS: A significant proportion of patients with advanced, progressive, B-cell lymphomas may experience elevated levels of distress. Yet, few of these distressed patients receive mental health treatment. Findings highlight the need to better identify and address barriers to mental health service utilization among patients with B-cell lymphoma, including among distressed patients who decline treatment.

Outcomes Among Classical Hodgkin Lymphoma Patients After an Interim PET Scan: A Real-World Experience.

INTRODUCTION: The utility of dose escalation after positive positron emission tomography following 2 cycles of ABVD (PET2) for Hodgkin Lymphoma (HL) remains controversial. We describe the United States real-world practice patterns for PET2 positive patients. PATIENTS AND METHODS: Data was collected from 15 sites on PET2 positive HL patients after receiving frontline treatment between January, 2015 and June, 2019. Descriptive analyses between those with therapy change and those continuing initial therapy were assessed. RESULTS: A total of 129 patients were identified; 111 (86%) were treated with ABVD therapy and 18 (14%) with an alternate regimen. At PET2 assessment, 74.4% (96/129) had Deauville score (DS) 4 and 25.6% (33/129) had DS 5. Of the 66 limited stage (LS) patients with PET2 DS score of 4/5, 77.3% (51/66) continued initial therapy and 22.7% (15/66) changed to escalated therapy. The 12-month progression-free survival (PFS) for DS 4/5 LS patients was 67.0% (95% CI; 54.9-81.7) for patients without escalation compared with 51.4% (95% CI; 30.8-85.8) for those who escalated. Of the 63 DS 4/5 patients with advanced stage (AS) disease, 76.2% (48/63) continued initial therapy and 23.8% (15/63) changed to escalated therapy. The 12-month PFS for DS 4/5 AS patients was 38.3% (95% CI: 26.3%-55.7%) for patients without escalation compared with 57.1% (95% CI: 36.3-89.9) for those with escalation. CONCLUSION: A minority of PET2 positive HL patients undergo therapy escalation and outcomes remain overall suboptimal. Improved prognostics markers and better therapeutics are required to improve outcomes for high-risk PET2 positive HL patients.

Venetoclax with dose-adjusted EPOCH-R as initial therapy for patients with aggressive B-cell lymphoma: a single-arm, multicentre, phase 1 study.

BACKGROUND: Dose-adjusted EPOCH-R (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab) is a front-line treatment for patients with aggressive B-cell lymphomas. Bcl-2 is associated with chemoresistance due to BCL2 gene rearrangement or protein overexpression and is antagonised by venetoclax. We aimed to assess the safety of venetoclax with dose-adjusted EPOCH-R as initial therapy in aggressive B-cell lymphoma. METHODS: We conducted a single-arm, phase 1 study across seven treatment centres in the USA. Eligible patients were aged 18-80 years with histologically confirmed, previously untreated diffuse large B-cell lymphoma, transformed indolent non-Hodgkin lymphoma, high-grade B-cell lymphoma with double-hit or not otherwise specified, or primary mediastinal B-cell lymphoma, with Ann Arbor stage II-IV and Eastern Cooperative Oncology Group performance status of 0-2. Participants received six cycles of oral venetoclax 400 mg, 600 mg, or 800 mg once daily for 10 days per cycle with dose-adjusted EPOCH-R (one cycle every 3 weeks; baseline doses were intravenous rituximab 375 mg/m2 on day 1, intravenous etoposide 50 mg/m2 on days 1-4, oral prednisone 60 mg/m2 twice daily on days 1-5, intravenous vincristine 0·4 mg/m2 on days 1-4, intravenous cyclophosphamide 750 mg/m2 on day 5, and intravenous doxorubicin 10 mg/m2 on days 1-4). A subsequent cohort received venetoclax 600 mg once daily for 5 days per cycle. The primary endpoints were the maximum tolerated dose, dose-limiting toxicities, and the recommended phase 2 dose of venetoclax. Analyses were done per protocol. This trial is registered with ClinicalTrials.gov, NCT03036904, and enrolment is now closed. FINDINGS: Between Feb 3, 2017, and June 4, 2019, 34 patients were assessed for eligibility, and 30 were enrolled and received venetoclax with dose-adjusted EPOCH-R. The median patient age was 64·0 years (IQR 51·6-69·4). The maximum tolerated dose was 800 mg for 10 days and the established recommended phase 2 dose was 600 mg for 5 days due to tolerability for treatment duration. One (3%) of 30 patients had a dose-limiting toxicity in cycle one (grade 4 thrombocytopenia with 800 mg dose). The most common grade 3-4 adverse events were cytopenias (28 [93%] of 30 patients); febrile neutropenia occurred in 19 (63%) patients. Grade 3-4 non-haematological adverse events included hypophosphataemia (n=10), hypokalaemia (n=7), and hyperglycaemia (n=5). Serious adverse events included infection (n=7) and gastrointestinal toxicities including abdominal pain (n=3), colonic perforation (n=1), and small intestinal obstruction (n=1). There was one treatment-related death (sepsis). Overall response rate was 96·7% (95% CI 82·8-99·9); 28 (93·3% [77·9-99·2]) of 30 patients had complete response and one (3·3% [0·1-17·2]) had a partial response. INTERPRETATION: Venetoclax with dose-adjusted EPOCH-R showed an acceptable safety profile at the recommended phase 2 dose and had encouraging preliminary activity in this population at high risk of adverse outcomes, and is worthy of further study. The combination is being investigated in Alliance 051701 (NCT03984448). FUNDING: Genentech.

Phase 1b study of the BET protein inhibitor RO6870810 with venetoclax and rituximab in patients with diffuse large B-cell lymphoma.

Bromodomain and extraterminal (BET) proteins are transcriptional activators for multiple oncogenic processes in diffuse large B-cell lymphoma (DLBCL), including MYC, BCL2, E2F, and toll-like receptor signaling. We report results of a phase 1b dose-escalation study of the novel, subcutaneous BET inhibitor RO6870810 (RO) combined with the BCL-2 inhibitor venetoclax, and rituximab, in recurrent/refractory DLBCL. RO was delivered for 14 days of a 21-day cycle, whereas venetoclax was delivered continuously. A 3 + 3 escalation design was used to determine the safety of the RO+venetoclax doublet; rituximab was added in later cohorts. Thirty-nine patients were treated with a median of 2.8 cycles (range, 1-11). Dose-limiting toxicities included grade 3 febrile neutropenia, grade 4 diarrhea, and hypomagnesemia for the doublet; and grade 3 hyperbilirubinemia and grade 4 diarrhea when rituximab was added. The doublet maximum tolerated dose (MTD) was determined to be 0.65 mg/kg RO+600 mg venetoclax; for RO+venetoclax+rituximab, the MTDs were 0.45 mg/kg, 600 mg, and 375 mg/m2, respectively. The most frequent grade 3 and 4 adverse events were neutropenia (28%) and anemia and thrombocytopenia (23% each). Responses were seen in all cohorts and molecular subtypes. Sustained decreases in CD11b on monocytes indicated pharmacodynamic activity of RO. Overall response rate according to modified Lugano criteria was 38.5%; 48% of responses lasted for ≥180 days. Complete response was observed in 8 patients (20.5%). Optimization of the treatment schedule and a better understanding of predictors of response would be needed to support broader clinical use. This trial is registered on www.clinicaltrials.gov as NCT03255096.

Sequential intensive chemotherapy followed by autologous or allogeneic transplantation for refractory lymphoma.

We evaluate the safety of bendamustine as a bridge to stem cell transplantation (SCT) in patients with relapsed/refractory lymphoma and residual disease after salvage therapy. Thirty-four subjects without complete responses (CR) received bendamustine 200 mg/m2/day for 2 days followed 14 days later by SCT. Sixteen subjects in partial remission (PR) with maximal FDG-PET SUVs ≤8 prior to bendamustine received autologous SCT, while 13 with suboptimal responses were allografted. Five subjects did not proceed to transplant. No bendamustine toxicities precluded transplantation and no detrimental effect on engraftment or early treatment-related mortality (TRM) was attributable to bendamustine. At 1 year, 75% of auto-recipients and 31% of allo-recipients were alive with CR. Two subjects in the autologous arm developed therapy-related myeloid neoplasia (t-MN). In conclusion, a bendamustine bridge to SCT can be administered without early toxicity to patients with suboptimal responses to salvage chemotherapy. However this approach may increase the risk of t-MN. (NCT02059239).Supplemental data for this article is available online at here.

Impact of bone marrow biopsy on response assessment in immunochemotherapy-treated lymphoma patients in GALLIUM and GOYA.

The utility of posttreatment bone marrow biopsy (BMB) histology to confirm complete response (CR) in lymphoma clinical trials is in question. We retrospectively evaluated the impact of BMB on response assessment in immunochemotherapy-treated patients with previously untreated follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL) in the phase 3 Study of Obinutuzumab (RO5072759) Plus Chemotherapy in Comparison With Rituximab Plus Chemotherapy Followed by Obinutuzumab or Rituximab Maintenance in Patients With Untreated Advanced Indolent Non-Hodgkin's Lymphoma (GALLIUM; NCT01332968) and A Study of Obinutuzumab in Combination With CHOP Chemotherapy Versus Rituximab With CHOP in Participants With CD20-Positive Diffuse Large B-Cell Lymphoma (GOYA; NCT01287741) trials, respectively. Baseline BMB was performed in all patients, with repeat BMBs in patients with a CR by computed tomography (CT) at end of induction (EOI) and a positive BMB at baseline, to confirm response. Positron emission tomography imaging was also used in some patients to assess EOI response (Lugano 2014 criteria). Among patients with an EOI CR by CT in GALLIUM and GOYA, 2.8% and 4.1%, respectively, had a BMB-altered response. These results suggest that postinduction BMB histology has minimal impact on radiographically (CT)-defined responses in both FL and DLBCL patients. In GALLIUM and GOYA, respectively, 4.7% of FL patients and 7.1% of DLBCL patients had a repeat BMB result that altered response assessment when applying Lugano 2014 criteria, indicating that bone marrow evaluation appears to add little value to response assessment in FL; however, its evaluation may still have merit in DLBCL.

Illness Understanding and Advance Care Planning in Patients with Advanced Lymphoma.

Background: The prognosis of an aggressive lymphoma can change dramatically following failure of first-line treatment. This sudden shift is challenging for the promotion of illness understanding and advance care planning (ACP). Yet, little is known about illness understanding and ACP in patients with aggressive lymphomas. Objective: To examine illness understanding, rates of engagement in ACP, and reasons for lack of ACP engagement in patients with advanced B cell lymphomas. Design: Cross-sectional observational study. Setting/Subjects: Patients (n = 27) with aggressive B cell lymphomas that relapsed after first- or second-line treatment treated at a single urban academic medical center. Measurements: Participants were administered structured surveys by trained staff to obtain self-report measures of illness understanding (i.e., aggressiveness, terminality, curability) and ACP (i.e., discussions of care preferences, completion of advance directives). Results: The majority of patients reported discussing curability (92.6%), prognosis (77.8%), and treatment goals (88.9%) with their medical team. Yet, less than one-third of patients reported being terminally ill (29.6%) and having incurable disease (22.2%). Most patients had a health care proxy (81.5%) and had decided about do-not-resuscitate status (63%), but the majority had not completed a living will (65.4%) or discussed their care preferences with others (55.6%). Conclusions: The accuracy of lymphoma patients' illness understanding following first-line treatment is difficult to determine due to the potential for cure following transplant. However, this study suggests that a large proportion of patients with advanced B cell lymphomas may underestimate the severity of their illness, despite discussing illness severity with their medical team. Providing patients with information on prognosis, and the ACP process may increase engagement in ACP.

Surveillance scanning in lymphoma.

Although the role of imaging in the management of most lymphomas is well established at baseline, during treatment, and following treatment, surveillance imaging after complete response remains controversial despite the numerous studies that have investigated follow-up computed tomography, positron emission tomography, and magnetic resonance imaging over the past 20 years. Although robust data do not support an impact of this strategy on survival in Hodgkin lymphoma, diffuse large B-cell lymphoma, or follicular lymphoma, many patients continue to undergo serial imaging studies. The role of imaging following treatment in peripheral T-cell lymphoma (PTCL) and mantle cell lymphoma (MCL) is poorly investigated, although the available literature questions the utility of scanning patients with PTCL or MCL in first remission. Of clear significance in all lymphoma subtypes is the effect of such imaging on patient anxiety, secondary cancers, and health care costs. Novel monitoring strategies, such as minimal residual disease detection with circulating tumor DNA, are being examined in lymphoma and may provide a more accurate method by which to survey patients. Here I review the current literature on follow-up imaging in lymphoma patients by subtype.

DLBCL Cell of Origin: What Role Should It Play in Care Today?

Diffuse large B-cell lymphoma (DLBCL) is curable in about two-thirds of patients. Research has focused on determining which patients have less favorable prognoses so that they can be considered for novel targeted-treatment strategies. In 2000, gene expression profiling was used to define two principal DLBCL molecular subtypes, germinal center B-cell-like (GCB) and activated B-cell-like (ABC). Patients with GCB DLBCL have more favorable outcomes than those with ABC DLBCL when treated with standard immunochemotherapy. Alternate strategies to characterize molecular subtype include approximation with immunohistochemistry algorithms, and more recently the NanoString gene expression platform. Numerous studies have investigated novel agents in DLBCL with respect to GCB and ABC (or non-GCB) subtypes, but R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) remains the standard of care for most patients. Here we review the methods of determining cell of origin (COO); use of COO in clinical practice; clinical trials in DLBCL according to COO; and future directions of tailoring treatment, including alternate categorization of genetic subtypes or clusters in DLBCL.

Extracellular vesicles in DLBCL provide abundant clues to aberrant transcriptional programming and genomic alterations.

The biological role of extracellular vesicles (EVs) in diffuse large B-cell lymphoma (DLBCL) initiation and progression remains largely unknown. We characterized EVs secreted by 5 DLBCL cell lines, a primary DLBCL tumor, and a normal control B-cell sample, optimized their purification, and analyzed their content. We found that DLBCLs secreted large quantities of CD63, Alix, TSG101, and CD81 EVs, which can be extracted using an ultracentrifugation-based method and traced by their cell of origin surface markers. We also showed that tumor-derived EVs can be exchanged between lymphoma cells, normal tonsillar cells, and HK stromal cells. We then examined the content of EVs, focusing on isolation of high-quality total RNA. We sequenced the total RNA and analyzed the nature of RNA species, including coding and noncoding RNAs. We compared whole-cell and EV-derived RNA composition in benign and malignant B cells and discovered that transcripts from EVs were involved in many critical cellular functions. Finally, we performed mutational analysis and found that mutations detected in EVs exquisitely represented mutations in the cell of origin. These results enhance our understanding and enable future studies of the role that EVs may play in the pathogenesis of DLBCL, particularly with regards to the exchange of genomic information. Current findings open a new strategy for liquid biopsy approaches in disease monitoring.