Flow-cytometry Assessment of DNA content and Immunophenotyping of Immune-cells in Lymph-node-specimens as a Potential Diagnostic Signature of Aggressiveness in B-Non-Hodgkin Lymphomas.

Flow-cytometry (FC) is a powerful tool that can assist in lymphoma diagnosis in lymph node (LN) specimens. Although lymphoma diagnosis and classification are mainly based on tumor cell characteristics, surrounding cells are less employed in this process. We retrospectively investigated alterations in the ploidy status, proliferative cell fraction (PF) and the percentages of surrounding immune cells in 62 consecutive LN specimens with B-Cell Non-Hodgkin Lymphoma (B-NHL) that were submitted for FC evaluation between 2019-2022. Compared with indolent B-NHLs, aggressive B-NHLs show increased DNA aneuploidy and PF, increased monocytes, immature-granulocytes, mature granulocytes, CD8+ T-cells, Double-Negative-T-cells and Double-Positive-T-cells, and decreased total CD45+ cells, total lymphocytes, CD4+ T-cells and CD4/CD8 ratio. Receiver operating characteristic analysis determined PF > 6.8% and immature-granulocytes > 0.9% as optimal cutoffs with highest specificity and sensitivity in differentiating aggressive and indolent B-NHLs. These findings further strength the diagnostic value of DNA content analysis by FC and suggest the utilization of tumor surrounding immune cells in NHL diagnosis and classification.

An international multicenter study comparing COVID-19 omicron outcomes in patients with hematological malignancies treated with obinutuzumab versus rituximab.

OBJECTIVES: Hematological malignancy (HM) patients treated with anti-CD20 monoclonal antibodies are at higher risk for severe COVID-19. A previous single-center study showed worse outcomes in patients treated with obinutuzumab compared to rituximab. We examined this hypothesis in a large international multicenter cohort. METHODS: We included HM patients from 15 centers, from five countries treated with anti-CD20, comparing those treated with obinutuzumab (O-G) to rituximab (R-G) between December 2021 and June 2022, when Omicron lineage was dominant. RESULTS: We collected data on 1048 patients. Within the R-G (n = 762, 73%), 191 (25%) contracted COVID-19 compared to 103 (36%) in the O-G. COVID-19 patients in the O-G were younger (61 ± 11.7 vs. 64 ± 14.5, p = 0.039), had more indolent HM diagnosis (aggressive lymphoma: 3.9% vs. 67.0%, p < 0.001), and most were on maintenance therapy at COVID-19 diagnosis (63.0% vs. 16.8%, p < 0.001). Severe-critical COVID-19 occurred in 31.1% of patients in the O-G and 22.5% in the R-G. In multivariable analysis, O-G had a 2.08-fold increased risk for severe-critical COVID-19 compared to R-G (95% CI 1.13-3.84), adjusted for Charlson comorbidity index, sex, and tixagevimab/cilgavimab (T-C) prophylaxis. Further analysis comparing O-G to R-G demonstrated increased hospitalizations (51.5% vs. 35.6% p = 0.008), ICU admissions (12.6% vs. 5.8%, p = 0.042), but the nonsignificant difference in COVID-19-related mortality (n = 10, 9.7% vs. n = 12, 6.3%, p = 0.293). CONCLUSIONS: Despite younger age and a more indolent HM diagnosis, patients receiving obinutuzumab had more severe COVID-19 outcomes than those receiving rituximab. Our findings underscore the need to evaluate the risk-benefit balance when considering obinutuzumab therapy for HM patients during respiratory viral outbreaks.

A phase 2 study of ibrutinib maintenance following first-line high-dose methotrexate-based chemotherapy for elderly patients with primary central nervous system lymphoma.

BACKGROUND: Elderly patients account for nearly 70% of all primary central nervous system lymphoma (PCNSL) cases. They cannot tolerate aggressive treatment and have poor prognosis with a median overall survival (OS) of less than 2 years and progression-free survival (PFS) of 6-16 months. Ibrutinib penetrates the blood-brain barrier and has shown activity in PCNSL. METHODS: This prospective study investigated whether ibrutinib maintenance is feasible, and whether it can benefit elderly PCNSL patients in terms of expected 2-year PFS. It is an open label, phase 2 study in newly diagnosed PCNSL patients 60-85 years old who responded to first-line high-dose methotrexate (HDMTX)-based treatment with partial or complete response. Ibrutinib maintenance (560 mg/d) was continued until disease progression or intolerable toxicity. RESULTS: Twenty patients were enrolled, with a median age of 72 years (range, 61-80). Median time on ibrutinib maintenance was 12.5 (range, 2-46) months. Twelve patients stopped treatment: five due to central nervous system relapse and seven due to adverse events that were mainly grade 2. Five patients died (25%) all due to relapse. The 1- and 2-year PFS are 90% and 72.6%, respectively, and the 2-year OS is 89%. CONCLUSIONS: The study reached its primary end points and also showed that ibrutinib maintenance is tolerated reasonably well by the elderly. Therefore, this study supports the concept that ibrutinib maintenance should be further evaluated as an optional consolidation measure in the elderly.

Clonal Myeloid Dysplasia Following CAR T-Cell Therapy: Chicken or the Egg?

Multiple myeloma (MM) is characterized by recurrent relapses. Consequently, patients receive multiple therapy lines, including alkylating agents and immune modulators, which have been associated with secondary malignancies such as myelodysplastic syndrome (MDS). Anti-B-cell maturation antigen (BCMA) chimeric antigen receptor T cell (CART) therapy is efficacious in patients with relapsed/refractory (R/R) MM. However, the long-term complications, particularly MDS, are not well understood. Whether CART therapy causes or promotes MDS has not been thoroughly investigated. In this study, we explored the causal relationship between MDS and CART therapy. We retrospectively examined the prevalence of MDS-related morphological and mutational changes before and after administration of CART therapy in five patients. Among them, four developed MDS after CART therapy, while one had pre-existing MDS prior to CART. None of the four patients who developed post-CART MDS showed morphological MDS changes prior to CART therapy. However, all four patients exhibited molecular alterations associated with MDS in their pre-CART as well as post-CART therapy bone marrow. No new mutations were observed. Our findings provide initial evidence suggesting that anti-BCMA CART therapy in MM may promote expansion of pre-existing MDS clones rather than causing development of new clones.

Thrombosis in Pregnant Women with Hematological Malignancies: A Case-Based Review.

Cancer and pregnancy induce a procoagulant environment which may lead to maternal and fetal complications, such as venous thromboembolism, fetal growth restriction, and fetal loss. The incidence of hematological malignancies diagnosed during pregnancy is rising, and thrombotic events in such malignancies are not rare. Management of thrombosis during pregnancy poses a therapeutic challenge, that is further exacerbated by the impact of cancer. The available data on managing pregnant women with hematological malignancies are limited to those with myeloproliferative neoplasms, mainly essential thrombocythemia, and, to a lesser extent, polycythemia vera. Low-dose aspirin is recommended throughout pregnancy, and considering treatment with low-molecular-weight heparin and interferon formulations is advised for high-risk patients. Currently, guidelines for handling thrombotic events in pregnant women with lymphoma or leukemia are lacking, and their management is based on data extrapolated from retrospective studies, and guidelines for prevention and treatment of cancer-associated thrombosis. The present case-based review will focus on the complex issue of thrombotic risk in pregnant women with hematological malignancies, specifically myeloproliferative neoplasms, lymphomas, and leukemias.

The role of additional chemotherapy prior to autologous HCT in patients with relapse/refractory DLBCL in partial remission-A retrospective multicenter study.

OBJECTIVES: To evaluate the role of additional chemotherapy before autologous hematopoietic cell transplantation (HCT) in patients with relapse/refractory diffuse large B-cell lymphoma (DLBCL) who achieve partial remission following first salvage therapy. METHODS: We conducted a multicenter retrospective study of all adult patients with DLBCL who underwent HCT between 2008 and 2020 and achieved partial response (PR) after the first salvage and were either referred directly to HCT (n = 47) or received additional salvage therapy before HCT (n = 22). RESULTS: Post-HCT CR rate and progression-free survival were comparable between the two groups (66% vs. 68%, p = .86 and median not reached vs. 10.2 months [95% confidence interval, CI 7.1-12.3], p = .27, respectively). Median overall survival (OS) and estimated 3-year OS favored patients who were directly referred to HCT (105.8 [95% CI 63-148] months vs. 14.5 [95% CI 0-44] months, p = .035, and 65% [95% CI 51%-75%] vs. 40% [95% CI 21%-53%], p = .035, respectively). In Cox regression model, while International Prognostic Index and primary refractory versus relapse disease did not impact OS, allocation to a second salvage regimen and older age were both associated with inferior survival (hazard ratio [HR] = 2.57 95% CI 1.1-5.8, p = .023 and HR = 1.04 95% CI 0.99-1.2, p = .064, respectively). CONCLUSIONS: Referring patients with chemotherapy-sensitive disease in PR directly to HCT is associated with better OS compared to those receiving additional lines of treatment.

Incidence and risk factors for central nervous system relapse in patients with primary mediastinal large B-cell lymphoma in the rituximab era.

Central nervous system (CNS) involvement is rare in primary mediastinal large B-cell lymphoma (PMLBCL). We aimed to evaluate the incidence of CNS relapse as first treatment failure event and the effect of the induction chemotherapy regimen, central nervous system - international prognostic index (CNS-IPI) and other clinical and laboratory variables on the risk of CNS relapse in 564 PMLBCL patients treated with immunochemotherapy. Only 17 patients (3.0%) received CNS prophylaxis. During a 55-month median follow-up only 8 patients experienced CNS relapse as first event, always isolated. The 2-year cumulative incidence of CNS relapse (CI-CNSR) was 1.47% and remained unchanged thereafter. The CI-CNSR was not affected by the chemotherapy regimen (R-CHOP or R-da-EPOCH). None of the established International Prognostic Index factors for aggressive lymphomas predicted CNS relapse in PMLBCL. The 2-year CI-CNSR in patients with versus without kidney involvement was 13.3% versus 0.96% (p < 0.001); 14.3% versus 1.13% with versus without adrenal involvement (p < 0.001); and 10.2% versus 0.97% with versus without either kidney or adrenal involvement. CNS-IPI was also predictive (2-year CI-CNSR in high-risk vs. intermediate/low-risk: 10.37% vs. 0.84%, p < 0.001). However, this association may be driven mainly by kidney and/or adrenal involvement. In conclusion, in PMLBCL, CNS relapse is rare and appears to be strongly associated with kidney and/or adrenal involvement.

In chronic lymphocytic leukemia, activation of the thrombopoietin receptor promotes T-cell inhibitory properties, contributing to immunosuppression.

In chronic lymphocytic leukemia (CLL), the immune system is skewed towards a suppressive milieu. Levels of thrombopoietin (TPO), promoting cellular immune regulatory activity in immune thrombocytopenic purpura, were shown to be elevated in CLL patients. This study explored TPO as a potential immunomodulator, supporting CLL progression. We evaluated CLL cell-induced expression of TPO receptor (TPO-R) on T-cells and effects of its activation on T-cell responses. CLL cell involvement in TPO generation was also assessed. Baseline TPO-R expression on CD4 + T-cells was found to be higher in CLL patients than in healthy controls (HC). Exposure of HC-T-cells to B-cells, especially to CLL-B-cells stimulated with B-cell activating molecules, resulted in enhanced TPO-R expression on T-cells. CLL-T-cell stimulation with TPO reduced their proliferation and expanded the regulatory T-cell (Treg) population. At baseline, phosphorylation of STAT5, known to impact the Treg phenotype, was elevated in CLL-T-cells relative to those of HC. Exposure to TPO further enhanced STAT5 phosphorylation in CLL-T-cells, possibly driving the observed Treg expansion. The CLL immune milieu is involved in promotion of inhibitory features in T-cells through increased TPO-R levels and TPO-induced intracellular signaling. TPO and its signaling pathway could potentially support immunosuppression in CLL, and may emerge as novel therapeutic targets.

Real-world experience with belantamab mafodotin therapy for relapsed/refractory multiple myeloma: A multicentre retrospective study.

Belantamab mafodotin, an immuno-conjugate targeting B-cell maturation antigen, showed single-agent activity in phase 1 and 2 studies, and was recently approved for heavily pretreated relapsed/refractory multiple myeloma (RRMM) patients. Real-world data and long-term follow-up are scarce. We conducted a multisite retrospective study aimed to assess safety and efficacy of belantamab mafodotin monotherapy administered via the GSK expanded access compassionate care programme. One-hundred and six RRMM patients were treated with belantamab mafodotin between July 2019 and March 2021. The median age was 69.4 years. Patients were heavily pretreated with a median of six (range 2-11) prior therapy lines. Major adverse effects included ocular toxicity (keratopathy 68.4%, grade ≥3: 40.5%; blurred vision 36.8%, grade ≥3: 6.3%), thrombocytopenia (27.4%, grade ≥3: 17.9%) and infections (11.3%, grade ≥3: 7.5%). Median follow-up time was 11.9 [95% confidence interval (CI) 10.0-13.8] months. Overall response rate was 45.5%. Median progression-free survival was 4.7 (95% CI 3.5-5.9) months in the entire cohort and 8.8 (95% CI 6.6-10.9) months among responders. Median overall survival was 14.5 (95% CI 9.5-19.6) months, and not reached for responders. To conclude, in a real-world setting, belantamab mafodotin monotherapy showed efficacy comparable with the prospective clinical trials, with a tolerable toxicity profile.

Clinical features, therapy patterns, outcomes and prognostic factors of solitary plasmacytomas: a report of the Israeli Myeloma Study Group.

Solitary plasmacytoma (SP) is a rare plasma cell dyscrasia. In this retrospective multicenter study, 68 SP patients were included. Compared to solitary extramedullary plasmacytoma (SEP), patients with solitary bone plasmacytoma (SBP) were younger (57.3 vs. 70.9 years, p = 0.031), had larger plasmacytoma (median: 5.4 vs. 3 cm, p = 0.007) and higher median involved free light chain level (61 vs. 25.8 mg/L, p = 0.056). 92.6% of patients were treated by radiotherapy and 11.8% received systemic anti-myeloma treatment. With a median follow-up of 42 months, 45.6% of patients progressed (8.8% - recurrent SP, 36.8% - active myeloma). The median PFS was 58 months and the median OS has not been reached (10-year OS: 84.8%). Patients who received also anti-myeloma treatment had longer PFS compared to those who did not (median not reached vs. 48 months, p = 0.056). In conclusion, SBP and SEP appear to be different diseases. Radiotherapy is the cornerstone in the SP treatment. A large prospective trial is needed to evaluate the impact of adding systemic anti-myeloma treatment to local radiotherapy.

Association between IgG antibody levels and adverse events after first and second Bnt162b2 mRNA vaccine doses.

OBJECTIVES: This study sought to correlate the SARS-CoV-2 IgG antibody response level to the BNT162b2 (Pfizer BioNTech) mRNA vaccine after the first and second doses with the reported adverse events. METHODS: This cohort study examined the adverse events profiles of people vaccinated with BNT162b2 in our institute between late 2020 and May 2021. Adverse events, age, and sex were reported using an electronic questionnaire, and their SARS-CoV-2 IgG antibody levels were retrieved from the hospital database. RESULTS: Between 20 December 2020 and 31 May 2021, the adverse events questionnaire was completed by 9700 individuals who received the first vaccine dose and 8321 who received the second dose. After the first and second doses, the average antibody levels were 62.34 AU/mL (mean 4-373) and 188.19 AU/mL (mean 20-392), respectively. All of the adverse events, except local pain, were more common after the second vaccine dose. Multivariate analysis showed that after the first vaccine dose, female sex and younger age (but not IgG titres) were associated with a higher probability of adverse events (OR 2.377, 95% CI, 1.607-3.515, p = 0.000; OR 0.959, 95% CI, 0.944-0.977, p £0.000; OR 1.002, 95% CI, 0.995-1.008, p £0.601; respectively); however, all three parameters were associated with the incidence of adverse events after the second dose (OR 2.332, 95% CI, 1.636-3.322, p = 0.000; OR 0.984, 95% CI, 0.970-0.999, p £0.039; OR 1.004, 95% CI, 1.001-1.007, p £0.022; respectively). DISCUSSION: Adverse events are significantly more common after the second BNT162b2 vaccine dose than after the first dose. We found an association between sex, age, and SARS-CoV-2 IgG antibody titre with the incidence of adverse events.

A prediction model for central venous catheter-related thrombosis in patients with newly-diagnosed acute myeloid leukemia: A derivation cohort analysis.

BACKGROUND: Catheter-related thrombosis (CRT) is a common complication in cancer patients, that may lead to chemotherapy deferral, elevated risk for systemic infections and pulmonary embolism. This study aimed to assess CRT incidence and risk factors in newly-diagnosed acute myeloid leukemia (AML) patients and create predictive models potentially allowing to decrease CRT occurrence in this population. METHODS: This retrospective single-center analysis included all AML patients treated at the Rambam Health Care Campus between 2006 and 2019. Patient clinical and laboratory data were collected to evaluate thrombosis occurrence and time from AML diagnosis to CRT development. Multivariate classification models were created using logistic regression (LR) and competing risk analyzes. RESULTS: The final analysis included 632 newly-diagnosed AML patients (mean age 54 ± 15 years). CRT incidence was 10.1% [confidence interval (CI) 7.7-12.9%], median time from AML diagnosis to CRT was 12.5 days [interquartile range 6-30]. In an LR multivariate model, prior history of venous thromboembolism [adjusted odds ratio (AOR) 12.046, p < 0.0001], acute promyelocytic leukemia (APL) (AOR 2.824, p = 0.015), a high body mass index and initial platelet counts <100 × 10E9/L (AOR 1.059 and 0.546; p = 0.011 and 0.040, respectively) were significantly associated with high CRT risk. Analysis of 587 non-APL patients demonstrated comparable results, with CRT incidence of 9.3% (CI 7.0%-12.1%) and emergence of chronic obstructive pulmonary disease (COPD) as a novel significant co-factor (AOR 34.491, p = 0.004). In both models, the area under curve (AUC) was ≥70%. CONCLUSIONS: Significant CRT risk factors defined using the created model could be used for identification of high-risk newly-diagnosed AML patients requiring CRT prophylaxis.

Revisiting SARS-CoV-2 environmental contamination by patients with COVID-19: The Omicron variant does not differ from previous strains.

SARS-CoV-2 Omicron strain emergence raised concerns that its enhanced infectivity is partly due to altered spread/contamination modalities. We therefore sampled high-contact surfaces and air in close proximity to patients who were verified as infected with the Omicron strain, using identical protocols applied to sample patients positive to the original or Alpha strains. Cumulatively, for all 3 strains, viral RNA was detected in 90 of 168 surfaces and 6 of 49 air samples (mean cycle threshold [Ct]=35.2±2.5). No infective virus was identified. No significant differences in prevalence were found between strains.

Polatuzumab-based regimen or CAR T cell for patients with refractory/relapsed DLBCL-a matched cohort analysis.

Polatuzumab (Pola)-based regimens and chimeric antigen receptor T (CAR T) cells provide superior outcome compared to conventional chemoimmunotherapy in patients with relapsed/refractory diffuse large B cell lymphoma (R/R DLBCL). Choosing between these strategies remains controversial. The efficacy of CAR T versus Pola-rituximab(R) /Pola-bendamustine(B)-R in R/R DLBCL patients after failing ≥2 lines of treatment was compared in a retrospective, 'real-world' study. Propensity score matching, for age, lymphoma category (de-novo/transformed), number of prior lines, Eastern Cooperative Oncology Group performance status and lactate dehydrogenase level, was applied to control for differences in patients' characteristics. Response rate, progression-free survival (PFS) and overall survival (OS) were analyzed. A total of 82 patients, treated with CAR T (n=41) or Pola-based regimens (n=41), were included. No treatment-related deaths occurred with CAR T vs. 3 (7.3%) with Pola. The overall and complete response rates were 83% and 58% with CAR T vs. 66% and 44% with Pola-based-regimens (p=0.077 and p=0.18, respectively). At a median follow-up of 9 months (range 1-19.2) and 16 months (range 0.7-25.3) for the CAR T and Pola arm respectively, the median PFS has not been reached for CAR T vs. 5.6 months for Pola (95% CI 3.6-7.6, p=0.014). Median OS has not been reached for CAR T vs. 10.8 months (95% CI 2.2-19.4) for Pola (p=0.026). To conclude, in a real-world setting, treatment with CAR T achieved superior PFS and OS compared to Pola-based regimens in patients with R/R DLBCL.

Brain-derived neurotrophic factor in hematological malignancies: From detrimental to potentially beneficial.

Emerging studies have highlighted brain-derived neurotrophic factor (BDNF), a neuronal growth factor abundant in the peripheral blood, and its tyrosine kinase receptor TRKB, as onco-genes and proteins that support the survival of malignant hematological cells. In contrast, other researchers reported on a favorable association between BDNF blood levels and prognosis, chemotherapy response and neurological side effects in patients with hematological malignancies. Here, we review the accumulated data regarding the expression of BDNF and its receptors in normal hematopoietic and lymphatic cells and tissue. In addition, in-vitro experiments, animal models and human sample studies that investigated the role of BDNF and its receptors in hematological malignancies are discussed. Finally, directions for future research aimed at revealing the mechanisms underlying the protective effect of BDNF in patients with these diseases are suggested.

Humoral serological response to the BNT162b2 vaccine is abrogated in lymphoma patients within the first 12 months following treatment with anti-CD2O antibodies.

Patients with lymphoma, especially those treated with anti-CD20 monoclonal antibodies, suffer high COVID-19-associated morbidity and mortality. The goal of this study was to assess the ability of lymphoma patients to generate a sufficient humoral response after two injections of BNT162b2 Pfizer vaccine and to identify factors influencing the response. Antibody titers were measured with the SARS-CoV-2 IgG II Quant (Abbott ) assay in blood samples drawn from lymphoma patients 4 2 weeks after the second dose of vaccine. The cutoff for a positive response was set at 50 AU/mL. Positive serological responses were observed in 51% of the 162 patients enrolled in this cross-sectional study. In a multivariate analysis, an interval of <12 months between the last anti-CD20 monoclonal antibody dose and the second vaccine dose (odds ratio=31.3 [95% confidence interval: 8.4-116.9], P<0.001) and presence of active lymphoma (odds ratio=4.2 (95% confidence interval: 2.1- 8.2), P=0.006) were identified as negative response predictors. The rate of seropositivity increased from 3% in patients vaccinated within 45 days after the last monoclonal antibody administration to 80% in patients vaccinated >1 year after this therapy. The latter percentage was equal to that of patients never exposed to monoclonal antibodies. In conclusion, lymphoma patients, especially those recently treated with anti- CD20 monoclonal antibodies, fail to develop sufficient humoral response to BNT162b2 vaccine. While a serological response is not the only predictor of immunity, its low level could make this population more vulnerable to COVID-19, which implies the need for a different vaccination schedule for such patients.

A Phase II Study to Assess the Safety and Efficacy of the Dual mTORC1/2 and PI3K Inhibitor Bimiralisib (PQR309) in Relapsed, Refractory Lymphoma.

Bimiralisib is an orally bioavailable pan-phosphatidylinositol 3-kinase and mammalian target of rapamycin inhibitor which has shown activity against lymphoma in preclinical models. This phase I/II study evaluated the response rate to bimiralisib at 2 continuous dose levels (60 mg and 80 mg) in patients with relapsed/refractory lymphoma. Fifty patients were enrolled and started treatment. The most common histologies were diffuse large B-cell lymphoma (n = 17), follicular lymphoma (n = 9), T-cell lymphoma (n = 8), and others (mostly indolent). Patients had been treated with a median of 5 prior lines of treatment and 44% were considered refractory to their last treatment. Mean duration of treatment (and standard deviations) with 60 mg once daily (o.d.) was 1.3 ± 1.2 months, and with 80 mg o.d. 3.7 ± 3.9 months. On an intention to treat analysis, the overall response rate was 14% with 10% achieving a partial response and 4% a complete response. Thirty-six percent of patients were reported as having stable disease. No dose-limiting toxicities were observed during the phase I portion of the study. Overall, 70% of patients had a grade 3 treatment emergent adverse events (TEAE) and 34% had a grade 4 TEAE; 28% of patients discontinued treatment due to toxicity. The most frequent TEAEs grade ≥3 was hyperglycemia (24%), neutropenia (20%), thrombocytopenia (22%), and diarrhea (12%). Per protocol, hyperglycemia required treatment with oral antihyperglycemic agents in 28% and with insulin in 14%. At 60 mg or 80 mg continuous dosing, bimiralisib showed modest efficacy with significant toxicity in heavily pretreated patients with various histological subtypes of lymphoma.

Dose-adjusted EPOCH-R is not superior to sequential R-CHOP/R-ICE as a frontline treatment for newly diagnosed primary mediastinal B-cell lymphoma: Results of a bi-center retrospective study.

PURPOSE: Primary mediastinal B-cell lymphoma (PMBCL) is a rare subtype of diffuse large B-cell lymphoma (DLBCL). Despite its aggressive course, PMBCL is considered curable. While in recent years dose-adjusted (DA) EPOCH-R (rituximab, etoposide, prednisone, vincristine, cyclophosphamide and doxorubicin) has become widely endorsed as first-line therapy for newly-diagnosed PMBCL, the optimal treatment for this disease and the role of radiotherapy (RT) remains unclear. DA-EPOCH-R provides good clinical outcomes, albeit is associated with short- and long-term toxicity. To address this issue, the current retrospective bi-icenter analysis compared efficacy and toxicity of DA-EPOCH-R and a less toxic R-CHOP/R-ICE regimen used for the treatment of newly-diagnosed PMBCL. PATIENTS AND METHODS: The study included all patients with a histologically confirmed PMBCL diagnosis treated with DA-EPOCH-R or R-CHOP/R-ICE between 01/2013-12/2020 at two tertiary medical centers. Patient demographic and clinical data were derived from institutional electronic medical records. The analysis included 56 patients: 31 received DA-EPOCH-R and 25 - R-CHOP/R-ICE. RESULTS: At a median follow-up of 1.9 years (IQR 3.1 years), similar progression-free survival (2.1 versus 2.4 years; p = 0.7667), overall survival (2.5 versus 2.7 years; p = 0.8047) and complete response (80%) were observed in both groups. However, DA-EPOCH-R was associated with significantly longer hospitalization required for its administration (p < 0.001) and a trend for higher frequency of infections, stomatitis, thrombotic complications and febrile neutropenia-related hospitalizations. CONCLUSION: DA-EPOCH-R and R-CHOP/R-ICE provide similarly encouraging outcomes in newly-diagnosed PMBCL patients. R-CHOP/R-ICE is associated with lower toxicity and significantly reduced hospitalization. Our findings suggest that this regimen may be considered as an alternative to DA-EPOCH-R in this patient population.