N-acetyltransferase 10 facilitates tumorigenesis of diffuse large B-cell lymphoma by regulating AMPK/mTOR signalling through N4-acetylcytidine modification of SLC30A9.

BACKGROUND: Accumulating studies suggested that posttranscriptional modifications exert a vital role in the tumorigenesis of diffuse large B-cell lymphoma (DLBCL). N4-acetylcytidine (ac4C) modification, catalyzed by the N-acetyltransferase 10 (NAT10), was a novel type of chemical modification that improves translation efficiency and mRNA stability. METHODS: GEO databases and clinical samples were used to explore the expression and clinical value of NAT10 in DLBCL. CRISPER/Cas9-mediated knockout of NAT10 was performed to determine the biological functions of NAT10 in DLBCL. RNA sequencing, acetylated RNA immunoprecipitation sequencing (acRIP-seq), LC-MS/MS, RNA immunoprecipitation (RIP)-qPCR and RNA stability assays were performed to explore the mechanism by which NAT10 contributed to DLBCL progression. RESULTS: Here, we demonstrated that NAT10-mediated ac4C modification regulated the occurrence and progression of DLBCL. Dysregulated N-acetyltransferases expression was found in DLBCL samples. High expression of NAT10 was associated with poor prognosis of DLBCL patients. Deletion of NAT10 expression inhibited cell proliferation and induced G0/G1 phase arrest. Furthermore, knockout of NAT10 increased the sensitivity of DLBCL cells to ibrutinib. AcRIP-seq identified solute carrier family 30 member 9 (SLC30A9) as a downstream target of NAT10 in DLBCL. NAT10 regulated the mRNA stability of SLC30A9 in an ac4C-dependent manner. Genetic silencing of SLC30A9 suppressed DLBCL cell growth via regulating the activation of AMP-activated protein kinase (AMPK) pathway. CONCLUSION: Collectively, these findings highlighted the essential role of ac4C RNA modification mediated by NAT10 in DLBCL, and provided insights into novel epigenetic-based therapeutic strategies.

Extranodal diffuse large B-cell lymphoma involving the uterine cervix.

This is a case of primary diffuse large B-cell lymphoma involving the uterine cervix which presented with irregular vaginal bleeding. The diagnosis was confirmed following multiple cervical biopsies. Treatment with a combination of immunotherapy, chemotherapy (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone (R-CHOP)) and radiotherapy produced a good response.

Omission of etoposide in the treatment of haemophagocytic lymphohistiocytosis secondary to primary central nervous system lymphoma with satisfactory response.

Haemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory condition that can be either familial or acquired and, if untreated, frequently results in multiorgan failure and death. Treatment of HLH typically requires a combination of glucocorticoids and cytotoxic chemotherapy. We describe the case of a woman who presented with signs and symptoms concerning for HLH who was later found to have a primary central nervous system (CNS) diffuse large B-cell lymphoma. Her HLH symptoms were successfully treated with high doses of dexamethasone, and her primary CNS lymphoma was treated with high-dose methotrexate and rituximab. This is a rare case of HLH secondary to primary CNS lymphoma where HLH was controlled with steroids alone and did not require the use of an etoposide-based regimen or cyclophosphamide, doxorubicin, vincristine and prednisone.

Disulfidptosis: A Novel Prognostic Criterion and Potential Treatment Strategy for Diffuse Large B-Cell Lymphoma (DLBCL).

Diffuse Large B-cell Lymphoma (DLBCL), with its intrinsic genetic and epigenetic heterogeneity, exhibits significantly variable clinical outcomes among patients treated with the current standard regimen. Disulfidptosis, a novel form of regulatory cell death triggered by disulfide stress, is characterized by the collapse of cytoskeleton proteins and F-actin due to intracellular accumulation of disulfides. We investigated the expression variations of disulfidptosis-related genes (DRGs) in DLBCL using two publicly available gene expression datasets. The initial analysis of DRGs in DLBCL (GSE12453) revealed differences in gene expression patterns between various normal B cells and DLBCL. Subsequent analysis (GSE31312) identified DRGs strongly associated with prognostic outcomes, revealing eight characteristic DRGs (CAPZB, DSTN, GYS1, IQGAP1, MYH9, NDUFA11, NDUFS1, OXSM). Based on these DRGs, DLBCL patients were stratified into three groups, indicating that (1) DRGs can predict prognosis, and (2) DRGs can help identify novel therapeutic candidates. This study underscores the significant role of DRGs in various biological processes within DLBCL. Assessing the risk scores of individual DRGs allows for more precise stratification of prognosis and treatment strategies for DLBCL patients, thereby enhancing the effectiveness of clinical practice.

ß-Sitosterol Inhibits Tumor Growth and Amplifies Rituximab Sensitivity through Acid Sphingomyelinase/Ceramide Signaling in Diffuse Large B-Cell Lymphoma.

Rituximab (RTX) resistance is a notable challenge in treating diffuse large B-cell lymphoma (DLBCL). ß-Sitosterol (ß-ST) is a plant sterol that has been found in a broad variety of fruits, spices, and medicinal plants. The antineoplastic properties of ß-ST are established in various solid malignancies; however, its effect on DLBCL is uncharted. This study investigates the role of ß-ST in DLBCL as well as the underlying mechanisms. Our findings indicated that ß-ST impeded DLBCL cell proliferation in a concentration- and time-dependent manner. ß-ST appeared to alter sphingolipid metabolism, facilitate acid sphingomyelinase (ASM) translocation to the plasma membrane, augment ceramide platforms through increased ceramide synthesis, and consequently induce apoptosis in DLBCL cells. Furthermore, we found that RTX initiated both apoptotic and survival pathways in vitro, with the former contingent on the transient activation of the ASM, and ß-ST could amplify the anti-DLBCL efficacy of RTX by modulating ASM/Ceramide (Cer) signaling. Collectively, our findings elucidate the mechanistic role of ß-ST in DLBCL and underscore its potential in amplifying the antineoplastic efficacy of RTX via ASM activation, proposing a potential avenue to improve the efficacy of RTX therapy.

Tumor purity-related genes for predicting the prognosis and drug sensitivity of DLBCL patients.

Background: Diffuse large B-cell lymphoma (DLBCL) is the predominant type of malignant B-cell lymphoma. Although various treatments have been developed, the limited efficacy calls for more and further exploration of its characteristics. Methods: Datasets from the Gene Expression Omnibus (GEO) database were used for identifying the tumor purity of DLBCL. Survival analysis was employed for analyzing the prognosis of DLBCL patients. Immunohistochemistry was conducted to detect the important factors that influenced the prognosis. Drug-sensitive prediction was performed to evaluate the value of the model. Results: VCAN, CD3G, and C1QB were identified as three key genes that impacted the outcome of DLBCL patients both in GEO datasets and samples from our center. Among them, VCAN and CD3G+ T cells were correlated with favorable prognosis, and C1QB was correlated with worse prognosis. The ratio of CD68 + macrophages and CD8 + T cells was associated with better prognosis. In addition, CD3G+T cells ratio was significantly correlated with CD68 + macrophages, CD4 + T cells, and CD8 +T cells ratio, indicating it could play an important role in the anti-tumor immunity in DLBCL. The riskScore model constructed based on the RNASeq data of VCAN, C1QB, and CD3G work well in predicting the prognosis and drug sensitivity. Conclusions: VCAN, CD3G, and C1QB were three key genes that influenced the tumor purity of DLBCL, and could also exert certain impact on drug sensitivity and prognosis of DLBCL patients. Funding: This work is supported by the Shenzhen High-level Hospital Construction Fund and CAMS Innovation Fund for Medical Sciences (CIFMS) (2022-I2M-C&T-B-062).

Real life clinical outcomes of relapsed/refractory diffuse large B cell lymphoma in the rituximab era: The STRIDER study.

BACKGROUND: Relapse and refractory (R/R) rates after first-line R-CHOP in diffuse large B cell lymphomas (DLBCL) are ~40% and ~15% respectively. AIMS: We conducted a retrospective real-world analysis aimed at evaluating clinical outcomes of R/R DLBCL patients. MATERIAL AND METHODS: Overall, 403 consecutive DLBCL patients treated in two large hematological centers in Torino, Italy were reviewed. RESULTS: At a median follow up of 50 months, 5-year overall survival from diagnosis (OS-1) was 66.5%, and 2-year progression free survival (PFS-1) was 68%. 134 (34.4%) patients relapsed (n = 46, 11.8%) or were refractory (n = 88, 22.6%) to R-CHOP. Most employed salvage treatments included platinum salt-based regimens in 38/134 (28.4%), lenalidomide in 14 (10.4%). Median OS and PFS after disease relapse or progression (OS-2 and PFS-2) were 6.7 and 5.1 months respectively. No significant difference in overall response rate, OS-2 or PFS-2 in patients treated with platinum-based regimens versus other regimens was observed. By multivariate analysis, age between 60 and 80 years, germinal center B cell type cell of origin and extranodal involvement of <2 sites were associated with better OS-2. DISCUSSION: Our findings confirm very poor outcomes of R/R DLBCL in the rituximab era. Widespread approval by national Medicine Agencies of novel treatments such as CAR-T cells and bispecific antibodies as second-line is eagerly awaited to improve these outcomes.

Bendamustine is a safe and effective lymphodepletion agent for axicabtagene ciloleucel in patients with refractory or relapsed large B-cell lymphoma.

BACKGROUND: Fludarabine in combination with cyclophosphamide (FC) is the standard lymphodepletion regimen for CAR T-cell therapy (CAR T). A national fludarabine shortage in 2022 necessitated the exploration of alternative regimens with many centers employing single-agent bendamustine as lymphodepletion despite a lack of clinical safety and efficacy data. To fill this gap in the literature, we evaluated the safety, efficacy, and expansion kinetics of bendamustine as lymphodepletion prior to axicabtagene ciloleucel (axi-cel) therapy. METHODS: 84 consecutive patients with relapsed or refractory large B-cell lymphoma treated with axi-cel and managed with a uniform toxicity management plan at Stanford University were studied. 27 patients received alternative lymphodepletion with bendamustine while 57 received FC. RESULTS: Best complete response rates were similar (73.7% for FC and 74% for bendamustine, p=0.28) and there was no significant difference in 12-month progression-free survival or overall survival estimates (p=0.17 and p=0.62, respectively). The frequency of high-grade cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome was similar in both the cohorts. Bendamustine cohort experienced lower proportions of hematological toxicities and antibiotic use for neutropenic fever. Immune reconstitution, as measured by quantitative assessment of cellular immunity, was better in bendamustine cohort as compared with FC cohort. CAR T expansion as measured by peak expansion and area under the curve for expansion was comparable between cohorts. CONCLUSIONS: Bendamustine is a safe and effective alternative lymphodepletion conditioning for axi-cel with lower early hematological toxicity and favorable immune reconstitution.

Unveiling the PDK4-centered rituximab-resistant mechanism in DLBCL: the potential of the "Smart" exosome nanoparticle therapy.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) represents a prevalent malignant tumor, with approximately 40% of patients encountering treatment challenges or relapse attributed to rituximab resistance, primarily due to diminished or absent CD20 expression. Our prior research identified PDK4 as a key driver of rituximab resistance through its negative regulation of CD20 expression. Further investigation into PDK4's resistance mechanism and the development of advanced exosome nanoparticle complexes may unveil novel resistance targets and pave the way for innovative, effective treatment modalities for DLBCL. METHODS: We utilized a DLBCL-resistant cell line with high PDK4 expression (SU-DHL-2/R). We infected it with short hairpin RNA (shRNA) lentivirus for RNA sequencing, aiming to identify significantly downregulated mRNA in resistant cells. Techniques including immunofluorescence, immunohistochemistry, and Western blotting were employed to determine PDK4's localization and expression in resistant cells and its regulatory role in phosphorylation of Histone deacetylase 8 (HDAC8). Furthermore, we engineered advanced exosome nanoparticle complexes, aCD20@ExoCTX/siPDK4, through cellular, genetic, and chemical engineering methods. These nanoparticles underwent characterization via Dynamic Light Scattering (DLS) and Transmission Electron Microscopy (TEM), and their cellular uptake was assessed through flow cytometry. We evaluated the nanoparticles' effects on apoptosis in DLBCL-resistant cells and immune cells using CCK-8 assays and flow cytometry. Additionally, their capacity to counteract resistance and exert anti-tumor effects was tested in a resistant DLBCL mouse model. RESULTS: We found that PDK4 initiates HDAC8 activation by phosphorylating the Ser-39 site, suppressing CD20 protein expression through deacetylation. The aCD20@ExoCTX/siPDK4 nanoparticles served as effective intracellular delivery mechanisms for gene therapy and monoclonal antibodies, simultaneously inducing apoptosis in resistant DLBCL cells and triggering immunogenic cell death in tumor cells. This dual action effectively reversed the immunosuppressive tumor microenvironment, showcasing a synergistic therapeutic effect in a subcutaneous mouse tumor resistance model. CONCLUSIONS: This study demonstrates that PDK4 contributes to rituximab resistance in DLBCL by modulating CD20 expression via HDAC8 phosphorylation. The designed exosome nanoparticles effectively overcome this resistance by targeting the PDK4/HDAC8/CD20 pathway, representing a promising approach for drug delivery and treating patients with Rituximab-resistant DLBCL.

Brentuximab vedotin therapy followed by autologous peripheral stem cell transplantation as a viable treatment option for an older adult with transformed lymphoma: a case report and literature review.

This report presents a case involving a woman aged >65 years who had been diagnosed with marginal zone lymphoma 3 years prior. The patient was hospitalized with enlarged inguinal lymph nodes, and pathological examination revealed that the lymphoma had transformed into diffuse large B-cell lymphoma. After two cycles of brentuximab vedotin in combination with rituximab, cyclophosphamide, doxorubicin, and prednisone (BV-R-CHP) chemotherapy, the patient achieved complete remission. This treatment was followed by autologous hematopoietic stem cell transplantation and lenalidomide maintenance therapy. At the last follow-up, the patient had been in continuous remission for 24 months. This case study suggests that the utilization of BV and R-CHP in conjunction can result in rapid remission, and it can be followed by autologous hematopoietic stem cell transplantation and maintenance therapy with lenalidomide. This treatment approach exhibits potential as a viable option for older individuals with transformed lymphoma.

Extranodal diffuse large B-cell lymphoma presenting with extensive organ involvement.

Extranodal involvement in diffuse large B-cell lymphoma (DLBCL) is defined as disease outside of the lymph nodes and occurs in up to one-third of patients, though multiorgan extranodal involvement is rare. Here, we describe a case of a patient presenting with widely metastatic lesions, including involvement of the lung, parotid gland, breast, pancreas, femur and multiple soft tissue masses, with initial concern for primary breast malignancy. Breast pathology and imaging were consistent with triple-expressor, double-hit stage IV high-grade B-cell lymphoma with extensive extranodal involvement. Extranodal involvement is a poor prognostic factor associated with high rates of treatment failure, and novel therapies targeting CD19 are currently being studied for relapsed and refractory DLBCL. Extranodal disease is a complex entity that can involve virtually any organ system and should be considered for new presentations of malignancy.

Ethyl pyruvate attenuates cellular adhesion and proliferation of diffuse large B-cell lymphoma by targeting c-Jun.

Diffuse large B-cell lymphoma (DLBCL) stands out as the most common type of malignant cancer, representing the majority of cases of non-Hodgkin's lymphoma. Ethyl pyruvate (EP) is a derivative of pyruvic acid and found to have potent anti-tumor properties. Despite its potential benefits, the impact of EP on DLBCL remains ambiguous. Our objective is to elucidate the role of EP in modulating the development of DLBCL. Analysis of cholecystokinin-8 (CCK-8) revealed that treatment with EP significantly diminished the viability of DLBCL cells. Furthermore, EP administration suppressed colony formation and hindered cell adhesion and invasion in DLBCL cells. Examination of cell cycle progression showed that EP treatment induced arrest at the G1 phase and subsequently reduced the S phase population in DLBCL cells. EP treatment consistently exhibited apoptosis-inducing properties in Annexin-V assays, and notably downregulated the expression of Bcl-2 while increasing levels of proapoptotic cleaved caspase 3 and BAX in DLBCL cells. Additionally, EP treatment decreased the overexpression of c-Jun in c-Jun-transfected DLBCL cells. Further, EP demonstrated DNA-damaging effects in TUNEL assays. In vivo, xenograft animal models revealed that EP treatment significantly mitigated DLBCL tumor growth and suppressed DLBCL cell adhesion to bone marrow stromal cells. In summary, these findings suggest that EP mitigates DLBCL progression by inducing apoptosis, inducing cell cycle arrest, and promoting DNA damage.

Combination Targeted Therapy in Relapsed Diffuse Large B-Cell Lymphoma.

BACKGROUND: The identification of oncogenic mutations in diffuse large B-cell lymphoma (DLBCL) has led to the development of drugs that target essential survival pathways, but whether targeting multiple survival pathways may be curative in DLBCL is unknown. METHODS: We performed a single-center, phase 1b-2 study of a regimen of venetoclax, ibrutinib, prednisone, obinutuzumab, and lenalidomide (ViPOR) in relapsed or refractory DLBCL. In phase 1b, which included patients with DLBCL and indolent lymphomas, four dose levels of venetoclax were evaluated to identify the recommended phase 2 dose, with fixed doses of the other four drugs. A phase 2 expansion in patients with germinal-center B-cell (GCB) and non-GCB DLBCL was performed. ViPOR was administered every 21 days for six cycles. RESULTS: In phase 1b of the study, involving 20 patients (10 with DLBCL), a single dose-limiting toxic effect of grade 3 intracranial hemorrhage occurred, a result that established venetoclax at a dose of 800 mg as the recommended phase 2 dose. Phase 2 included 40 patients with DLBCL. Toxic effects that were observed among all the patients included grade 3 or 4 neutropenia (in 24% of the cycles), thrombocytopenia (in 23%), anemia (in 7%), and febrile neutropenia (in 1%). Objective responses occurred in 54% of 48 evaluable patients with DLBCL, and complete responses occurred in 38%; complete responses were exclusively in patients with non-GCB DLBCL and high-grade B-cell lymphoma with rearrangements of MYC and BCL2 or BCL6 (or both). Circulating tumor DNA was undetectable in 33% of the patients at the end of ViPOR therapy. With a median follow-up of 40 months, 2-year progression-free survival and overall survival were 34% (95% confidence interval [CI], 21 to 47) and 36% (95% CI, 23 to 49), respectively. CONCLUSIONS: Treatment with ViPOR was associated with durable remissions in patients with specific molecular DLBCL subtypes and was associated with mainly reversible adverse events. (Funded by the Intramural Research Program of the National Cancer Institute and the National Center for Advancing Translational Sciences of the National Institutes of Health and others; ClinicalTrials.gov number, NCT03223610.).

[A Case of Small Lymphocytic Lymphoma with -X Transformed Into Diffuse Large B-Cell Lymphoma].

An 80-year-old woman had developed a slight fever and loss of appetite since October 20XX. In November of the same year, the patient visited our hospital. Peripheral blood tests revealed the presence of atypical lymphocytes and a significant increase in sIL-2R. Tests of bone marrow aspiration samples showed the infiltration of small lymphocytes positive for CD19, CD20, CD23, and lambda. Therefore, a diagnosis of small lymphocytic lymphoma(SLL)was made. A complex karyotype including -X and del(13q)was observed in 19/20. Additionally, an enlarged spleen and retroperitoneal tumors were observed. As a result of 3 courses of fludarabine plus rituximab therapy, atypical lymphocytes were no longer observed in the peripheral blood and the enlarged spleen decreased in size. However, the retroperitoneal tumors could not be reduced. Consequently, a needle biopsy from the same area was performed in February 20XX+1, and a diagnosis of diffuse large B-cell lymphoma(DLBCL)was made. Because massive infiltration of CD23-negative lymphocytes was observed in the bone marrow, it was suggested that chronic lymphocytic leukemia(CLL)had transformed into DLBCL. Following 4 courses of CHOP therapy, the retroperitoneal tumors were reduced. In cases where -X is a microclone, the mutation is often age-related. However, in cases of advanced chronogenesis, as occurred in this patient, a correlation with hematopoietic tumors is arguable. Moreover, cases of CLL with -X have been reported to be related to de(l 13q). Our results strongly suggest that -X with del(13q)may be a clonal expansion in CLL/SLL.

[Primary renal triple expressor DLBCL treated with chemotherapy under continuous hemodialysis and filtration support].

A 69-year-old woman was previously treated with antibiotics for suspected pyelonephritis due to fever but showed limited improvement. Contrast-enhanced CT revealed heterogeneous areas of decreased contrast enhancement in both kidneys, along with an elevated soluble level of the IL-2 receptor (5,090 U/ml), and thus the patient was referred to our department for further evaluation. A percutaneous renal biopsy performed due to suspected malignant lymphoma confirmed lymphoma cell infiltration into the renal interstitium. Immunohistochemical staining was positive for MYC/BCL2/BCL6, leading to the diagnosis of stage IVB primary renal triple expressor diffuse large B cell lymphoma (DLBCL). Due to acute kidney injury, continuous hemodiafiltration (CHDF) was initiated, followed by rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy. The patient's renal function improved rapidly, and complete response was achieved after six cycles of R-CHOP. Although DLBCL is a common lymphoma, the primary renal subtype is extremely rare and poses both diagnostic and therapeutic challenges. This case highlights the potential clinical implications of combining CHDF with chemotherapy to achieve complete response despite an initial poor prognosis based on the patient's overall clinical condition and pathology.

Revisiting beta-2 microglobulin as a prognostic marker in diffuse large B-cell lymphoma.

BACKGROUND: Several clinical prognostic models for diffuse large B-cell lymphoma (DLBCL) have been proposed, including the most commonly used International Prognostic Index (IPI), the National Comprehensive Cancer Network IPI (NCCN-IPI), and models incorporating beta-2 microglobulin (ß2M). However, the role of ß2M in DLBCL patients is not fully understood. METHODS: We identified 6075 patients with newly diagnosed DLBCL treated with immunochemotherapy registered in the Danish Lymphoma Registry. RESULTS: A total of 3232 patients had data available to calculate risk scores from each of the nine considered risk models for DLBCL, including a model developed from our population. Three of four models with ß2M and NCCN-IPI performed better than the International Prognostic Indexes (IPI, age-adjusted IPI, and revised IPI). Five-year overall survival for high- and low-risk patients were 43.6% and 86.4% for IPI and 34.9% and 96.2% for NCCN-IPI. In univariate analysis, higher levels of ß2M were associated with inferior survival, higher tumor burden (advanced clinical stage and bulky disease), previous malignancy and increased age, and creatinine levels. Furthermore, we developed a model (ß2M-NCCN-IPI) by adding ß2M to NCCN-IPI (c-index 0.708) with improved discriminatory ability compared to NCCN-IPI (c-index 0.698, p < 0.05) and 5-year OS of 33.1%, 56.2%, 82.4%, and 96.4% in the high, high-intermediate, low-intermediate and low-risk group, respectively. CONCLUSION: International Prognostic Indices, except for NCCN-IPI, fail to accurately discriminate risk groups in the rituximab era. ß2M, a readily available marker, could improve the discriminatory performance of NCCN-IPI and should be re-evaluated in the development setting of future models for DLBCL.

Discovery of KT-413, a Targeted Protein Degrader of IRAK4 and IMiD Substrates Targeting MYD88 Mutant Diffuse Large B-Cell Lymphoma.

Developing therapies for the activated B-cell like (ABC) subtype of diffuse large B-cell lymphomas (DLBCL) remains an area of unmet medical need. A subset of ABC DLBCL tumors is driven by activating mutations in myeloid differentiation primary response protein 88 (MYD88), which lead to constitutive activation of interleukin-1 receptor associated kinase 4 (IRAK4) and cellular proliferation. IRAK4 signaling is driven by its catalytic and scaffolding functions, necessitating complete removal of this protein and its escape mechanisms for complete therapeutic suppression. Herein, we describe the identification and characterization of a dual-functioning molecule, KT-413 and show it efficiently degrades IRAK4 and the transcription factors Ikaros and Aiolos. KT-413 achieves concurrent degradation of these proteins by functioning as both a heterobifunctional degrader and a molecular glue. Based on the demonstrated activity and safety of KT-413 in preclinical studies, a phase 1 clinical trial in B-cell lymphomas, including MYD88 mutant ABC DLBCL, is currently underway.

Outcomes of Rituximab-abbs versus Rituximab in Patients with Diffuse Large B-Cell Lymphoma in a Noninferiority Study.

BACKGROUND: Rituximab with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) is one of the first line treatments for diffuse large B-cell lymphoma (DLBCL). Rituximab comprises most of the treatment cost for this regimen; therefore, biosimilars, such as rituximab-abbs are crucial to provide affordable care. Although rituximab-abbs was studied primarily in follicular lymphoma, the Food and Drug Administration (FDA) approved this drug for all indications of the reference product on the basis of extrapolation. Effectiveness and safety data surrounding the use of rituximab-abbs in DLBCL is lacking. OBJECTIVE: To evaluate the effectiveness and safety of rituximab-abbs and reference product rituximab as R-CHOP treatment for patients with DLBCL. PATIENTS AND METHODS: This noninferiority (NI) study compared the 2-year overall survival (OS), overall response rate (ORR), and incidence of adverse events (AEs) between rituximab-abbs and its reference product (RP) in R-CHOP among adult patients with newly diagnosed DLBCL. The study inclusion period was from 1 January 2019 to 31 December 2020. Analyses were performed on the basis of a noninferiority lower limit of 10% for OS and ORR, and an upper limit of 10% for serious AEs. RESULTS: There were 240 patients who received RP rituximab, while 295 patients received rituximab-abbs. The cohort had a mean age of 63.7±12.2 years and 43% were female. The 2-year OS was 81.0% and 79.6% (NI p < 0.01) while the ORR was 80.0% and 69.6% (NI p < 0.01), among the rituximab-abbs and rituximab groups, respectively. The incidence of infusion reaction AEs (NI p < 0.01) and noninfusion reaction AEs (NI p < 0.01) also met noninferiority. CONCLUSIONS: We demonstrated that rituximab-abbs was noninferior to rituximab in both effectiveness and safety among patients receiving R-CHOP for DLBCL in this study. Long-term follow-up would be needed to confirm these results.