Background/Objectives: Diffuse large B-cell lymphoma (DLBCL) is molecularly heterogeneous, and approximately 30-50% of patients fail to achieve cure with standard R-CHOP. Genotype-directed first-line therapy may improve outcomes by targeting subtype-specific oncogenic pathways. This study evaluated the feasibility, efficacy, and safety of a molecularly adapted R-CHOP-X strategy with two-year follow-up. Methods: In this single-center, prospective, non-randomized study conducted between September 2023 and the data cut-off (16 September 2025), 43 adults with newly diagnosed DLBCL (excluding high-grade B-cell lymphoma, primary immune-privileged, and primary mediastinal large B-cell lymphomas) underwent tumor genotyping using the LymphGen classification after targeted sequencing: a 19-gene Sanger panel (Cohort 1, n = 35) or an expanded 60-gene panel (Cohort 2, n = 8; proof-of-concept). All patients received one initial cycle of R-CHOP as bridge therapy pending molecular profiling results, followed by five cycles of R-CHOP-X, with the additional agent (vorinostat, acalabrutinib, decitabine, or lenalidomide) selected according to molecular subtype. Response was assessed by PET/CT per Lugano criteria; adverse events were graded per NCI CTCAE v5.0. Results: The overall study population was predominantly high-risk: 72% had an IPI of 3–5, 58% had stage III–IV disease, and 67% exhibited a non-GCB immunophenotype. Expansion from the 19-gene to the 60-gene panel reduced unclassifiable (NOS) cases from 34% to 12%. The overall response rate was 100% (43/43); complete response among patients completing therapy was 100% (35/35). At two years, overall survival was 92% (95% CI 83–100%) and progression-free survival was 94% (95% CI 86–100%). Two early relapses occurred (NOS and N1 subtypes), both resulting in death. Grade 3–4 neutropenia, thrombocytopenia, and anemia occurred in 26%, 12%, and 7% of patients, respectively; no dose reductions or treatment discontinuations were recorded. Conclusions: Molecularly adapted R-CHOP-X is feasible and associated with high response rates and favorable two-year survival in newly diagnosed DLBCL, comparing favorably with historical R-CHOP outcomes in high-risk populations. Expanded genomic panels substantially improve molecular classifiability. These findings warrant validation in larger, multicenter, randomized clinical trials.

Diffuse large B-cell lymphoma (DLBCL) is molecularly heterogeneous; genotype-directed first-line therapy may improve outcomes. We conducted a single-center, prospective, non-randomized interventional study evaluating a molecularly adapted R-CHOP-X strategy with two-year follow-up. Between February 2023 and the data cut-off (September 16, 2025), 43 adults with newly diagnosed DLBCL (excluding high-grade B-cell lymphoma, primary immune-privileged, and primary mediastinal large B-cell lymphomas) underwent tumor genotyping using LymphGen after targeted sequencing: an initial cohort had Sanger sequencing of a 19-gene panel (n = 35) and a second cohort an expanded 60-gene panel (n = 8). All patients received one cycle of R-CHOP followed by five cycles of R-CHOP-X, with the additional agent (vorinostat, acalabrutinib, decitabine, or lenalidomide) selected according to molecular subtype. Response assessment followed Lugano criteria; adverse events were recorded per NCI CTCAE v5.0. The overall response rate was 100% (n = 43); complete response among patients completing therapy (n = 35) was 100%. At two years, overall survival was 92% (95% CI 83%–100%) and progression-free survival was 94% (95% CI 86%–100%); two early relapses occurred. These findings indicate that molecularly adapted R-CHOP-X is feasible and associated with high response rates and favorable two-year survival and warrant validation in larger randomized clinical trials.

Background: Diffuse large B-cell lymphoma (DLBCL) with TP53 abnormalities, corresponding to the LymphGen A53 molecular subtype, represents a biologically high-risk group associated with primary resistance to standard R-CHOP therapy. Epigenetic sensitization using hypomethylating agents may enhance chemosensitivity in this setting. We prospectively evaluated the clinical activity and safety of a molecularly adapted DAC-R-CHOP regimen in newly diagnosed A53-DLBCL. Methods: In this single-center prospective pilot cohort study, 70 consecutive patients with newly diagnosed DLBCL underwent targeted next-generation sequencing using a 60-gene panel with integrated copy number variation analysis. Six patients (8.5%) were classified as the A53 subtype. All patients received one cycle of standard R-CHOP. From cycle 2 onward, A53 patients received decitabine (10 mg/m² IV, days 1–5) prior to R-CHOP (DAC-R-CHOP), for a total of six cycles. The primary endpoint was complete metabolic response (CMR) according to Lugano 2014 criteria. Exact 95% confidence intervals (CI) were calculated. Results: The median age of the A53 cohort was 65 years. CMR was achieved in all six patients (100%; 95% CI, 54–100%). At a median follow-up of 6 months, all patients remained alive in confirmed CMR. Grade III–IV hematologic toxicity occurred in all cases. Febrile neutropenia developed in 100% of patients, requiring mandatory G-CSF support and anti-infective therapy; no treatment-related mortality or permanent dose reductions were observed. Two patients (33%) experienced gastrointestinal bleeding related to local tumor lysis, which was managed conservatively without protocol discontinuation. Conclusions: In this prospective molecularly stratified pilot cohort, integration of decitabine into front-line immunochemotherapy showed promising clinical activity in A53-DLBCL, albeit at the cost of substantial hematologic toxicity requiring intensive supportive care. Given the small sample size, short follow-up, and absence of a comparator arm, these findings should be considered hypothesis-generating and warrant validation in larger multicenter phase II studies with integrated translational biomarker analyses.

Background: Diffuse large B-cell lymphoma (DLBCL) with TP53 abnormalities, corresponding to the LymphGen A53 molecular subtype, represents a biologically high-risk group associated with primary resistance to standard R-CHOP therapy. Epigenetic sensitization using hypomethylating agents may enhance chemosensitivity in this setting. We prospectively evaluated the clinical activity and safety of a molecularly adapted DAC-R-CHOP regimen in newly diagnosed A53-DLBCL. Methods: In this single-center prospective pilot cohort study, 70 consecutive patients with newly diagnosed DLBCL underwent targeted next-generation sequencing using a 60-gene panel with integrated copy number variation analysis. Six patients (8.5%) were classified as the A53 subtype. All patients received one cycle of standard R-CHOP. From cycle 2 onward, A53 patients received decitabine (10 mg/m² IV, days 1–5) prior to R-CHOP (DAC-R-CHOP), for a total of six cycles. The primary endpoint was complete metabolic response (CMR) according to Lugano 2014 criteria. Exact 95% confidence intervals (CI) were calculated. Results: The median age of the A53 cohort was 65 years. CMR was achieved in all six patients (100%; 95% CI, 54%–100%). At a median follow-up of 6 months, all patients remained alive in confirmed CMR. Grade III–IV hematologic toxicity occurred in all cases. Febrile neutropenia developed in 100% of patients, requiring mandatory G-CSF support and anti-infective therapy; no treatment-related mortality or permanent dose reductions were observed. Two patients (33%) experienced gastrointestinal bleeding related to local tumor lysis, which was managed conservatively without protocol discontinuation. Conclusions: In this prospective molecularly stratified pilot cohort, integration of decitabine into front-line immunochemotherapy showed promising clinical activity in A53-DLBCL, albeit at the cost of substantial hematologic toxicity requiring intensive supportive care. Given the small sample size, short follow-up, and absence of a comparator arm, these findings should be considered hypothesis-generating and warrant validation in larger multicenter phase II studies with integrated translational biomarker analyses.