Rafael Hernani

CAR-T therapy is a powerful treatment for pediatric B-cell acute lymphoblastic leukemia (B-ALL). However, the impact of bridging therapy prior to CAR-T infusion on patient outcomes remains insufficiently explored. In this retrospective study of patients with relapse/refractory B-ALL (N = 103), we compared outcomes across different bridging therapy groups: Low-Intensity Chemotherapy (LIC, N = 50), Immunotherapy (N = 20), or High-Intensity Chemotherapy (HIC, N = 33). At day +28 post-infusion, LIC and Immunotherapy showed significantly higher rates of Complete Remission with negative Minimal Residual Disease compared with HIC (96% vs 85% vs 75%), along with lower rates of disease progression (4% vs 10% vs 15.2%) and treatment-related mortality (0% vs 5% vs 9.1%). Additionally, patients who received three or more prior lines of therapy before CAR-T infusion exhibited significantly lower response rates. Despite potential biases, such as intrinsic disease aggressiveness or unidentified genomic alterations, present findings suggest that using LIC or immunotherapy as bridging strategies, in patients with fewer prior treatment lines, may be associated with a lower overall disease and treatment burden and could potentially contribute to improved CAR-T cell efficacy and clinical outcomes. Nevertheless, additional investigations are required to elucidate biological and clinical mechanisms by which bridging approaches and treatment history modulate CAR-T responses.

The interplay between the commensal microbiota and the mammalian immune system may influence the outcomes of T cell‐driven cancer immunotherapies. However, clinical studies supporting microbiota‐based interventions in chimeric antigen receptor T‐cell (CAR‐T) therapy remain scarce. This study included 30 adult patients with B‐cell lymphoma treated with axicabtagene ciloleucel (axi‐cel) or 4‐1BB investigational product. Shotgun metagenomics sequencing (SMS) of fecal samples, collected before lymphodepletion and 1 month post infusion, enabled species‐level resolution. We also trained 25 microbiome‐based machine‐learning (ML) models for response prediction. Neither prior “high‐risk” antibiotics exposure nor alpha diversity influenced toxicity, response, or survival. However, dysbiosis was observed between 11 healthy controls and patients, particularly in those treated with axi‐cel. SMS identified species associated with clinical outcomes. Increased abundance of Alistipes senegalensis and Alistipes onderdonkii correlated with lower neurotoxicity and improved survival, respectively. Bifidobacterium longum was associated with reduced cytokine release syndrome, whereas Bifidobacterium adolescentis , Bifidobacterium bifidum , and Bifidobacterium breve correlated with poorer survival. ML models demonstrated strong predictive performance, with some identifying non‐responders using only six species selected by the Boruta method ( Bacteroides xylanisolvens , Bifidobacterium bifidum , Bifidobacterium breve , Eubacteriaceae bacterium Marseille‐Q4139 , Negativibacillus massiliensis , and Sellimonas intestinalis ). These findings deepen current knowledge and support prospective microbiota‐based strategies in CAR‐T therapy.

Hematotoxicity after anti‐CD19 chimeric antigen receptor T‐cell therapy has drawn attention for potential long‐term effects, and yet, recovery of lymphocyte subsets and immunoglobulin levels beyond B‐cell aplasia remains poorly understood. We retrospectively analyzed 76 consecutive axicabtagene ciloleucel (axi‐cel) recipients with relapsed/refractory aggressive B‐cell lymphoma between 2020 and 2024, focusing on basic immune recovery patterns and their impact on outcomes. Median CD8 ⁺ T and NK cells increased to >300/mm ³ and >100/mm ³ , respectively, within 2 months after infusion. CD4 ⁺ T‐cell recovery was slower, with 42% cumulative incidence of >200/mm ³ cell count at 12 months. B‐cells were detectable in 18% at 12 months. Immunoglobulin levels initially declined and then plateaued, with 51% incidence of immunoglobulin G (IgG) levels > 400 mg/dL at 12 months. Modified EASIX > 2.00 was associated with delayed kinetics of CD3 ⁺ T‐cells, CD4 ⁺ T‐cells, and CD8 ⁺ T‐cells, and cumulative dexamethasone dose > 120 mg with delayed recovery of CD4 ⁺ T‐cells, NK cells, and IgG. At 1 month post‐infusion, low CD4 ⁺ T‐cell count and high CAR‐HEMATOTOX predicted worse 12‐month progression‐free survival (hazard ratio [HR] 2.81 and 3.34) and overall survival (HR 3.21 and 4.41), respectively. After axi‐cel, CD4 ⁺ T‐cells and IgG recovered slowly during the first year, while CD8 ⁺ T and NK cells increased rapidly. A higher modified EASIX score may predict slower cellular recovery, while corticosteroids may delay both cellular and humoral recovery. Lower CD4 ⁺ T‐cell count was associated with worse outcomes.

Introduction: Current guidelines do not mandate CD19 tumor expression assessment before chimeric antigen receptor T‐cell (CAR‐T) therapy in large B‐cell lymphoma (LBCL) patients due to limitations of immunohistochemistry (IHC) or flow cytometry. Quantitative polymerase chain reaction (qPCR) offers a more sensitive alternative for detecting CD19 expression, with the primary advantage that mRNA can be easily extracted from paraffin‐embedded tissues.Methods & Results: In our study, we included 51 adult patients with LBCL treated with axicabtagene ciloleucel. Among them, 16 were classified as CD19‐negative by IHC; however, qPCR reclassified six (37.5%) as CD19‐positive. We then compared the outcomes between consistently CD19‐negative (IHC⁻qPCR⁻) and CD19‐positive (IHC⁺ and IHC⁻qPCR⁺) patients. CD19‐negative cohort showed worse 1‐year progression‐free survival (15 vs. 45%, p = 0.044) and a trend toward shorter duration of response (29 vs. 55%, p = 0.065). Only one (10%) of the CD19‐negative patients remained alive and disease‐free at last follow‐up (6 months), having previously responded to bridge therapy.Discussion: If confirmed in a large patient cohort, these findings could form the basis for modifying current patient selection criteria. Consistently negative patients may be suboptimal candidates for anti‐CD19 CAR‐T therapy. Alternative therapeutic options, such as bispecific antibodies or polatuzumab‐based regimens, could be considered for this subset of patients.