Comparative performance of scFv-based anti-BCMA CAR formats for improved T cell therapy in multiple myeloma.

In multiple myeloma (MM), B cell maturation antigen (BCMA)-directed CAR T cells have emerged as a novel therapy with potential for long-term disease control. Anti-BCMA CAR T cells with a CD8-based transmembrane (TM) and CD137 (41BB) as intracellular costimulatory domain are in routine clinical use. As the CAR construct architecture can differentially impact performance and efficacy, the optimal construction of a BCMA-targeting CAR remains to be elucidated. Here, we hypothesized that varying the constituents of the CAR structure known to impact performance could shed light on how to improve established anti-BCMA CAR constructs. CD8TM.41BBIC-based anti-BCMA CAR vectors with either a long linker or a short linker between the light and heavy scFv chain, CD28TM.41BBIC-based and CD28TM.CD28IC-based anti-BCMA CAR vector systems were used in primary human T cells. MM cell lines were used as target cells. The short linker anti-BCMA CAR demonstrated higher cytokine production, whereas in vitro cytotoxicity, T cell differentiation upon activation and proliferation were superior for the CD28TM.CD28IC-based CAR. While CD28TM.CD28IC-based CAR T cells killed MM cells faster, the persistence of 41BBIC-based constructs was superior in vivo. While CD28 and 41BB costimulation come with different in vitro and in vivo advantages, this did not translate into a superior outcome for either tested model. In conclusion, this study showcases the need to study the influence of different CAR architectures based on an identical scFv individually. It indicates that current scFv-based anti-BCMA CAR with clinical utility may already be at their functional optimum regarding the known structural variations of the scFv linker.

The CAR-HEMATOTOX score as a prognostic model of toxicity and response in patients receiving BCMA-directed CAR-T for relapsed/refractory multiple myeloma.

BACKGROUND: BCMA-directed CAR T-cell therapy (CAR-T) has altered the treatment landscape of relapsed/refractory (r/r) multiple myeloma, but is hampered by unique side effects that can lengthen hospital stays and increase morbidity. Hematological toxicity (e.g. profound and prolonged cytopenias) represents the most common grade ≥ 3 toxicity and can predispose for severe infectious complications. Here, we examined the utility of the CAR-HEMATOTOX (HT) score to predict toxicity and survival outcomes in patients receiving standard-of-care idecabtagene vicleucel and ciltacabtagene autoleucel. METHODS: Data were retrospectively collected from 113 r/r multiple myeloma patients treated between April 2021 and July 2022 across six international CAR-T centers. The HT score-composed of factors related to hematopoietic reserve and baseline inflammatory state-was determined prior to lymphodepleting chemotherapy. RESULTS: At lymphodepletion, 63 patients were HTlow (score 0-1) and 50 patients were HThigh (score ≥ 2). Compared to their HTlow counterparts, HThigh patients displayed prolonged severe neutropenia (median 9 vs. 3 days, p < 0.001), an increased severe infection rate (40% vs. 5%, p < 0.001), and more severe ICANS (grade ≥ 3: 16% vs. 0%, p < 0.001). One-year non-relapse mortality was higher in the HThigh group (13% vs. 2%, p = 0.019) and was predominantly attributable to fatal infections. Response rates according to IMWG criteria were higher in HTlow patients (≥ VGPR: 70% vs. 44%, p = 0.01). Conversely, HThigh patients exhibited inferior progression-free (median 5 vs. 15 months, p < 0.001) and overall survival (median 10.5 months vs. not reached, p < 0.001). CONCLUSIONS: These data highlight the prognostic utility of the CAR-HEMATOTOX score for both toxicity and treatment response in multiple myeloma patients receiving BCMA-directed CAR-T. The score may guide toxicity management (e.g. anti-infective prophylaxis, early G-CSF, stem cell boost) and help to identify suitable CAR-T candidates.

Identifying Early Infections in the Setting of CRS With Routine and Exploratory Serum Proteomics and the HT10 Score Following CD19 CAR-T for Relapsed/Refractory B-NHL.

Early fever after chimeric antigen receptor T-cell (CAR-T) therapy can reflect both an infection or cytokine release syndrome (CRS). Identifying early infections in the setting of CRS and neutropenia represents an unresolved clinical challenge. In this retrospective observational analysis, early fever events (day 0-30) were characterized as infection versus CRS in 62 patients treated with standard-of-care CD19.CAR-T for relapsed/refractory B-cell non-Hodgkin lymphoma. Routine serum inflammatory markers (C-reactive protein [CRP], interleukin-6 [IL-6], procalcitonin [PCT]) were recorded daily. Exploratory plasma proteomics were performed longitudinally in 52 patients using a multiplex proximity extension assay (Olink proteomics). Compared with the CRSonly cohort, we noted increased event-day IL-6 (median 2243 versus 64 pg/mL, P = 0.03) and particularly high PCT levels (median 1.6 versus 0.3 µg/L, P < 0.0001) in the patients that developed severe infections. For PCT, an optimal discriminatory threshold of 1.5 µg/L was established (area under the receiver operating characteristic curve [AUCROC] = 0.78). Next, we incorporated day-of-fever PCT levels with the patient-individual CAR-HEMATOTOX score. In a multicenter validation cohort (n = 125), we confirmed the discriminatory capacity of this so-called HT10 score for early infections at first fever (AUCROC = 0.87, P < 0.0001, sens. 86%, spec. 86%). Additionally, Olink proteomics revealed pronounced immune dysregulation and endothelial dysfunction in patients with severe infections as evidenced by an increased ANGPT2/1 ratio and an altered CD40/CD40L-axis. In conclusion, the high discriminatory capacity of the HT10 score for infections highlights the advantage of dynamic risk assessment and supports the incorporation of PCT into routine inflammatory panels. Candidate markers from Olink proteomics may further refine risk-stratification. If validated prospectively, the score will enable risk-adapted decisions on antibiotic use.

Influence of Adipose Tissue Distribution, Sarcopenia, and Nutritional Status on Clinical Outcomes After CD19 CAR T-cell Therapy.

Although CD19-directed chimeric antigen receptor T-cell therapy (CD19.CAR-T) has proven clinical efficacy for multiple refractory B-cell malignancies, over 50% of patients ultimately relapse. Recent evidence has underlined the critical role of the host in determining treatment responses. In this retrospective observational study of 106 patients with relapsed/refractory large B-cell lymphoma receiving standard-of-care CD19.CAR-T, we analyzed the impact of immunometabolic host features and detailed body composition measurements on post-CAR T clinical outcomes. We extracted muscle and adipose tissue distributions from prelymphodepletion CT images and assessed laboratory-based immuno-nutritional scores. Early responders displayed increased total abdominal adipose tissue deposits (TAT: 336 mm3 vs. 266 mm3, P = 0.008) and favorable immuno-nutritional scores compared to nonresponding patients. On univariate Cox regression analysis, visceral fat distribution, sarcopenia, and nutritional indices significantly impacted both progression-free (PFS) and overall survival (OS). Patients with a low skeletal muscle index (SMI; e.g.<34.5), a sarcopenia indicator, exhibited poor clinical outcomes (mOS 3.0 months vs. 17.6 months, log-rank P = 0.0026). Prognostically adverse immuno-nutritional scores were linked to inferior survival [low PNI: HROS, 6.31; 95% confidence interval (CI), 3.35-11.90; P < 0.001]. In a multivariable analysis adjusting for baseline Eastern Cooperative Oncology Group performance status, C-reactive protein, and lactate dehydrogenase, increased TAT was independently associated with improved clinical outcomes (adjusted HROS, 0.27; 95% CI, 0.08-0.90; P = 0.03). We noted particularly favorable treatment outcomes in patients with both increased abdominal fat and muscle mass (TAThigh/SMIhigh: 1-year PFS 50%, 1-year OS 83%). These real-world data provide evidence for a role of body composition and immuno-nutritional status in the context of CD19.CAR-T and suggest that the obesity paradox may extend to modern T cell-based immunotherapies. See related Spotlight by Nawas and Scordo, p. 704.

Survival and immunotoxicities in association with sex-specific body composition patterns of cancer patients undergoing immune-checkpoint inhibitor therapy - A systematic review and meta-analysis.

BACKGROUND: Imbalanced body composition is mechanistically connected to dysregulated immune activities. Whether overweight/obesity or sarcopenia has an impact on treatment results in cancer patients undergoing immune checkpoint inhibitor (ICI) therapy is currently under debate. We aimed to answer if survival rates and occurrence of immune-related adverse events (irAEs) were different in obese or sarcopenic patients. METHODS: A systematic search was conducted in PubMed, Embase and CENTRAL for all records published until July 2022 using specific search terms for body composition in combination with terms for ICI regimens. Two authors screened independently. All studies that reported on body mass index or sarcopenia measures were selected for further analysis. RESULTS: 48 studies reporting on overweight/obesity comprising of 19,767 patients, and 32 studies reporting on sarcopenia comprising of 3193 patients fulfilled the inclusion criteria. In the entire cohort, overweight/obesity was significantly associated with better progression-free survival (PFS; p = 0.009) and overall survival (OS; p <0.00001). Subgroup analyses stratified by sex revealed that overweight/obese males had the strongest survival benefit (PFS: p = 0.05; OS: p = 0.0005), and overweight/obese female patients did not show any. However, overweight/obese patients of both sexes had a higher risk to develop irAEs grade ≥3 (p = 0.0009). Sarcopenic patients showed significantly shorter PFS (p <0.0001) and OS (p <0.0001). The frequency of irAEs did not differ between sarcopenic and non-sarcopenic patients. CONCLUSION: This meta-analysis suggests that body composition is associated in a sex-specific manner with survival and irAEs in cancer patients undergoing ICI treatment.

Risk Stratification Based on a Pattern of Immunometabolic Host Factors Is Superior to Body Mass Index-Based Prediction of COVID-19-Associated Respiratory Failure.

Overweight and obesity are associated with chronic low-grade inflammation and represent risk factors for various diseases, including COVID-19. However, most published studies on COVID-19 defined obesity by the body mass index (BMI), which does not encounter adipose tissue distribution, thus neglecting immunometabolic high-risk patterns. Therefore, we comprehensively analyzed baseline anthropometry (BMI, waist-to-height-ratio (WtHR), visceral (VAT), epicardial (EAT), subcutaneous (SAT) adipose tissue masses and liver fat, inflammation markers (CRP, ferritin, interleukin-6), and immunonutritional scores (CRP-to-albumin ratio (CAR), modified Glasgow prognostic score, neutrophile-to-lymphocyte ratio, prognostic nutritional index)) in 58 consecutive COVID-19 patients of the early pandemic phase with regard to the necessity of invasive mechanical ventilation (IMV). Here, metabolically high-risk adipose tissues represented by increased VAT, liver fat, and WtHR strongly correlated with higher levels of inflammation, pathologic immunonutritional scores, and the need for IMV. In contrast, the prognostic value of BMI was inferior and absent with regard to SAT. Multivariable logistic regression analysis identified an optimized IMV risk prediction model employing liver fat, WtHR, and CAR. In summary, we suggest an immunometabolically risk-adjusted model to predict COVID-19-induced respiratory failure better than BMI-based stratification, which warrants prospective validation.

Age Is a Prognostic Factor for the Overall Survival of Patients with Multiple Myeloma Undergoing Upfront Autologous Hematopoietic Stem Cell Transplantation.

In this retrospective analysis, we evaluated the impact of age on the outcome of patients with multiple myeloma who received an autologous hematopoietic stem cell transplantation (auto-HCT) at our institution. A total of 1128 patients were divided into the older (>70 years; 182 [16%]) and the younger (≤70 years; 946 [84%]) groups. Compared with the younger cohort, older patients had a higher International Staging System (ISS) stage (ISS-II, 57 [31%] versus 215 [23%]; ISS-III, 52 [28%] versus 211 [22%]; P = .01), higher use of reduced-dose melphalan as a conditioning regimen (140 mg/m², 59 [32%] versus 29 [3%]; P < .001), and a higher comorbidity index (median, 3 versus 2; P = .01). Nonrelapse mortality at 1 year after auto-HCT was significantly higher in older patients (7 [4%] versus 9 [1%]; hazard ratio [HR], 4.1; P = .005). Complete remission rates after auto-HCT for the older and the younger groups were 41% and 46%, respectively. With a median follow-up of 52 months, the 5-year progression-free survival (PFS) was 24% (95% confidence interval [CI], 17% to 32%) and 37% (95% CI, 33% to 40%) in the older and younger groups, respectively (HR, 1.3; P = .02). Five-year OS for the older and younger groups was 56% (95% CI, 47% to 64%) and 73% (95% CI, 70% to 76%; P < .001), respectively. Older age emerged as one of the predictors of shorter OS but not PFS in the multivariate classification and regression tree analysis. In conclusion, age ≥70 years was associated with shorter PFS and OS in patients with multiple myeloma who underwent an auto-HCT.

MAP3K7 is recurrently deleted in pediatric T-lymphoblastic leukemia and affects cell proliferation independently of NF-κB.

BACKGROUND: Deletions of 6q15-16.1 are recurrently found in pediatric T-cell acute lymphoblastic leukemia (T-ALL). This chromosomal region includes the mitogen-activated protein kinase kinase kinase 7 (MAP3K7) gene which has a crucial role in innate immune signaling and was observed to be functionally and prognostically relevant in different cancer entities. Therefore, we correlated the presence of MAP3K7 deletions with clinical parameters in a cohort of 327 pediatric T-ALL patients and investigated the function of MAP3K7 in the T-ALL cell lines CCRF-CEM, Jurkat and MOLT-4. METHODS: MAP3K7 deletions were detected by multiplex ligation-dependent probe amplification (MLPA). T-ALL cell lines were transduced with adeno-associated virus (AAV) vectors expressing anti-MAP3K7 shRNA or a non-silencing shRNA together with a GFP reporter. Transduction efficiency was measured by flow cytometry and depletion efficiency by RT-PCR and Western blots. Induction of apoptosis was measured by flow cytometry after staining with PE-conjugated Annexin V. In order to assess the contribution of NF-κB signaling to the effects of MAP3K7 depletion, cells were treated with TNF-α and cell lysates analyzed for components of the NF-κB pathway by Western blotting and for expression of the NF-κB target genes BCL2, CMYC, FAS, PTEN and TNF-α by RT-PCR. RESULTS: MAP3K7 is deleted in approximately 10% and point-mutated in approximately 1% of children with T-ALL. In 32 of 33 leukemias the deletion of MAP3K7 also included the adjacent CASP8AP2 gene. MAP3K7 deletions were associated with the occurrence of SIL-TAL1 fusions and a mature immunophenotype, but not with response to treatment and outcome. Depletion of MAP3K7 expression in T-ALL cell lines by shRNAs slowed down proliferation and induced apoptosis, but neither changed protein levels of components of NF-κB signaling nor NF-κB target gene expression after stimulation with TNF-α. CONCLUSIONS: This study revealed that the recurrent deletion of MAP3K7/CASP8AP2 is associated with SIL-TAL1 fusions and a mature immunophenotype, but not with response to treatment and risk of relapse. Homozygous deletions of MAP3K7 were not observed, and efficient depletion of MAP3K7 interfered with viability of T-ALL cells, indicating that a residual expression of MAP3K7 is indispensable for T-lymphoblasts.