Independent prognostic impact of CD15 on complete remission achievement in patients with acute myeloid leukemia

Modified CD15/CD16-CLL1 inhibitory CAR-T cells for mitigating granulocytopenia toxicities in the treatment of acute myeloid leukemia

CLL1 Chimeric antigen receptor T-cell (CAR-T) therapy, as a promising immunotherapeutic approach, has demonstrated its potential to enhance the prognosis of patients diagnosed with acute myeloid leukemia (AML). However, due to the overexpression of CLL1 on neutrophils, CAR-T cells not only eliminated tumor cells but also eradicated neutrophils simultaneously, resulting in severe granulocytopenia and subsequent infections. Considering the distinct expression levels of CD15/CD16 on neutrophils and AML blasts, we have devised novel modified CD15 /CD16-CLL1 iCAR structures incorporating diverse inhibitory elements. Through extensive screening of structural optimization, we have successfully identified CD16-CLL1 iCAR-T cells that combine PD1 and 2B4 blockade, as well as a single VHH fragment replacing the entire CD16 scFv recognition domain. These modified cells demonstrate enhanced cytotoxicity against blasts while minimizing neutrophil elimination. Furthermore, their functionality has been effectively validated through both in vitro and in vivo experiments. In conclusion, we have successfully engineered innovative CD16-CLL1 iCAR-T cells, which preserves the cytotoxicity against tumor cells while preventing elimination of neutrophils, thereby significantly reducing the incidence of granulocytopenia during CAR-T therapy. Furthermore, our future objectives encompass the meticulous validation of both the efficacy and safety profile of this groundbreaking CAR-T therapy in clinical trials, as well as a comprehensive assessment of its potential to enhance the prognosis of patients diagnosed with AML.

The Prognostic Significance of C-Reactive Protein to Albumin Ratio in Newly Diagnosed Acute Myeloid Leukaemia Patients

Background

The ratio of C-reactive protein to albumin (CAR) is an inflammatory marker that has been demonstrated to be a simple and reliable prognostic factor in several solid tumours and chronic lymphocytic leukaemia (CLL). However, no studies have investigated the prognostic value of the CAR in patients with acute myeloid leukaemia (AML).

Objectives and Methods

We retrospectively analysed 212 newly diagnosed non-M3 AML patients. Using the receiver operating characteristic curve (ROC) method, the optimal cut-off value for CAR was determined. We investigated the correlations of the pretreatment CAR levels with clinical characteristics, treatment response of induction chemotherapy, overall survival (OS) and event-free survival (EFS). We also assessed the prognostic value of the CAR compared with other inflammation-based prognostic parameters by the area under the curve (AUC).

Results

According to the ROC curve, the optimal cut-off value of CAR was 1.015. CAR was associated with age, C-reactive protein (CRP) levels, albumin levels, ferritin levels, bone marrow blast percentage, French-American-British (FAB) classification, immunophenotype and 2017 European Leukemia Net (2017 ELN) risk stratification. Importantly, we found that high CAR was a powerful indicator of a lower complete remission (CR) rate (p<0.001), worse OS (p<0.001) and worse EFS (p<0.001). Subgroup analysis showed that a high CAR was associated with shorter OS and EFS in patients with intermediate risk stratification or those aged ≤65 years or those without haematopoietic stem cell transplantation (HSCT). In the multivariate analysis, the CAR was an independent prognostic factor for OS and EFS. Furthermore, the predictive value of CAR for OS is superior to that of CRP, albumin and GPS in de novo AML patients aged ≤65 years old.

Conclusion

CAR is a simple and effective prognostic marker in patients with AML. It could be an additional prognostic factor that help further precise the current risk stratification of non-M3 AML, particularly for patients in intermediate risk stratification and those aged ≤65 years and those who did not undergo HSCT.

Increased PD-1+Tim-3+ exhausted T cells in bone marrow may influence the clinical outcome of patients with AML

Background

Altered expression of T cell immune inhibitory receptors may result in immunosuppression and associate with the poor prognosis of leukemia patients in which the leukemic bone marrow (BM) microenvironment may contribute to such immunosuppression. We found higher numbers of programmed death-1 (PD-1) + exhausted T cells in peripheral blood (PB) from acute myeloid leukemia (AML) patients. To investigate the leukemic BM influence on immunosuppression, we further compared the distributions of PD-1 and T cell immunoglobulin mucin-3 (Tim-3) and the exhausted T cell phenotype in PB and BM from AML patients and characterized their relationship with clinical outcome.

Methods

PB and BM samples from 15 patients with newly diagnosed AML were collected and analyzed for the expression of PD-1, Tim-3, CD244, and CD57 on CD3+, CD4+, and CD8+ T cells by multicolor flow cytometry.

Results

The proportions of PD-1 + CD3+ and PD-1 + CD8+ T cells were significantly higher in BM compared with PB. Similarly, higher PD-1 + CD244 + CD3+ and PD-1 + CD244 + CD8+ T cells were found in BM, and an increased tendency for PD-1 + CD244 + CD4+ T cells was also detected in this group. In contrast, increased Tim-3 + CD4+/Tim-3 + CD244 + CD4+ T cells were predominant in BM compared with PB, but there was no statistically significant difference in Tim-3 + CD8+ T cells. Moreover, PD-1 and Tim-3 double-positive CD3+/CD4+/CD8+ T cells were significantly increased in the BM group. In addition, a higher proportion of PD-1 + Tim-3 + CD3+ T cells in the BM and PD-1 + Tim-3 + CD4+ T cells in PB was detected in non-complete remission (NCR) compared with complete remission (CR) patients after first-cycle chemotherapy.

Conclusions

Upregulation of PD-1 and Tim-3 and the exhausted phenotype of CD4+ and CD8+ T cells in the BM of AML patients may contribute to mediating the leukemic immunosuppressive microenvironment, and increased PD-1 + Tim-3+ CD8+ T cells may be related to T cell dysfunction in AML, which may influence clinical outcome.

Blast vacuolization in AML patients indicates adverse-risk AML and is associated with impaired survival after intensive induction chemotherapy

Introduction

Vacuolization is a frequently found morphological feature in acute myeloid leukemia (AML) blasts. Subcellular origin and biological function as well as prognostic impact are currently unknown. The aim of this study was to evaluate whether vacuolization correlates with clinically relevant AML features.

Materials & methods

Bone marrow smears of patients diagnosed with AML at the University Hospital Frankfurt between January 2011 and August 2013 were analyzed for blast vacuolization and correlated with clinically relevant AML features. Patients undergoing standard induction chemotherapy were further analyzed for molecular and cytogenetic features as well as treatment response and survival.

Results

14 of 100 patients diagnosed with AML receiving standard induction chemotherapy had evidence of blast vacuolization. Positivity for vacuolization correlated with a CD15 positive immunophenotype and with a higher incidence of high-risk AML according to the European LeukemiaNet risk stratification. AML patients with blast vacuolization had a poor blast clearance after standard induction chemotherapy and poor survival.

Discussion

In conclusion, our findings demonstrate that vacuolization can easily be determined in myeloid leukemia blasts and may be a useful biomarker to predict AML risk groups as well as early treatment response rates and survival.

Factors Affecting Early Death and Survival of Patients With Acute Promyelocytic Leukemia Treated With ATRA-Based Therapy Regimens

PURPOSE

To perform a retrospective analysis of the prognostic relevance of clinicopathologic parameters in a well-documented cohort of patients treated with all-trans-retinoic acid (ATRA)-based induction regimens in order to discover which indicators can predict a high risk of early death (ED) and patient survival.

PATIENTS AND METHODS

We analyzed data of 288 newly diagnosed adult acute promyelocytic leukemia patients in Hangzhou, China. The median follow-up time was 32 months (range, 6-78 months).

RESULTS

The 3-year disease-free and overall survival rates were 90.83% and 91.69%, respectively. In the multivariable analysis, older age (≥ 60 years) was the only independent risk factor for ED (hazard ratio [HR] = 15.057; P = .004). High white blood cell count was not a risk factor for ED (P = .055), but it was for relapse (HR = 2.7; P = .009). FLT3 mutation (HR = 3.9; 95% confidence interval, 1.4 to 10; P = .007) and older age (≥ 60 years) (HR = 5.3; 95% confidence interval, 2.4 to 11; P < .001) were prognostic factors for poorer disease-free and overall survival. Interestingly, CD15 negativity (HR = 0.23; P = .049) was a prognostic factor for relapse. The ED rate was 5.9% (17/288 patients).

CONCLUSION

The perceived impact of the identification of these high-risk factors should be described in order to decide whether any modifications to treatment strategy should be entertained.