Prevalence and clinical outcomes of germline variants among patients with myeloid neoplasms.

AIMS: Myeloid neoplasms (MNs) with germline predisposition have been recognised as a distinct entity. Emerging evidence suggests that sporadic myelodysplastic syndromes may also harbour undetected germline predispositions. We investigated germline alterations in a cohort of 122 adult Thai MNs. METHODS: MN patients were recruited and tested for germline variants using deep targeted next-generation sequencing. The germline variant was filtered using American College of Medical Genetics classifications and then evaluated for the association with clinical characteristics and outcomes. RESULTS: Our findings revealed pathogenic/likely pathogenic germline alterations in 12 (10%) of the patients. These germline lesions were commonly found in the DNA damage response pathway (n=6, 50%). We also identified novel deleterious FANCA A1219GfsTer59 variants in two patients diagnosed with secondary acute myeloid leukaemia (sAML) from aplastic anaemia and AML with myelodysplasia related. Among sAML, individuals with germline mutations had inferior overall survival compared with those with wild-type alleles (2 months vs 12 months) with HR 4.7 (95% CI 1.0 to 20), p=0.037. Therefore, the presence of pathogenic or likely pathogenic mutations may be linked to inferior survival outcomes. CONCLUSIONS: Our study highlighted that the prevalence of germline predisposition in Southeast Asian populations is comparable to that in Caucasians. This underscores the importance of germline genetic testing within the Asian population.

Adding MYC/BCL2 double expression to NCCN-IPI may not improve prognostic value to an acceptable level.

BACKGROUND: MYC/BCL2 double expression (DE) is associated with poor prognosis in patients with diffuse large B-cell lymphoma (DLBCL) receiving rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP). This study aimed to determine whether the addition of DE to the National Comprehensive Cancer Network Internal Prognostic Index (NCCN-IPI) could improve the prediction of disease progression in patients with DLBCL treated with R-CHOP. METHODS: This confirmatory prognostic factor study retrospectively recruited patients with newly diagnosed DLBCL between January 1, 2014, and January 31, 2018, at Ramathibodi Hospital (RA) and Thammasat University Hospital (TU). The follow-up period ended on July 1, 2022. Tumors expressing MYC ≥ 40% and BCL2 ≥ 50% were classified as DE. We calculated the hazard ratios (HR) for progression-free survival (PFS) from the date of diagnosis to refractory disease, relapse, or death. Discrimination of the 5-year prediction was based on Cox models using Harrell's concordance index (c-index). RESULTS: A total of 111 patients had DE (39%), NCCN-IPI (8%), and disease progression (46%). The NCCN-IPI adjusted HR of DE was 1.6 (95% confidence interval [CI]: 0.9-2.8; P = 0.117). The baseline NCCN-IPI c-index was 0.63. Adding DE to the NCCN-IPI slightly increased Harrell's concordance index (c-index) to 0.66 (P = 0.119). CONCLUSIONS: Adding DE to the NCCN-IPI may not improve the prognostic value to an acceptable level in resource-limited settings. Multiple independent confirmatory studies from a large cohort of lymphoma registries have provided additional evidence for the clinical utility of DE.

Cytotoxicity and exhaustion markers of chimeric antigen receptor T cells targeting BCMA in multiple myeloma cell lines between patients and healthy donors.

OBJECTIVES: Multiple myeloma (MM) accounts for 10% of hematologic malignancies. However, most of the patients suffered from relapsed/refractory disease. We would like to expand CAR T cell therapy to treat MM using our current platform. METHODS: BCMA CAR T lymphocytes were generated for volunteers or MM patients. The transduction efficiency was detected by the ddPCR technique. Immunophenotyping and exhaustion markers were monitored by flow cytometry. The efficacy of BCMA CAR T cells was tested using coculturing with BCMA CAR or mock, and the positive and negative targets, K562/hBCMA-ECTM and K562, respectively. RESULTS: BCMA CAR T cells were generated from consented volunteers or MM patients and could be detected CAR BCMA expression at a mean of 4.07 ± 1.95 or 4.65 ± 1.21 copies/cell, respectively. Those modified T cells were primarily effector memory T cells. Our BCMA CAR T cells could explicitly eradicate the K562/hBCMA-ECTM cell line while the K562 cell line survived. Interestingly, the BCMA CAR, mock T cells, and peripheral blood mononuclear cells from MM patients expressed similar levels of the exhaustion makers, TIM-3, LAG-3, and PD1. CONCLUSIONS: Our BCMA CAR T cells, mainly effector/effector memory, could eliminate BCMA-expressing cells in vitro and had similar levels of exhaustion markers among different populations.

Endothelial activation and stress index as a prognostic factor of diffuse large B-cell lymphoma: the report from the nationwide multi-center Thai Lymphoma Study Group.

Several prognostic models have been introduced to predict outcomes of patients with diffuse large B-cell lymphoma (DLBCL). Endothelial activation and stress index (EASIX) is a surrogate of endothelial dysfunction which has been shown to predict outcomes of patients with various hematologic malignancies. However, the prognostic implication of EASIX for DLBCL is limited and warrants exploration. We conducted a retrospective study enrolling adult DLBCL patients including a discovery cohort from the single-centered university hospital database and a validation cohort from the independent nationwide multi-center registry. EASIX scores were calculated using creatinine, lactate dehydrogenase, and platelet levels. The receiver operating characteristic curve analysis was used to determine optimal cutoff. Statistical analysis explored the impact of EASIX on survival outcomes. A total of 323 patients were included in the discovery cohort. The optimal EASIX cutoff was 1.07 stratifying patients into low (53.9%) and high EASIX (46.1%) groups. Patients with high EASIX had worse 2-year progression-free survival (PFS) (53.4% vs. 81.5%, p<0.001) and overall survival (OS) (64.4% vs. 88.7%, p<0.001) than patients with low EASIX. Multivariate analysis revealed that older age, bulky disease, impaired performance status, and high EASIX were associated with an unfavorable OS. In the validation cohort of 499 patients, the optimal EASIX cutoff was 1.04. Similar to the discovery cohort, high EASIX score was associated with high-risk diseases, worse PFS, and inferior OS. In conclusion, EASIX score was significantly associated with survival outcomes and may be used as a simple prognostic tool to better risk-classify DLBCL.

Committed change of real-time quantitative PCR to droplet digital PCR for monitoring BCR::ABL1 transcripts in tyrosine kinase inhibitor treated CML.

OBJECTIVES: We performed a feasibility study of an FDA-approved commercial ddPCR assay to measure BCR::ABL1 in CML patients treated using TKI therapy. METHODS: Assay performance of standard RQ-PCR and commercially available FDA-approved ddPCR were compared to measure BCR::ABL1 p210 transcripts in RNA samples from 100 CML patients who received TKI therapy. RESULTS: %BCR::ABL1/ABL1IS levels obtained from both methods were not statistically significant difference after normalization with batch-specific conversion factor (p = 0.0651). The correlation and agreement of %BCR::ABL1/ABL1IS between the two assays were high. Molecular response stratification data showed 56% concordance between RQ-PCR and ddPCR, and 37% higher residual disease detection using ddPCR. Furthermore, 21.21% (7/33) of RQ-PCR undetectable samples were detected by ddPCR, representing high sensitivity to quantify the low abundance of BCR::ABL1 transcripts. CONCLUSION: ddPCR was proven to be a highly sensitive method with the potential to overcome some limitations of traditional RQ-PCR, and has the potential of being a valuable tool for monitoring BCR::ABL1 transcripts in CML during TKI therapy. (163 words).

A customized mass array panel for BCR::ABL1 tyrosine kinase domain mutation screening in chronic myeloid leukemia.

Introduction: The therapeutic strategy and management of chronic myeloid leukemia (CML) have rapidly improved with the discovery of effective tyrosine kinase inhibitors (TKIs) to target BCR::ABL1 oncoprotein. However, nearly 30% of patients develop TKI resistance due to acquired mutations on the tyrosine kinase domain (TKD) of BCR::ABL1. Methods: We customized a mass array panel initially intended to detect and monitor the mutational burden of hotspot BCR::ABL1 TKD mutations accumulated in our database, including key mutations recently recommended by European LeukemiaNet. Additionally, we extended the feasibility of using the assay panel for the molecular classification of myeloproliferative neoplasms (MPNs) by incorporating primer sets specific for analyzing JAK2 V617F, MPL 515 K/L, and CALR types 1 and 2. Results: We found that the developed mass array panel was superior for detecting and monitoring clinically significant BCR::ABL1 TKD mutations, especially in cases with low mutational burden and harboring compound/polyclonal mutations, compared with direct sequencing. Moreover, our customized mass array panel detected common genetic alterations in MPNs, and the findings were consistent with those of other comparable assays available in our laboratory. Conclusions: Our customized mass array panel was practicably used as a routine robust assay for screening and monitoring BCR::ABL1 TKD mutations in patients with CML undergoing TKI treatment and feasible for analyzing common genetic mutations in MPNs.

Outcomes of polatuzumab vedotin-containing regimens in real-world setting of relapsed and or refractory diffuse large B-cell lymphoma patients: a matched-control analysis from the Thai Lymphoma Study Group (TLSG).

Relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL) is a challenging condition to treat, and there is an unmet clinical need for effective therapies. Recently, polatuzumab vedotin (Pola), an anti-CD79b antibody-drug-conjugate (ADC), combined with bendamustine-rituximab (BR), has been approved for R/R DLBCL patients. However, real-world data on Pola-based regimens in R/R DLBCL patients, especially in Thailand, are limited. This study aimed to evaluate the efficacy and safety of Pola-based salvage treatment in R/R DLBCL patients in Thailand. Thirty-five patients who received Pola-based treatment were included in the study, and their data were compared to 180 matched patients who received non-Pola-based therapy. The overall response rate (ORR) in the Pola group was 62.8%, with complete remission and partial remission rates of 17.1% and 45.7%, respectively. The median progression-free survival (PFS) and overall survival (OS) were 10.6 months and 12.8 months, respectively. The study found a significantly higher ORR in Pola-based salvage treatments compared to non-Pola-based therapy (62.8% vs. 33.3%). The survival outcomes were also significantly superior in the Pola group, with longer median PFS and OS than the control group. Grades 3-4 adverse events (AEs) were mainly hematological, and they were tolerable. In conclusion, this study provides real-world evidence of the efficacy and safety of Pola-based salvage treatment in R/R DLBCL patients in Thailand. The results of this study are promising and suggest that Pola-based salvage treatment could be a viable option for R/R DLBCL patients who have limited treatment options.

Does leukocytosis remain a predictive factor for survival outcomes in patients with acute promyelocytic leukemia receiving ATRA plus a chemotherapy-based regimen? A prospective multicenter analysis from TALWG.

INTRODUCTION: Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia (AML) with a unique clinical presentation and prognosis. This study aimed to investigate the epidemiology, clinical characteristics, treatments, and clinical outcomes of Thai APL patients dominantly treated with all-trans-retinoic acid (ATRA) combined with a chemotherapy-based therapy. METHODS: This was an eight-year prospective, observational study from nine academic hospitals in the Thai Acute Leukemia Working Group (TALWG) of the Thai Society of Hematology, which included newly diagnosed Thai APL patients, aged 18 years or older. The web-based registration collected baseline charateristic, and clinical outcomes. RESULTS: From 992 newly diagnosed AML patients, 79 APL patients were enrolled in this study. Almost all subjects were de novo APL (94.9%), while the others were therapy-related APL. The commonest clinical presentation was disseminated intravascular coagulation (38%). One-third of the patients were categorized as high risk according to the initial WBC. Almost all patients received ATRA combined with idarubicin regimen. The complete response rate was as high as 95.7%, which translated into excellent four-year overall survival (OS) (75.6%) and four-year leukemia-free survival (LFS) (75.4%). The multivariate analysis demonstrated that the older age and WBC count >20 × 109/L conferred a significantly unfavorable OS with the hazard ratios of 3.03 (95% confidence interval [CI]: 1.14-8.05) and 4.18 (95%CI: 1.69-10.35), respectively. Similarly, these two parameters remained independent of the poor prognosis factors for LFS. CONCLUSION: This report confirmed that APL had a favorable prognosis. However, advanced age and high WBC count >20 × 109/L contributed to a worse outcome. ABBREVIATIONS: APL; acute promyelocytic leukemia; ATRA; all-transretinoic acid; CR; complete remission; DS; differentiation syndrome; ECOG; Eastern Cooperative Oncology Group; ED; early death; HR; hazard ratio; IQR; interquartile range; LFS; leukemia-free survival; OS; overall survival; WBC; white blood cell.

Comparison of Molecular International Prognostic Scoring System (M-IPSS) and Revised International Prognostic Scoring System (R-IPSS) in Thai patients with myelodysplastic neoplasms.

INTRODUCTION: Risk stratification is essential for treatment decision in myelodysplastic neoplasms (MDS). Molecular international prognostic scoring system (M-IPSS) has been recently developed combining somatic mutations and clinical information being used in the revised international prognostic scoring system (R-IPSS). OBJECTIVE: We aimed to explore the performances of M-IPSS and R-IPSS in Thai patients with MDS. METHOD: MDS patients were stratified into risk categories using R-IPSS and M-IPSS scores. The performance of both models were evaluated for prognostic prediction. RESULTS: One hundred and sixty-two MDS patients were recruited from the multicenter study. Survival analysis revealed that both R-IPSS and M-IPSS were good prediction models with the Concordance Index (C-index) of 0.71 (95% Confidence interval [CI] 0.64-0.78) and 0.75 (95% CI 0.69-0.80), respectively (p = 0.22). Comparing the two, 13 of 162 (8%) cases were re-staged between lower and higher risks which would have affected treatment decisions. CONCLUSION: Our study showed that R-IPSS score can be used for risk stratification in most Thai patients. A prediction model using somatic mutations specifically in Asian patients should be formulated in the future.

External validation and comparison of IPI, R-IPI, and NCCN-IPI in diffuse large B-cell lymphoma patients treated with R-CHOP to predict 2-year progression-free survival.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is the most common aggressive lymphoma. The standard first-line therapy for DLBCL consists of rituximab cyclophosphamide doxorubicin vincristine and prednisone (R-CHOP). About 50-70% of patients may be cured by R-CHOP. There was no data on external validation and comparison of the international prognostic index, revised-IPI (R-IPI), and enhanced-IPI (NCCN-IPI) to predict treatment outcomes in the middle-income country with a resourced-limited setting. OBJECTIVES: We aimed to externally validate and compare IPI, R-IPI, and NCCN-IPI in predicting 2-year progression-free survival (2-y PFS) of newly diagnosed DLBCL patients treated with R-CHOP. METHODS: This ambispective observational study recruited consecutive patients diagnosed between 1 January 2014 and 30 June 2020, with the last follow-up on 1 July 2022 from Thammasat University Hospital and Ramathibodi Hospital. We assessed discrimination by Harrell's concordance index (c-index), calibration by calibration plot, and absolute difference in survival (ADS) between the lowest-and the highest-risk groups. RESULTS: The cohort of 292 patients (median age 63 years and median follow-up 3.6 years) had 131 progressions and 96 deaths. The 2-y PFS was 63%. The c-indices were NCCN-IPI 0.6216, R-IPI 0.6004 (P = 0.215), and IPI 0.6104 (P = 0.463). The calibration plots of NCCN-IPI and R-IPI showed nearly perfect agreement (moderate strength), while IPI had miscalibrations. The ADSs were NCCN-IPI 52%, R-IPI 42%, and IPI 25%. CONCLUSION: NCCN-IPI is the best prognostic index compared to IPI and R-IPI in prior studies. However, the prognostic model for DLBCL patients treated with R-CHOP requires updating or integrating biomarkers to improve discrimination to the acceptable level (c-index 0.7).