Long-term results of the sequential combination of cladribine and rituximab in Hairy cell leukemia.

We report on the long-term efficacy and safety of a phase 2 trial of sequential cladribine and rituximab in hairy cell leukemia (HCL). One-hundred and thirty-nine patients were enrolled: 111 in the frontline setting, 18 in first relapse, and 10 with variant HCL (HCLv). A complete response (CR) was achieved in 133 of 137 evaluable participants (97%) with measurable residual disease (MRD) negativity in 102 (77%). MRD status was not associated with significant differences in event-free survival (EFS) or overall survival (OS). With a median follow-up of 7.8 years (range: 0.40-18.8), eight patients have experienced disease relapse (5.8%), 4/111 with newly diagnosed HCL (3·6%) and 4/10 with HCLv (40%) (p = 0.002). The 10-year EFS and OS rates were 86.7% and 91.1%, respectively. Grade 3 adverse events were observed in 28 participants (20·1%), mostly due to infections. Treatment of HCL with sequential cladribine followed by rituximab is associated with excellent efficacy and safety results both in the frontline and relapsed settings.

Integrative immunophenotypic and genetic characterization of acute myeloid leukemia with CBFB rearrangement.

OBJECTIVES: We sought to characterize the immunophenotype of acute myeloid leukemia (AML) with CBFB rearrangement and correlate the results with cytogenetic and molecular data. METHODS: Sixty-one cases of AML with CBFB rearrangement were evaluated. RESULTS: The sample population consisted of 33 men and 28 women, with a median age of 49 years. Flow cytometry immunophenotypic analysis showed that myeloblasts were positive for CD34 and CD117 in all cases, and myeloperoxidase was positive in 52 of 55 (95%) cases. The most common abnormalities included decreased CD38 in 90%, increased CD13 in 85%, increased CD123 in 84%, and decreased HLA-DR in 84% of cases. Monocytes were increased, with a mature immunophenotype, and accounted for 23.7% of total cells. Among 60 cases with available karyotype, inv(16)(p13.1q22) was most common in 50 (83%) cases, followed by t(16;16) (p13.1;q22) in 6 (10%). Type A CBFB::MYH11 transcript was most common, detected in 84% of cases. Mutational analysis showed mutations of NRAS in 37%, FLT3 in 25%, and KIT in 24% of cases. Comparing cases with type A vs non-type A transcripts, blasts in type A cases more frequently exhibited CD64 positivity and increased CD13 levels while showing a lower frequency of CD7 and CD56 expression. Trisomy 22 and mutations in KIT, NF1, and TET2 were identified only in cases with type A transcript. CONCLUSIONS: Myeloblasts of AML with CBFB rearrangement are positive for CD34, CD117, and myeloperoxidase. These neoplasms most frequently carry inv(16)(p13.1q22) and type A fusion transcript. NRAS mutation was the most common mutation. Some immunophenotypic and genetic correlations occurred with different types of transcripts.

Diagnostic utility of immunohistochemistry in detection of NPM1 mutations in acute myeloid leukemia with a patchy distribution.

Nucleophosmin 1 (NPM1) mutations occur in approximately one-third cases of adult de novo acute myeloid leukemia (AML). Identification of NPM1 mutations is important for classification, risk stratification, tailored therapy, and monitoring minimal residual disease. Mutational analysis is widely used for detecting NPM1 mutations. Immunochemistry assessing abnormal cytoplasmic localization of NPM1 protein has been used as a surrogate marker for NPM1 mutations. We present a case of AML with mutated NPM1 that was missed by sequencing analysis but detected by immunohistochemistry. This case highlights the value of immunohistochemistry in identifying NPM1 mutations in a subset of AML cases.

Characteristics and outcomes of acute myeloid leukaemia patients with baseline CD7 expression.

Targeted therapy development for acute myeloid leukaemia (AML) requires an understanding of specific expression profiles. We collected flow cytometry data on 901 AML patients and recorded aberrant CD7 expression on leukaemic blasts. 263 (29.2%) had blasts positive for CD7. CD7+ AML was more likely to be adverse risk (64.6% vs. 55.6%, p = 0.0074) and less likely to be favourable risk (15.2% vs. 24.1%, p = 0.0074) by European LeukemiaNet 2022 criteria. Overall survival was inferior (11.9 [95% CI, 9.7-15.9] vs. 19.0 months [95% CI, 16.1-23.0], p = 0.0174). At relapse, 30.4% lost and 19.0% gained CD7, suggesting moderate instability over time.

Predictors of clinical outcome in myeloproliferative neoplasm, unclassifiable: A Bone Marrow Pathology Group study.

OBJECTIVES: Myeloproliferative neoplasm, unclassifiable (MPN-U, revised to MPN, not otherwise specified in the fifth edition of the World Health Organization classification) is a heterogeneous category of primary marrow disorders with clinical, morphologic, and/or molecular features that preclude classification as a more specific MPN subtype due to stage at diagnosis, overlapping features between MPN subtypes, or the presence of coexisting disorders. Compared with other MPN subtypes, the contribution of the mutational landscape in MPN-U in conjunction with other clinical and morphologic biomarkers to prognosis has been less well investigated. METHODS: We performed a multicenter, retrospective study of MPN-U (94 cases) to better define the clinicopathologic features, genetic landscape, and clinical outcomes, including subgroups of early-stage, advanced-stage, and coexisting disorders. The Dynamic International Prognostic Scoring System (DIPSS) plus scoring system was applied to assess its relevance to MPN-U prognosis. RESULTS: Multivariate analysis demonstrated bone marrow blast count and DIPSS plus score as statistically significant in predicting overall survival. Univariate analysis identified additional potential poor prognostic markers, including abnormal karyotype and absence of JAK2 mutation. Secondary mutations were frequent in the subset analyzed by next-generation sequencing (26/37 cases, 70.3%) with a borderline association between high molecular risk mutations and overall survival. CONCLUSIONS: This study, as one of the largest of MPN-U studies incorporating both clinicopathologic and molecular data, moves toward identification of biomarkers that better predict prognosis in this heterogeneous category.

Acute myeloid leukemia with mast cell differentiation is characterized by interstitial mast cells, complex karyotype, TP53 alterations and poor prognosis.

Not available.

Multicolor flow cytometric immunophenotyping is highly sensitive and specific in identifying aberrant mast cells in the diagnostic workup of systemic mastocytosis.

OBJECTIVES: Flow cytometric immunophenotyping (FCI) is a fast and sensitive method for characterizing hematolymphoid neoplasms. It is not widely used in the workup of systemic mastocytosis (SM), in part because of the technical challenges and in part because the utility of FCI in assessing mast cells is not well understood. The objectives of this study were to assess the diagnostic utility of FCI in establishing a diagnosis of SM and distinguishing SM from nonneoplastic mast cells and to examine the immunophenotypic findings among SM subtypes. METHODS: We performed FCI on bone marrow samples suspicious for SM using a panel consisting of CD2, CD25, CD30, CD45, CD117, and HLA-DR. RESULTS: The cohort included 88 SM cases: 67 without an associated hematologic neoplasm (AHN) (PureSM) and 21 with an AHN (SM-AHN). We also assessed 40 normal/reactive controls. Overall, FCI was adequate for interpretation in 87 of 88 (99%) cases and detected at least 1 immunophenotypic aberrancy in 100% of SM cases. CD2, CD25, and CD30 were positive in 78%, 98%, and 90% of SM cases vs 0%, 13%, and 13% of cases with normal/reactive mast cells (P < .0001 for all). Two or 3 abnormalities were observed in 92% of SM cases but not in normal/reactive mast cells. Among SM cases, SM-AHN showed statistically significant less CD2 (38% vs 91%, P < .0001) and less co-expression of all 3 aberrant markers (CD2, CD25, and CD30 positive in 38% vs 86% of cases; P < .0001) than PureSM. Immunohistochemical analysis showed consistently weaker or focal expression of CD2, CD25, and CD30 than FCI, with CD2 and CD30 being falsely negative in 40% and 50% cases, respectively. A KIT D816V mutation was detected in 67% of PureSM cases and 76% of SM-AHN cases. CONCLUSIONS: Flow cytometric immunophenotyping is a quick, sensitive, high-yield tool for evaluating the immunophenotype of mast cells. An abnormal FCI finding should prompt careful histologic evaluation and sensitive KIT D816V mutation testing to address the possibility of SM. CD2, CD25, and CD30 are important markers for the detection of immunophenotypic aberrancy of mast cells, and their frequencies of aberrancy differ across SM subtypes.

Increased expression of CD70 in relapsed acute myeloid leukemia after hypomethylating agents.

Acute myeloid leukemia (AML) is the most common acute leukemia in adults. While induction chemotherapy leads to remission in most patients, a significant number will experience relapse. Therefore, there is a need for novel therapies that can improve remission rates in patients with relapsed and refractory AML. CD70 is the natural ligand for CD27 (a member of the TNF superfamily) and appears to be a promising therapeutic target. Consequently, there is considerable interest in developing chimeric antigen receptor (CAR) T-cell therapy products that can specifically target CD70 in various neoplasms, including AML. In this study, we employed routine diagnostic techniques, such as immunohistochemistry and flow cytometry, to investigate the expression of CD70 in bone marrow samples from treatment-naïve and relapsed AML patients after hypomethylating agents (HMA). Also, we evaluated the impact of HMA on CD70 expression and examined CD70 expression in various leukemic cell subsets and normal hematopoietic progenitors.

Phase 2 study of inotuzumab ozogamicin for measurable residual disease in acute lymphoblastic leukemia in remission.

ABSTRACT: The detection of measurable residual disease (MRD) is the strongest predictor of relapse in acute lymphoblastic leukemia (ALL). Using inotuzumab ozogamicin in the setting of MRD may improve outcomes. Patients with ALL in first complete remission (CR1) or beyond (CR2+) with MRD ≥ 1 × 10-4 were enrolled in this phase 2 trial. Inotuzumab was administered at 0.6 mg/m2 on day 1 and 0.3 mg/m2 on day 8 of cycle 1, then at 0.3 mg/m2 on days 1 and 8 of cycles 2-6. Twenty-six consecutive patients with a median age of 46 years (range, 19-70 years) were treated. Nineteen (73%) were in CR1 and seven (27%) in CR2+; 16 (62%) had Philadelphia chromosome-positive ALL. Fifteen (58%) had baseline MRD ≥ 1 × 10-3. A median of 3 cycles (range, 1-6) were administered. Eighteen (69%) patients responded and achieved MRD negativity. After a median follow-up of 24 months (range, 9-43), the 2-year relapse-free survival rate was 54% and the 2-year overall survival rate was 60% in the entire cohort. Most adverse events were low grade; sinusoidal obstruction syndrome was noted in 2 patients (8%). In summary, inotuzumab ozogamicin resulted in favorable survival, MRD negativity rates, and safety profiles for patients with ALL and MRD-positive status. This study was registered at www.ClinicalTrials.gov as #NCT03441061.

STAT5B mutations in myeloid neoplasms differ by disease subtypes but characterize a subset of chronic myeloid neoplasms with eosinophilia and/or basophilia.

STAT5B has been reported as a recurrent mutation in myeloid neoplasms (MNs) with eosinophilia, but the overall frequency and importance across a spectrum of MNs are largely unknown. We conducted a multicenter study on a series of 82 MNs with STAT5B mutations detected by next-generation sequencing. The estimated frequency of STAT5B mutation in MNs was low.

Differences in the EEG Power Spectrum and Cross-Frequency Coupling Patterns between Young and Elderly Patients during Sevoflurane Anesthesia.

Electroencephalography (EEG) is widely used for monitoring the depth of anesthesia in surgical patients. Distinguishing age-related EEG features under general anesthesia will help to optimize anesthetic depth monitoring during surgery for elderly patients. This retrospective cohort study included 41 patients aged from 18 to 79 years undergoing noncardiac surgery under general anesthesia. We compared the power spectral signatures and phase-amplitude coupling patterns of the young and elderly groups under baseline and surgical anesthetic depth. General anesthesia by sevoflurane significantly increased the spectral power of delta, theta, alpha, and beta bands and strengthened the cross-frequency coupling both in young and elderly patients. However, the variation in EEG power spectral density and the modulation of alpha amplitudes on delta phases was relatively weaker in elderly patients. In conclusion, the EEG under general anesthesia using sevoflurane exhibited similar dynamic features between young and elderly patients, and the weakened alteration of spectral power and cross-frequency coupling patterns could be utilized to precisely quantify the depth of anesthesia in elderly patients.

Validation of a 12-color flow cytometry assay for acute myeloid leukemia minimal/measurable residual disease detection.

BACKGROUND: Acute myeloid leukemia (AML) minimal/measurable residual disease (MRD) by multicolor flow cytometry is a complex laboratory developed test (LDT), challenging for implementation. We share our experience in the validation of a 12-color AML MRD flow cytometry assay to meet stringent regulatory requirements. METHODS: We worked under the guidelines of the CLSI HL62 publication, illustrated the details of the validation process that was tailored to uniqueness of AML MRD, and tested its clinical validity in 61 patients. The "trueness" was determined by correlating with concurrent molecular genetic testing and follow-up bone marrow examinations. RESULTS: Under assay specificity, we shared the details of panel design, analysis, and criteria for interpretation and reporting. The assay accuracy was assessed by testing known positive and negative samples and correlating with molecular genetic testing and follow-up bone marrow examination. The limit of detection (LOD) and limit of quantification (LOQ) were validated to a level between 0.01% and 0.1%, varied from the leukemia-associated immunophenotypes (LAIP) and the numbers of events obtained for analysis. Assay linearity, precision and carry over studies all met acceptable criteria. In the clinical validity test, the concordance was 93%, specificity 98% and sensitivity 83%. The most challenging aspects of the assay were the discrimination of pre-leukemic cells (persistent clonal hematopoiesis) or underlying myelodysplastic clones from AML MRD with immunophenotypic switch or subclone selection. CONCLUSION: The validation met all criteria and obtained FDA IDE (investigational device exemption) approval. This study provides ample technical and professional details in setting up the AML MRD flow cytometry assay and illustrates through the example of the "fit for purpose" validation process. We also highlight the need for further characterization of abnormal blasts bearing the potential for AML relapse.

Phase II study of cladribine, idarubicin, and ara-C (CLIA) with or without sorafenib as initial therapy for patients with acute myeloid leukemia.

The addition of cladribine, or sorafenib to standard chemotherapy have each demonstrated improved survival in patients with newly-diagnosed acute myeloid leukemia (AML). We studied the combination of cladribine, idarubicin, and intermediate-dose cytarabine (CLIA) in patients ≤65 years of age with newly diagnosed AML, fit to receive intensive therapy. Cladribine (5 mg/m2) IV was administered on days (D)1-5, cytarabine (1 g/m2) on D1-5, and idarubicin (10 mg/m2) on D1-3. Sorafenib was added to the CLIA backbone for patients with FLT3-ITD mutated AML. 80 patients were enrolled: 65 with newly diagnosed AML and 15 with AML arising from previously treated MDS (ts-AML). The median age was 55 years (range, 21-65). CR + CRi was 83% (54/65) and 27% in the untreated and ts-AML cohorts, respectively; 74% and 75% of responding patients, respectively, had undetectable measurable residual disease (MRD). Among patients with FLT3-ITD mutated AML receiving CLIA+sorafenib, the CR + CRi rate was 95%, with 81% negative for MRD. With a median follow-up of 76 months, the 2- and 4-year OS of 57% and 50% compared to 20%, and 13% for ts-AML, respectively. Patients treated with CLIA+sorafenib had 2- and 5-year OS rates of 63% and 59%, respectively. The most common Grade ≥3 adverse events were infection/fever, elevated bilirubin, rash, and nausea. CLIA was safe and effective in young, fit patients with newly diagnosed AML with inferior outcomes among patients with ts-AML. The addition of sorafenib to CLIA in FLT3-ITD mutated AML resulted in high rates of durable remission and excellent long-term survival.

Beyond traditional light: NIR-II light-activated photosensitizers for cancer therapy.

With increasing demand for the accurate and safe treatment of cancer, non-invasive photodynamic therapy (PDT) has received widespread attention. However, most conventional photosensitizers are typically excited by short-wavelength visible light (400-700 nm), thus substantially hindering the penetration of light and the therapeutic effectiveness of the PDT procedure. Fortunately, near-infrared (NIR) light (>700 nm), in particular, light in the second near-infrared region (NIR-II, 1000-1700 nm) has a higher upper radiation limit, greater tissue tolerance, and deeper tissue penetration compared with traditional short-wavelength light excitation, and shows considerable potential in the clinical treatment of cancer. Therefore, it is of paramount importance and clinical value to develop photosensitizers that are excited by NIR-II light. In this review, for the first time we focus completely on recent progress made with various NIR-II photosensitizers for cancer treatment via PDT, and we briefly present the ongoing challenges and prospects of currently developed NIR-II photosensitizers for clinical practice in the near future. We believe that the above topics will inspire broad interest in researchers from interdisciplinary fields that include chemistry, materials science, pharmaceuticals, and clinical medicine, and provide insightful perspectives for exploiting new NIR-II photosensitizers for biomedical applications.