A comparison of WHO-5 and ICC classifications in a series of myeloid neoplasms, considerations for hematopathologists and molecular pathologists.

OBJECTIVES: The International Consensus Classification (ICC) and 5th Edition of the World Health Organization Classification (WHO-5) made substantive updates to the classification of myeloid neoplasms. This study compares the systems in a series of myeloid neoplasms with increased blasts, analyzing implications for diagnostic workflow and reporting. METHODS: Bone marrow biopsies categorized as myelodysplastic syndrome with excess blasts (MDS-EB) or acute myeloid leukemia (AML) by WHO-R4 were identified. Results of morphology review, karyotype, fluorescence in situ hybridization, and next-generation sequencing were compiled. Cases were retrospectively re-classified by WHO-5 and ICC. RESULTS: 46 cases were reviewed. 28 cases (61 %) had ≥20 % blasts, with the remaining cases having 5-19.5 % blasts. The most common differences in classification were 1) the designation of MDS versus MDS/AML (10/46, 22 %) for cases with 10-19 % blasts and 2) the ICC's designation of TP53 variants as a separate classifier for AML (8/46, 17 %). Bi-allelic/multi-hit TP53 alterations were identified in 15 cases (33 %). Variants of potential germline significance were identified in 29 (63 %) cases. CONCLUSIONS: While terminology differences between WHO-5 and ICC exist, both systems invoke similar opportunities for improved reporting: standardized classification of pathogenic variants (notably TP53), streamlined systems to evaluate for potential germline variants, and integrated reporting of morphologic and genetic data.

[Analysis of the efficacy and prognostic factors of allogeneic hematopoietic stem cell transplantation in patients with myelodysplastic syndrome with blastomycosis and survival comparison of different subtypes after the WHO 2022 reclassification].

Objective: To evaluate the efficacy and prognostic factors of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with myelodysplastic syndrome accompanied by myelodysplasia (MDS-EB) and to compare the prognosis of different subtypes of patients classified by World Health Organization (WHO) 2022. Methods: A total of 282 patients with MDS-EB who underwent allo-HSCT at the Hematology Hospital of the Chinese Academy of Medical Sciences from October 2006 to December 2022 were included in the study. The WHO 2022 diagnostic criteria reclassified MDS into three groups: myelodysplastic tumors with type 1/2 of primitive cell proliferation (MDS-IB1/IB2, 222 cases), MDS with fibrosis (MDS-f, 41 cases), and MDS with biallelic TP53 mutation (MDS-biTP53, 19 cases). Their clinical data were retrospectively analyzed. Results: ① The median age of 282 patients was 46 (15-66) years, with 191 males and 91 females. Among them, 118 (42% ) and 164 (58% ) had MDS-EB1 and MDS-EB2, respectively. ②Among the 282 patients, 256 (90.8% ) achieved hematopoietic reconstruction after transplantation, with 11 (3.9% ) and 15 (5.3% ) having primary and secondary implantation dysfunctions, respectively. The cumulative incidence of acute graft-versus-host disease (GVHD) 100 days post-transplantation was (42.6±3.0) %, and the cumulative incidence of grade Ⅱ-Ⅳ acute GVHD was (33.0±2.8) %. The cumulative incidence of chronic GVHD 1 year post-transplantation was (31.0±2.9) %. Post-transplantation, 128 (45.4% ), 63 (22.3% ), 35 (12.4% ), and 17 patients (6.0% ) developed cytomegalovirus infection, bacteremia, pulmonary fungal infection, and Epstein-Barr virus infection. ③The median follow-up time post-transplantation was 22.1 (19.2-24.7) months, and the 3-year overall survival (OS) and disease-free survival (DFS) rates were 71.9% (95% CI 65.7% -78.6% ) and 63.6% (95% CI 57.2% -70.7% ), respectively. The 3-year non-recurrent mortality rate (NRM) is 17.9% (95% CI 13.9% -22.9% ), and the 3-year cumulative recurrence rate (CIR) is 9.8% (95% CI 6.7% -13.7% ). The independent risk factors affecting OS post-transplantation include monocyte karyotype (P=0.004, HR=3.26, 95% CI 1.46-7.29), hematopoietic stem cell transplantation complication index (HCI-CI) of ≥3 points (P<0.001, HR=2.86, 95% CI 1.72-4.75), and the occurrence of acute gastrointestinal GVHD of grade Ⅱ-Ⅳ (P<0.001, HR=5.94, 95% CI 3.50-10.10). ④The 3-year OS and DFS rates in the MDS-IB1/IB2 group post-transplantation were better than those in the MDS-biTP53 group [OS: 72.0% (95% CI 63.4% -80.7% ) vs 46.4% (95% CI 26.9% -80.1% ), P=0.020; DFS: 67.4% (95% CI 60.3% -75.3% ) vs 39.7% (95% CI 22.3% -70.8% ), P=0.015]. The 3-year CIR was lower than that of the MDS-biTP53 group [7.3% (95% CI 4.3% -11.4% ) vs 26.9% (95% CI 9.2% -48.5% ), P=0.004]. The NRM at 3 years post-transplantation in the MDS-IB1/IB2, MDS-f, and MDS-biTP53 groups were 16.7% (95% CI 12.1% -22.1% ), 20.5% (95% CI 9.4% -34.6% ), and 26.3% (95% CI 9.1% -47.5% ), respectively (P=0.690) . Conclusion: Allo-HSCT is an effective treatment for MDS-EB, with monomeric karyotype, HCI-CI, and grade Ⅱ-Ⅳ acute gastrointestinal GVHD as independent risk factors affecting the patient's OS. The WHO 2022 classification helps distinguish the efficacy of allo-HSCT in different subgroups of patients. Allo-HSCT can improve the poor prognosis of patients with MDS-f, but those with MDS-biTP53 have a higher risk of recurrence post-transplantation.

Subsequent Malignancies after CD19-Targeted Chimeric Antigen Receptor T cells in Patients with Lymphoma.

Chimeric antigen receptor (CAR) T cells are an established treatment for B cell non-Hodgkin lymphomas (B-NHL). With the remarkable success in improving survival, understanding the late effects of CAR T cell therapy is becoming more relevant. The aim of this study is to determine the incidence of subsequent malignancies in adult patients with B-NHL. We retrospectively studied 355 patients from two different medical centers treated with four different CAR T cell products from 2016 to 2022. The overall cumulative incidence for subsequent malignancies at 36 months was 14% (95% CI: 9.2%, 19%). Subsequent malignancies were grouped into three primary categories: solid tumor, hematologic malignancy, and dermatologic malignancy with cumulative incidences at 36 months of 6.1% (95% CI: 3.1%-10%), 4.5% (95% CI: 2.1%-8.1%) and 4.2% (95% CI: 2.1%-7.5%) respectively. Notably, no cases of T cell malignancies were observed. In univariable analysis, increasing age was associated with higher risk for subsequent malignancy. While the overall benefits of CAR T products continue to outweigh their potential risks, more studies and longer follow ups are needed to further demonstrate the risks, patterns, and molecular pathways that lead to the development of subsequent malignancies.

Myelodysplastic syndrome occurring after enfortumab vedotin treatment for metastatic urothelial carcinoma.

Introduction: Enfortumab vedotin is an antibody-drug conjugate targeting Nectin-4 for the treatment of advanced urothelial carcinoma in patients previously treated with platinum-containing chemotherapy and immune checkpoint inhibitors. Common adverse events include rashes, peripheral neuropathy, and hyperglycemia. However, there are no reports on the development of myelodysplastic syndrome during enfortumab vedotin therapy in clinical settings. Case presentation: A 72-year-old male patient experienced prolonged and severe thrombocytopenia 18 weeks after the start of enfortumab vedotin therapy for metastatic urothelial carcinoma, requiring daily platelet transfusions. Bone marrow examination and chromosomal analysis confirmed the diagnosis of myelodysplastic syndrome. Treatment with eltrombopag proved to be effective. Conclusion: This is the first report of the development of myelodysplastic syndrome during enfortumab vedotin therapy in a clinical setting. Although rare, myelodysplastic syndrome can occur during enfortumab vedotin therapy.

WT1 gene mutations impact post-transplant relapse in myelodysplastic syndrome with excess blasts 2 patients.

Wilms tumor 1 (WT1) gene mutations are infrequent in myelodysplastic syndrome (MDS), but MDS with WT1 mutations (WT1mut) is considered high risk for acute myeloid leukemia (AML) transformation. The influence of WT1 mutations in patients with MDS after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is unclear. We performed a retrospective analysis of 136 MDS with excess blasts 2 (MDS-EB2) patients with available WT1 status who underwent their first allo-HSCT between 2017 and 2022 in our center. There were 20 (20/136, 15%) cases in the WT1mut group and 116 (116/136, 85%) cases in the WT1 wild-type (WT1wt) group. WT1mut patients had a higher 2-year cumulative incidence of relapse (CIR) than WT1wt cases (26.2% vs. 9.4%, p = 0.037) after allo-HSCT. Multivariate analysis of relapse showed that WT1 mutations (HR, 6.0; p = 0.002), TP53 mutations (HR, 4.2; p = 0.021), and ≥ 5% blasts in bone marrow (BM) at transplantation (HR, 6.6; p = 0.004) were independent risk factors for relapse. Patients were stratified into three groups according to the risk factors. Two-year CIR differed significantly in high-, intermediate-, and low-risk groups (31.8%, 11.6%, and 0%, respectively). Hence, WT1 mutations may be related to post-transplant relapse in patients with MDS-EB2, which warrants further study.

Remission of hypersensitivity pneumonitis after allogeneic hematopoietic stem cell transplantation.

A 50-year-old man was diagnosed with hypersensitivity pneumonitis caused by the environment of his bar owing to worsening symptoms, laboratory test results, and computed tomography images after an environmental inhalation challenge test. His hypersensitivity pneumonitis exacerbated despite receiving prednisolone 20 mg/day. The patient underwent allogeneic hematopoietic stem cell transplantation (HSCT) from a human leukocyte antigen-matched unrelated donor for myelodysplastic syndrome. No exacerbation of hypersensitivity pneumonitis was observed after HSCT. An environmental inhalation challenge test involving exposure to his bar confirmed the remission of hypersensitivity pneumonitis after HSCT. This case demonstrates that hypersensitivity pneumonitis can be remitted by HSCT.

Current landscape of CD3 bispecific antibodies in hematologic malignancies.

Over the past 30 years the incorporation of monoclonal antibody (mAb) treatments into the management of hematologic malignancies has led to significant improvements in patient outcomes. The key limitation of mAb treatments is the necessity for target antigen presentation on major histocompatibility complex (MHC) and costimulatory molecules to elicit a cytotoxic immune response. With the advent of bispecific antibodies (BsAbs), these limitations can be overcome through direct stimulation of cytotoxic T cells, thus limiting tumor cell evasion. BsAbs are rapidly being incorporated into treatment regimens for hematologic malignancies, and there are now seven FDA-approved treatments in this class, six of which have been approved in the past year. In this review we describe the function, complications, and clinical trial data available for CD3 BsAbs in the treatment of lymphoma, myeloma, and leukemia.

TP53 mutations in myeloid neoplasms: implications for accurate laboratory detection, diagnosis, and treatment.

Genetic alterations that affect the function of p53 tumor suppressor have been extensively investigated in myeloid neoplasms, revealing their significant impact on disease progression, treatment response, and patient outcomes. The identification and characterization of TP53 mutations play pivotal roles in subclassifying myeloid neoplasms and guiding treatment decisions. Starting with the presentation of a typical case, this review highlights the complicated nature of genetic alterations involving TP53 and provides a comprehensive analysis of TP53 mutations and other alterations in myeloid neoplasms. Currently available methods used in clinical laboratories to identify TP53 mutations are discussed, focusing on the importance of establishing a robust testing protocol within clinical laboratories to ensure the delivery of accurate and reliable results. The treatment implications of TP53 mutations in myeloid neoplasms and clinical trial options are reviewed. Ultimately, we hope that this review provides valuable insights into the patterns of TP53 alterations in myeloid neoplasms and offers guidance to establish practical laboratory testing protocols to support the best practices of precision oncology.

The ratio of bone marrow myeloid progenitor cell proportion to mature lymphocytes proportion can effectively differentiate aplastic anemia and hypoplastic myelodysplastic syndrome and evaluate the quality of bone marrow aspirates.

INTRODUCTION: Aplastic anemia (AA) and hypoplastic myelodysplastic syndrome (MDS-h) are bone marrow failure disease and difficult to distinguish merely by morphological analysis. In this study, we investigated the value of flow cytometry (FCM) in the differential diagnosis of AA and MDS-h. METHODS: We included 822 patients (626 control, 69 AA, 22 MDS-h and 105 dilution patients) from January 2017 to December 2022 for a retrospective study. Bone marrow myeloid progenitor (MP) cell and mature lymphocytes proportions were analyzed by FCM. The ratio of MP cell proportion and mature lymphocytes proportion, MPLR, was calculated. Data were compared by Kruskal-Wallis test. Differential diagnostic efficacy was evaluated by receiver operating characteristic (ROC) curve. Cutoff value was determined by the maximum Youden index. RESULTS: Bone marrow MP cell proportion and MPLR of MDS-h patients were higher than AA patients. Mature lymphocytes proportion of MDS-h patients was lower than AA patients. Area under ROC curve (AUC of ROC) of MP cell proportion, MPLR and mature lymphocytes proportion to distinguish AA from MDS-h were 0.992, 0.988, and 0.850, respectively. Moreover, MPLR of dilution patients was higher than AA patients but lower than MDS-h patients. The AUC of ROC curves of MPLR to distinguish MDS-h and AA from dilution were 0.854 and 0.871, respectively. CONCLUSION: Bone marrow MP cell proportion and MPLR can effectively discriminate AA from MDS-h with similar differential efficacy, which is higher than mature lymphocytes proportion. Moreover, MPLR can evaluate the quality of bone marrow aspirates, which would interfere with the differential diagnosis.

Proteomic and phenotypic characteristics of memory-like natural killer cells for cancer immunotherapy.

BACKGROUND: Human and mouse natural killer (NK) cells have been shown to develop memory-like function after short-term exposure to the cocktail of IL-12/15/18 or to overnight co-culture with some tumor cell lines. The resulting cells retain enhanced lytic ability for up to 7 days as well as after cryopreservation, and memory-like NK cells (mlNK) have been shown to induce complete remissions in patients with hematological malignancies. No single phenotype has been described for mlNK and the physiological changes induced by the short-term cytokine or tumor-priming which are responsible for these enhanced functions have not been fully characterized. Here, we have generated mlNK by cytokine and tumor-priming to find commonalities to better define the nature of NK cell "memory" in vitro and, for the first time, in vivo. METHODS: We initiated mlNK in vitro from healthy donors with cytokines (initiated cytokine-induced memory-like (iCIML)-NK) and by tumor priming (TpNK) overnight and compared them by high-dimensional flow cytometry, proteomic and metabolomic profiling. As a potential mechanism of enhanced cytolytic function, we analyzed the avidity of binding of the mlNK to NK-resistant tumors (z-Movi). We generated TpNK from healthy donors and from cancer patients to determine whether mlNK generated by interaction with a single tumor type could enhance lytic activity. Finally, we used a replication-incompetent tumor cell line (INKmune) to treat patients with myeloid leukaemias to potentiate NK cell function in vivo. RESULTS: Tumor-primed mlNK from healthy donors and patients with cancer showed increased cytotoxicity against multiple tumor cell lines in vitro, analogous to iCIML-NK cells. Multidimensional cytometry identified distinct memory-like profiles of subsets of cells with memory-like characteristics; upregulation of CD57, CD69, CD25 and ICAM1. Proteomic profiling identified 41 proteins restricted to mlNK cells and we identified candidate molecules for the basis of NK memory which can explain how mlNK overcome inhibition by resistant tumors. Finally, of five patients with myelodysplastic syndrome or refractory acute myeloid leukemia treated with INKmune, three responded to treatment with measurable increases in NK lytic function and systemic cytokines. CONCLUSIONS: NK cell "memory" is a physiological state associated with resistance to MHC-mediated inhibition, increased metabolic function, mitochondrial fitness and avidity to NK-resistant target cells.

Computing cell state discriminates the aberrant hematopoiesis and activated microenvironment in Myelodysplastic syndrome (MDS) through a single cell genomic study.

BACKGROUND: Myelodysplastic syndrome (MDS) is a complicated hematopoietic malignancy characterized by bone marrow (BM) dysplasia with symptoms like anemia, neutropenia, or thrombocytopenia. MDS exhibits considerable heterogeneity in prognosis, with approximately 30% of patients progressing to acute myeloid leukemia (AML). Single cell RNA-sequencing (scRNA-seq) is a new and powerful technique to profile disease landscapes. However, the current available scRNA-seq datasets for MDS are only focused on CD34+ hematopoietic progenitor cells. We argue that using entire BM cell for MDS studies probably will be more informative for understanding the pathophysiology of MDS. METHODS: Five MDS patients and four healthy donors were enrolled in the study. Unsorted cells from BM aspiration were collected for scRNA-seq analysis to profile overall alteration in hematopoiesis. RESULTS: Standard scRNA-seq analysis of unsorted BM cells successfully profiles deficient hematopoiesis in all five MDS patients, with three classified as high-risk and two as low-risk. While no significant increase in mutation burden was observed, high-risk MDS patients exhibited T-cell activation and abnormal myelogenesis at the stages between hematopoietic stem and progenitor cells (HSPC) and granulocyte-macrophage progenitors (GMP). Transcriptional factor analysis on the aberrant myelogenesis suggests that the epigenetic regulator chromatin structural protein-encoding gene HMGA1 is highly activated in the high-risk MDS group and moderately activated in the low-risk MDS group. Perturbation of HMGA1 by CellOracle simulated deficient hematopoiesis in mouse Lineage-negative (Lin-) BM cells. Projecting MDS and AML cells on a BM cell reference by our newly developed MarcoPolo pipeline intuitively visualizes a connection for myeloid leukemia development and abnormalities of hematopoietic hierarchy, indicating that it is technically feasible to integrate all diseased bone marrow cells on a common reference map even when the size of the cohort reaches to 1,000 patients or more. CONCLUSION: Through scRNA-seq analysis on unsorted cells from BM aspiration samples of MDS patients, this study systematically profiled the development abnormalities in hematopoiesis, heterogeneity of risk, and T-cell microenvironment at the single cell level.

Prognostic significance of GATA2 in patients with MDS/AML: a systematic review and meta-analysis.

GATA2 deficiency syndrome is a heterogeneous disorder characterized by a high risk of developing myelodysplastic syndrome (MDS)/acute myeloid leukaemia (AML). We conducted a meta-analysis of the literature to explore the prognostic significance of GATA2 mutations in patients diagnosed with MDS/AML, as previous studies have yielded conflicting findings regarding the impact of GATA2 mutations on patient outcomes. We conducted a comprehensive literature search of databases such as PubMed, Embase, the Cochrane Library, and the Web of Science to obtain studies on the prognostic significance of GATA2 mutations in patients with MDS/AML that were published through January 2024. We extracted the hazard ratio (HR) and 95% confidence interval (CI) for overall survival (OS), disease-free survival (DFS), and event-free survival (EFS). The meta-analysis was conducted by choosing either a fixed-effect model or a random-effect model, depending on the variability observed among the studies. A total of 13 cohort studies were included in the final meta-analysis, including 2714 patients with MDS, of whom 644 had GATA2 mutations. The results revealed that GATA2 mutations had an adverse impact on OS (HR = 1.54, 95% CI = 1.08-2.18, P = 0.02) and EFS (HR = 1.32, 95% CI = 1.01-1.72, P = 0.04), but no significant effect on DFS (HR = 1.21, 95% CI = 0.89-1.64, P = 0.23). GATA2 mutations were associated with a significantly shorter OS in MDS patients (HR = 2.56, 95% CI = 1.42-4.06, P = 0.002) but not in AML patients (HR = 1.08, 95% CI = 0.92-1.26, P = 0.37). Our meta-analysis revealed that GATA2 mutations are associated with unfavourable outcomes in patients with MDS/AML. Furthermore, patients harbouring these mutations should be prioritized for aggressive therapeutic interventions.

Predicting which subsets of patients with myelodysplastic neoplasms are more likely to progress to overt chronic myelomonocytic leukemia.

The boundary between myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML) has been revised in the latest World Health Organization classification of myeloid malignancies. These changes were motivated by the description of a subgroup of MDS patients identified as oligomonocytic chronic myelomonocytic leukemia (OM-CMML) at risk of evolving into overt CMML. Various studies will be reviewed describing the clinical and biological features of MDS patients evolving to CMML. The efforts to discover biomarkers enabling the identification of these patients at the time of MDS diagnosis will be discussed. Finally, the molecular landscape of these patients will be presented with a specific focus on the biallelic inactivation of TET2 in light of its functional impact on hematopoietic stem cells, granule-monocytic differentiation, and its tight interplay with inflammation.

Cranial hypertrophic pachymeningitis with myelodysplastic syndrome.

Hypertrophic pachymeningitis (HP) is a rare inflammatory disease characterized by thickening of the dura mater. HP develops with several inflammatory diseases. Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis and IgG4 related disease are reported as 2 major causes. With hematologic diseases, only 3 cases have been reported. We report the case of myelodysplastic syndrome (MDS) developing HP. Our case provides a thought-provoking hypothesis regarding the potential relationship between MDS and HP.

Low Levels of Natural Killer Cell in Newly Diagnosed Myelodysplastic Syndromes Patients May Confer Poor Prognosis: A Retrospective Cohort Study.

Background: Immune imbalance appears to have a critical role in tumor growth according to emerging research. Peripheral lymphocyte subsets are considered to reflect the systemic immune response and clinical prognosis. The prognostic value of lymphocyte subpopulations in myelodysplastic syndrome (MDS) patients remains unclear. Methods: A total of 94 MDS patients were enrolled for the study. X-tile software was performed to determine the prognostic significance of various lymphocyte subpopulations, CD3, CD4, CD8, CD4/CD8 ratio, natural killer cell (NK) and CD19. Among them, the appropriate threshold of NK percent could be found only. Patients were divided into the high NK percent group and the low NK percent group. The prognostic significance was determined by univariate and multivariate Cox hazard models. Results: MDS patients with lower NK level had significantly shorter overall survival (OS). Based on univariate analysis, male gender (P = 0.030), lower HB (<10 g/dl, P = 0.029), higher BM blast (>5%, P < 0.0001), higher-risk IPSS-R cytogenetic (P = 0.032) and lower NK percent (P < 0.0001) were significantly associated with shorter OS. Multivariate Cox proportional hazards regression analysis indicated that low NK was also independent adverse prognostic factor for OS in MDS. Conclusion: Decreased NK level predicts poor prognosis independent of the IPSS-R and provide a novel evaluation factor for MDS patients.

Abstracts of the Cell Therapy Transplant Canada 2023 Annual Conference.

On behalf of Cell Therapy Transplant Canada (CTTC), we are pleased to present the Abstracts of the CTTC 2023 Annual Conference. The conference was held in-person, 31 May-2 June 2023, in Halifax, Nova Scotia at the Westin Nova Scotian hotel. Poster authors presented their work during a lively and engaging welcome reception on Thursday, 1 June, and oral abstract authors were featured during the oral abstract session in the afternoon of Friday, 2 June 2023. Twenty-three (23) abstracts were selected for presentation as posters and four (4) as oral presentations. Abstracts were submitted within four categories: (1) Basic/Translational Sciences, (2) Clinical Trials/Observations, (3) Laboratory/Quality, and (4) Pharmacy/Nursing/Other Transplant Support. The top four (4) oral abstracts and top four (4) poster abstracts were selected to receive an award. All of these were marked as "Award Recipient" within the relevant category. We congratulate all the presenters on their research and contributions to the field.

Severe B12 Deficiency Causing a Maturation Defect Mimicking Myelodysplastic Syndrome With Excess Blasts.

Vitamin B12 deficiency is a common condition that is often asymptomatic, though in severe cases may cause megaloblastic anemia and even neurologic symptoms. Occasionally, the clinical presentation can include pancytopenia and thus mimic a more concerning myelodysplastic syndrome (MDS) until corrected by B12 supplementation. In this unusual case, we present a patient with B12 deficiency who presents with severe macrocytic anemia, neutropenia, lymphocytosis, and a bone marrow morphology consistent with MDS.

Clinicians' Perspectives on the Telehealth Serious Illness Care Program for Older Adults With Myeloid Malignancies: Single-Arm Pilot Study.

BACKGROUND: Serious illness conversations may help patients avoid unwanted treatments. We previously piloted the telehealth Serious Illness Care Program (SICP) for older adults with acute myeloid leukemia and myelodysplastic syndrome. OBJECTIVE: In this study, we aimed to understand the experience of the telehealth SICP from the clinician's perspective. METHODS: We studied 10 clinicians who delivered the telehealth SICP to 20 older adults with acute myeloid leukemia or myelodysplastic syndrome. Quantitative outcomes included confidence and acceptability. Confidence was measured using a 22-item survey (range 1-7; a higher score is better). Acceptability was measured using an 11-item survey (5-point Likert scale). Hypothesis testing was performed at α=.10 (2-tailed) due to the pilot nature and small sample size. Clinicians participated in audio-recorded qualitative interviews at the end of the study to discuss their experience. RESULTS: A total of 8 clinicians completed the confidence measure and 7 clinicians completed the acceptability measure. We found a statistically significant increase in overall confidence (mean increase of 0.5, SD 0.6; P=.03). The largest increase in confidence was in helping families with reconciliation and goodbye (mean 1.4, SD 1.5; P=.04). The majority of clinicians agreed that the format was simple (6/7, 86%) and easy to use (6/7, 86%). Clinicians felt that the telehealth SICP was effective in understanding their patients' values about end-of-life care (7/7, 100%). A total of three qualitative themes emerged: (1) the telehealth SICP deepened relationships and renewed trust; (2) each telehealth SICP visit felt unique and personal in a positive way; and (3) uninterrupted, unrushed time optimized the visit experience. CONCLUSIONS: The telehealth SICP increased confidence in having serious illness conversations while deepening patient-clinician relationships. TRIAL REGISTRATION: ClinicalTrials.gov NCT04745676; https://www.clinicaltrials.gov/study/NCT04745676.