Identification of drugs including a dopamine receptor antagonist that selectively target cancer stem cells.

Selective targeting of cancer stem cells (CSCs) offers promise for a new generation of therapeutics. However, assays for both human CSCs and normal stem cells that are amenable to robust biological screens are limited. Using a discovery platform that reveals differences between neoplastic and normal human pluripotent stem cells (hPSC), we identify small molecules from libraries of known compounds that induce differentiation to overcome neoplastic self-renewal. Surprisingly, thioridazine, an antipsychotic drug, selectively targets the neoplastic cells, and impairs human somatic CSCs capable of in vivo leukemic disease initiation while having no effect on normal blood SCs. The drug antagonizes dopamine receptors that are expressed on CSCs and on breast cancer cells as well. These results suggest that dopamine receptors may serve as a biomarker for diverse malignancies, demonstrate the utility of using neoplastic hPSCs for identifying CSC-targeting drugs, and provide support for the use of differentiation as a therapeutic strategy.

Final report of TKI discontinuation trial with dasatinib for the second attempt of treatment-free remission after failing the first attempt with imatinib: Treatment-free Remission Accomplished by Dasatinib (TRAD) study.

Multiple studies have reported a significant treatment-free remission (TFR) rate of 50%-60% in patients with chronic myeloid leukaemia (CML) who discontinue tyrosine kinase inhibitor (TKI) therapy. However, the remaining half of these patients still require re-initiation of TKI therapy for leukaemia control. It remains unclear if TKI drugs should be switched for re-therapy in patients who failed the first TFR (TFR1) attempt. Our study attempted to determine whether dasatinib therapy after TFR1 failure post-imatinib discontinuation could improve the likelihood of TFR2. Of 59 patients who lost molecular response after imatinib discontinuation for TFR1, 55 patients (93.2%) were treated with dasatinib, of whom 49 (89.1%) regained MR4.5 or deeper response, with a median time of 1.85 months to achieve MR4.5. Dasatinib was discontinued in 35 patients for TFR2 attempt, of whom 26 patients (74.28%) lost MMR and 6 (17.14%) MR4. Risk factor analysis for the TFR2 after dasatinib discontinuation suggested three significant factors: (1) doubling time of BCR::ABL1 transcript following TFR1 attempt, (2) rapid regaining of molecular response following dasatinib therapy and (3) undetectable BCR::ABL1 transcript prior to TFR2 attempt. The present study showed that dasatinib does not increase the TFR2 rate in general, but a selected group of patients could benefit from this approach.

Outpatient consolidation chemotherapy with intermediate dose cytarabine has similar survival and relapses rates in acute myeloid leukemia as compared to high dose cytarabine: A single center analysis.

INTRODUCTION: The last decade has seen advances in delivering outpatient consolidation therapy for acute myeloid leukemia (AML). The standard of care involves high-dose cytarabine or intermediate-dose cytarabine, given twice daily for three alternating days. At the London Regional Cancer Program, we have transitioned the administration of outpatient cytarabine to a once-daily regimen over six consecutive days. The outcomes of a longer duration interval of high-dose cytarabine and intermediate-dose cytarabine is currently unknown. This study aims to assess the feasibility of administering a continuous 6-day protocol of high-dose (HDAC-16) and intermediate-dose cytarabine (IDAC-16) consolidation therapy in the outpatient setting. METHODS: This is a retrospective chart review to analyze AML patients treated with outpatient high-dose or intermediate-dose cytarabine consolidation therapy at the London Regional Cancer Program from January 1, 2019, through November 1, 2022. The primary objective was to determine the outcomes of the 6-day outpatient administration of once daily high-dose cytarabine or intermediate-dose cytarabine. RESULTS: Forty-five patients received 89 cycles of cytarabine as outpatients; males were 55.6% of the total population, with a median age of ~57 years. Our overall 2-year survival of HDAC-16 (57.1%) and IDAC-16 (83.3%) is consistent with the reported literature. There was no difference in delays, relapse rates, and nonrelapse mortality between both HDAC and IDAC groups. The 2-year relapse free survival was 57.1% for HDAC-16 and 66.7% for IDAC-16. CONCLUSION: Outpatient administration of intermediate-dose cytarabine once daily over six consecutive days results in similar overall survival and relapse rates as compared to high dose cytarabine consolidation chemotherapy. Moving to a once daily administration schedule can alleviate logistical and/or accessibility hurdles for outpatient oncology clinics. Prospective randomized trials are needed in this setting to validate our results.

BCR-ABL1 transcript doubling time as a predictor for treatment-free remission failure after imatinib discontinuation in chronic myeloid leukaemia in chronic phase.

The doubling time (DT) of the BCR-ABL1 quantitative polymerase chain reaction (qPCR) transcript level reflects the re-growing fraction of leukaemic cells after discontinuation of tyrosine kinase inhibitor (TKI). The present study analyzed monthly DT within six months after imatinib discontinuation in 131 patients. Monthly DT was calculated as x = ln(2)/K, where x is the DT and K is the fold BCR-ABL1 change from the previous value divided by the number of days between each measurement. The optimal DT value was determined as 12·75 days at two months using a recursive partitioning method. The patients were stratified into three groups: the high-risk group (DT<12·75 days but >0, with rapidly proliferating chronic myeloid leukaemia (CML) cells; n = 26) showed the lowest molecular relapse-free survival (mRFS) of 7·7% at 12 months, compared to 53·6% in the intermediate-risk group (DT≥12·75 days, with slowly proliferating CML cells; n = 16) or 90·0% in the low-risk group (DT≤0, i.e., without proliferating CML cells; n = 71; P < 0·001). Monthly assessment of DT helps identify high-risk patients for treatment-free remission failure with an imminent risk of molecular recurrence, and to define low-risk patients who can be spared the frequent monitoring of monthly molecular tests.

Optimal duration of imatinib treatment/deep molecular response for treatment-free remission after imatinib discontinuation from a Canadian tyrosine kinase inhibitor discontinuation trial.

Although total duration of tyrosine kinase inhibitor (TKI) therapy and of molecular response at 4 log reduction or deeper (MR4) correlates with treatment-free remission (TFR) success after TKI discontinuation, the optimal cut-off values of the duration remain unresolved. Thus, 131 patients were enrolled into the Canadian TKI discontinuation study. The molecular relapse-free survival (mRFS) was defined from imatinib discontinuation till molecular recurrence, that is, major molecular response (MMR) loss and/or MR4 loss. We evaluated mRFS at 12 months after imatinib discontinuation, analyzed it according to the imatinib treatment duration and MR4 duration, and calculated P value, positive (PPV) and negative predictive value (NPV) in the yearly cut-off period of time. The shortest cut-off was sought that met the joint criteria of a P value ≤ 0·05, PPV ≥ 60% and NPV ≥ 60%. We propose six years as the shortest imatinib duration cut-off with a P value 0·01, PPV 68% and NPV 62%: The patients treated with imatinib duration ≥ 6 years showed a superior mRFS rate (61·8%) compared to those with less treatment (36·0%). Also, 4·5 years MR4 duration as the shortest cut-off with a P value 0·003, PPV 63% and NPV 61%: those with MR4 duration ≥ 4·5 years showed a higher mRFS rate (64·2%) than those with a shorter MR4 duration (41·9%).

Clinical value of next-generation sequencing compared to cytogenetics in patients with suspected myelodysplastic syndrome.

Next-generation sequencing (NGS) increasingly influences diagnosis, prognosis and management of myelodysplastic syndrome (MDS). In addition to marrow morphology and flow cytometry, our institution performs cytogenetics (CG) and NGS-based testing routinely in patients with suspected MDS. We evaluated the relative value of NGS in the assessment of patients with suspected MDS. We initially compared the diagnostic and prognostic information derived from CG and NGS in 134 patients. NGS enhanced the diagnostic yield compared to CG for clonal myeloid disorders (sensitivity 77% vs. 42·2%; specificity 90·2% vs. 78%; positive predictive value 92·8% vs. 76%; and negative predictive value 70·8% vs. 45·5%). The identification of poor prognosis mutations by NGS altered risk category in 27/39 (69·2%) patients with MDS with good/intermediate risk CG. Subsequently, we prospectively evaluated 70 patients with suspected MDS using an 'NGS-first approach' with CG restricted to samples with morphological abnormalities. We rarely identified mutations or CG abnormalities in patients without dysplastic features. NGS has a superior diagnostic performance compared to CG in patients with suspected MDS. We estimate that by using an 'NGS-first approach' we could reduce karyotyping by approximately 30%.

Human Multipotent Stromal Cell Secreted Effectors Accelerate Islet Regeneration.

Human multipotent stromal cells (hMSC) can induce islet regeneration after transplantation via the secretion of proteins that establish an islet regenerative niche. However, the identity of hMSC-secreted signals and the mechanisms by which pancreatic islet regeneration is induced remain unknown. Recently, mammalian pancreatic α-cells have been shown to possess considerable plasticity, and differentiate into ß-like cells after near complete ß-cell loss or overexpression of key transcriptional regulators. These studies have generated new excitement that islet regeneration during diabetes may be possible if we can identify clinically applicable stimuli to modulate these key regulatory pathways. Herein, we demonstrate that intrapancreatic-injection of concentrated hMSC-conditioned media (CM) stimulated islet regeneration without requiring cell transfer. hMSC CM-injection significantly reduced hyperglycemia, increased circulating serum insulin concentration, and improved glucose tolerance in streptozotocin-treated mice. The rate and extent of endogenous ß-cell mass recovery was dependent on total protein dose administered and was further augmented by the activation of Wnt-signaling using GSK3-inhibition during CM generation. Intrapancreatic hMSC CM-injection immediately set in motion a cascade of regenerative events that included the emergence of proliferating insulin+ clusters adjacent to ducts, NKX6.1 expression in glucagon+ cells at days 1-4 suggesting the acquisition of ß-cell phenotype by α-cells, and accelerated ß-cell maturation with increased MAFA-expression for >1 month postinjection. Discovery and validation of islet regenerative hMSC-secreted protein may lead to the development of cell-free regenerative therapies able to tip the balance in favor of ß-cell regeneration versus destruction during diabetes. Stem Cells 2019;37:516-528.

Implementation of an NGS-based sequencing and gene fusion panel for clinical screening of patients with suspected hematologic malignancies.

OBJECTIVES: The diagnosis of hematologic malignancies integrates multiple diagnostic and clinical disciplines. Historically, targeted (single-analyte) genetic testing has been used as reflex to initial prescreening by other diagnostic modalities including flow cytometry, anatomic pathology, and clinical cytogenetics. Given the wide range of mutations associated with hematologic malignancies a DNA/RNA-based NGS panel can provide a more effective and economical approach to comprehensive testing of patients as an initial, tier-1 screen. METHODS: Using a cohort of 380 patients, we performed clinical validation of a gene panel designed to assess 40 genes (DNA), and 29 fusion driver genes with over 600 gene fusion partners (RNA), including sample exchange data across three clinical laboratories, and correlation with cytogenetic testing results. RESULTS: The clinical validation of this technology demonstrated that its accuracy, sensitivity, and specificity are comparable to the majority of targeted single-gene approaches, while assessment of the initial patient cohort data demonstrated a high diagnostic yield of 50.5%. CONCLUSIONS: Implementation of a tier-1 NGS-based protocol for gene panel screening provides a comprehensive alternative to targeted molecular testing in patients with suspected hematologic malignancies, with increased diagnostic yield, scalability, reproducibility, and cost effectiveness, making it ideally suited for implementation in clinical laboratories.

Quality of life trajectories during the first year following hematopoietic cell transplantation: an inception cohort study.

BACKGROUND: Allogeneic hematopoietic cell transplantation (HCT) affects quality of life (QOL). Patient-reported outcomes examine symptoms, side effects, distress, and physical and social problems, but positive outcomes have been ignored. This inception cohort study followed people over the first year following HCT to document positive and negative outcomes. METHODS: People with hematologic cancers treated by HCT completed complementary self-report instruments at four milestones: (a) pre-transplant (N = 88); (b) engraftment (N = 80); (c) short-term post-discharge (N = 60); and (d) long-term post-discharge (N = 45). We examined symptoms, side effects, illness intrusiveness, depressive symptoms, positive and negative affect, and self-esteem. We compared QOL in HCT with diverse published values. RESULTS: QOL deteriorated following HCT. Most variables returned to baseline by short-term post-discharge, but self-esteem and illness intrusiveness required more time. Illness intrusiveness at 1 year post-discharge was higher in HCT than other cancer groups; negative affect, too, was higher, but HCT survivors also reported higher positive affect. HCT and other cancer survivors reported similar depressive symptom levels. Compared to healthy people, HCT survivors reported more severe depressive symptoms, but similar positive and negative affect. CONCLUSIONS: QOL changes dramatically following HCT. People report more interference with valued activities and interests after 1 year than survivors of other cancers, but depressive symptoms are not higher. Positive and negative affect are equivalent to healthy community residents. Continued involvement in psychologically meaningful activities may preserve QOL.

Improved Prediction of CD34+ Cell Yield before Peripheral Blood Hematopoietic Progenitor Cell Collection Using a Modified Target Value-Tailored Approach.

The most commonly used stem cell source for both autologous and allogeneic transplantation is mobilized peripheral blood hematopoietic progenitor cells collected by apheresis. In the 1990s, an Italian group used the correlation between the preapheresis peripheral blood CD34+ cell count and the final number of CD34+ cells collected to devise a formula for "target value-tailored" (TVT) apheresis. Using local patient data, the Canadian Blood Services Stem Cell Laboratory created a similar model to determine the blood volume to process during apheresis collection. The objectives of this study were to determine the correlation between the number of CD34+ cells predicted by the TVT formula and the actual number of CD34+ cells collected and to determine whether the TVT formula remains predictive when applied to an external data set. All apheresis collections performed at the Ottawa Hospital between January 1, 2003 and October 2, 2013 were reviewed. The primary outcome was the correlation between the number of CD34+ cells predicted by the TVT formula and the actual number of CD34+ cells collected on day 1 of apheresis. For the external data set, all autologous collections performed at the London Health Sciences Centre between December 1, 2008 and December 1, 2013 were reviewed. The external data set was divided into test and validation sets to determine whether a model could be created to predict the final number of CD34+ cells collected on day 1 based on the preapheresis CD34+ count. A total of 1252 collections were included in the analysis. The Ottawa data set included 1012 collections, 836 of which were autologous and 176 of which were from donors. Of the autologous collections in Ottawa, 764 (92.5%) were first collections. In 759 (91%) collections, chemotherapy plus granulocyte colony-stimulating factor (G-CSF) was used as the mobilization regimen. In 747 collections (89%), only 1 collection day was required to achieve the desired number of CD34+ cells. The TVT estimate was highly predictive of the number of CD34+ cells × 10(6)/kg actually collected on apheresis day 1 (r = .90, P < .0001). The London data set included 240 autologous collections. All mobilizations were with G-CSF alone. For the test set, the precollection CD34+ count was highly predictive of the number of CD34+ cells × 10(6)/kg collected on day 1 of apheresis. Applying this model to the validation set, the correlation between the predicted and final and day 1 CD34+ cells × 10(6)/kg count was .9186 (P < .0001). Using a modified TVT approach, the preapheresis CD34+ count can be used to accurately predict the number of CD34+ cells × 10(6)/kg collected on day 1. This approach can be applied at other centers and for different diseases and mobilization regimens. This method can be used to individualize the blood volume processed and, thus, optimize resource utilization.

Favorable outcomes from allogeneic and autologous stem cell transplantation for patients with transformed nonfollicular indolent lymphoma.

The role of allogeneic (allo-) and autologous stem cell transplantation (auto-SCT) in the management of patients with transformed indolent nonfollicular non-Hodgkin lymphoma is unknown. This is a multicenter, retrospective cohort study of patients with biopsy-proven indolent B cell nonfollicular non-Hodgkin lymphoma and simultaneous or subsequent biopsy-proven aggressive histology transformation who were treated with allo-SCT or auto-SCT between 1996 and 2013. All patients received myeloablative conditioning regimens. Outcomes were compared with a cohort of 246 patients with transformed follicular lymphoma who also underwent allo-SCT (n = 47) or auto-SCT (n = 199) across the same institutions and time frame. Thirty-four patients were identified with the following underlying indolent histologies: 15 (44%) marginal zone lymphoma, 11 (32%) chronic lymphocytic leukemia, 6 (18%) small lymphocytic lymphoma, and 2 (6%) lymphoplasmacytic lymphoma. Patients received various anthracycline or platinum-containing chemotherapy regimens for transformation, incorporating rituximab in 25 (74%). Twelve (35%) subsequently underwent allo-SCT, whereas 33 (65%) underwent auto-SCT. The 3-year overall survival rate after transplantation was 67% (allo-SCT 54%, auto-SCT 74%), and 3-year progression-free survival rate was 49% (allo-SCT 40%, auto-SCT 54%). The 3-year nonrelapse mortality rate was 14% (allo-SCT 15%, auto-SCT 7%). Transplant-related mortality at 100 days was 17% for allo-SCT and 0% for auto-SCT. Adjusted for type of stem cell transplantation, 3-year overall survival, progression-free survival, and nonrelapse mortality rates were similar to those of patients with transformed follicular lymphoma receiving allo-SCT and auto-SCT (P = .38, P = .69, and P = .54, respectively). Allo-SCT and auto-SCT may be reasonable treatments for selected patients with transformed nonfollicular indolent lymphoma, although medium-term outcomes and toxicity appear to be more favorable with auto-SCT.

Merkel cell carcinoma mimicking acute leukemia.

Bone marrow aspirate showed diffuse infiltration by a population of monomorphic cells with scant cytoplasm, markedly increased nuclear-to-cytoplasmic ratio, and numerous indistinct nucleoli. Bone marrow biopsy confirmed extensive marrow infiltration by a malignant neoplasm with strong and diffuse expression of synaptophysin by immunohistochemistry, consistent with metastases from Merkel Cell carcinoma.

Serologic Response to Vaccine for COVID-19 in Patients with Hematologic Malignancy: A Prospective Cohort Study.

BACKGROUND: Patients with hematological cancers have increased COVID-19 morbidity and mortality, and these patients show attenuated vaccine responses. This study aimed to characterize the longitudinal humoral immune responses to COVID-19 vaccination in patients with hematological malignancies. PATIENTS AND METHODS: We conducted a prospective cohort study, collecting samples from March 2021 to July 2022, from patients seen at a cancer treatment center in London, Ontario, Canada, who met the following eligibility criteria: age ≥18 years, diagnosed with a hematological malignancy, recipient of a COVID-19 vaccine during the study period, and able to provide informed consent. RESULTS: Median anti-S titers (MST) were 0.0, 64.0, and 680.5 U/mL following first (V1), second (V2), and third (V3) vaccine doses, respectively. Patients with lymphoid malignancies' response to vaccination was attenuated compared to myeloid malignancy patients after V2 and V3 (P < .001, P < .01). Active treatment was associated with lower antibody titers (MST 10) compared to treatment 12-24 months (MST 465, P = .04367) and >24 months (MST 1660.5, P = .0025) prior to vaccination. V3 significantly increased antibody titers compared to V2 for patients less than 3 months from treatment. Increasing age was associated with smaller antibody response following V2 (P < .05), but not following V3. Patients receiving anti-CD20 therapy did not demonstrate increased antibody titer levels after V3 (V2 MST 0, V3 MST 0; P > .05). CONCLUSION: We report an attenuated serologic response to COVID-19 vaccination in our study population of patients with hematological malignancy. The immune response to vaccination was affected by patient age, diagnosis, treatment, and timing of treatment exposure.

Identification of cells of leukemic stem cell origin with non-canonical regenerative properties.

Despite most acute myeloid leukemia (AML) patients entering remission following chemotherapy, outcomes remain poor due to surviving leukemic cells that contribute to relapse. The nature of these enduring cells is poorly understood. Here, through temporal single-cell transcriptomic characterization of AML hierarchical regeneration in response to chemotherapy, we reveal a cell population: AML regeneration enriched cells (RECs). RECs are defined by CD74/CD68 expression, and although derived from leukemic stem cells (LSCs), are devoid of stem/progenitor capacity. Based on REC in situ proximity to CD34-expressing cells identified using spatial transcriptomics on AML patient bone marrow samples, RECs demonstrate the ability to augment or reduce leukemic regeneration in vivo based on transfusion or depletion, respectively. Furthermore, RECs are prognostic for patient survival as well as predictive of treatment failure in AML cohorts. Our study reveals RECs as a previously unknown functional catalyst of LSC-driven regeneration contributing to the non-canonical framework of AML regeneration.

Identification of T-lymphocytic leukemia-initiating stem cells residing in a small subset of patients with acute myeloid leukemic disease.

Xenotransplantation of acute myeloid leukemia (AML) into immunodeficient mice has been critical for understanding leukemogenesis in vivo and defining self-renewing leukemia-initiating cell subfractions (LICs). Although AML-engraftment capacity is considered an inherent property of LICs, substrains of NOD/SCID mice that possess additional deletions such as the IL2Rγc(null) (NSG) have been described as a more sensitive recipient to assay human LIC function. Using 23 AML-patient samples, 39% demonstrated no detectable engraftment in NOD/SCID and were categorized as AMLs devoid of LICs. However, 33% of AML patients lacking AML-LICs were capable of engrafting NSG recipients, but produced a monoclonal T-cell proliferative disorder similar to T-ALL. These grafts demonstrated self-renewal capacity as measured by in vivo serial passage and were restricted to CD34-positive fraction, and were defined as LICs. Molecular analysis for translocations in MLL genes indicated that these AML patient-derived LICs all expressed the MLL-AFX1 fusion product. Our results reveal that the in vivo human versus xenograft host microenvironment dictates the developmental capacity of human LICs residing in a small subset of patients diagnosed with AML harboring MLL mutations. These findings have implications both for the basic biology of CSC function, and for the use of in vivo models of the leukemogenic process in preclinical or diagnostic studies.

Glycogen synthase kinase-3 is an in vivo regulator of hematopoietic stem cell repopulation.

The in vivo regulation of hematopoietic stem cell (HSC) function is poorly understood. Here, we show that hematopoietic repopulation can be augmented by administration of a glycogen synthase kinase-3 (GSK-3) inhibitor to recipient mice transplanted with mouse or human HSCs. GSK-3 inhibitor treatment improved neutrophil and megakaryocyte recovery, recipient survival and resulted in enhanced sustained long-term repopulation. The output of primitive Lin(-)c-Kit(+)Sca-1(+) cells and progenitors from HSCs increased upon GSK-3 inhibitor treatment without altering secondary repopulating ability, suggesting that the HSC pool is maintained while overall hematopoietic reconstitution is increased. GSK-3 inhibitors were found to modulate gene targets of Wnt, Hedgehog and Notch pathways in cells comprising the primitive hematopoietic compartment without affecting mature cells. Our study establishes GSK-3 as a specific in vivo modulator of HSC activity, and suggests that administration of GSK-3 inhibitors may provide a clinical means to directly enhance the repopulating capacity of transplanted HSCs.

Predictors of unsuccessful mobilization with granulocyte colony-stimulating factor alone in patients undergoing autologous hematopoietic stem cell transplantation.

Mobilization of hematopoietic stem cells is achieved with hematopoietic growth factors with or without chemotherapy or other agents. Although studies comparing granulocyte colony-stimulating factor (G-CSF) alone to combined regimens demonstrate an increase in stem cell yield in the latter, mobilization with G-CSF alone is still effective and has been widely practiced. We conducted a retrospective cohort study of consecutive patients at our institution who underwent at least one mobilization attempt with G-CSF between January 2000 and December 2008 to identify the proportion of patients failing one or more mobilization attempts and the potential predictors of mobilization failure with this regime. Out of 293 patients, 251 (86.6%) were successfully mobilized and 244 (83.6%) underwent hematopoietic stem cell transplantation. Median yield was 3.55 × 106 CD34⁺ cells/kg. On univariate analysis, mobilization success was influenced by degree of previous treatment and underlying diagnosis (P < 0.001 each) but not by age (P = 0.114), sex (P = 0.860), or radiotherapy (P = 0.454). A diagnosis of non-Hodgkin's lymphoma (NHL) and number of previous chemotherapy regimens were predictors of failure on multivariate analysis. CD34⁺ yield was influenced by diagnosis and previous chemotherapy (P < 0.001 each). Mobilization with G-CSF alone yields adequate collections for most patients; however, heavily pretreated NHL patients with one failed attempt had high rates of remobilization failure and should be considered for alternative regimens.

A Multicenter, Retrospective Study Evaluating Clinical Outcomes of Ruxolitinib Therapy In Heavily Pretreated Chronic GVHD Patients With Steroid Failure.

Although ruxolitinib is emerging as the treatment of choice for steroid-refractory or -dependent chronic graft versus host disease (cGVHD) based on randomized control trial data, there is relatively little real-world data published on ruxolitinib for this indication. We wanted to evaluate the real-world efficacy and safety of ruxolitinib in cGVHD patients who have failed any previous systemic therapy for cGVHD. We retrospectively evaluated the efficacy of ruxolitinib in 115 heavily pretreated patients with steroid-refractory or -dependent chronic GVHD across 5 transplantation centers. The majority of the study population had severe cGVHD (60%) and received ruxolitinib at the fourth treatment line or beyond (82%, n = 96). The median duration of follow-up in this study population was 13 months. The overall response rate (ORR) was 48.6%, 54.9%, and 48.5% at 3, 6, and 12 months, respectively. Clinical benefit (an outcome metric combining ORR with steroid reduction) was observed in 58.7%, 64.8%, and 60.6% of patients at 3, 6, and 12 months, respectively. Approximately one third of patients (37.9%) were able to discontinue prednisone at 12 months, and 63.8% were able to taper prednisone to a daily dose <0.1 mg/kg at 12 months. Failure-free survival at 12 months was 64.6% (54.1%-73.2%). Multivariate analysis identified that patients with severe cGVHD were at a higher risk of failure because of a therapy switch, whereas a pretransplantation hematopoietic stem cell transplantation-comorbidity index score ≥ 3 was associated with a high risk of failure because of increasing risk of non-relapse mortality. Overall, this study demonstrates the therapeutic efficacy of ruxolitinib for cGVHD in a heavily pretreated real-world population.

Propensity score matching analysis comparing the efficacy of Ruxolitinib to historical controls in second-line or beyond treatment for chronic GvHD after steroid failure.

Established first-line therapy for chronic graft-versus-host disease (cGvHD) comprises corticosteroids with/without calcineurin inhibitors, but about half of cGvHD patients are refractory to corticosteroid therapy. The present study retrospectively analyzed treatment outcomes in 426 patients and undertook a propensity-score matching (PSM) analysis between ruxolitinib (RUX) treated group and a historical group of cGvHD patients treated with best available treatment (BAT). PSM process adjusted unbalanced risk factors between the 2 groups, including GvHD severity, HCT-CI score, and treatment line, extracting 88 patients (44 in BAT/RUX groups each) for final analysis. In PSM subgroup, RUX group showed 74.7% 12 months' FFS rate vs 19.1% for BAT group (p < 0.001), whereas 12 months' OS rates were 89.2% and 77.7%, respectively. Multivariate analysis for FFS confirmed RUX superiority over BAT together with HCT-CI score 0-2 vs ≥3. For OS, RUX was superior to BAT, while age ≥60 years and severe grade cGvHD adversely impacted OS. In PSM subgroup, at months 0, 3, and 6, 4.5%, 12.2% and 22.2% more patients in RUX group could discontinue prednisone compared to BAT group, respectively. In conclusion, the current study showed that for FFS, RUX was superior to BAT as second-line therapy or beyond in cGvHD patients after therapy failure.