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  • 1
    In: Blood, American Society of Hematology, Vol. 134, No. Supplement_1 ( 2019-11-13), p. 3733-3733
    Abstract: Increasing evidence suggests that bone marrow microenvironment act as a sanctuary site for acute myeloid leukemia (AML) cells and provides protection from conventional chemotherapy agents. Recently, extracellular vesicles (EVs) have attracted substantial attention as a carrier of complex intercellular information by transferring microRNA, mRNA and proteins. We undertook a study to delineate the molecular mediators and potential role of extracellular vesicles in stromal microenvironment mediated drug resistance in AML. We performed a series of in vitro experiments with AML cell lines (U937, THP-1, Kasumi-1) and primary cells to evaluate their response to daunorubicin (DNR) and cytarabine (AraC) with stromal cells (HS-5 cell line). Towards this we co-cultured the leukemic cells with stromal cells in a contact dependent and contact independent (transwell plates) system and with EVs derived from HS-5 culture media using well established methods (Suzanne et al, Blood 2015). The percentage of viability was calculated using Annexin V/7AAD staining by flow cytometry. Gene expression profiling was done using Agilent Human Whole Genome 8x60K Gene Expression Array. The quantification of extracellular vesicle was performed using NanoSight LM10. Direct stromal co-culture experiments with AML cells demonstrated a significant stromal cell mediated protective effect against AraC and DNR in cell lines (figure 1A) and primary cells [AraC p 〈 0.01; DNR p 〈 0.001 (n=50)]. A similar significant protective effect was also seen in contact independent system and EVs alone treated leukemic cells (supplemented in place of HS-5 co-culture). Gene expression profiling analysis of leukemic cells (U937) and stromal cell (HS-5) post co-culture revealed a bidirectional enrichment of genes involved in extracellular vesicle biogenesis and secretion (p 〈 0.001) along with a significant dysregulation of PI3K-AKT signaling in leukemic cells. We have previously reported that stromal EVs activates PI3K-AKT signaling and mediates drug resistance in leukemic cells similar to direct stromal co-culture (Blood 2017 130:1160). In addition to PI3K-AKT signaling, our qPCR validation also confirmed the significant up regulation of genes which are involved in EVs secretion (RAB27A, RAB35 and VAMP7) in leukemic cells as well as stromal cells post co-culture (figure 1B). Hence, we quantified the amount of EVs production in leukemic and stromal cells post 48hrs of co-culture where the number of EVs showed a trend towards increase in co-cultured leukemic and stromal cells when compared to the cells cultured alone (figure 1C). We also noted that treatment with neutral sphingomyelinease inhibitor GW4869 a known inhibitor of EVs secretion was able overcome the stroma mediated drug resistance significantly in leukemic cell lines (figure 1D) and also in primary AML cells [AraC p 〈 0.01; DNR p 〈 0.001 (n=6)]. Our results illustrate that reciprocal interaction of leukemic and stromal cells influences the secretion of extracellular vesicles and plays a significant role in mediating drug resistance. We further demonstrated that inhibiting extracellular vesicles secretion was able to overcome the stromal microenvironment mediated drug resistance in AML illustrating a potentially novel therapeutic strategy. Additional studies are required to explore and characterize the cargo (microRNA and proteins) in detail of these EVs and the mechanism/s by which they mediate drug resistance. Disclosures No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2019
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
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  • 2
    In: Bone Marrow Transplantation, Springer Science and Business Media LLC, Vol. 58, No. 2 ( 2023-02), p. 160-167
    Type of Medium: Online Resource
    ISSN: 0268-3369 , 1476-5365
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    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2023
    detail.hit.zdb_id: 2004030-1
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  • 3
    In: Cell Transplantation, SAGE Publications, Vol. 32 ( 2023-01)
    Abstract: Refractory acute myeloid leukemia (AML), defined as failure of two cycles of induction therapy at diagnosis or of one cycle at relapse, represents a subgroup with poor outcomes. Haploidentical natural killer cell (NK) therapy is a strategy that is being explored in refractory malignancies. Historically, at our center, patients with refractory AML have been treated with cytoreductive therapy (fludarabine + cytosine + granulocyte colony-stimulating factor ± idarubicin or mitoxantrone + etoposide) followed by 1-week rest and then reduced-intensity transplant with fludarabine + melphalan. We used the same backbone for this trial (CTRI/2019/02/017505) with the addition of CD56-positive cells from a family donor infused 1 day after the completion of chemotherapy. CD56-positive selection was done using a CliniMACS Prodigy system (Miltenyi Biotec, Bergisch Gladbach, Germany) followed by overnight incubation in autologous plasma with 2 micromolar arsenic trioxide and 500 U/mL of interleukin-2. From February 2019, 14 patients with a median age of 29 years (interquartile range [IQR]: 16.5–38.5) were enrolled in this trial. Six were females. Six had primary refractory AML while eight had relapsed refractory AML. The median CD56-cell dose infused was 46.16 × 106/kg (IQR: 25.06–70.36). One patient withdrew consent after NK cell infusion. Of the 13 patients who proceeded to transplant, five died of immediate post-transplant complications while two did not engraft but were in morphologic leukemia-free state (both subsequently died of infective complications after the second transplant). Of the remaining six patients who engrafted and survived beyond 1 month of the transplant, two developed disease relapse and died. The remaining four patients are alive and relapse free at the last follow-up (mean follow-up duration of surviving patients is 24 months). The 2-year estimated overall survival for the cohort was 28.6% ± 12.1% while the treatment-related mortality (TRM) with this approach was 38.5% ± 13.5%. Haploidentical NK cell therapy as an adjunct to transplant is safe and needs further exploration in patients with AML. For refractory AML, post-transplant NK infusion and strategies to reduce TRM while using pre-transplant NK infusion merit exploration.
    Type of Medium: Online Resource
    ISSN: 0963-6897 , 1555-3892
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2023
    detail.hit.zdb_id: 2020466-8
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  • 4
    In: Blood, American Society of Hematology, Vol. 124, No. 21 ( 2014-12-06), p. 2462-2462
    Abstract: Management of acute myeloid leukemia (AML) in India remains a challenge. A major constraint is the cost of therapy. In a predominantly self paying system the majority of patients will not have the resources to manage a subsequent relapse. Hence, the choice of consolidation therapy has to be carefully considered to balance cost and efficacy. An allogeneic SCT (alloSCT) with a reduced intensity conditioning regimen (RIC) in first remission (CR1) is an attractive option to fulfill these requirements of relatively low cost without compromising efficacy. The need for consolidation chemotherapy prior to offering a RIC alloSCT for AML CR1 remains controversial. To evaluate these aspects we undertook a retrospective analysis of patients with AML CR1 who received a RIC alloSCT from multiple centers in India. Conventional criteria were used for definition of conditioning regimens to be considered RIC (CIBMTR). Data from 8 centers in India was collected between 2005 and 2013. A total of 138 patients fulfilled the criteria of AML CR1 having received an alloSCT with a RIC regimen. The median age was 34 years (range: 2 – 63) and 60% were males. The median time from diagnosis of AML to transplant was 99 days (range: 41 – 504). 123 (89%) were HLA matched related donors, 3 (2.1%) were MUD transplants and the rest were HLA mismatched related donors. The majority by cytogenetics (n=115) were intermediate risk (76%) followed by high risk (23%). 70 (51%) received chemotherapy consolidation prior to transplant, 61 (44%) did not and data was not available in 7 (5%). 68% of those that received consolidation received intermediate or low dose cytosine based regimens. 129 (94%) were CMV serology positive pre-transplant. Fludarabine with melphalan (140mg/m2) (128{93%}) was the most commonly used regimen and cyclosporine with short course low dose methotrexate (126{91%}) the most commonly used GVHD prophylaxis regime. All patients received a PBSC graft with a median CD34 cell dose of 9.1x106/kg (range: 1.3 – 43). With the exception of one, all patients engrafted. The median time to ANC 〉 500/mm3 was 13 days (range: 7 – 22) and platelet count of 〉 20,000/mm3 was 15 days (range: 0-33). Of those that engrafted, 97% achieved complete chimerism at one month post transplant (data not available in 4). Post transplant CMV reactivation was seen in 32% and a fungal infection (possible, probable or definitive) in 13%. Acute GVHD Grade 2-4 was seen in 29% and of patients evaluated 62% had chronic GVHD, the majority of these being limited (61%). The 100 day treatment related mortality (TRM) was 7.5% and the one year TRM was 25.6%. At a median follow up of 24 months the 5 year EFS and OS was 64.0±5.07 (Figure 1A) and 71.1±4.0 respectively. The 5 year cumulative incidence of relapse was 21.8% (Figure 1A). The baseline characteristics as mentioned above were not significantly different between the group that received consolidation and the group that did not. The use of consolidation therapy prior to alloSCT did not have a significant impact on EFS or OS (Figure 1B). On univariate analysis the factors that adversely impacted EFS were mismatched non sibling family donor (RR 8.1; P-value 0.001), CMV reactivation (RR 2.6; P-value 0.001), fungal infection post transplant (RR 6.8; P-value 0.000) and acute GVHD (RR 2.1; P-value 0.02). On a forward stepwise multivariate analysis adjusting for these and other conventional risk factors only CMV reactivation (RR 2.0; 95% CI 1.03-3.87; P-value 0.042) and fungal infection (RR 7.1; 95%CI 3.154-16.12; P-value 0.000) retained their adverse impact. There was no correlation between CMV reactivation and relapse of disease post transplant. The mean costs of induction chemotherapy for these patients was US$ 9239±3596 (n=74), for consolidation chemotherapy it was 5007±3490 (n=21) and for alloSCT it was 18138±13826 (n=118; costing up to 1 year post transplant). Induction chemotherapy followed by HLA matched RIC alloSCT is likely to be a cost effective and affordable treatment option for young adults with AML in CR1in an Indian context. With an average gross net income in India of US$3500/year (http://indiabudget.nic.in) the limitation still remains the cost of treatment and number of centers that can offer this therapy. Figure 1 Figure 1. Disclosures Srivastava: Octapharma: Consultancy, Other. Off Label Use: Bortezomib in the treatment of acute promyelocytic leukemia.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2014
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
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  • 5
    In: Blood, American Society of Hematology, Vol. 138, No. Supplement 1 ( 2021-11-05), p. 2338-2338
    Abstract: In the setting of clinical trials, high cure rates have been reported for acute promyelocytic leukemia (APL) with the chemotherapy-free combination of arsenic trioxide (ATO) and all-trans retinoic acid (ATRA) for low-intermediate risk disease, and with the addition of gemtuzumab ozogamicin or minimal anthracycline for high-risk disease. Despite clear in-vitro synergy between ATO and ATRA, most clinical trial protocols in APL have not used these drugs concurrently beyond induction. There is limited real world data on the use of chemotherapy-free combination of ATO and ATRA with minimal anthracycline use in the treatment of APL, especially in the high risk group. We did a retrospective analysis of the clinical outcomes of patients with newly diagnosed APL treated at our center from January 2015 to May 2020 using concurrent ATO, ATRA and minimal anthracycline in a risk stratified manner. The data was frozen and analyzed as on 1st June 2021. During the study period, 167 patients were diagnosed to have APL at our hospital. Of these, we excluded 5 patients who had presented with relapsed disease and 28 patients who were treated with single agent ATO. The remaining 134 patients were treated with a uniform protocol as summarized in Figure 1a. Figure 1b shows the KM plot for EFS (2 year: 90.8±2.5%) for these 134 patients. For analysis of regimen safety and efficacy, we excluded patients who wished to pursue treatment elsewhere within the first 1 week of treatment (n=7), and patients who had severe infections or life-threatening bleeding at presentation or before therapy initiation and subsequently died (n=4). Thus, a total of 123 patients with newly diagnosed APL were included for further analysis. The median age was 35 years (IQR: 24 to 45 years). Forty-six (37.4%) were females. The median duration of symptoms prior to admission was 14 days (IQR: 7 to 28 days). Sixty-one (49.6%) had high risk APL while the remaining 62 (50.4%) had low-intermediate risk APL. During induction, 28 (22.7%) patients had major bleeding while 5 (4%) patients developed major thrombosis. Sixty-seven (55%) patients had at least one documented infection during induction therapy. The median number of packed red cell concentrates, fresh frozen plasma, platelet rich concentrates and cryoprecipitates transfused during induction therapy was 5 (IQR: 3 to 6.5), 10 (IQR: 3 to 30), 40 (IQR: 23 to 55) and 6 (IQR: 0 to 18) respectively. Nineteen (15.4%) patients developed differentiation syndrome; all were treated with steroids, 8 required transient cessation of treatment and 6 required intensive care. Eight (6.5%) patients died during induction. During induction, grade 3 hepatotoxicity was noted in 8 (6.5%) patients, 10 (8.1%) patients had ATRA related headache or benign intracranial hypertension of which 5 required transient cessation of ATRA, while 11 (8.9%) patients had transient QTc prolongation of which 6 required transient cessation of ATO. Seventeen (13.8%) patients developed symptomatic sensory neuropathy requiring treatment. None required permanent discontinuation of therapy. At a median follow up of 854 days, there were 2 (1.6%) hematologic relapses and no deaths beyond induction therapy. The 2-year OS and EFS for the cohort (n=123) are 93.4% ± 2.3% and 91.6% ± 2.6% respectively (Figure 1c). Two (1.6%) patients have developed second malignancies. In a real world setting, concurrently administered ATO and ATRA with minimal anthracycline use results in excellent long term survival, even in the high risk group. Early deaths due to delayed presentation with infections and life threatening bleeding remain an unmet need for future research along with the need for strategies to reduce treatment-related toxicities. Figure 1 Figure 1. Disclosures Mathews: Christian Medical College: Patents & Royalties: US 2020/0345770 A1 - Pub.Date Nov.5, 2020; AML: Other: Co-Inventor.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2021
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
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  • 6
    In: Journal of Immunological Methods, Elsevier BV, Vol. 511 ( 2022-12), p. 113375-
    Type of Medium: Online Resource
    ISSN: 0022-1759
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    Language: English
    Publisher: Elsevier BV
    Publication Date: 2022
    detail.hit.zdb_id: 1500495-8
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  • 7
    In: Transplantation and Cellular Therapy, Elsevier BV, Vol. 28, No. 3 ( 2022-03), p. S172-S173
    Type of Medium: Online Resource
    ISSN: 2666-6367
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2022
    detail.hit.zdb_id: 3056525-X
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  • 8
    In: Blood Advances, American Society of Hematology, Vol. 6, No. 2 ( 2022-01-25), p. 652-663
    Abstract: Acquired genetic mutations can confer resistance to arsenic trioxide (ATO) in the treatment of acute promyelocytic leukemia (APL). However, such resistance-conferring mutations are rare and do not explain most disease recurrence seen in the clinic. We have generated stable ATO-resistant promyelocytic cell lines that are less sensitive to all-trans retinoic acid (ATRA) and the combination of ATO and ATRA compared with the sensitive cell line. Characterization of these resistant cell lines that were generated in-house showed significant differences in immunophenotype, drug transporter expression, anti-apoptotic protein dependence, and promyelocytic leukemia-retinoic acid receptor alpha (PML-RARA) mutation. Gene expression profiling revealed prominent dysregulation of the cellular metabolic pathways in these ATO-resistant APL cell lines. Glycolytic inhibition by 2-deoxyglucose (2-DG) was sufficient and comparable to the standard of care (ATO) in targeting the sensitive APL cell line. 2-DG was also effective in the in vivo transplantable APL mouse model; however, it did not affect the ATO-resistant cell lines. In contrast, the resistant cell lines were significantly affected by compounds targeting mitochondrial respiration when combined with ATO, irrespective of the ATO resistance-conferring genetic mutations or the pattern of their anti-apoptotic protein dependency. Our data demonstrate that combining mitocans with ATO can overcome ATO resistance. We also show that this combination has potential for treating non-M3 acute myeloid leukemia (AML) and relapsed APL. The translation of this approach in the clinic needs to be explored further.
    Type of Medium: Online Resource
    ISSN: 2473-9529 , 2473-9537
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2022
    detail.hit.zdb_id: 2876449-3
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  • 9
    In: Blood, American Society of Hematology, Vol. 134, No. Supplement_1 ( 2019-11-13), p. 1306-1306
    Abstract: Introduction Acute lymphoblastic leukemia (ALL) diagnosed in adolescent and young adults (AYA) poses unique challenges. Despite using more intensive "pediatric-type" protocols, outcomes are generally inferior to those seen in children. The reasons are wide ranging, but when compared to pediatric ALL, AYA ALL has higher-risk biology, poorer tolerance to intensive treatments, and worse compliance with treatment regimens. India has one of the largest AYA populations in the world and AYA-ALL form a significant proportion of leukemias. The Indian acute leukemia research database [INwARD] was established in 2018 and had reported outcomes of ALLs from various centers of all age groups (Korula A, et al. Blood 2018 132:1374). Here, we present data focused on AYA-ALL from this database. Methods Retrospective data of AYA (15-29 years) patients with ALL (diagnosed between January 2012 to December 2017) from 9 centers were entered into an independent centralized online data capture system and analyzed for presenting characteristics, treatment and survival outcomes. Protocol choice was based on individual-center preference. For the purpose of this analysis, patients with WBC ≥30000 (B cell) and ≥100,000 (T-cell and other subtypes) were considered as high risk. Intensive protocols (MCP-841, BFM-95, COG), predominantly meant for children were labeled as "pediatric-type" and less intense protocols (GMALL, Hyper CVAD, UKALL) were considered as "adult-type". Results In the 6-year period, 1454 patients were registered [Males: 1114(76%), Median age: 20 years (15-29), Fig. 1.B; Subtype: B -ALL: 916(63%), T-ALL: 396 (27%); Fig. 1.C; High risk disease: 406 (28%)]. Of these,1100 (75%) underwent treatment. Poor financial support was the major reason for not taking treatment (Fig. 1.A). "Pediatric-type" protocols were used in 881 (81%) patients. After induction, 72% achieved complete remission (CR), 11% were refractory, 4% died during induction and 14% were not evaluable. Minimal residual disease was assessed in 581 and was present in 356 (61%). Attainment of CR, induction mortality, or MRD achievement was not affected by the type of regimen. Among these 1100 patients, 138 (12%) were lost to follow up and did not complete treatment. BCR ABL was tested in 636 and was positive in 112 (17%) [19% among patients with B-ALL (107/557)]and 106 of these were treated with additional tyrosine kinase inhibitors [imatinib (N=83) and dasatinib (N=23)] . Survival analysis: After a median follow up of 21 months, 270 patients relapsed [median time to relapse: 24 months (73% medullary, 17% CNS or testis, and 10% had a combined relapse) and 259 had died. The estimated 2-year event-free (EFS), relapse-free (RFS) and overall survival (OS) were 64%, 75% and 75% respectively. On univariate analysis the factors associated with inferior survival were as follows: EFS: WBC count ≥30,000/cmm, and ECOG PS 2-4; RFS: WBC count ≥30,000/cmm and ECOG PS 2-4; OS: use of "adult-type" protocols, ECOG PS 2-4, and BCR-ABL positive disease. On multivariate cox regression analysis, the only factors associated with inferior OS were: use of "adult" protocols (HR: 1.6), and BCR -ABL positive status (HR1.56) (Fig. 1.D). High WBC count at presentation predicted for inferior RFS while no factor could predict EFS on multivariate analysis. Conclusions In a multicenter analysis of AYA-ALL from different parts of India, we found that a quarter of newly diagnosed patients do not start treatment and another 12% are lost from follow up before treatment completion. Majority (80%) of the centers used "pediatric-type" protocols to treat AYA-ALL. Though superior survival was achieved with "pediatric-type" protocols, results must be interpreted with caution as these regimens were likely to be used more often in in younger patients. Variations in treatment protocols used between centers and the retrospective nature of the data are other caveats. Despite these limitations, this is one of the largest reports of AYA ALL from any part of the world and serves as a benchmark for planning prospective studies. Disclosures No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    RVK:
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2019
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
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  • 10
    In: Biology of Blood and Marrow Transplantation, Elsevier BV, Vol. 21, No. 2 ( 2015-02), p. S298-
    Type of Medium: Online Resource
    ISSN: 1083-8791
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2015
    detail.hit.zdb_id: 3056525-X
    detail.hit.zdb_id: 2057605-5
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