Recurrent Hematologic Malignancies Research Articles

Efficacy and safety of secondary allogeneic hematopoietic stem cell transplantation in 70 patients with recurrent hematologic malignancies after transplantation

Objectives: To investigate the role of donor change in the second hematopoietic stem cell transplantation (HSCT2) for hematological relapse of malignant hematology after the first transplantation (HSCT1) . Methods: We retrospectively analyzed patients with relapsed hematological malignancies who received HSCT2 at our single center between Mar 1998 and Dec 2020. A total of 70 patients were enrolled[49 males and 21 females; median age, 31.5 (3-61) yr]. Results: Forty-nine male and 21 female patients were enrolled in the trial. At the time of HSCT2, the median age was 31.5 (3-61) years old. Thirty-one patients were diagnosed with acute myeloid leukemia, 23 patients with ALL, and 16 patients with MDS or other malignant hematology disease. Thirty patients had HSCT2 with donor change, and 40 patients underwent HSCT2 without donor change. The median relapse time after HSCT1 was 245.5 (26-2 905) days. After HSCT2, 70 patients had neutrophil engraftment, and 62 (88.6%) had platelet engraftment. The cumulative incidence of platelet engraftment was (93.1±4.7) % in patients with donor change and (86.0±5.7) % in patients without donor change (P=0.636). The cumulative incidence of CMV infection in patients with and without donor change was (64.0±10.3) % and (37.0±7.8) % (P=0.053), respectively. The cumulative incidence of grade Ⅱ-Ⅳ acute graft versus host disease was (19.4±7.9) % vs (31.3±7.5) %, respectively (P=0.227). The cumulative incidence of TRM 100-day post HSCT2 was (9.2±5.1) % vs (6.7±4.6) % (P=0.648), and the cumulative incidence of chronic graft versus host disease at 1-yr post-HSCT2 was (36.7±11.4) % versus (65.6±9.1) % (P=0.031). With a median follow-up of 767 (271-4 936) days, 38 patients had complete remission (CR), and three patients had persistent disease. The CR rate was 92.7%. The cumulative incidences of overall survival (OS) and disease-free survival (DFS) 2 yr after HSCT2 were 25.8% and 23.7%, respectively. The cumulative incidence of relapse, OS, and DFS was (52.6±11.6) % vs (62.4±11.3) % (P=0.423), (28.3±8.6) % vs (23.8±7.5) % (P=0.643), and (28.3±8.6) % vs (22.3±7.7) % (P=0.787), respectively, in patients with changed donor compared with patients with the original donor. Relapses within 6 months post-HSCT1 and with persistent disease before HSCT2 were risk factors for OS, DFS, and CIR. Disease status before HSCT2 and early relapse (within 6 months post-HSCT1) was an independent risk factor for OS, DFS, and CIR post-HSCT2. Conclusion: Our findings indicate that changing donors did not affect the clinical outcome of HSCT2.

Editing Mutations of GABRB3 Using CRISPR-Cas9 as a Potential Treatment for Epilepsy and Autism Spectrum Disorders

The treatment of a variety of recurrent or resistant hematologic malignancies with chimeric antigen receptor T cell (CAR- T) cell therapy has seen significant success in recent years. The current CAR- T cell therapy approach is not without flaws, nevertheless, and there are still several issues with clinical treatment, including antigen escape, significant toxicity, and sus-ceptibility to drug-resistant recurrence. This paper introduces the structural development and characteristics of CAR-T cells, reviews the limitations of CAR- T cell therapy, including an-tigen escape, toxicity, CAR-T cell depletion and drug-resistant relapse after treatment, and summarizes the related improvement and optimization strategies. The paper concludes that CAR-T cell immunotherapy has brought new hope to patients with hematologic malignancies, making a cure for refractory and recurrent hematologic malignancies possible. Although CAR-T cell therapy still has many challenges at present, such as immunogenicity, drug re-sistance, and toxicity.

Structural and Research Advances in CAR-T Cell Therapy

The treatment of a variety of recurrent or resistant hematologic malignancies with chimeric antigen receptor T cell (CAR- T) cell therapy has seen significant success in recent years. The current CAR- T cell therapy approach is not without flaws, nevertheless, and there are still several issues with clinical treatment, including antigen escape, significant toxicity, and sus-ceptibility to drug-resistant recurrence. This paper introduces the structural development and characteristics of CAR-T cells, reviews the limitations of CAR- T cell therapy, including an-tigen escape, toxicity, CAR-T cell depletion and drug-resistant relapse after treatment, and summarizes the related improvement and optimization strategies. The paper concludes that CAR-T cell immunotherapy has brought new hope to patients with hematologic malignancies, making a cure for refractory and recurrent hematologic malignancies possible. Although CAR-T cell therapy still has many challenges at present, such as immunogenicity, drug re-sistance, and toxicity.

Inducement of ER Stress by PAD Inhibitor BB-Cl-Amidine to Effectively Kill AML Cells.

Acute myeloid leukemia (AML) is a highly heterogeneous and recurrent hematological malignancy. Despite the emergence of novel chemotherapy drugs, AML patients' complete remission (CR) remains unsatisfactory. Consequently, it is imperative to discover new therapeutic targets or medications to treat AML. Such epigenetic changes like DNA methylation and histone modification play vital roles in AML. Peptidylarginine deminase (PAD) is a protein family of histone demethylases, among which the PAD2 and PAD4 expression have been demonstrated to be elevated in AML patients, thus suggesting a potential role of PADs in the development or maintenance of AML and the potential for the identification of novel therapeutic targets. AML cells were treated in vitro with the pan-PAD inhibitor BB-Cl-Amidine (BB-Cl-A). The AML cell lines were effectively induced into apoptosis by BB-Cl-A. However, the PAD4-specific inhibitor GSK484 did not. PAD2 played a significant role in AML. Furthermore, we found that BB-Cl-A could activate the endoplasmic reticulum (ER) stress response, as evidenced by an increase in phosphorylated PERK (p-PERK) and eIF2α (p-eIF2α). As a result of the ER stress activation, the BB-Cl-A effectively induced apoptosis in the AML cells. Our findings indicated that PAD2 plays a role in ER homeostasis maintenance and apoptosis prevention. Therefore, targeting PAD2 with BB-Cl-A could represent a novel therapeutic strategy for treating AML.

Efficacy and safety of Venetoclax in the treatment of 25 patients with recurrent hematologic malignancies after an allogeneic hematopoietic stem cell transplantation

目的观察维奈克拉（VEN）治疗异基因造血干细胞移植（allo-HSCT）后复发恶性血液病患者的疗效及安全性。方法回顾性分析2021年2月至2021年11月在中国医学科学院血液病医院接受VEN治疗的25例allo-HSCT后复发患者的临床资料，其中微小残留病（MRD）阳性患者15例（抢先治疗组），形态学复发患者10例（挽救治疗组）。两组VEN剂量均为400 mg/d，联合唑类抗真菌药物时减量至100 mg/d。结果①抢先治疗组男7例，女8例，中位年龄32（18～52）岁；急性髓系白血病（AML）13例，急性淋巴细胞白血病（ALL）1例，原发性骨髓纤维化（PMF）1例；MRD阳性至应用VEN中位时间为2.5（0～12.5）个月。VEN中位疗程数为2（1～4）个。第1疗程治疗第7天VEN中位血药浓度为1 945（688～5 383）µg/L。VEN治疗1疗程后8例患者MRD转为阴性（获得主要反应），4例MRD较治疗前下降50％，3例无效，总体反应率（ORR）为80％（12/15）。9例治疗第7天VEN血药浓度<1 000 µg/L或>3 000 µg/L患者中3例（33.3％）MRD转阴，6例VEN血药浓度1 000～3 000 µg/L患者中5例（83.3％）MRD转阴。5例患者出现3/4级中性粒细胞减少，5例患者出现3/4级血小板减少，无新发严重感染致死病例。②挽救治疗组男7例，女3例，中位年龄44（28～59）岁；AML 6例，ALL 2例，不典型慢性髓性白血病（aCML）1例，骨髓增生异常综合征难治性血细胞减少伴有多系发育异常（MDS-RCMD）1例；复发至应用VEN中位时间为0（0～1）个月；VEN中位疗程数为1（1～2）个；第1疗程治疗第7天VEN中位血药浓度为2 419（1 200～6 155）µg/L。VEN治疗1疗程后3例获得完全缓解（CR）（主要反应），3例获得部分缓解（PR），4例无效，ORR为60％（6/10）。4例治疗第7天VEN血药浓度>3 000 µg/L患者中1例获得CR，6例VEN血药浓度1 000～3 000 µg/L患者中2例获得CR。10例患者均出现3/4级中性粒细胞减少及3/4级血小板减少。1例患者因严重肺感染死亡。③中位随访4.5（1～8.5）个月，抢先治疗组、挽救治疗组总生存（OS）率分别为（70.2±12.7）％、（50.0±15.8）％（χ2＝1.873，P＝0.171）。1疗程VEN治疗获得主要反应、未获得主要反应患者的OS率分别为（90.9±8.7）％、（36.2±14.7）％（χ2＝6.843，P＝0.009）。3例存在TP53突变的患者在VEN治疗后均获得主要反应。结论应用VEN对allo-HSCT后复发的恶性血液病患者进行抢先/挽救治疗有一定疗效且耐受性良好，监测VEN血药浓度有望提高疗效。VEN抢先/挽救治疗1个疗程未获得主要反应的患者预后较差，需尽早转换其他治疗方案。

Sustained Immunogenic and Clinical Effects of Low-Dose Interleukin-2 Therapy with an Intermittent Maintenance Method for Refractory Chronic Graft-Versus-Host Disease: Results of Phase1/2a LDIL2-01 Study

Introduction and Objectives Regulatory T cells (Treg) play a central role in the maintenance of immune tolerance. We previously reported that the altered Treg homeostasis in the prolonged lymphopenia after HSCT is one of the major pathogenesis of impaired Treg recovery leading to the onset of chronic GVHD and low-dose IL-2 can restore normal Treg homeostasis by a PD-1-dependent mechanism, resulting in the improvement of clinical GVHD symptoms. In these years, the tolerogenic effects of IL-2 have been tested for various autoimmune diseases by clinical trials. However, the schedules of IL-2 dosing in each trial are different and the optimal strategy to expand Treg is still unclear. Our murine study has shown that daily administration of IL-2 seems to be optimal for the initial expansion of Treg but less frequent dosing within the threshold could be preferable for the following maintenance of expanded Treg. Methods Based on the findings, we conducted a phase1/2a clinical trial of low-dose IL-2 for steroid-refractory chronic GVHD with a distinctive dosing schedule consisting of an initial induction phase (IL-2 dosing everyday for the first 4 weeks) and a subsequent maintenance phase (IL-2 dosing 3 times a week for the following 8 weeks). Patients who obtained clinical benefit by the 3 months could proceed to the extended therapy up to total 12 months. The appropriate single dose of IL-2 was examined by a three-step dose escalation design. Results A total of 12 patients were enrolled. None had progression of chronic GVHD or recurrent hematologic malignancy. Dose-limiting toxicity did not occur even at the maximum dose. All patients were evaluable for response, and 7 had clinically significant responses involving multiple sites. Response was observed most often in the joints (67%). One patient with oral GVHD and another patient with gastrointestinal GVHD achieved complete response. One patient with severe lung GVHD markedly improved pulmonary functional test (%FEV1; from 24.8% to 64.8 %) and activity of daily life (from bedridden to return to work). Treg were preferentially increased in all patients, with a peak median value almost 10 times the baseline value (P Conclusion These results indicate that the sustained efficacy of IL-2 against chronic GVHD does not necessarily require that Treg is maintained at a high level by continuing daily IL-2 administration over the long term. Our data provide important information for reconsidering IL-2 dosing methods from the viewpoint of long-term safety and possible combination with other treatments.

Outcomes of renal transplantation in patients with previous hematologic malignancies

Recommendations regarding the appropriateness of renal transplantation in patients with prior hematologic malignancies are limited. Given the lack of available data, studies are needed to assess which of these patients will maximally benefit from renal transplantation. This study was undertaken to describe the incidence of new or recurrent malignancy as well as patient and allograft survival, acute rejection, and serious infections in patients with prior hematologic malignancies receiving renal transplantation. This was a single center retrospective review of all adult patients with a previous hematologic malignancy who received a living or deceased renal transplantation between January 2009 and January 2016. Eight renal transplantation recipients with prior hematologic malignancies were identified and followed for a minimum of 3 years. Six patients received prior chemotherapy and five had a prior hematopoietic stem cell transplant. Median time from remission to transplant was 2.6 years. Three-year patient and allograft survival were 87% and 75%, respectively. Three patients were diagnosed with new cancers within 3 years post-renal transplantation; one of which died from cancer-related complications with a functioning allograft. There was concern for recurrent hematologic malignancies in two patients based on serologic studies, but, both of these patients were alive with functioning allografts at 3-year follow-up. Our experience suggests that renal transplantation can be successfully performed in select patients with prior hematologic malignancy but with a significant risk for de novo malignancy post-transplant, which may be associated with an overall poor prognosis. Decisions regarding renal transplantation candidacy should be made based on risk stratification and multidisciplinary discussions with patients, hematologists, and transplant providers.

Transcriptome analysis identifies key regulators and networks in Acute myeloid leukemia

ABSTRACTObjectives: Acute myeloid leukemia (AML) is a heterogeneous and highly recurrent hematological malignancy. Studies have shown an association between microRNAs and drive genes in AMLs. However, the regulatory roles of miRNAs in AML and how they act on downstream targets and the signaling pathway has been little studied.Methods: As to understand the mechanism of mRNA-miRNA interaction in the blood malignancy from a large scale of transcriptomic sequencing studies, we applied a comprehensive miRNA-mRNA association, co-expression gene network and ingenuity pathway analysis using TCGA AML datasets.Results: Our results showed that his-mir-335 was a critical regulatory of homeobox A gene family. PBX3, KAT6A, MEIS1, and COMMD3-BMI1 were predicted as top transcription regulators in the regulatory network of the HOXA family. The most significantly enriched functions were cell growth, proliferation, and survival in the mRNA-miRNA network.Conclusion: Our work revealed that regulation of the HOXA gene family and its regulation played an important role in the development of AML.

Sequential Infusion of Tcrαβ- and CD45RA-Depleted Haploidentical Progenitor Cells Is Safe and Allows for Rapid Immune Reconstitution in Pediatric Patients with Recurrent Hematological Malignancies

Background: Haploidentical hematopoietic cell transplantation (haploHCT) is an attractive option for patients, who have no suitable matched-related or -unrelated donor. While the increased alloreactivity of haploidentical grafts enhances graft-vs-leukemia effects, it also increases the risk of acute graft-vs-host disease (aGVHD). Therefore, extensive in vivo or ex vivo T-cell depletion is required to reduce the incidence of severe aGVHD. However, global T-cell depletion is associated with delayed immune recovery, serious viral infections, and relapse. To overcome this limitation, selective TCRɑß and CD45RA T-cell depletion was developed. Both aim to remove alloreactive T-cell subsets, and initial clinical experience has demonstrated the feasibility and safety of each individual approach. We reasoned that combining both approaches might further increase immune reconstitution and bolster graft-vs-leukemia effects. We therefore designed an early phase clinical study, NCT02790515, to evaluate the safety and efficacy of infusing two haploidentical allografts, one TCRɑß T-cell depleted and one CD45RA T-cell depleted, in pediatric patients with very-high risk hematological malignancies, who had recurrent disease after a previous allogeneic HCT.Methods: Patients received their second (n=16) or third (n=2) allogeneic HCT utilizing TCRαβ-depleted and CD45RA-depleted haploidentical donor progenitor cell grafts following conditioning with rabbit ATG (5mg/kg), fludarabine(150mg/m2), cyclophosphamide(60mg/kg), thiotepa(10mg/kg), and melphalan(120mg/m2) on an IRB and FDA approved single institution protocol. Tacrolimus (n=5) or sirolimus (n=13) was given for post HCT GVHD prophylaxis. At the time of HCT, 6 patients remained refractory with active disease and 9 more were in morphologic remission but had detectible minimal residual disease (MRD).Results: The conditioning regimen and progenitor cell infusions were well tolerated without dose limiting toxicities. Patients received a median T-cell dose of 11.9x106/kg (including 0.01x106 TCRαβ T cells/kg; range: 0.00-0.09) with the TCRαβ-depleted graft, and a median T-cell dose of 50.3x106/kg (including 0.00x106 CD45RA+ T-cells/kg; range: 0.00-0.02) with the CD45RA-depleted graft. All patients experienced rapid donor engraftment, with median neutrophil engraftment on Day +11 (range: 10-12). At Day +30, the median T-cell count was 91.5 TCRγδ T-cells/µl and 263 CD45RO+ (memory) T-cells/µL (range 0-2,286; Table 1). The frequency of regulatory T-cells (Tregs) was significantly (p<0.05) increased at Day +30 in patients who received sirolimus, with a median concentration of 17 cell/µl (range 1-67), compared to patients treated with tacrolimus (median: 2.5 cell/µl; range: 1-13). Four of 5 patients, who received tacrolimus prophylaxis, developed Grade III-IV GVHD, all of which occurred after tacrolimus was stopped either as per protocol (Day +60; n=2) or due to drug-toxicity (n=2). To date, only 2 of 13 patients who received sirolimus prophylaxis have developed grade III-IV GVHD, with 10 patients being at least 100 days post haploHCT. Fourteen patients remain alive with a median follow up of 347 days (range 61-727). One patient died of treatment related causes (Day +370), and 3 patients died of progressive disease (Days +144, 233, and 321).Conclusion: Our results indicate that TCRɑß- and CD45RA-depletion can be safely combined in the haploHCT setting, allowing for rapid engraftment and immune reconstitution, with a low incidence of aGVHD using sirolimus prophylaxis. Overall survival is encouraging (78%) at a median follow up of 11½ months in this high-risk population receiving 2nd/3rd allogeneic HCT, warranting further active exploration of our modified approach to haploHCT. [Display omitted] DisclosuresTriplett:Miltenyi Biotec: Other: Travel Support, to present previously published work at EBMT symposium.

Abnormal Coagulation Function in Chimeric Antigen Receptor T Cell Treatment of Hematologic Malignancies

Chimeric Antigen Receptor T cell( CAR-T) is an effective treatment for refractory recurrent hematologic malignancies nowdays. However, CAR T cells can potentially damage normal tissues by specifically targeting a tumor-associated antigen that is also expressed on those tissues. Cytokine release syndrome (CRS), a systemic inflammatory response caused by cytokines, is the most common type of toxicity, including fever, hyoxemia, pain and so on. In our study, we found 6 cases abnormal coagulation function which was not very common complication after CAR-T infusion. 4 cases relapsed/refractory acute B lymphoblastic leukemia(B-ALL), including 2 female 53 and 45 years old, 2 male 20 and 6 years old. 1 case multiple myeloma(MM), female 65 years old and 1 case relapsed/refractory diffuse large B-cell lymphoma (DLBCL), male 17 years old. After conditioning chemotherapy with fludarabine and cyclophosphamide, CAR-T cells were infused into patients. In these cases, female 65 years old B-ALL patient had the most severe cytokine release reactions, multiple organ function damage, and abnormal coagulation function that prothrombin time (PT) and activated partial thromboplastin time (APTT) were prolonged and reached a peak (Too long to detect) on the 14th day after CAR-T infusion, while fibrinogen (FIB) was reduce d (peak on the 14 day, 0.328g/L) and D-Dimer, fibrinogen degradation products (FDP) significantly increased (peak on the 12th day, 28.7ug/mL and more than 10mg/L respectively). After positive hemostasis and other treatments with amperenic acid, vitamin K1 and so on, the level of PT, APTT, FIB, etc were returned to normal on the 19thday. The other 5 patients went through the same process, only slightly. Patients with severe abnormal coagulation function were prone to bleed and even life-threatening, and giving active treatment, finally they all recovered. For the first time, we reported the abnormal coagulation function after CAR-T infusion in hematologic malignancies. DisclosuresNo relevant conflicts of interest to declare.

The Potential Roles and Advantages of Single Cell Sequencing in the Diagnosis and Treatment of Hematological Malignancies.

Hematological malignancies (HM) are a heterogeneous group of life-threatening hematological diseases. The heterogeneity and clonal evolution of HM subpopulations are the main obstacles for precise diagnoses, risk stratification, and even targeted therapies. Standard bulk-sample genomic examinations average total mutations from multiple subpopulations and conceal the clonal diversity that may play a significant role in HM progression. Therefore, the development of novel methods that detect intra-tumor heterogeneity is critical for the discovery of novel potential therapeutic targets. The recently developed single cell sequencing (SCS) technologies can analyse genetic polymorphisms at a single cell level. SCS requires the precise isolation of single cells and amplification of their genetic material. It allows the analysis of genomic, transcriptomic, and epigenomic information in single cancer cells. SCS may also be able to monitor minimal residual disease (MRD) of HM by sequencing circulating tumor cells (CTCs) from peripheral blood. Functional heterogeneity and clonal evolution exist in acute leukemia, multiple myeloma (MM) and chronic myeloid leukemia (CML) subpopulations and have prognostic value. In this thesis, we provide an overview of SCS technologies in HM and discuss the heterogeneous genetic variation and clonal structure among subpopulations of HM. Furthermore, we aimed to shed light on the clinical applications of SCS technologies, including the development of new targeted therapies for drug-resistant or recurrent HM.

New strategies of DLI in the management of relapse of hematological malignancies after allogeneic hematopoietic SCT

DLI is an effective strategy for patients with recurrent hematological malignancies after allogeneic hematopoietic SCT (allo-HSCT). DLI has been widely applied to boost the graft vs tumor (GVT) or GVL effects. However, given the potentially severe complications associated with conventional DLI and transient GVL effect, new strategies for DLI are emerging. In this review, we have discussed the recent important studies on DLI as a prophylactic or therapeutic modality for relapsed hematological disorders after allo-HSCT. The strategies to separate GVL from GVHD have also been discussed. Leukemia-targeting therapy and lymphodepletion combined with DLI, and prophylactic DLI after allo-HSCT are often employed for patients with high risk of relapse, which has been reviewed as well. In addition, we have also discussed the issues on DLI to be further addressed, such as the doses, timing and frequency of DLI in different clinical settings, leukemic antigen-specific DLI as well as how to augment GVL effect while attenuating GVHD.

A Phase I Dose Finding Study of Panobinostat in Children with Hematologic Malignancies: Initial Report of TACL Study T2009-012 in Children with Acute Leukemia

Background: Approximately 3540 children are diagnosed with leukemia in the United States yearly (Bhatia and Robison, Oncology of Infancy and Childhood, 2008). Cooperative group trials have increased survival, particularly for acute lymphoblastic leukemia (ALL), but successful treatment of recurrent leukemia remains an unmet medical need. Resistance pathways and epigenetic alterations suggest a role for histone deacetylase (HDAC) inhibitors in children with leukemia (Burke and Bhatla, Frontiers in Pediatrics, 2014). Panobinostat is an orally administered pan-deacetylase inhibitor with activity against HDACs at concentrations in the nanomolar range (Atadja, Cancer Letters, 2009), and for which there is pre-clinical evidence of activity in pediatric leukemia (Stubbs, et al., ASH 2010). Panobinostat shows promise in a variety of adult hematologic malignancies (Khot et al., Expert Opinion on Investigational Drugs, 2013). We undertook a phase I trial of panobinostat in children with recurrent hematologic malignancies, and herein report the safety and pharmacokinetics (PK) from enrolled children with leukemia.Methods: T2009-012 is a first-in-child study coordinated by Therapeutic Advances in Childhood Leukemia and Lymphoma (TACL). Children with relapsed or refractory leukemia between the ages of 1 and 21 years were enrolled to a multi-center, single agent trial of panobinostat dosed once per day three days per week for four successive weeks. Dose escalation was a standard 3+3 design with three dose levels planned. Subjects underwent lumbar puncture with prophylactic chemotherapy at treatment start and after a 28 day course. Blood was sampled pre-dose, at 0.5, 1, 6, 24 and 28-48 hours following the first dose. PK was obtained from blood on patients concurrently with optional specimens obtained from cerebrospinal fluid (CSF) on Day 29. Subjects who received fewer than 11 of the 12 planned doses and did not experience a dose limiting toxicity (DLT) were considered not evaluable for DLT, but were included in the summary of toxicities. Serial ECGs were monitored.Results: Seventeen subjects were enrolled with a diagnosis of acute leukemia, 10 with ALL and 7 with acute myelogenous leukemia (AML). Five were enrolled at dose level 1, 24 mg/m2/dose, 6 at dose level 2, 30 mg/m2/dose, and 6 at dose level 3, 34 mg/m2/dose. There have been no DLTs. Nine subjects are evaluable for DLT and 4 subjects were taken off study early due to increasing blast count. No subjects required removal from protocol therapy for QTc prolongation. One subject with infant ALL was removed early for progressive Aspergillus infection, 1 subject only received 10 doses owing to electrolyte abnormalities, and 2 subjects had nausea and vomiting after administration of 4 doses and did not continue. Grade 3/4 adverse events occurring in more than 20% of subjects included anemia in 82%, diarrhea in 24%, febrile neutropenia in 65%, hypokalemia in 41%, and hypophosphatemia in 24%. Concentration-time profiles were obtained from 9 subjects ages 16 months to 14 years in the 3 dose levels. Mean ± SE of PK for all subjects were Cmax 28.8 ± 6.1 ng/mL, Tmax 2.0 ± 0.8 hours, and T1/2 12.8 ± 3.0 hours. Two toddlers had the highest dose-normalized AUC0-inf and lowest oral clearance. Apparent oral clearance proportionally increased with increase in BSA. To date, 4 CSF specimens have been evaluated and found to have panobinostat below the lower limit of the quantification of 0.1 ng/mL, despite appreciable levels in the plasma. Two subjects on dose level two began a second cycle of therapy; one completed a second cycle for MLL rearranged leukemia and one discontinued study participation in the second cycle to undergo hematopoietic stem cell transplant for secondary AML after achieving a CRp in the first cycle.Conclusions: Panobinostat was tolerated these heavily pre-treated patients without unanticipated toxicities. PK in larger children and adults appears similar but PK in smaller children needs to be further explored. Penetration of panobinostat into the CSF was negligible. Two of 17 patients were able to receive a second cycle of therapy, but 4 had to be withdrawn early because of rapid increase in blast counts. Future trials will explore combination therapy in children with refractory hematologic malignancies, particularly those known to be driven by epigenetic mechanisms, in order to better control risk of rapid progression and improve efficacy through synergy. DisclosuresOff Label Use: panobinostat for leukemia. Manley:Seattle Genetics, Inc.: Employment, Equity Ownership. Thomson:Epizyme, Inc: Employment.

Abstract B70: Modification of hematopoietic stem cells with CD19-specific chimeric antigen receptors as a novel approach for cancer immunotherapy

Abstract Pediatric patients with recurrent B-lineage hematological malignancies have less than 50% of chance of cure, despite intensive therapy. Chimeric Antigen Receptors (CARs) redirect immune cells to tumor-associated antigens. CD19 is proposed as target because its B-lineage restriction and expression in the majority of hematological malignancies. Current clinical trials use CD19-specific CAR-modified T-cells, but the effector cells are only transiently present. The main hypothesis is that modification of hematopoietic stem cells (HSCs) with anti-CD19 CAR will generate persistent anti-leukemic activity through production of multilineage effectors. Gene transfer did not impair HSC differentiation and proliferation when transduced at 1-2 copies/cell. CAR-bearing myeloid and NK cells specifically lysed CD19-positive targets, with second-generation CAR including CD28 domains being more efficient in NK cells. CAR-modified human HSCs engrafted in NSG mice, producing functional cell progenies. Furthermore, ex vivo leukocytes presented antigen-specific target lysis, and animals engrafted with CAR-modified cells presented inhibition or elimination of CD19-positive tumors, and consequent survival advantage. First-generation CAR did not present tumor development inhibition or survival advantage when compared to non-modified HSCs, confirming that the addition of co-stimulatory moieties to the CAR construct is necessary for effectiveness. This approach is untested in cancer immunotherapy, implies the use of a patient's own cells, and can be applied to different cancers just by adjusting the target specificity. It bears the possibility of decreased morbidity and mortality, being desirable for vulnerable populations such as children, and offers alternative treatment for patients with no available HLA-matched sources for bone marrow transplantation, benefiting ethnic minorities. Citation Format: Satiro N. De Oliveira, Christine Ryan, Jennifer Wherley, Andy Tu, David Elashoff, Laurence JN Cooper, Roger P. Hollis, Donald B. Kohn. Modification of hematopoietic stem cells with CD19-specific chimeric antigen receptors as a novel approach for cancer immunotherapy. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr B70.

Donor Lymphocyte Infusion for Relapsed Hematological Malignancies after Allogeneic Hematopoietic Cell Transplantation: Prognostic Relevance of the Initial CD3+ T Cell Dose

The impact of donor lymphocyte infusion (DLI) initial cell dose on its outcome is known in patients with chronic myeloid leukemia but limited in patients with other hematological malignancies. In this retrospective study, we evaluated the effect of initial DLI CD3+ cell dose on graft-versus-host disease (GVHD) and overall survival after DLI given for relapse of any hematological malignancies after allogeneic hematopoietic cell transplantation (HCT) with high- or reduced-intensity conditioning. The cohort included 225 patients. Initial DLI CD3+ cell dose per kilogram of recipient body weight was ≤1 × 107 (n = 84; group A), >1.0 to <10 × 107 (n = 58; group B), and ≥10 × 107 (n = 66; group C). The initial cell dose was unknown for the remaining 17 patients. Cumulative incidence rates of GVHD at 12 months after DLI were 21%, 45%, and 55% for groups A, B, and C, respectively. Multivariate analysis showed that initial DLI CD3+ cell ≥10 × 107 dose per kilogram is associated with an increased risk of GVHD after DLI (P = .03). Moreover, an initial DLI CD3+ cell dose of 10 × 107 or higher did not decrease the risk of relapse and did not improve overall survival. Thus, these results support the use of less than 10 × 107 CD3+ cell per kilogram as the initial cell dose of DLI for treatment of persistent or recurrent hematological malignancy after HCT.

Rehabilitation in Advanced, Progressive, Recurrent Cancer: A Randomized Controlled Trial

ContextTwo million people across the U.K. are living with cancer, often experienced as a long-term condition. They may have unmet needs after active treatment. Rehabilitation aims to address these needs, maximize psychological and physical function, and enable minimum dependency regardless of life expectancy. ObjectivesWe aimed to test, in a randomized controlled trial, the clinical and cost effectiveness of a rehabilitation intervention for patients with advanced, recurrent cancer. MethodsWe conducted a two-arm, wait-list control, randomized trial of a complex rehabilitation intervention delivered by a hospice-based multidisciplinary team vs. usual care for active, progressive, recurrent hematological and breast malignancies, with a follow-up at three months. The primary outcome was the psychological subscale of the Supportive Care Needs Survey (SCNS). Secondary outcomes were other domains of the SCNS, psychological status, continuity of care, quality of life, and resource use. ResultsForty-one participants were enrolled and 36 completed the trial. The primary outcome was significantly lower in the intervention arm (adjusted difference −16.8, 95% CI −28.34 to −5.3; P = 0.006). The SCNS physical and patient care subscales (−14.2, 95% CI −26.2 to −2.2; P = 0.02 and −7.4, 95% CI −13.7 to −1.1; P = 0.02, respectively) and self-reported health state (12.8, 95% CI 3.2 to 22.4; P = 0.01) also differed significantly. The incremental cost-effectiveness ratio was £19,390 per quality-adjusted life year. ConclusionThis intervention significantly reduced the unmet needs of cancer survivors and it is likely that it is cost-effective. Despite small numbers, the main effect size was robust. We recommend implementation alongside evaluation in wider clinical settings and patient populations.

Donor Lymphocyte Infusion for Relapsed Hematological Malignancies After Allogeneic Hematopoietic Cell Transplantation: Prognostic Relevance of the Initial CD3+ T Cell Dose

AbstractAbstract ▪354▪This icon denotes a clinically relevant abstractRelapse is the leading cause of death after allogeneic hematopoietic cell transplantation (HCT) for hematological malignancies. Relapse after HCT can be treated with donor lymphocyte infusion (DLI). Initial low dose DLI followed by escalating DLI doses has been used to minimize the risk of GVHD in patients with relapsed chronic myeloid leukemia. The impact of initial CD3+ cell dose on outcome after DLI in patients treated for other hematological malignancies is limited. We conducted a retrospective analysis of 225 patients with relapsed hematological malignancies after HCT treated with DLI over the last 20 years. The primary objective of this study was to determine the effect of the initial DLI CD3+ cell dose on graft-versus-host disease (GVHD) and overall survival (OS). Other potential risk factors for the development of GVHD (i.e. patient/donor gender, patient age, HLA-match, diagnosis, conditioning type, prior acute or chronic GVHD, donor chimerism, lymphocyte count, interval between transplant to DLI, and initial DLI TNC dose) and for survival after DLI (i.e. diagnosis, disease status at DLI, transplant conditioning type, time from transplant to relapse and to DLI, prior history of GVHD) were included in the analysis. For assessment of survival, patients were classified into a high risk group (AML, MDS, ALL, CML (BC, AP), high grade lymphomas (Hodgkin lymphoma, DLBCL, transformed NHL)) (n=145) or low risk group (CML-CP, CLL, MM, other lymphomas) (n=80). The median age of the cohort was 46 (range, 3–74) and 59% (n=132) were male. DLI was given for treatment of chronic myeloid leukemia (n=56), acute myeloid leukemia (n=71), myelodysplastic syndrome (n=25), acute lymphoblastic leukemia (n=21), multiple myeloma (n=23), lymphoma (n=21) and chronic lymphocytic leukemia/lymphoma (n=11). Patients received transplants from HLA-matched related (n=171) or unrelated (n=41) donors. Thirteen patients had HLA-mismatched donors. 58 patients (26%) received non-myeloablative conditioning regimens. The median time intervals were 11.3 months (range, 0–180) from HCT to relapse and 15.5 months (range, 21.1–215) from HCT to DLI. 144 patients (64%) received cytoreductive therapy before DLI, and 55 patients (24%) had complete remission at time of DLI. Initial DLI CD3+ cell dose/kg was ≤1×107 (n=84; Group A), >1.0 to <10 x107 (n=58; Group B), and ≥ 10×107 (n=66; Group C). Of the 225 patients, 86 (39%) developed GVHD after DLI. The median time to onset of GVHD after DLI was 39 days (range, 6–1029). The cumulative incidence (CI) of GVHD at 12 months after DLI was 39%. In the multivariate analysis, risk factors that were statistically significant for the development of GVHD after DLI included higher initial DLI CD3+ cell dose/kg with a hazard ratio (HR), 3.16; 95% CI, 1.7 to 5.9 (P=0.0003) for Group C and HR, 2.24; 95% CI, 1.2 to 4.2 (P=0.01) for Group B compared to Group A, and shorter interval between transplant and DLI with a HR, 3.38; 95% CI, 2.0 to 5.6; P <0.0001 for DLI less than one year after transplant. The CI of GVHD at 12 months after DLI were 21%, 45% and 55% for Groups A, B, and C respectively (Figure 1, Panel A). Acute or chronic GVHD before DLI and donor type were not statistically significantly associated with increased risk of DLI-associated GVHD. Initial DLI CD3+ cell/kg ≥ 10×107 was statistically significantly associated with an increased risk of overall mortality after DLI (HR, 1.84; 95% CI, 1.2 to 2.9; P=0.01) compared to lower doses. OS rates at 3 years were 47%, 45%, and 32% for Groups A, B, and C respectively (Figure 1, Panel B). Additional factors that had a statistically significant association with an increased risk of mortality after DLI included high risk disease (HR, 3.53; 95% CI, 2.2 to 5.7; P <0.0001), absence of complete remission state at time of DLI (HR, 2.17; 95% CI, 1.4 to 3.4; P =0.0008), and relapse within one year after HCT (HR, 2.42; 95% CI, 1.6 to 3.6; P <0.0001). A low initial CD3+ cell dose was not associated with an increased risk of relapse after DLI.Our results show that an initial DLI CD3+ cells dose/kg ≥ 10×107 is associated with increased risks of GVHD and mortality after DLI, without reducing the risk of relapse. These findings are clinically relevant, since they support a recommendation to infuse less than 10×107 CD3 cell/kg as the initial cell dose of DLI for treatment of recurrent hematological malignancy after allogeneic HCT. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Prolonged subcutaneous administration of 852A, a novel systemic toll‐like receptor 7 agonist, to activate innate immune responses in patients with advanced hematologic malignancies

The toll-like receptor (TLR) 7 agonist 852A, a small-molecule imidazoquinoline, stimulates plasmacytoid dendritic cells to produce multiple cytokines. We conducted a Phase II study of 852A in patients with recurrent hematologic malignancies. The primary objective was assessing the activity of 852A administered subcutaneously twice weekly for 12 weeks. Secondary objectives were assessing the safety of 852A and its ability to activate the immune system with prolonged dosing. Patients with relapsed hematologic malignancies of any age with adequate organ function were eligible. Patients initiated dosing at 0.6 mg/m(2) twice weekly and escalated by 0.2 mg/m(2) after every two doses as tolerated to a target dose of 1.2 mg/m(2) . Patients with responses or stable disease were eligible for additional cycles. Seventeen patients (15 males) entered the study: 6 with AML, 5 ALL, 4 NHL, 1 Hodgkin's lymphoma, and 1 multiple myeloma. The mean age was 41 years (12-71 years). The median number of prior chemotherapy regimens was 5 (range = 1-14). Thirteen patients completed all 24 injections. Grade 3-4 toxicities included nausea, dyspnea, fever, myalgia, malaise, and cough. Responses included one complete response (ALL), one partial response (AML), two stable disease (AML and NHL), and 9 progressive disease. This is the first in-human hematologic malignancy trial of a subcutaneously (SC) delivered TLR7 agonist using a prolonged dosing schedule. 852A was safely administered up to 1.2 mg/m(2) twice weekly with evidence of sustained tolerability and clinical activity in hematologic malignancies. Systemic TLR agonists for the treatment of hematologic malignancies warrant further study.

Drug Resistance Gene Therapy to Augment Allogeneic Transplantation for the Treatment of Leukemia Following Relapse

Abstract 2050Relapse remains a significant problem after allogeneic hematopoietic cell transplantation (HCT) for high-risk hematopoietic malignancies. Unfortunately treatment options for recurrent disease after HCT have remained limited and are often ineffective. In addition, chemotherapy to treat relapse after HCT results in myelosuppression and thus infectious complications. Here we investigated a novel concept of conferring donor cell resistance to the chemotherapy thus preventing or minimizing these complications.To model this approach we used a mutant version of the chemotherapeutic resistance gene methylguanine-methyltransferase (MGMT) that are insensitive to O6-benzylguanine (O6BG), an agent that can be used to sensitize unmodified/tumor cells prior to alkylating agents. Overexpression of MGMT mediates resistance to hematopoietic stem cells (HSCs) to alkylating agents like Carmustine (BCNU) and methylating agents like Temozolomide (TMZ). Chemotherapeutic effects can be further enhanced with O6BG, which blocks the endogens MGMT, a mechanism that can be exploited with the O6BG resistant human MGMT mutant MGMT(P140K) or the equivalent dog mutant MGMT(P144K). We have previously demonstrated in dog and nonhuman primate large animal models that MGMT(P140K) gene transfer to HSCs provided multilineage hematopoietic chemoprotection and allowed for dose intense chemotherapy.Using a DLA-identical transplantation setting in the dog we established donor chimerism following non-myeloablative conditioning with 300 cGy total body irradiation and infusion of whole bone marrow. To model the treatment of a hypothetical relapse 10 weeks after the initial HCT, the animals received chemotherapy with O6BG/TMZ and the infusion of MGMT(P144K) gene-modified cells from the same donor. Dogs then receive several cycles of chemotherapy, consisting of a combination of O6BG and TMZ or BCNU. Donor chimerism was assessed by analyzing the variable number of tandem repeats (VNTR) and gene marking was analysed with a quantitative real-time PCR.We have treated 2 dogs thus far. Gene marked cells increased ∼100-fold up to 11% after two rounds of O6BG and TMZ. The overall chimerism increased by 10% up to 90% during selection. After a third round of chemotherapy for dog 2 we observed protection from myelosuppression indicated by a drop of platelet counts to only 200,000/μl which compared to historical treatments would have resulted in pronounced myelosuppression.Here we successfully developed a clinical relevant dog model to test a new treatment option for patients with a a recurrent hematologic malignancy after HCT that combines aggressive alkylating agent chemotherapy and drug resistant allogeneic HCT. We demonstrate that allogeneic transplantation of genetic modified HSCs into a recipient that previously received a HCT is feasible and well tolerated. MGMT(P144K) modified cells engraft in the recipient and provide efficient chemoprotection of hematopoiesis following aggressive chemotherapy that would likely be required to achieve a response in patients with recurrent disease This strategy should the protection of donor cells using MGMT(P140K) and/or cytidine deaminase modified HSCs that confers protection to alkylating agents, methylating agents, or antimetabolites and and thus allow high dose and/or dose dense chemotherapy for patients with recurrent hematologic malignancy. Disclosures:No relevant conflicts of interest to declare.

Phase I Trial of Prophylactic Rituximab for the Prevention of Post Transplant Epstein-Barr Related Lymphoproliferative Disease (EBV-PTLD) Following T Cell Depleted (TCD) Unrelated or HLA-Mismatched Related Hematopoietic Cell Transplantation (HCT): Efficacy, Toxicity, and Effect on Subsequent B Cell Reconstitution

Abstract 1971Rituximab, a chimeric IgG1 kappa monoclonal antibody against the pan-B cell marker CD20, has proven effective in treating B cell malignancies, including EBV-PTLD. To determine its potential role in prevention of EBV-PTLD, 25 patients were enrolled on a prospective IRB approved trial (11/1/03-2/1/07) of monthly rituximab (375 mg/m2/dose, maximum 6 doses), starting 30–45 days after a TCD unrelated (n=23) or HLA-mismatched HCT (n=2). Eligibility included EBV seropositive patient, negative hepatitis B surface antigen, ANC >1500 cells/uL, remission, and negative plasma EBV PCR at baseline. Per protocol, rituximab was stopped prior to 6 doses in patients who achieved a circulating CD4 count >200 cells/ul, at which time their risk of EBV-PTLD was considered minimal. The median patient age (range) was 22.0 (8.0-68.0) years. Patients underwent transplantation for acute leukemia (n=18), CML (n=2), NHL (n=2), MDS (n=2), or Fanconi anemia/AML (n=1). Only two patients developed fever and chills, without respiratory distress or hypotension, within the first hour of their initial infusions, which proved to be due to coincidental line infections for which both were treated and recovered uneventfully. Both patients refused further rituximab. Six patients received all 6 planned doses; 5 patients received fewer than 6 doses due to recovery of CD4 count >200 cells/ul before the planned 3rd (n=4) or 5th dose (n=1). The remaining 12 patients received 1 (n=2), 2 (n=4), 3 (n=2), or 4 doses (n=4), due to persistent neutropenia (<1500 cells/ul) >45d after the prior rituximab dose (n=4), recurrent disease (n=2), prolonged parainfluenza upper respiratory tract infection (n=1), secondary graft failure (n=1), abnormal LFTs of unclear etiology (n=1), GVHD requiring phase I therapy (n=1), aseptic meningitis (n=1) attributed to intravenous gammaglobulin, or pneumococcal sepsis (n=1). At a median follow-up of 5.8 (4.4-5.7) years, 16 of 25 patients are alive, 13 disease-free. Five patients died of recurrent hematologic malignancy, three of GVHD, and one of non-alcoholic steatohepatitis. Of the 25 patients accrued to the protocol, none developed EBV viremia or EBV-PTLD, compared to 23% (p<0.01) and 7%, respectively of patients (n=95) not given prophylactic rituximab following a TCD unrelated or HLA –mismatched related donor performed during the same time period. Despite recovery of normal numbers of CD20+ B cells at a median of 8.4 months post rituximab, 5 of 13 recipients of prophylactic rituximab have had prolonged hypogammaglobulinemia, a paucity of memory switched (CD27+ IgD-) B cells, and no specific antibody responses persisting at least 4 years from their last dose of rituximab. B cell dysfunction did not correlate with the number of doses of prophylactic rituximab administered. To estimate how frequently persistent B cell dysfunction occurs following rituximab treatment, serum immunoglobulin levels +/− specific antibody production was assessed in an additional 44 patients who received rituximab following TCD unrelated or HLA-mismatched related HCTs for the treatment of EBV viremia, EBV-PTLD, autoimmune cytopenias, or as prophylaxis against recurrent EBV (-) B-cell NHL, or EBV-LPD. Patients received a median of 4 doses of rituximab at a dose of 375 mg/m2 given weekly in most patients. Despite recovery of normal numbers of circulating B cells in all 44 patients, 10 patients have had prolonged hypogammaglobulinemia (>18 months), including 6 patients who remain on monthly IVIG a median of 40 (25–66) months following rituximab. In this cohort, 30 patients were immunized with a series TDAP, PCV7 or PCV13, HIB, and/or inactivated polio vaccines. Following the third vaccine, 13 patients (43%) failed to respond to any vaccine, 6 patients (20%) had incomplete responses, and 11 patients (37%) responded to all vaccines administered. Lack of vaccine response was associated with a paucity of memory switched B cells. This study demonstrates the effectiveness of rituximab in preventing EBV viremia in high risk recipients of a T cell depleted HCT. It also suggests that rituximab affects B cell function long-term, despite quantitative, but not necessarily qualitative recovery of B cells. Further studies investigating the minimal number of rituximab doses required to prevent EBV viremia/EBV-PTLD in high risk patients and the mechanism of prolonged B cell impairment following its use are needed. Disclosures:Off Label Use: Rituximab for the prevention of EBV-LPD post HCT. Papadopoulos:Biogen-Idec: Membership on an entity's Board of Directors or advisory committees, family member on board of Biogen-Idec who receives royalties from Hoffman La-Roche.