ALBERT

Description: Introduction: MAVORIC was an open-label, multicenter, randomized phase 3 study evaluating the safety and efficacy of mogamulizumab (moga) compared to vorinostat (vori) in patients with mycosis fungoides (MF) or Sézary syndrome (SS) who had failed at least one prior course of systemic therapy (NCT01728805). Primary results have been reported (Kim et al. Lancet Oncol 2018) and were based on a data cutoff date of December 31, 2016. The primary endpoint was progression-free survival (PFS); patients in the moga treatment arm experienced significantly longer PFS compared to patients in the vori treatment arm (median 7.7 months vs 3.1 months; p

Description: B ackground: Current therapies for CLL/SLL have frequent toxicities, are non-curative, and several trials have demonstrated that early treatment of the disease doesn't result in longer overall survival. In high doses, both curcumin (CM), from turmeric, and vitamin D (VD) have been shown to be safe in multiple clinical trials of solid tumors. Curcumin was shown to disrupt CLL cell interactions with the microenvironment, induce apoptosis independent of DNA damage, and upregulate vitamin D receptor (VDR) in malignant lymphoid cells. We hypothesized that the combination of CM and VD is safe and active in CLL/SLL and would delay disease progression. Methods: This was an open-label phase II trial for previously untreated patients with asymptomatic,Rai stage 0-II CLL/SLL not currently meeting National CancerInstitute Working Group (NCI-WG) Criteria for treatment. All patients received 8 gm of CM and 10,000 IU of vitamin D3 (VD) orally daily. VD was started 1 week after CM and both agents were maintained for up to six 4-week cycles. The primary endpoint was the overall response rate (ORR) based on NCI-WG criteria. Secondary endpoints were event-free (EFS), overall survival (OS), and time to next treatment (TTNT). VD-25-OH and CM major metabolites; CM glucuronide (COG) and CM sulfate (COS), were measured in plasma by liquid chromatography-tandem mass spectrometry. Phosphorylated-NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells), a validated pharmacodynamic marker of CM activity, as well as VDR, were measured in CLL cells by flow cytometry. Results: A total of 35 patients (pts), 51% males, were accrued to the trial, 30 (86%) were evaluable for response. Median age was 60 years (range 45-80). Most had CLL (97%); 51% were Rai stage 0 and 49% were Rai stage 1. Cytogenetic abnormalities included del13q14 (37%), trisomy 12 (11%), del 11q22 (11%) and del 17p (3%); 20% had ZAP-70 levels 〉20%. Median number of cycles received was 5 (range 1-6) and treatment was well tolerated overall. The most frequent adverse effects (AE) were diarrhea/gastrointestinal upset in 69% of patients (14% were grade 3). No serious AEs were observed. Eighteen pts (51%) completed all 6 cycles of treatment; 10 (29%) withdrew consent, 4 (11%) discontinued treatment because of diarrhea, and 3 (9%) patients progressed on treatment. Best response was stable disease in 28/30 (93%) evaluable pts. After a median follow up of 29 months, EFS was 72.0% (95% CI 52.1 - 84.7%), 74.1% (95% CI 58.7-89.6%) had not started new CLL treatment, and OS was 100%. Median VD-25-OH levels were 28.75ng/ml (range 12.5-55.6) at baseline and 49.5 ng/ml (24.8-69) at 28 days. Median COG/COS levels were 15.8 (2.73-75)/6.71(0-33.5) and 18 (0-75.9)/7.21(0-35.2) ng/ml at 8 and 28 days, respectively. Flow cytometric analysis of CLL cells showed no significant change in VDR or Phosphorylated-NF-κB with CM-VD treatment. Conclusion: Curcumin and high-dose vitamin D combination is safe and well tolerated in patients with early stage CLL. Although no responses were seen, the majority of patients maintained stable disease on treatment. Longer follow up is planned on this study to determine long - term CLL progression rates of patients treated with CM-VD. Disclosures Afable: Eli Lilly: Employment. Lazarus:Pluristem Ltd.: Consultancy. Nagabhushanam:Sabinsa Corporation: Employment. Grote:BTR Group Inc: Employment. Kunati:Symrise AG: Employment.

Description: Abstract 288 This is phase I/II trial designed to evaluate the safety and clinical activity of Dasatinib, a potent, broad spectrum inhibitor of 5 critical oncogenic tyrosine kinase families: BCR-ABL, SRC, c-KIT, PDGF receptors (α and β) and ephrin (EPH) receptor kinases, in NHL. The primary end point was maximum tolerable dose (MTD) of dasatinib in the phase I stage and overall response rate (ORR) in phase II stage of the study. Eligible patients must be at least 19 y/o with relapsed or refractory NHL after at least one prior systemic therapy, ECOG performance status 0–2, and able to take oral medications. The Phase I trial utilized a 3+3 design where patients received Dasatinib once daily for 28 day cycles in one of 3 dose cohorts (100, 150, 200 mg daily). Patients continued on Dasatinib until disease progression. NCI grade IV non-hematological toxicity defined dose-limiting toxicity (DLT) in phase I. The phase II stage used a two-stage design. Patients who are in complete or partial remission (CR or PR) after one cycle were considered responders. The study enrolled 27 patients until June 2010. The median age was 58 years (range 34–87). 12 were females and 15 were males. The median number of prior therapies was 4 (range 1–20). The median follow-up period for survivors was 24 months (range 2–30 months). 14 patients were treated in the phase I part of the study and 13 patients were enrolled in phase II so far. 3 patients received 100 mg, 3 patients received 150 mg, and 8 patients received 200 mg daily. The MTD was determined to be 200 mg PO daily. This was later reduced to 150 mg PO daily when a higher incidence of grade 3 pleural effusions was noted (2 of 10 patients receiving 200 mg dose in the first stage of phase II) . 19 patients were evaluable for clinical response after 2 cycles of treatment and are as follows: CR 2, PR 4, SD 8, and PD 5. The ORR was 6/19 (32%). PFS was 17% (with a 95% CI of 5–34%) at 1 year, and 13% (3-29%) at 2 years. Overall survival was 60% (95% CI 38–76%) at 1 year and 50% (95% CI 29–68%) at 2 years. The 2 patients who sustained a CR had peripheral T-cell lymphoma (PTCL). Both patients remained alive, and disease free, for over 2 years since start of treatment. The histological subtypes of the 4 patients who had a PR were: diffuse center follicular lymphoma (2), marginal zone lymphoma (1), and peripheral T-cell lymphoma (1). NCI grade III-IV toxicities noted were hematological (5 thrombocytopenia, 2 anemia, 1 leukopenia, 3 neutropenia), pleural effusion (6), rash (1), diarrhea (2), weakness/orthostasis (1), prolonged QTc interval (1), flash pulmonary edema (1), and skin graft failure (1). In conclusion, Dasatinib shows encouraging activity in heavily pre-treated, recurrent or refractory NHL patients. Toxicity is acceptable and pleural effusions, in addition to cytopenias, were the major toxicities. Dasatinib may be particularly effective in patients with PTCL; possibly because of high expression of PDGFR-α. Phase II of the study is ongoing. Disclosures: No relevant conflicts of interest to declare.

Description: Introduction Blocking Bruton tyrosine kinase (BTK) with ibrutinib has demonstrated efficacy in chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphoma (NHL) patients (pts). However, resistance to therapy is common. Preclinical data suggest selinexor (oral selective inhibitor of nuclear export) downregulates BTK (Hing 2015). We hypothesized that dual BTK blockade by combining ibrutinib and selinexor would be tolerable and efficacious in CLL/NHL pts. Herein, we report the phase I combination study with expansion cohorts. Methods Pts with histologically confirmed CLL/NHL were enrolled (n=33). Eligible pts were age ≥18 years (yrs), had ≥1 prior therapy and ECOG performance status of 0-1. CLL pts met iwCLL 2008 criteria for therapy. Pts received selinexor orally 1-2 times weekly (3 weeks of 4-week cycle) and daily oral ibrutinib (420mg) starting Cycle 1 Day 8. Treatment cycles were repeated until disease progression, intolerance, death or discontinuation of trial participation. Primary endpoint was determination of maximum tolerated dose (MTD). Dose-finding proceeded using a modified continual reassessment method targeting a probability of dose limiting toxicity (DLT)

Description: Introduction Both blinatumomab and lenalidomide have proven, but limited, efficacy in relapsed/refractory (R/R) non-Hodgkin's lymphoma (NHL). Failure of blinatumomab to mediate durable responses is due to its inability to recruit competent cytotoxic T cells which leads to eventual T cell exhaustion. Lenalidomide has been shown to improve efficacy of rituximab through T and NK cell activation even in patients who have previously failed rituximab containing regimens. Based on this, we hypothesized that lenalidomide, when combined with blinatumomab, will enhance its efficacy. We report safety, efficacy and correlative analysis of blinatumomab and lenalidomide in R/R NHL. Methods We conducted a phase I, open-label trial involving patients 18 years and older with R/R CD19+ NHL who have received at least two prior chemotherapeutic or biologic regimens and were not eligible for standard curative options at time of enrollment. Previous CD19-targeted therapy was allowed. Study consisted of a dose escalation followed by a dose expansion phase once the maximum tolerated dose (MTD)/ recommended phase II dose (RP2D) was established using a Phase I Queue modified 3+3 design. The escalation phase has been completed and consisted of blinatumomab continuous infusion (level 1 and 2: 9 mcg/day to 112 mcg/day) from days 1-56 and lenalidomide (level 1: 10 mg and level 2: 20 mg daily) days 29-49 of a 56-day induction cycle. Patients who responded underwent consolidation with blinatumomab continuous infusion days 1-7 and lenalidomide days 1-21 of a 28-day cycle for a maximum of 6 cycles followed by lenalidomide maintenance for 2 years or until unacceptable toxicity or disease progression. Dose limiting toxicities (DLT) included any grade 3/4 drug related adverse events (AE) observed during and up to 7 days after blinatumomab/lenalidomide simultaneous administration. Additional patients were accrued to replace patients who had grade 3/4 AE or progressed before receiving lenalidomide for dose-finding purposes. Primary endpoints included toxicity and determination of the MTD/RP2D during the first 8 weeks of blinatumomab/ lenalidomide induction. Secondary endpoints included overall response rate (ORR), complete response (CR) rate, progression free survival (PFS) which was censored at time of transplant and immune response biomarkers. Results As of July 17, 2019, 18 patients initiated therapy; 7 with diffuse large B cell lymphoma, 3 with mantle cell lymphoma, 3 with follicular lymphoma, 2 with nonspecified B cell lymphoma and 1 each with marginal zone lymphoma, Burkitt's lymphoma and small lymphocytic lymphoma. Median age was 58 (range 30-84) years and the median number of prior regimens was 2.5 (range 2-5); 5 patients had previous stem cell transplant (SCT). 6 patients had disease progression prior to starting lenalidomide. 3 patients received blinatumomab/lenalidomide at dose level 1 with no DLT noted. 9 patients received blinatumomab/lenalidomide at dose level 2 with 4 requiring blinatumomab dose reduction prior to starting lenalidomide. Due to favorable safety profiles with the combination using the MTD/RP2D of lenalidomide 20 daily, upfront doublet therapy was initiated as part of the planned expansion phase. Most common grade 3/4 adverse events were lymphopenia (39%), hypophosphatemia (22%) and hyponatremia (11%). 1 patient (5.5%) experienced grade 3 neurotoxicity. No grade 3/4 cytokine release syndrome or treatment related deaths were seen. At time of data cutoff, three patients remain on active treatment. At a median follow-up time of 14.3 months, ORR was 56% for all patients and 83% (50% CR) for those who received blinatumomab/lenalidomide combination therapy. Median PFS was 3.8 months (95% CI, 1.1 to NR) for all patients and 8.3 months (95% CI, 2.2 to NR) for those who received blinatumomab/lenalidomide combination therapy. 3 patients who achieved response underwent allogeneic SCT and remained in remission for 14.2 to 22.3 months thereafter. Correlative studies are pending and will be reported at time of presentation. Conclusions The combination of blinatumomab and lenalidomide, given at the RP2D dose of 20 mg daily, is safe and well tolerated. This regimen demonstrates encouraging efficacy in this heavily pretreated patient population and is a promising alternative treatment option for R/R NHL patients who are not candidates for aggressive cytotoxic chemotherapy or as a bridge to allogeneic SCT. Disclosures Abedi: Abbie: Speakers Bureau; Takeda: Speakers Bureau; BMS: Speakers Bureau; Celgene: Speakers Bureau; Gilead: Speakers Bureau. Costello:Takeda: Honoraria, Research Funding; Janssen: Research Funding; Celgene: Consultancy, Honoraria, Research Funding. Zain:Seattle Genetics: Consultancy; Spectrum: Consultancy. Budde:F. Hoffmann-La Roche Ltd: Consultancy. William:Defined Health: Consultancy; Techspert: Consultancy; Celgene Corporation: Consultancy; Kyowa Kirin, Inc.: Consultancy; Guidepoint Global: Consultancy. Foss:Spectrum: Other: fees for non-CME/CE services ; Acrotech: Consultancy; miRagen: Consultancy; Eisai: Consultancy; Mallinckrodt: Consultancy; Seattle Genetics: Consultancy, Other: fees for non-CME/CE services . Jonas:AbbVie, Accelerated Medical Diagnostics, AROG, Celgene, Daiichi Sankyo, Esanex, Forma, Genentech/Roche, GlycoMimetics, Incyte, LP Therapeutics, Pharmacyclics: Research Funding; AbbVie, Amgen, Celgene, GlycoMimetics, Jazz, Pharmacyclics, Tolero: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie, Amgen, GlycoMimetics: Other: Travel expenses. Rosenberg:Amgen: Consultancy, Research Funding. Tuscano:Seattle Genetics: Honoraria; Amgen: Honoraria; Celgene: Honoraria, Research Funding; Novartis: Research Funding; Spectrum: Research Funding; Takada: Research Funding; Abbvie: Research Funding; Genentech: Research Funding; Pharmacyclics: Research Funding. OffLabel Disclosure: The use of blinatumomab and lenalidomide in patients with aggressive lymphoma

Description: Background: Disease relapse and graft vs host disease (GvHD) following alloHSCT are major causes of treatment (Tx) failure in patients (pts) with MDS and AML (Paietta, 2012). Studies of parenteral azacitidine, an epigenetic modifier, have shown efficacy in preventing post-transplant relapse in MDS and AML pts, and possibly reducing GvHD severity (Platzbecker, 2012; de Lima, 2010). Azacitidine maintenance after alloHSCT may enhance graft vs leukemia (GvL) effects and reduce GvHD by expansion of regulatory T cells (Goodyear, 2010, 2012). CC-486 is a novel oral formulation of azacitidine which, as well as potentially allowing easier administration over extended schedules, could increase the duration of drug exposure to residual malignant cells. We now report preliminary results from a prospective phase I/II dose-finding study of CC-486 as maintenance Tx after alloHSCT in pts with MDS or AML. Objective: To evaluate the maximum tolerated dose (MTD), dose-limiting toxicities (DLT), pharmacokinetics (PK), and safety outcomes of CC-486 following alloHSCT in pts with MDS or AML. Methods: Pts with WHO-defined MDS or AML who have undergone alloHSCT with myeloablative (MAC) or reduced-intensity conditioning (RIC) regimens and who had sibling or unrelated donors with ≤1 antigen mismatch at the HLA-A, -B, -C, -DRB1 or -DQB1 locus, are enrolled. CC-486 Tx is initiated between days (d) 42 and 84 after alloHSCT. Pts receive prophylactic Tx for GvHD and infections per institutional standard. A standard 3x3 MTD design is being used to evaluate 4 dosing schedules: CC-486 200 mg or 300 mg QD, administered for 7 d (Cohorts 1 and 2) or 14 d (Cohorts 3 and 4) of repeated 28d Tx cycles. MTD determination is based on DLT that occur during the first 2 Tx cycles (pts are not evaluable if unable to complete 2 Tx cycles for reasons other than a DLT). Adverse events (AEs) are graded using NCI-CTCAE v4.0. Pts are followed for safety, incidence of acute and chronic GvHD, and relapse. PK of azacitidine after CC-486 administration, alone or with standard concomitant medications, are evaluated on d 1 of CC-486 Tx cycles 1 and 2. Results: At data cut-off (7/17/2014), outcome data were available for 7 pts enrolled in the first 2 cohorts (Table): 1 pt had IPSS Int-2 MDS and 6 had AML with high-risk features. Stem cell source was from bone marrow (n=2) or peripheral blood (n=5) from unrelated (n=5) or sibling (n=2) donors. Two pts had 1 antigen mismatch and 5 had a full match.Conditioning included MAC (n=3) and RIC (n=4) regimens. One pt in Cohort 2 was not evaluable for DLT or PK assessments due to early discontinuation (AML relapse) during the first CC-486 Tx cycle. Of the 6 evaluable pts, 4 completed ≥6 CC-486 Tx cycles and 2 ongoing pts had not reached 6 cycles on-study at data cut-off (Table). One pt who had GvHD before CC-486 Tx subsequently withdrew from the study after developing febrile neutropenia and diarrhea related to GvHD of the bowel; 1 pt withdrew for personal reasons; and 1 pt discontinued after 6 Tx cycles due to relapse. At data cut-off, 3 pts remained on-study, all with continued CR (Table). No pt in Cohort 2 developed GvHD. For all pts, most AEs were grade 1-2. Grade 3-4 AEs were reported for 2 pts: both had nausea and vomiting, which were controlled with antiemetic agents upon onset; 1 also had device-related infection and dyspnea, and 1 also had febrile neutropenia and rash. No DLT emerged with these CC-486 regimens and no pt experienced secondary graft failure. Overall azacitidine plasma concentration profiles (Figure) and PK parameters were similar following CC-486 given alone or with concomitant medications, and were within range of values observed following similar CC-486 doses in pts with MDS, CMML, and AML (Garcia-Manero, 2011). The AUC range for oral CC-486 is ~10% of that seen with subcutaneous azacitidine administered at 75 mg/m2 (Garcia-Manero, 2011). Conclusion: Preliminary data from this analysis suggest that CC-486 administered at doses of 200 or 300 mg QD for 7 days every 4 weeks is safe and well tolerated in the post-transplant setting. Overall, azacitidine plasma concentration profiles and PK parameters were not affected by use of concomitant medications. No DLT and a low rate of GvHD support the ongoing evaluation of 14d extended CC-486 dosing regimens in this ongoing study, as a preliminary to a prospective, randomized trial of this new agent post-transplant. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures de Lima: Celgene: Consultancy. Champlin:Celgene: Consultancy. Giralt:Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau. Scott:Celgene: Consultancy, Honoraria, Research Funding. Hetzer:Celgene: Employment, Equity Ownership. Wang:Celgene: Employment, Equity Ownership. Laille:Celgene: Employment, Equity Ownership. Skikne:Celgene: Employment, Equity Ownership. Craddock:Celgene: Honoraria, Research Funding.

Description: The prognosis of BCR-ABL-induced B-ALL remains dismal with no effective chemotherapies currently available. Curcumin, a natural compound derived from tumeric, has been shown to induce apoptosis in the leukemic cell line K562 and in many solid tumor cells. We tested whether curcumin has an inhibitory effect on B-lymphoid transformation by wild type BCR-ABL or BCR-ABL-T315I mutant. We first used BCR-ABL-expressing pre-B cells isolated from B-ALL mice and BCR-ABL-expressing BaF/3 cells. We treated these cells with different concentrations of curcumin (10, 30, or 50 uM), and found that proliferation of the cells was significantly inhibited at concentrations as low as 10 uM. Curcumin also induced apoptosis of the cells, as shown by increased Annexin V-positive cells detected by FACS. Western blot analysis showed that Curcumin treatment resulted in decreased JNK2 activation and a significant increase in IKKa/b expression. To further investigate the underlying mechanisms for cellular apoptosis induced by curcumin, we screened for apoptosis related transcription factors that were activated or inactivated in curcumin-treated BCR-ABL-expressing pre-B cells isolated from B-ALL mice. To do so, we probed nuclear extracts of these cells onto a commercial DNA oligonucleotide arrays (Panomics) representing the canonical binding sites for 52 transcription factors. We observed decreased expression of NFkB at 48 hours and a significant increase in expression of AP-2, p53, and vitamin D receptor 3 (VDR3) at 24 hours. The p53 induction by curcumin was further demonstrated by Western blotting. To examine the efficacy of curcumin on B-ALL, we induced B-ALL in BALB/c mice by transplanting BCR-ABL-transduced donor bone marrow cells into lethally irradiated recipient mice. The B-ALL mice were treated with intraperitoneally injected curcumin (40 mg/kg, once a day), and the treated mice survived significantly longer than the vehicle-treated B-ALL mice (p=0.04; Peto-Wilcoxon test). Taken together, our results suggest a potential use of curcumin in treating BCR-ABL-induced B-ALL.

Description: Abstract 4668 Background: Heparin-induced thrombocytopenia (HIT) is an adverse immune-mediated drug reaction, resulting in a platelet count decrease of 50% within 5 to 10 days after heparin administration. HIT is often associated with venous and/or arterial thrombosis (HITT). The clinical course of HIT developing after liver transplantation (LT) had not been reported. Direct thrombin inhibitors (DTI) were reported to be safe and efficacious in patients who developed HIT yet their safety and efficacy had not been determined in patients who had LT. Also, the optimal management of HIT developing after LT has not been defined. Objectives: To evaluate the incidence and the clinical course of patients who developed HIT after LT and the safety of use of DTI in this population. Methods: We performed a retrospective analysis of all patients who had a LT and had clinical HIT confirmed by the anti-PF4/heparin (HIT) antibody by ELISA at our institution between January 2006 and July 2011. A positive test is defined as optical density of 〉 0.4 with 〉 50% inhibition. Bleeding was defined per GUSTO (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Arteries) scale. Alternate causes of thrombocytopenia were excluded by relevant hematologic testing. Results: During the study period, 438 patients received LT and163 patients were diagnosed with clinical HIT in our 689 bed hospital. Clinical HIT was confirmed in 11 LT patients (2.5%) based on a positive HIT antibody. LT cases constitute 11/163 (6.75%) of all HIT diagnosed in our center. Clinical characteristics of these are described in attached table. Previous thrombosis was reported in 7/11 (63%) patients, of these 5/11 (46%) received prior therapeutic anticoagulation. Baseline thrombocytopenia below 150K was present in 10/11 (90%) cases and 7/11 (63%) had INR prolongation ≥ 1.5. HIT was documented in 2 patients before LT, in 3 patients within 14 days of surgery and in 6 patients more than 14 days post LT. Six (54%) developed HITT and 7/11 (63%) were treated with a DTI (bivalirudin in 6 cases and argatroban in 1 case). On discharge 2/11 (18%) received fondaparinux and 5/11 (45%) received warfarin. Median dose of IV bivalirudin was 0.3 (0.09-0.89) mg/kg/hr. Platelet recovery was noted in all patients at mean of 9.8 (3-30) days. Progressive thrombosis was noted in 2/11 (18%). Moderate bleeding events within 40 days of LT included 2 gastrointestinal bleeds and one episode of epistaxis. Two traumatic bleeds occurred with prolonged anticoagulation for HITT. No deaths or amputations were documented as a direct consequence of HIT. Only one patient with HIT and LT died as a complication of sepsis. Clinical characteristics of HIT in LT patients: n=11 Conclusion: HIT is common (2.5%) in LT recipients despite low rates of deep venous thromboprophylaxis with heparin due to underlying coagulopathy. Basal thrombocytopenia is frequent in these patients and widely accepted 4T probability score has low predictive value. The risk of HITT and progressive thrombosis is high. Despite baseline coagulopathy, in our experience the use of DTI, especially bivalirudin, seems to be well tolerated and efficacious in this population. Future studies are needed to optimize dosing to reduce bleeding risk. Disclosures: Off Label Use: Use of bivalirudin and fondaparinaux in the treatment of heparin-induced thrombocytopenia.

Description: Introduction: Targeting the maturation arrest in acute myeloid leukemia (AML) to induce differentiation instead of killing rapidly dividing cells can lead to more efficacious and less toxic therapies for AML. Inhibition of the GSK3 enzyme with lithium sensitizes AML cells to the differentiating effects of all-trans-retinoic acid (ATRA), resulting in differentiation and inhibition of proliferation (Gupta K, et al. and Wald DN. Leukemia. 2012;26:1277-85.). In vitroand animal studies suggest the combination of ATRA and lithium has therapeutic activity against AML. We are conducting a phase I study of ATRA and lithium for the treatment of relapsed, non-progranulocytic AML (NCT01820624). Methods: Eligible patients were older than 18 years of age and had relapsed /refractory non-progranulocytic AML. Lithium carbonate 300 mg by mouth thrice daily was started on day -3 and given continuously and was titrated to achieve a target plasma concentration of 0.6 – 1.0 mmol/l. ATRA, at a starting dose of 22.5 mg/m2by mouth daily in two divided doses, was given from day 1 through 7 and day 15 through 21 of a 28-day cycle. GSK3b activity was measured using flow cytometry-based assays with antibodies against its inhibited form: serine-9-phosphorylated GSK3β (pGSK3) in AML cells. phosphoGSK3α (pGSKα) and β-Catenin were also evaluated with flow cytometry. The AML blasts (CD34+CD38+) as well as AML stem cells (CD34+CD38-) were quantitated by flow cytometry and changes in surface markers (CD11b, CD14 and CD15) were followed after treatment. Results: Correlative data were available on the first 5 subjects. Median age was 67.5 (range 42-83) years; median number of prior therapies was 2.5 (range 1 - 6). Mean expression of pGSK3, compared to baseline, increased by 1.6-fold when the target lithium plasma concentration of 0.6 mmol/L was reached (95% CI 1.14- 2.07), whereas there was no increased expression at levels below 0.6 mmol/L (change in expression: 0.94; 95% CI 0.65-1.27). The difference between pGSK3 expression levels above and below the threshold was significant (p = 0.04). After 10 days of treatment, lithium plasma concentration and pGSK3b expression presented a positive correlation, with a Pearson correlation coefficient of 0.82 (p = 0.024, R20.67). The same cutoff value for lithium plasma concentration did not identify statistically significant differences in the expression of pGSK3α or β-catenin. The mean proportion of circulating blasts (CD34+) increased 4-fold after 4 weeks of treatment; correlating with the absence of clinical response in patients enrolled in this first cohort at low doses of ATRA. However, at the same time point, the proportion of leukemia stem cells (CD34+/CD38-) decreased to 38% of baseline (95% CI 21%-98%, p = 0.04). One subject presented evidence of differentiation after 1 week of treatment with the combination, with decreased blast expression of CD11b (from 20% to 3%) and CD15 (66 to 2%) and a concomitant 5-fold increase in CD14 expression in AML stem cells. An additional patient presented a 4-fold induction of CD15 expression in blasts, suggestive of partial AML differentiation. Conclusion: Lithium is capable of effecting GSK3β inhibition in vivo at plasma concentrations that are achievable in clinical settings. Study accrual continues and larger number of patients will allow for ROC analysis to determine the specific lithium concentration for optimal GSK3β inhibition. Treatment with the ATRA and lithium combination can decrease circulating AML stem cells and induce AML cell differentiation. Disclosures No relevant conflicts of interest to declare.

Description: INTRODUCTION: To protect normal bone marrow from chemotherapy in glioblastoma patients, we have developed a novel strategy by introducing a strong DNA repair protein, mutant (P140K) of human methylguanine methyltransferase (MGMT), into patients’ CD34+ hematopoietic progenitors (HPC) by lentiviral gene transfer leading to selective expansion of drug-resistant P140K-MGMT CD34+ cells and their myeloid and immune cell progeny. METHODS: To achieve long-term stable expression of the P140K-MGMT gene, we used a lentiviral vector which integrates into the host genome. However, viral insertion mutagenesis has raised safety concerns; as the previous γ-retroviral vectors were associated with insertion mutations leading to development of acute lymphoblastic leukemia in 20% of treated patients. Nevertheless, new improved lentiviral vector with safe feature of insertion site far away from gene transcription start site has been developed. Here we evaluated the safety of a lentivirus vector under selection pressure of chemotherapy. HYPOTHESIS: Our lentiviral vector is safer than traditional γ-retroviral vectors as evident by lack of early clonal dominance even with a chemo-selection. RESULTS: Three glioblastoma patients were recruited and underwent resection, after which CD34+ HPC were mobilized with filgrastim, isolated by magnetic bead separation (Miltneyi CliniMACS), and transduced ex vivo with a GMP-grade lentiviral P140K-MGMT vector (Lentigen Corp). Subsequently, patients received radiation/temozolomide for 6 weeks and up to five cycles of monthly O6-benzylguanine/temozolomide (BG/TMZ) treatment. As a result, all three patients demonstrated a 5-15 fold selective expansion of P140K-MGMT positive HPC and their progeny granulocyte and mononuclear cells in peripheral blood and a small number of CFUs from bone marrow indicating a drug-selection mechanism. The viral insertion sites in the cells of these three patients were closely monitored in each chemotherapy cycle and the patients were followed for up to 1 year after the last therapy. We mapped a total of 17,308 viral insertion sites (VIS), for patient 1(6,146), patient 2(2,081) and patient 3(9,081) and the unique viral insertion sites (UVIS) was 382, i.e. 135, 76 and 171 for patient 1, patient 2 and patient 3 respectively. Overall, during the drug-treatment period, there were no persistent UVIS. Moreover, at the conclusion of BG/TMZ treatment, the VIS number sharply diminished. CONCLUSION: Gene transfer of LV MGMTP140K vector into hematopoietic progenitor cells did not lead to clonal dominance during or after drug selection. Dose escalation of BG/TMZ will define hematopoietic tolerance and treatment response. Disclosures Embree: Lentigen Technology Inc: Employment. Dropulic:Lentigen Technology Inc: Employment, Patents & Royalties.