Transient Remission Research Articles

Abstract 4489: Developing dual FLT3/MNK inhibitors to overcome sorafenib resistance in FLT3-ITD AML cells

Abstract Acute myeloid leukemia (AML) patients with FLT3-ITD mutations are associated with poor prognosis. FLT3-ITD inhibitors developed only result in transient disease remission with disease relapse and resistance. Agents overcoming FLT3-ITD inhibitor resistance need to be developed. Sorafenib is one of FLT3-ITD inhibitors used in clinic. Using FLT3-ITD AML MOLM-13 cell line, we established a sorafenib resistant subclone MOLM-13/Sor, explored the resistance mechanism and revealed the overactivated mTOR signaling. MNK as one of the alternative mTOR signaling pathways is activated. MNK inhibitor eFT508 could overcome sorafenib resistance. Previously we developed a dual pyrido[3,2-d]pyrimidine MNK/PIM inhibitor 21o. Through optimization of 21o we obtained two new compounds H104 (IC50 values: MNK1 19 nM; MNK2 8 nM; FLT3-ITD 46 nM; PIM1 1388 nM) and H118 (IC50 values: MNK1 35 nM; MNK2 21 nM; FLT3-ITD 25 nM; PIM1 518 nM) with selective inhibition of MNK and FLT3 and losing PIM inhibition ability. H104 and H118 show better antiproliferative efficacy in FLT3-ITD MOLM-13 cells (GI50: 1.07±0.04 μM and 0.99±0.08 μM) than non-FLT3-ITD HL-60 cells (GI50: 7.04±0.15 μM and 4.78±0.31 μM). More intriguingly H104 and H118 exhibit superior antiproliferative effects in sorafenib resistant MOLM-13/Sor cells (GI50: 0.44±0.05 μM and 0.24±0.06 μM). H104 and H118 decreased the levels of p-eIF4E, c-myc and Mcl-1, the downstream substrates of FLT3-ITD and MNK. Our data indicate that the activated MNK is one mechanism of FLT3-ITD resistance and the dual MNK/FLT3 inhibitors have advantage for FLT3-ITD AML treatment. Citation Format: Linxiang Zhao, Shuwei Zuo, Kun Xing, Xiaoshuang Yue, Huimin Zhang, Jingyi Zhang, Samuel Waxman, Yongkui Jing. Developing dual FLT3/MNK inhibitors to overcome sorafenib resistance in FLT3-ITD AML cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4489.

Transient Spontaneous Remission of Acute Myeloid Leukemia with Mutated RUNX1: A Rare Report.

Transient Spontaneous Remission of Acute Myeloid Leukemia with Mutated RUNX1: A Rare Report.

1483-P: Distinct Immune Features in the Partial Remission Phase of Type 1 Diabetes Identified by Single-Cell RNA Sequencing and Functional Analysis

Type 1 diabetes (T1D) patients might experience a transient partial remission (PR) stage. However, the immunological mechanisms responsible for the PR stage still need to be elucidated. Here, we have applied single-cell RNA sequencing to delineate the immune underpinnings of peripheral immune cells among healthy individuals, new-onset T1D patients, and T1D patients in the PR phase. Combined with cohort validation and functional assays, the expansion of TIGIT+ CCR7− Tregs as well as the decrease of CD226+ CCR7− CD8+ T cells helps to maintain a window in which to transit the immune balance in the remission stage via the TGF-β signal. These findings, especially the identified cell subsets may provide novel mechanism for future therapeutic interventions. Disclosure X.Li: None. T.Zhong: None. X.Li: None. L.Kang: None. R.Tang: None.

The GSK3β/Mcl-1 axis is regulated by both FLT3-ITD and Axl and determines the apoptosis induction abilities of FLT3-ITD inhibitors

Acute myeloid leukemia (AML) patients with FLT3-ITD mutations are associated with poor prognosis. FLT3-ITD inhibitors are developed and result in transient disease remission, but generally resistance develops. We propose that resistance occurs due to apoptosis evasion. We compared the abilities of five clinically used FLT3-ITD inhibitors, namely, midostaurin, crenolanib, gilteritinib, quizartinib, and sorafenib, to induce apoptosis. These drugs inhibit FLT3-ITD and induce apoptosis. Apoptosis induction is associated with GSK3β activation, Mcl-1 downregulation, and Bim upregulation. Sorafenib-resistant MOLM-13/sor cells have the secondary D835Y mutation and increased Axl signaling pathway with cross-resistance to quizartinib. Gilteritinib and crenolanib inhibit both FLT3-ITD and Axl and induce apoptosis in MOLM-13/sor cells, in which they activate GSK3β and downregulate Mcl-1. Inactivation of GSK3β through phosphorylation and inhibitors blocks apoptosis and Mcl-1 reduction. The Axl/GSK3β/Mcl-1 axis works as a feedback mechanism to attenuate apoptosis of FLT3-ITD inhibition. Homoharringtonine decreases the protein levels of Mcl-1, FLT3-ITD, and Axl. Moreover, it synergistically induces apoptosis with gilteritinib in vitro and prolongs survival of MOLM-13/sor xenografts. The GSK3β/Mcl-1 axis works as the hub of FLT3-ITD inhibitors and plays a critical role in resistance against FLT3-ITD AML-targeted therapy.

Новые подходы к ведению пациентов с нестойкой ремиссией круглогодичного аллергического ринита на фоне персистирующей хламидийной инфекции

Currently, allergic rhinitis is a global socioeconomic problem. According to current statistics, from 15 to 30% of the world’s population suffers from year-round or seasonal allergic rhinitis. Increasingly, the attention of Russian clinicians is attracted by the problem of year-round allergic rhinitis as there is an increase in the incidence in patients of the central zone of the Russian Federation with this form of rhinitis due to sensitization to house dust mite allergens, epidermal allergens of domestic animals, insect and mold allergens. Despite a timely diagnosis and received basic treatment, patients suffering from year-round allergic rhinitis often fail to achieve stable remission. Therefore, we can conclude that a more thorough diagnosis of the disease is needed, aimed at identifying other factors that affect the course of the disease. Objective. To develop a scheme for diagnosing a possible persistent respiratory chlamydial infection that affects the course of year-round allergic rhinitis in patients with a tendency to transient remissions. Materials and methods. Computed tomography of the paranasal sinuses, nasal swab for flora, PCR scraping of the nasal mucosa for the detection of Epstein–Barr virus (EBV) DNA, determination of viral DNA of cytomegalovirus infection (CMV) (PCR scraping of the nasal mucosa), determination of DNA in the scraping of epithelial cells of the nasal mucosa (PCR scraping) of human herpes virus type 6 (HHV-6 type). Patients who had pathological changes in computed tomography of the paranasal sinuses, deviations from the normal flora during bacteriological culture, and positive results in the PCR study of the above infections were excluded from the study. Then, PCR scraping of the nasopharyngeal mucosa for the detection of chlamydia pneumoniae, a survey of complaints (SNOT-22 questionnaire), data from an objective examination method (examination of ENT organs using video endoscopic technologies), an immunological examination of blood serum for IgG antibodies to chlamydial infection, further avidity of IgG antibodies to chlamydia pneumoniae and serum IL-6. Conclusion. The proposed diagnostic scheme will allow identifying a possible persistent respiratory chlamydial infection, which is the cause of transient remission of year-round allergic rhinitis, and developing a new integrated approach to the management of patients with year-round allergic rhinitis associated with this infection.

Electrical Status Epilepticus during Sleep: Risk Factors, Clinical Course, and Treatment Approaches

Abstract Background The efforts of clinicians are focused on determining the predictors for electrical status epilepticus in sleep (ESES) manifestation, due to the negative effect of ESES on cognition. Treatment approaches remain a leading problem because of therapeutic resistance. Objective We looked for potential risk factors for ESES manifestation and summarize the clinical course and therapeutic approaches in patients with idiopathic and symptomatic ESES. Patients and Methods We retrospectively reviewed the medical data of 51 children with idiopathic ESES and 20 children with symptomatic ESES. Results We observed an earlier age of seizure onset (p = 0.0002) and a higher percentage of cases with multiple seizures (p < 0.00001) and with postictal paralysis (p < 0.00001) in idiopathic ESES compared with childhood epilepsy with centrotemporal spikes. In the idiopathic ESES, the treatment consisted of corticosteroids in patients with permanent ESES remission and transient remission, levetiracetam (LEV) children with permanent ESES remission and transient, clonazepam (CZP) children with permanent ESES remission and transient, ethosuximide (ESM), and sulthiame. The patients with symptomatic ESES had more unfavorable evolution, as 19 children had persistent or relapsing ESES course. Conclusion We consider the earlier age of seizure onset (below 5 years) and the presence of multiple seizures and postictal paresis as risk factors for ESES manifestation. ESES is characterized by a significant therapeutic resistance, especially in the group of symptomatic cases. Good results are observed with LEV, ESM, CZP, and steroids.

Response to Hypomethylating Agents Plus Venetoclax in Patients with Acute Myeloid Leukemia and Myelodysplastic Syndrome: Real World Data from a Developing Country

Background: Myelodysplastic syndrome (MDS) is a pre-malignant condition characterized by ineffective hematopoiesis, cytopenias and potential to transform into acute leukemia. Acute myeloid leukemia (AML) is a hematological malignancy deriving from myeloid progenitor cells. About one quarter of patients fail to respond to initial therapy (refractory AML). In addition, around 50% of initial responders relapse after a transient remission (relapsed AML). Commonly used salvage chemotherapy regimens include FLAG, FLAG-Ida, HIDAC and Hypomethylating agents (HMA) with or without Venetoclax. In patients who are ineligible for transplant or with poor functional status and in relapsed/refractory cases, treatment options are minimal. However recent data from Western countries has shown promising results with HMA plus Venetoclax in such patients. No such data is available from Pakistan. Objectives: To assess response of HMA plus Venetoclax in patients with AML and MDS treated at Armed Forces Bone Marrow Transplant Center, Rawalpindi, Pakistan. Methods: Study design: Single arm observational prospective study Research Setting: Armed Forces Bone Marrow Transplant Center, Rawalpindi, Pakistan. Study population: Cases included in study were patients of AML and MDS who received HMA plus Venetoclax. A total of 35 patients (25 AML, 10 MDS) were found eligible and included in the final analysis. The primary outcome measured was response to HMA plus Venetoclax. Results: Out of 25 AML patients 17 (68%) were male and 8 (32%) were female. Median age of patients was 44 (range 20-67). Six (24%) patients had AML MRC, 18 (72%) had AML NOS which included 2 (8%) AML-M0, 1 (4%) AML-M1, 9 (36%) AML-M2, 3 (12%) AML-M4 and 3 (12%) patients with AML-M5 while other 3 patients included 1 (4%) patient each of t-AML and AML transformed from Fanconi anemia and aplastic anemia. One (4%) AML-M2 patient had Monosomy 7 and 1 (4%) AML-M5 had trisomy 8. Three (12%), 16 (64%) and 6 (24%) patients were categorized into favorable, intermediate and high risk respectively. Nine (36%) had relapsed disease including 3 (12%) who had relapsed after allogenic HSCT, 8 (32%) had refractory disease while 7 (28%) were unfit for intensive chemotherapy due to advanced age or poor functional status. Median number of HMA+ Venetoclax cycles given were 3 (range 1-16). Overall response rate (ORR) was 44% (n=11), including 9 (36%) patients with CR and 1 (4%) with CRi. One (4%) patient had partial response (PR). Fourteen (56%) patients were non-responders. Of the 10 patients who responded, 6 (24%) achieved remission after 2 cycles while other 4 achieved remission, 1 (4%) patient each, after 1, 3, 5 and 6 cycles. Two (8%) patients underwent allogenic HSCT after achieving remission, including 1 (4%) who had relapsed after first HSCT and underwent second HSCT after achieving CR with HMA+Venetoclax. Out of 10 MDS patients 8 (80%) were male and 2 (20%) were female. Median age of patients was 51 (range 29-71). Two (25%) patients had MDS-MLD, 6 (60%) MDS-EB2 and 2 (20%) had fibrotic MDS. One (10%), 7 (70%) and 2 (20%) patients had intermediate, high and very high risk disease (as per R-IPSS score) respectively. One (10%) patient had relapsed after allogenic HSCT. Median no of cycles of HMA+Venetoclax given were 2 (range 1-6). Three (30%) patients achieved CR (after 2 cycles each), 2 (20%) had stable disease and 5 (50%) patients were non-responders. Two (20%) patients underwent allogenic HSCT after receiving HMA+Venetoclax (Table:1) Common side effects noted were prolonged cytopenias, febrile neutropenia and infections (cellulitis, perianal infections and fungal infections). No treatment related mortality was noted. Conclusion: HMA plus Venetoclax is effective treatment regimen in relapsed/ refractory AML and MDS, however our population shows inferior results as compared to Western population and further large randomized controlled trials are needed to validate this observation. Key Words: Relapsed AML, refractory AML, MDS, salvage chemotherapy, Hypomethylating agents, Venetoclax Research funding: None Word count: 691 Presentation type: Oral Category: Acute Leukemia/ Myelodysplastic syndrome Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Response to [ 177 Lu]Lu-PSMA radioligand therapy in metastatic castration-resistant prostate cancer patients presenting with only lymph node metastases.

Objective[177Lu]Lu-PSMA radioligand therapy (PSMA-RLT) is a promising therapy for patients with metastatic castration-resistant prostate cancer (mCRPC) and offers a survival benefit particularly to patients with only lymph node metastases. We therefore sought to evaluate the clinical outcome of this therapy in such a cohort.MethodsOf all prostate cancer patients admitted to our department between September 2015 and March 2019 to receive 1–4 courses of PSMA-RLT (each course consisted of three cycles of highly standardized PSMA-RLT every 4 weeks), only 10 consecutive men were found to have nodal metastases only and were analyzed retrospectively.ResultsNine out of 10 patients responded to their first PSMA-RLT course with a mean prostate-specific antigen (PSA) decline of 71.8 ± 25.2%, seven of them demonstrated a PSA decline of ≥50%. Collectively, seven of eight patients responded to further PSMA-RLT courses with a total PSA reduction of 59.8 ± 30.0%, five of which showed a PSA reduction of ≥50%. One patient experienced complete remission. Median progression-free survival was 85 weeks (range 14–255 weeks) and median overall survival was not reached during the median observation time of 209 weeks (30–298 weeks). Univariate Cox-regression identified initial PSA decline as the only predictive parameter for progression-free survival (P = 0.047).ConclusionmCRPC patients with only lymph node metastases showed favorable survival and excellent response to PSMA-RLT, leading to transient partial remission of the disease in most of them.

Association of key species of vaginal bacteria of recurrent bacterial vaginosis patients before and after oral metronidazole therapy with short- and long-term clinical outcomes.

Bacterial vaginosis (BV) is associated with a state of vaginal dysbiosis typically involving depletion of otherwise dominant populations of Lactobacillus. The causes of this microbial succession are not known; there may be multiple causes. Standard treatment includes oral metronidazole, which typically restores Lactobacillus species to dominance. However, recurrence rates are high; recurrent BV patients recur 3–4 times annually and are often refractory to treatment. Our previous qPCR-based study of recurrent BV patients pointed to putatively more virulent species of Gardnerella that were associated with refractory responses to oral metronidazole, and less robust recovery of Lactobacillus species associated with recurrence after an initial period of remission. However, these associations did not account for outcomes in all patients, suggesting that other bacterial species were involved. In this follow-up study, we sequenced the V4 domain of 16S rRNA sequences of 41of these same patients pre- and posttreatment. Overall compositions among pretreatment clinical outcome groups were not different, although alpha diversity significantly decreased: refractory > recurrent > remission. Combinations of key species were associated with and prognostic for outcome. Higher pretreatment abundance of Megasphaera lornae together with lower abundance of Gardnerella Gsp07 and Finegoldia magna predicted long term remission after oral metronidazole. Furthermore, a subset of refractory patients that did not have high levels of Gardnerella Gsp07, instead had elevated levels of alternative species including Atopobium vaginae, Mageeibacillus indolicus (BVAB3), and Prevotella timonensis. Patients who recurred after transient remission had elevated abundance of species including Atopobium vaginae, Gardnerella, and Aerococcus christensenii, compared to long-term remission patients. Core bacterial species among refractory patients did not change in abundance after metronidazole, suggesting resistance or tolerance, in contrast to the loss in abundance of the same species among recurrent or remission patients. These findings have potential prognostic and therapeutic implications.

PB1925: VENETOCLAX IN COMBINATION WITH AZACITIDINE OR LOW-DOSE CYTARABINE IN PATIENTS WITH HIGH-RISK MDS AND AML - EXPERIENCE OF A CZECH HAEMATOLOGY CENTRE.

Background: The prognosis of older patients diagnosed with high-risk myelodysplastic syndrome (HR-MDS) or acute myeloid leukemia (AML) ineligible of intensive treatment that are progressing on hypomethylating therapy (HMA) remains dismal. Recently two international, randomized, placebo-controlled clinical trials VIALE-A and VIALE-C compared administration of azacitidine (AZA) or low-dose cytarabine (LD-AraC) alone or in combination with BCL-2 inhibitor venetoclax (VTX) in patients diagnosed with de novo AML. Results were promising with significant prolongation of median overall survival (OS) and achieving early remissions in combination cohort groups. Recently was published also trials involving 78 HMA-naïve high-risk MDS patients (Garcia JS et al., 2020) and a similar trial of 44 patients (Zeidan AM et al. 2020). Aims: To monitor the toxicity of therapy, to identify how many patients received reduced treatment due to cytopenia and to identify markers associated with worse outcome in patients treated with VTX combination therapy. Methods: Panel of 33 genes frequently mutated in MDS was used for mutation screening. Description of Cohort: Patients were treated either with combination of AZA-VTX or LD-AraC-VTX. Our cohort consists of 22 patients (males, N=12, females, N=10) diagnosed with MDS-AML (N=16) or de novo AML (N=6) at the time of VTX administration. Median age was 75 years. Average cytogenetic risk was 1.9 according to IPSS-R. Results: Median total dose of VTX was 1500 mg during standard azacitidine 5-2-2 regimen (75 mg/sqm, 28 day period) or standard LD-AraC regimen (10 mg or 20 mg, 28 day period). The average dose of VTX was 53 mg/day which is lower compared to therapeutic dose used in treatment of other hematologic malignancies due to risk of life-threatening cytopenia. In the group of de novo AML patients we observed ORR of 67% (CR=33%, PR=17%, HI=17%) with median OS on therapy of 6.5 months. In the group of MDS/AML patients we observed ORR of 57% (CR=29%, PR=21%, hematologic improvement (HI)=7%) with median OS on therapy of 5.4 months. We also included 13 patients (59%) after AZA failure as 1 st line of therapy and addition of VTX led to transient remission. Summary/Conclusion: Venetoclax in combination with azacitidine or LD-AraC provides an effective treatment for patients with de novo AML, MDS-AML or MDS patients after azacitidine failure. Total dose of venetoclax is significantly lower due to cytopenia. Reduction of azacitidine dose during first two cycles was associated with worse overall survival (p=0.0191). Mutation of TP53 was associated with worse overall survival (p=0.0184). Achieving of HI-P during first two cycles was associated with better overall survival (p=0.0341). Failure of combination therapy remains unclear and will be studied further.

P142 Inflammatory bowel diseases associated with primary immunodeficiency: a multicenter study

Abstract Background Inflammatory bowel diseases (IBD) associated with primary immunodeficiency (PID) remain poorly known. We aimed to isolate characteristics of IBD associated with PID. Methods Using a GETAID register, we reviewed medical files of recorded patients with PID and IBD (Crohn’s disease, ulcerative colitis (UC) or microscopic colitis) followed in 9 adult university hospitals. Results of genetic investigations were available for 46 patients (62%). Results 74 patients (30 F, 44M) were included with a mean age of 26 years (median: 24 years) at diagnosis of IBD. Forty-four (59%) patients had Crohn’s disease with anoperineal lesions in 12, 26(35%) patients had microscopic (mainly lymphocytic) colitis and 4 patients had UC. PID was predominantly antibody deficiency in 40(54%) patients [34 common variable immunodeficiency, 4 X-linked agammaglobulinemia, 2 selective IgA deficiencies], disease of immune dysregulation in 18(24%) patients [CTLA4, LRBA, NFKB1, TNFAi3, XIAP deficiencies, STAT3 and STAT1 hyperactivation], phagocytosis deficiency in 15(20%) patients (12 chronic granulomatous diseases (CGD), 3 congenital neutropenia] and C1s deficiency (n=1). In order of frequency, Crohn’s disease was associated with antibody deficiencies (52%), phagocytosis deficiencies (29%) and immune dysregulation (18%), microscopic colitis with antibody deficiencies (65%), immune dysregulation (27%) and more rarely with phagocytosis deficiencies (8%) and UC with antibody deficiencies (75%) and immune dysregulation (25%). 46% of patients received immunoglobulin supplementation, 70% steroids, equally corticosteroids and budesonide, 49% biotherapy mainly anti-TNF-alpha antibody (38%) and ustekinumab (16%), 23% immunosuppressive drugs, mainly azathioprine and sirolimus and 18% aminosalicylates. Three patients (2 CGD, 1 XIAP) had been treated with allogeneic stem cell transplantation (SCT) and one patient (TNFRS13B deficiency) with autologous SCT. Eleven (15%) patients had intestinal surgery, mainly ileocecal resection. During follow-up [mean: 16 years], 51% of patients had transient or sustained clinical remission mainly with an anti-TNF-alpha antibody, ustekinumab, steroids (budesonide) and specific therapy (targeted therapy such as abatacept and ASCT), 41% of patients had severe infections, 22% developed neoplasia mainly gastrointestinal dysplasia and/or cancers (n=8), B cell lymphoma (n=3) and 4 patients died. Conclusion At adulthood in our series, IBD associated with PID are mainly Crohn’s disease and lymphocytic colitis. The first most frequent associated PID is antibody deficiency. Biotherapies (anti-TNF-alpha antibody, ustekinumab), steroids and specific therapies are commonly used to induce clinical remission.

Transient remission of chronic active EBV infection after chemotherapy alone.

Transient remission of chronic active EBV infection after chemotherapy alone.

PNC¯27 Targeting Plasma Membrane HDM2: A Potentially Novel Therapeutic Approach for Acute Myeloid Leukemia (AML)

Acute myeloid leukemia (AML) is a devastating hematopoietic malignancy. The vast majority of AML patients are immediately refractory to induction therapy or subsequently relapses following transient complete remission, due to persistence of treatment-resistant leukemia stem cells (LSC). Thus, there is a clear need to identify new targets and develop novel and effective therapeutic approaches in this population. HDM2, an E3 ubiquitin-protein ligase, binds to p53 tumor suppressor in the cytoplasm, repressing p53 transcriptional activity and facilitating its proteasomal degradation. Overexpression of HDM2 plays a key role in tumorigenesis. Recently, it has been reported that HDM2 is not only localized to the cytoplasm but can also be found highly expressed on the plasma membrane of various cancer cells (i.e., colon, breast, pancreas) but not on normal counterparts (PNAS 2010 :107(5):1918-23). PNC-27(Oncolyze, Inc.), a 32-amino acid synthetic peptide with a penetratin domain and a HDM-2-binding domain of p53, can bind with cell membrane HDM2, causing membrane pore formation, thus inducing necrosis in solid tumor cells. However, the activity of PNC-27 in AML has not been established. Using flow cytometry analysis and confocal microscopy with anti-HDM2 antibody (Santa Cruz,N-20), we showed that HDM2 was expressed on the membrane of LSC-enriched CD34+CD38- primary blast populations procured from consecutive AML patients (n=6) at levels greater than those observed on normal CD34+CD38- cells [hematopoietic stem cells (HSC)] from healthy individuals (n=12) [median fluorescence intensity (MFI) (HDM-2/IgG control) 2.5±0.6 vs 1.1±0.1; p<0.01)]. Similar results were also observed in AML cell lines (i.e., THP-1, MV4-11,MOLM-13, NOMO1).Further, we showed that exposure to PNC-27 (50-200ug/ml) for 72 hours resulted in significantly reduced viability and colony formation activity (P<0.001) in both AML cell lines and human AML CD34+ cells compared with normal CD34+ cells, in a dose- and time-dependent manner. PNC-27 antileukemia activity was significantly and directly correlated with cell membrane HDM2 expression levels (p<0.05), more HDM2 expression, higher PNC-27 efficacy. Confocal microscopy using fluorescent anti-HDM2 and anti-PNC-27 antibodies showed that PNC-27 and HDM-2 co-localized to the membrane of primary AML CD34+ blasts. Consistent with the previous studies, we also observed membrane pore formation by electron microscopy and cell necrosis by increased LDH levels rather than apoptosis(no change in Annexin V+ cell percentage and pro-apoptosis protein levels) in PNC-27 treated cells.We further evaluated the efficacy of PNC-27 in vivo . First, CD45.2 BM cells from a MLLPTD/WTFLT3ITD/ITD AML mouse model were transplanted into CD45.1 congenic recipient mice. After confirming AML development, mice were treated with PNC-27 (40mg/kg/day; n= 7) or vehicle (n=9) for two weeks. BM cells from the treated mice were transplanted into 2nd recipient mice (2×106 cells/mouse). A significantly longer survival was observed in the 2nd BM recipients from PNC-27-treated donors (n=8) compared to the 2nd BM recipients from vehicle-treated donors (n=8) (median survival: 41 days vs 32 days; p<0.01). Next, human AML cells were transplanted into NSG-SGM3 mice. Upon confirming >10% human CD45+ cell engraftment in periphery blood (PB), the mice were treated with PNC-27 (40mg/kg/day; n=10) or vehicle (n=10) for 2 weeks, and BM cells (2×106 cells/mouse) from the treated mice were transplanted into 2nd recipient mice. Significantly reduced human CD45+ engraftment in PB at 12 weeks (59.2±7.4 vs 94.6±0.94, p<0.05) and prolonged survival were observed in the 2nd BM recipients from PNC-27-treated donors (n=10) compared to the 2nd BM recipients from vehicle-treated donors (n=7). After four months follow-up, all recipients receiving BM cells from PNC-27-treated donors survived while all recipients receiving BM cells from vehicle-treated donors died (median survival was “not reached” vs 93 days, p<0.0001). Of note wild-type B6 mice treated with PNC-27 (80mg/kg) or vehicle for 2 weeks showed no difference on WBC counts and BM cell counts, suggesting no toxicity on normal hematopoiesis.In conclusion, our results suggest PNC-27 effectively targets AML LSC-enriched population by binding with cell membrane HDM2 to induce necrosis, providing a rationale for a rapid translation of this drug into the clinic. DisclosuresStein:Stemline: Consultancy; Amgen: Consultancy, Speakers Bureau.

Overcoming Leukemia-Induced Immune Suppression in BCR-ABL+ Acute Lymphoblastic Leukemia

BCR-ABL+ acute lymphoblastic leukemia patients have transient responses to current therapies. However, the fusion of BCR to ABL generates a potential leukemia-specific antigen that could be a target for immunotherapy. Herein we demonstrate that the immune system can limit BCR-ABL+ leukemia progression although ultimately this immune response fails. To address how BCR-ABL+ leukemia escapes immune surveillance, we developed a peptide: MHC-II tetramer that labels endogenous BCR-ABL-specific CD4+ T cells. Naïve mice have a small population of BCR-ABL-specific T cells that proliferate modestly upon immunization with the BCR-ABL fusion peptide (referred to as BAp hereafter). In response to BCR-ABL+ leukemia, BCR-ABL specific T cells proliferated and converted into regulatory T cells (Treg cells), a process that was dependent on MHC-II antigen presentation by leukemic cells. Treg cells were critical for leukemia progression in C57Bl/6 mice, as transient Treg cell ablation led to extended survival of leukemic mice. Leukemic B cells produced significantly more TGb1, IL10 and PDL1 than control non-transformed B cells. We are currently extending these studies to determine if leukemia-specific production of TGFb, IL10, or PDL1 plays a critical role in driving tolerance induction. Thus, BCR-ABL+ leukemia actively suppresses the anti-leukemia immune responses by converting cross-reactive leukemia-specific T cells into Treg cells. To determine if we could reverse tolerance we examined whether checkpoint blockade or therapeutic vaccination with BAp peptide could improve survival in mice with pre-established BCR-ABL+ leukemia. Consistent with the low mutation load in our leukemia model, we found that checkpoint blockade with anti-PDL1 and CTLA-4 alone had only modest effects on survival. In contrast, robust heterologous vaccination using LCMV, Listeria, and VSV infection plus a peptide derived from the BCR-ABL fusion (BAp), a key driver mutation, resulted in a small population of mice that survived long-term. Checkpoint blockade strongly synergized with heterologous vaccination to enhance overall survival in mice with leukemia. Enhanced survival did not correlate with numbers of BAp:I-Ab-specific T cells, but rather with increased expression of IL10, IL17, and GrzmB and decreased expression of PD1 on these cells. Our findings demonstrate that vaccination to key driver mutations cooperates with checkpoint blockade and allows for immune control of cancers with low non-synonymous mutation loads. We are currently examining whether we can further improve survival via combination chemotherapy (using Nilotinib which typically only induces transient remission) and immunotherapy (using checkpoint blockade with anti-PD1 or anti-PDL1). DisclosuresFarrar:Merck: Research Funding.

Continuous Complete Remission in Two Patients with Acute Lymphoblastic Leukemia and Severe Fungal Infection Following Short-Term, Dose-Reduced Chemotherapy.

Spontaneous remission in acute lymphoblastic leukemia (ALL) is a rare phenomenon, which typically involves a pattern of feverish or septic disease followed by quick but mostly transient remission. We report on two male patients (46-year-old (pt. 1) and 19-year-old (pt. 2)) with CD20 positive, BCR-ABL negative common B-ALL. Patient 1 had received dexamethasone and cyclophosphamide (1.2 g) as a prephase therapy, followed by rituximab and a cumulative dose of 200 mg daunorubicin combined with 2 mg vincristine as an induction therapy. Patient 2 was treated with a reduced therapy regimen (Vincristine 1 mg, dexamethasone and 80 mg daunorubicin, 12-month mercaptopurine maintenance) due to (alcohol-related) toxic liver failure and pontine myelinolysis. Both patients developed severe septic disease just few days into induction treatment. Patient 1 suffered from pulmonary mycosis, which had to be resected eventually. Histological work-up revealed invasive mucor mycosis. Patient 2 presented with elevated serum aspergillus antigen and radiographic pulmonary lesions, indicative of pulmonary mycosis. In both patients, chemotherapy had to be interrupted and could not be resumed. Both patients recovered under broad antimicrobial, antifungal and prophylactic antiviral therapy and achieved molecular complete remission. At data cut-off remissions had been on-going for 34 months (pt. 1) and 8 years (pt. 2). Short-term, reduced intensity induction chemotherapy accompanied by severe fungal infections was followed by long-lasting continuous complete remissions in ALL. Thus, we hypothesize that infection-associated immunogenic responses may not only prevent early relapse of ALL but could also eradicate minimal residual disease. The effects of combined cytotoxic therapy and severe infection may also be mimicked by biomodulatory treatment strategies aiming at reorganizing pathologically altered cellular signaling networks. This could reduce toxicity and comorbidity in adult patients requiring leukemia treatment. Therefore, these two cases should encourage systematic studies on how leukemia stroma interaction can be harnessed to achieve long lasting control of ALL.

CD4+CD25+CD127hi cell frequency predicts disease progression in type 1 diabetes.

Transient partial remission, a period of low insulin requirement experienced by most patients soon after diagnosis, has been associated with mechanisms of immune regulation. A better understanding of such natural mechanisms of immune regulation might identify new targets for immunotherapies that reverse type 1 diabetes (T1D). In this study, using Cox model multivariate analysis, we validated our previous findings that patients with the highest frequency of CD4+CD25+CD127hi (127-hi) cells at diagnosis experience the longest partial remission, and we showed that the 127-hi cell population is a mix of Th1- and Th2-type cells, with a significant bias toward antiinflammatory Th2-type cells. In addition, we extended these findings to show that patients with the highest frequency of 127-hi cells at diagnosis were significantly more likely to maintain β cell function. Moreover, in patients treated with alefacept in the T1DAL clinical trial, the probability of responding favorably to the antiinflammatory drug was significantly higher in those with a higher frequency of 127-hi cells at diagnosis than those with a lower 127-hi cell frequency. These data are consistent with the hypothesis that 127-hi cells maintain an antiinflammatory environment that is permissive for partial remission, β cell survival, and response to antiinflammatory immunotherapy.

Standardized Plant Immunomodulator Increases the Effect of MEK and BRAF Inhibitors with Clinical Benefit. Case Report of a Patient with Carcinoma in Biliary Duct

Background: Targeting hyperactive mitogen-activated protein kinase (MAPK) signaling cascade has proven to be an effective treatment for a variety of different cancers. Using an important member of this cascade, namely MEK (mitogen-activated extracellular signal regulation kinase) inhibitors, the clinical responses are often transient and complete remission is rarely observed. It was shown that growth factor receptor signaling pathway inhibitors can increase the immune sensitivity of tumor cells but they can’t activate the down regulated immune effectors. Consequently, the combination of MAPK cascade signaling pathway inhibitors and the immune effectors activating immunomodulators may be a promising new strategy. Material and Methods: In a now 59 years old patient with inoperable (BRAF-mutant) low differentiated adenocarcinoma of biliary ducts after 30GY radiotherapy and two cycles (Gemcitabin+ Cisplatin) chemotherapy a rapid progression of lung, liver and brain metastases were by CT and MR established. A treatment was tarted with BRAF+MEK inhibitors (2x150 mg dabrafenib and 1 x 2 mg trametinib). These inhibitors were combined with daily 45 mg/kg rice bran arabinoxylan concentrate (using Biobran/MGN-3) which was shown to be a pathogenic associated molecular pattern (PAMP)-like molecule and can stimulate the type-1 innate immune cells against tumor cells. Results: After the chemotherapy and before the start of second-line treatment, the patient had a nearly terminal state of her rapidly progressive disease. Eight months after the combination of MEK / BRAF inhibitor and immunomodulator therapy nearly complete remissions of all metastases were established in CT and MR. Conclusion: This case report may support a hypothesis that MEK/BRAF inhibitors and type-1 immune cells activating immunomodulators together may synergistically inhibit the tumor growth. Further clinical investigations are necessary to clarify this question.

S219. SINGLE-SUBJECT PREDICTION OF FUNCTIONAL OUTCOMES ACROSS DIAGNOSTIC GROUPS USING CLINICAL DATA

BackgroundPsychotic disorders are associated with serious deterioration in functioning even before the first psychotic episode. Also on clinical high risk (CHR) states of developing a first psychotic episode, several studies reported a decreased global functioning. In a considerable proportion of CHR individuals, functional deterioration remains even after (transient) remission of symptomatic risk indicators. Furthermore, deficits in functioning cause immense costs for the health care system and are often more debilitating for individuals than positive symptoms. However in the past, CHR research has mostly focused on clinical outcomes like transition. Prediction of functioning in CHR populations has received less attention. Therefore, the current study aims at predicting functioning in CHR individuals at a single subject level applying multi pattern recognition to clinical data. Patients with a first depressive episode who frequently have persistent functional deficits comparable to patients in the CHR state were investigated in addition.MethodsPRONIA (‘Personalized Prognostic Tools for Early Psychosis Management’) is a prospective collaboration project funded by the European Union under the 7th Framework Programme (grant agreement n°602152). Considering a broad set of variables (MRI, clinical data, neurocognition, genomics and other blood derived parameters) as well as advanced statistical methods, PRONIA aims at developing an innovative multivariate prognostic tool enabling an individualized prediction of illness trajectories and outcome. 11 university centers in five European countries and in Australia (Munich, Basel, Birmingham, Cologne, Düsseldorf, Münster, Melbourne, Milan, Udine, Bari, Turku) participate in the evaluation of three clinical groups (subjects clinically at high risk of developing a psychosis [CHR], patients with a recent onset psychosis [ROP] and patients with a recent onset depression [ROD]) as well as healthy controls.In the current study, we analysed data of 114 CHR and 106 ROD patients. Functioning was measured by the ‘Global Functioning: Social and Role’ Scales (GF S/R). In a repeated, nested cross validation framework we trained a l1-regularized SVM to predict good versus bad outcome. Multivariate pattern recognition analysis allowed to identify most predictive variables from a multitude of clinical, environmental as well as sociodemographic potential predictors assessed in PRONIA.ResultsBased on the 5 to 20 identified most predictive features, prediction models revealed a balanced accuracy (BAC) up to 77/72 for social functioning in CHR/ROD patients and up to 73/69 for role functioning. These models showed satisfying performance of BACs up to 69/63 for social functioning and 67/60 for role functioning in an independent test sample. As expected, prior functioning levels were identified as main predictive factor but also distinct protective and risk factors were selected into the prediction models.DiscussionResults suggest that especially prediction of the multi-faceted construct of role functioning could benefit from inclusion of a rich set of clinical variables.To the best of our knowledge this is the first study that has validated clinical prediction models of functioning in an independent test sample. Identification of predictive variables enables a much more efficient prognostic process. Moreover, understanding the mechanisms underlying functional decline and its illness related pattern might enable an improved definition of targets for intervention. Future research should aim at further maximisation of prediction accuracy and cross-centre generalisation capacity. In addition, other functioning outcomes as well as clinical outcomes need to be focused on.

Diagnosis, treatment, and survival analysis of adrenocortical carcinomas: a multicentric study.

Current guidelines specify controversial areas in adrenocortical carcinomas (ACC), such as optimal follow-up time after remission and identification of prognostic markers. We aim to address these topics by analyzing four reference centers in our country. Cross-sectional multicentric study of 69 patients (mean age: 51.7 ± 16.7 years-old; women, 72.5%). Kaplan-Meier survival curves and Cox regression analysis were used to calculate overall survival and its predictors. Thirty-eight individuals (55.0%) had hormonal autonomous production, and 40.6% of the patients presented with metastasis. Surgery was performed in 84.1% of them. Most of these patients (72.4%) were then assigned to adjuvant therapy, while 27.6% were actively surveilled. Among patients undergoing surgery, those who achieved transient remission presented a longer survival time (66 months) than those who never reached the disease-free status (21 months) (p = 0.021). One patient presented with recurrence more than 7 years after complete tumor resection. The lowest overall survival was observed in patients (n = 11) assigned to palliative care since diagnosis (9 months). Tumor stage was identified as the only independent predictor of survival in our cohort (p = 0.006). Five-year survival was 67% for tumors confined to the adrenal space (stage I/II), 56% for locally advanced disease (stage III), and 0% for metastatic disease (stage IV). This study reinforces the dismal prognosis of ACC, the need for long-term follow-up, and tumor stage as the most important survival predictor. Reviewing medical records in such rare conditions is an opportunity to identify insufficiencies and to improve medical care.

Decitabine shows synergistic effects with arsenic trioxide against myelodysplastic syndrome cells via endoplasmic reticulum stress-related apoptosis

Most of the International Prognostic Scoring System (IPSS) high-risk patients with myelodysplastic syndrome partly responded to hypomethylating therapy even with transient remission, while arsenic trioxide (ATO) had partial effect in...