ALBERT

Description: Key Points The genetic cause of SCID impacts on survival and immune reconstitution and should be considered in tailoring HCT for individual patients. Total and naive CD4+ cell counts in SCID patients 6 and 12 months post-HCT predict long-term survival and sustained immune reconstitution.

Description: Pathogenic gain-of-function variants in the genes encoding phosphoinositide 3-kinase δ (PI3Kδ) lead to accumulation of transitional B cells and senescent T cells, lymphadenopathy, and immune deficiency (activated PI3Kδ syndrome [APDS]). Knowing the genetic etiology of APDS afforded us the opportunity to explore PI3Kδ inhibition as a precision-medicine therapy. Here, we report in vitro and in vivo effects of inhibiting PI3Kδ in APDS. Treatment with leniolisib (CDZ173), a selective PI3Kδ inhibitor, caused dose-dependent suppression of PI3Kδ pathway hyperactivation (measured as phosphorylation of AKT/S6) in cell lines ectopically expressing APDS-causative p110δ variants and in T-cell blasts derived from patients. A clinical trial with 6 APDS patients was conducted as a 12-week, open-label, multisite, within-subject, dose-escalation study of oral leniolisib to assess safety, pharmacokinetics, and effects on lymphoproliferation and immune dysregulation. Oral leniolisib led to a dose-dependent reduction in PI3K/AKT pathway activity assessed ex vivo and improved immune dysregulation. We observed normalization of circulating transitional and naive B cells, reduction in PD-1+CD4+ and senescent CD57+CD4− T cells, and decreases in elevated serum immunoglobulin M and inflammatory markers including interferon γ, tumor necrosis factor, CXCL13, and CXCL10 with leniolisib therapy. After 12 weeks of treatment, all patients showed amelioration of lymphoproliferation with lymph node sizes and spleen volumes reduced by 39% (mean; range, 26%-57%) and 40% (mean; range, 13%-65%), respectively. Thus, leniolisib was well tolerated and improved laboratory and clinical parameters in APDS, supporting the specific inhibition of PI3Kδ as a promising new targeted therapy in APDS and other diseases characterized by overactivation of the PI3Kδ pathway. This trial was registered at www.clinicaltrials.gov as #NCT02435173.

Description: Interleukin-2 (IL-2) is able to induce the regression of metastatic cancers when administered in vivo. IL-2-activated natural killer cells and lymphocytes show, in vitro, activities against leukemic cells. To assess if in vitro observations could have significant clinical relevance, we evaluated the in vivo activity of high-dose recombinant IL-2 (6 to 8 x 10(6) IU/m2/8H intravenous bolus for 5 days) in 10 patients with acute myeloid leukemias (AML) in relapse after chemotherapy (n = 7) or autologous bone marrow transplantation (n = 3). Two patients achieved a complete remission and one had a minimal improvement in his marrow blast cells. Response was observed after one cycle of IL-2 in the two patients achieving a complete remission. These two patients relapsed at 3 and 4 months. These results showing clinical activity of high-dose recombinant IL-2 in AML invite further evaluation of this new form of immunotherapy in other clinical situations, like an adjuvant setting for selected groups of high-risk patients.

Description: Key Points Donor-derived Tc17 cells differentiate early after allogeneic transplant in response to IL-6 and alloantigen presentation by host DCs. Tc17 are highly proinflammatory and pathogenic posttransplant, but exert limited or no GVL activity.

Description: Background: CD19-directed chimeric antigen receptor (CAR) T cell therapy is FDA approved for relapsed/refractory diffuse large B cell lymphoma (R/R DLBCL) and variants. Due to active lymphoma, "bridging" therapy may be needed to maintain disease control during the 3 or more weeks required for autologous CAR T manufacturing. Bridging therapy was not allowed in trials of axicabtagene ciloleucel (axi-cel), but could improve outcomes by reducing tumor burden. Bridging chemotherapy is one option, however toxicity and chemo-refractory disease are potential concerns. Here we report a case series of patients receiving bridging radiation therapy (XRT) prior to axi-cel therapy, of which the majority had double hit lymphoma. Patient Characteristics: As of July 31, 2018 eight patients received XRT as part of their bridging therapies. Overall, patients had a median of 3 prior lines of chemotherapy (range 2 to 5). Two were primary refractory to their first two lines of chemotherapy. Six of the 8 patients had double hit lymphoma by FISH. All patients received 3-4 Gy per fraction to a total median dose of 20 Gray (range 9 - 30 Gy). The most commonly used regimen was 30 Gy in 10 fractions (3/7 patients). Four patients received bridging chemotherapy in addition to XRT, mainly oral cytoxan. In 2 patients the XRT was given up until the day of leukapheresis and in 1 of these patients it was continued after leukapheresis. In 6 additional patients the XRT started after leukapheresis. Overall, XRT was completed at a median of 9 days (range 3 - 22 days) prior to starting Flu/Cy conditioning. The median mass diameter receiving XRT was 13.6 cm (range 3 - 30 cm). Outcomes: No significant adverse events were noted at the local site of XRT before or after CAR T infusion. Response assessment within the field of radiation is complicated by a short duration between end of XRT and restaging prior to Flu/Cy conditioning. Nonetheless, only one patient experienced progressive disease in-field after XRT and most had stable disease in-field. Of the 4 cases where the baseline LDH was elevated, only the patient with PD saw their LDH rise after the completion of XRT, while the other 3 of 4 patients had declining LDH at the time of Flu/Cy conditioning. In 7 patients evaluable for toxicity, there was one case of severe cytokine release syndrome (CRS). This event occurred in the patient who progressed through XRT and had rising LDH and declining performance status prior to CAR T infusion (this patient later died of infection). In the other 6 patients the maximum CRS was grade 1 or 2. Three out of the 7 patients had grade 3 or 4 CAR T related encephalopathy syndrome (CRES). For lymphoma outcomes at day 30, 1 patient was in CR, 2 patients PR, 2 patients with SD and 1 patient with PD (Lugano criteria). Two patients are evaluable at day 90 with PR, although one of these patients subsequently relapsed at month 4 (in-field to the prior radiation). Conclusions: Bridging XRT (with or without chemotherapy) can be safely administered and provides disease control in refractory poor risk DLBCL patients prior to axi-cel therapy. All patients were able to receive axi-cel. CAR T-related toxicity occurred, but in this case series was most likely related to disease aggressiveness (6 of 8 patients were double hit) and tumor burden. Further research should focus on the immunologic effects of XRT and its impact on CAR T cell efficacy and toxicity. Table. Table. Disclosures Chavez: Humanigen: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Kite: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Speakers Bureau; Merck: Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Davila:Celyad: Consultancy, Membership on an entity's Board of Directors or advisory committees. Locke:Cellular BioMedicine Group Inc.: Consultancy; Kite Pharma: Other: Scientific Advisor; Novartis Pharmaceuticals: Other: Scientific Advisor.

Description: Introduction: Aggressive chemo-immunotherapy followed by peripheral blood stem cell autografting (ASCT) in CALGB 59909 achieved a median progression-free survival (PFS) in MCL of 5 years (Damon et al JCO, 2009), but late recurrences occurred. Bortezomib has a 33% response rate in relapsed/refractory MCL. Using the CALGB 59909 treatment backbone, we evaluated tolerability and efÞcacy of adding post-transplant BC or BM in a randomized phase II trial. Methods: The primary endpoint was PFS estimated from study entry for each treatment arm. Induction therapy was with 2-3 cycles of augmented R-CHOP (2000 mg/m2 cyclophosphamide) and methotrexate (300 mg/m2) followed by high-dose cytarabine/etoposide/rituximab(R)/Þlgrastim (EAR) stem cell mobilization and cyclophosphamide/carmustine/etoposide (CBV) ASCT. After 2 doses of post-transplant R, patients were randomized to BC (1.3 mg/ m2 days 1, 4, 8, 11 of a 3 week cycle for 4 cycles) or BM (1.6 mg/m2 weekly 4 of 8 weeks for 18 months) beginning at approximately day 90. Minimal residual disease (MRD) was analyzed using patient-specific PCR probes for the bcl-1 / IgH junction or the IgH CDR3 region. Results: 151 patients were enrolled at 14 sites and 147 received treatment. Median age was 59 (29-69); stage II (2.7%), III (12%), IV (86%); MIPI low (52.4%), int. (30.6%), high (17%); blastoid histology (14%); bone marrow involvement (81%). 118 (88%) underwent ASCT and 102 (68%) were randomized. Most withdrawals (45) were for progression (10) or adverse events (AEs) (19) including 4 treatment-related deaths. Following randomization, 34 (65%) completed BM and 33 (66%) completed BC. Withdrawal for AEs occurred in 14 (28%) of BC and 7 (13%) of BM patients (p = 0.088), most for cytopenias or peripheral neuropathy. Median follow-up was 5.5 years from registration. Median PFS was significantly greater than the null hypothesis (4 years) for both BM and BC (1-sided test of exponential parameter p 〈 0.001). The 5-year PFS estimates from study entry in the BM and BC arms were 70% (55-81%) and 69% (54-80%), respectively. Progression occurred in 17 BM (12 post-treatment) and 19 BC patients (all post-treatment). Five-year PFS from time of transplantation in CALGB studies 50403 (n=118) and 59909 (n=66) was 72.7% (63-80%) and 51.5% (36.7-62%), respectively (log rank p=0 0006) favoring the 50403 trial which differed from 59909 only by the addition of post-transplant bortezomib. MRD results were available in 47 patients. Five-year PFS from study entry was 93% if MRD-negative (n=15) and 51% if MRD-positive (n=32) following induction chemo-immunotherapy (log rank p=.003) (See figure). Conclusions: Induction chemotherapy followed by ASCT and either BC or BM was efficacious and tolerable, although BC was associated with more withdrawals for toxicity. The comparison between studies 50403 and 59909 suggests a PFS benefit from the addition of BC or BM. MRD-negativity following induction chemo-immunotherapy is highly associated with improved PFS and could provide an important tool for designing future trials. Figure 1. Figure 1. Disclosures Off Label Use: Post-autotransplant use of bortezomib . Bartlett:Seattle Genetics: Consultancy, Research Funding; Gilead: Consultancy; Janssen: Research Funding; Pharmacyclics: Research Funding; Astra Zeneca: Research Funding; ImaginAB: Research Funding; Genentech: Research Funding; Pfizer: Research Funding; Novartis: Research Funding; Medimmune: Research Funding; Millenium: Research Funding; Celgene: Research Funding. Byrd:Acerta Pharma BV: Research Funding. Blum:cephalon: Research Funding; Janssen: Research Funding; Celgene: Research Funding; Pharmacyclics: Research Funding. Hurd:Procter and Gamble: Equity Ownership; Medtronic: Equity Ownership; Pfizer: Equity Ownership; Merck: Equity Ownership; Bristol Myers Squib: Equity Ownership. Czuczman:MorphoSys: Consultancy; Cellgene: Employment; Immunogen: Membership on an entity's Board of Directors or advisory committees; Boehringer-Ingelheim: Membership on an entity's Board of Directors or advisory committees. Leonard:Weill Cornell Medical College: Employment; Genentech: Consultancy; Medimmune: Consultancy; AstraZeneca: Consultancy; Spectrum: Consultancy; Boehringer Ingelheim: Consultancy; Vertex: Consultancy; ProNAI: Consultancy; Biotest: Consultancy; Seattle Genetics: Consultancy; Pfizer: Consultancy; Mirati Therapeutics: Consultancy; Gilead: Consultancy; Novartis: Consultancy. Cheson:AstraZeneca: Consultancy; Astellas: Consultancy; Ascenta: Research Funding; Spectrum: Consultancy; Teva: Research Funding; MedImmune: Research Funding; Pharmacyclics: Consultancy, Research Funding; Gilead: Consultancy, Research Funding; Roche/Genentech: Consultancy, Research Funding; Celgene: Consultancy, Research Funding.

Description: Background: Therapy for patients (pts) with high risk AML remains unsatisfactory. Retrospective studies have demonstrated activity of fludarabine, cytarabine, GCSF and idarubicin (FLAG-IDA) and of mitoxantrone, etoposide and cytarabine (NOVE-HiDAC) as salvage therapy in pts with relapsed or refractory AML. A recent randomized trial indicated high complete remission (CR) rates with improved relapsed-free survival when FLAG-IDA is administered as frontline induction therapy (Burnett et al. J Clin Oncol 2013). Since 01/2011, we have used FLAG-IDA as a first line therapeutic option in pts with high risk AML (poor risk cytogenetics, antecedent myeloproliferative neoplasm or myelodysplastic syndrome, and/or therapy-related AML) in an attempt to improve CR rates and permit more patients with AML to advance to allogeneic hematopoietic cell transplantation (alloHCT). Prior to 2011, either 3&7 or NOVE-HiDAC was used as first line therapy in patients with AML. Methods: We conducted a retrospective review of consecutive patients with high risk AML treated with front-line (a) FLAG-IDA between 01/2011 to 03/2015, (b) NOVE-HiDAC from 01/2006 to 12/2014, or (c) 3&7 from January 01/2011 to 12/2014 at the Princess Margaret Cancer Centre, to determine the CR rates and overall survival (OS) associated with the different regimens. Results: Patients characteristics are in Table 1. Fifty-two, 32, and 30 pts received FLAG-IDA, NOVE-HiDAC or 3&7 as first induction, respectively. Patients receiving FLAG-IDA had more high-risk features (i.e. complex cytogenetics, more azacytidine failures) compared to those receiving 3&7. Overall CR rate (i.e. CR + [CRi] + [CRp]) with FLAG-IDA, NOVE-HiDAC, and 3&7 respectively was 86% (n=42/49), 84% (n=21/25) and 50% (n=13/26), respectively. Median CR duration, censored at time of transplant, for pts receiving FLAG-IDA, NOVE-HiDAC and 3&7 was 3 mos (0.5-15), 3.5 mos (1-9) and 5.5 mos (0.5-42), respectively. OS at 1 year with FLAG-IDA, NOVE-HiDAC and 3&7 was 61% (95% CI, 41% -75%), 55% (95% CI, 34%-72%) and 21.6% (95% CI, 7.4%-40.7%), respectively (log-rank test p-value=0.0076). On subgroup analysis, there was no statistical difference in OS for pts ≥70 years. Of those with a donor identified, 35% (n=13/37), 73% (n=11/15) and 29% (n=5/17) of pts who were treated with FLAG-IDA, NOVE-HiDAC and 3&7 underwent an alloSCT, respectively. Pts with sAML may have had a higher transplant rate due to donor searches initiated earlier. Probable and possible invasive aspergillosis infections in pts receiving FLAG-IDA, NOVE-HiDAC and 3&7 were 50%, 34% and 33% respectively. Institution of earlier bronchoscopies led to increased fungal detection in the FLAG-IDA group. Median length of stay and ICU transfers were similar between groups. Induction deaths were secondary to sepsis, respiratory failure, invasive aspergillosis, and hemorrhage; these were similar across groups. Two pts receiving NOVE-HiDAC, with prior MPN, died of progressive splenomegaly and liver failure. Conclusions: Toxicities associated with frontline FLAG-IDA and NOVE-HIDAC induction are acceptable. FLAG-IDA and NOVE-HiDAC induction can result in durable CR, permitting patients with high risk AML to proceed to alloSCT and providing more favourable survival rates than frontline 3&7. Randomized studies are needed to confirm these findings for pts with poor-risk sAML and tAML. Table 1. Patient Characteristics FLAG-IDA(2013-2015) NOVE-HiDAC(2006-2014) 3&7(2011-2014) N=52 N=32 N=30 Median Age,y (range) Age

Description: Background: The Wiskott-Aldrich syndrome (WAS) including X-linked thrombocytopenia (XLT) is a complex disorder with a wide range of disease severity and unique hematological and immunological manifestations. Based on this complexity, several approaches are available to these patients, including observation, symptomatic treatment, splenectomy, gene therapy (GT), or allogeneic hematopoietic stem cell transplantation (HSCT). In many instances more than one of these therapeutic options may seem appropriate for any given patient. A prospective, randomized study comparing the pros and cons of these therapeutic options in WAS/XLT would be desirable, but is not feasible due to the rarity and variable severity of the disease, as well as the need for long-term follow-up. Methods and Definitions: We retrospectively assessed via an international, anonymized, file-based survey the consequences of different therapies based on the severity of the disease phenotype and how these therapies affected patients' quality of life as perceived by their treating physician. The frequency of disease- and therapy-related complications with respect to the specific treatment was recorded. "Severe events" were defined as: all fatal events or sepsis, meningitis, pneumonia requiring respiratory support, systemic viral/fungal infections or serious bleeding episodes (intracranial and gastrointestinal) requiring transfusion support. Allogeneic HSCT, splenectomy and GT were defined as "procedures", HSCT and GT as "definitive". Results: A total of 575 patients with a documented WAS gene mutation from 51 centers in 27 countries with a median follow-up of 7.4 years (range: 0.2-75.6), resulting in 5632 patient years, were included in the study. Of these, 240 (42%) carried missense, 67 (12%) nonsense, 90 (16%) splice-site mutations, 77 (13%) deletions, 40 (7%) insertions and 61 (11%) had incomplete or inconclusive mutation information. An allogeneic HSCT was performed in 252 (44%), splenectomy in 78 (14%), GT in 14 (2%) patients, while 264 (46%) patients never had a procedure. At the time of last follow-up or before the first procedure the WAS disease severity score was 1 in 55 (10%), 2 in 144 (25%), 3 in 161 (28%), 4 in 109 (19%) and 5 in 86 (15%) patients. Overall survival of the entire cohort (censored at the time of first definitive procedure, thereby representing the "natural" disease outcome) was 82% (95% confidence interval 78-87) at 15 years and 70% (61-80) at 30 years of age. Ten year overall survival after HSCT was 80 % (74-85). The cumulative incidence (CI) of severe bleeding, severe infection, autoimmunity or malignancy in patients without a procedure at last follow-up or censored before the first procedure was 45% (39-50), 61% (55-66), 46% (40-52) and 31% (25-37) respectively at 15 years of age and 61% (51-69), 70% (62-76), 62% (52-70) and 45% (35-53) at 30 years. The frequency of definitive procedures (HSCT or GT) increased in patients with higher WAS scores, while better natural disease outcomes were associated with lower WAS scores. Overall quality of life (QoL) as perceived by the treating physician was very good, good, limited or unacceptable in 85/457 (19%), 172/457 (38%), 176/457 (39%) and 24/457 (5%) of patients without or before a procedure respectively. QoL was also strongly correlated with the WAS score. At last follow-up after successful HSCT QoL improved to very good in 123/184 (67%), good in 47/184 (26%), limited in 12/184 (7%) and unacceptable in 2/184 (1%). Splenectomy also had a favorable effect on QoL with 16/52 (31%) very good, 24/52 (46%) good, 9/52 (17%) limited and 3/52 (6%) unacceptable. Platelet counts improved from a baseline mean of 36G/l to 91G/l after GT, 159G/l after splenectomy and 204G/l after HSCT. Conclusion: This study presents outcome data of the largest cohort of patients with a WAS gene mutation studied so far and confirms the anticipated spectrum of disease severity and the curative effect of HSCT. The data show that untreated patients with WAS suffer from increasing rates of disease-associated complications over time which correlates well with a significant reduction of QoL. Both HSCT and splenectomy have a positive effect on physician-perceived QoL. Due to the large cohort size this study's data will allow us to assess the influence of specific genotypes on outcome in WAS (analysis ongoing), possibly allowing for more individualized treatment recommendations in the future. Disclosures Albert: GSK: Research Funding.

Description: Interleukin-2 (IL-2) is able to induce the regression of metastatic cancers when administered in vivo. IL-2-activated natural killer cells and lymphocytes show, in vitro, activities against leukemic cells. To assess if in vitro observations could have significant clinical relevance, we evaluated the in vivo activity of high-dose recombinant IL-2 (6 to 8 x 10(6) IU/m2/8H intravenous bolus for 5 days) in 10 patients with acute myeloid leukemias (AML) in relapse after chemotherapy (n = 7) or autologous bone marrow transplantation (n = 3). Two patients achieved a complete remission and one had a minimal improvement in his marrow blast cells. Response was observed after one cycle of IL-2 in the two patients achieving a complete remission. These two patients relapsed at 3 and 4 months. These results showing clinical activity of high-dose recombinant IL-2 in AML invite further evaluation of this new form of immunotherapy in other clinical situations, like an adjuvant setting for selected groups of high-risk patients.

Description: Background: Activating mutations of NRAS and KRAS genes are common in newly diagnosed acute myeloid leukemia (AML), occurring in 11-16% and 4-5% of patients, respectively. RAS mutations are frequently acquired at time of progression from MDS to AML and are associated with poor survival. Next generation sequencing (NGS) at diagnosis and during complete remission has shown that RAS mutations have high clearance rates with induction chemotherapy. In the CALGB 8525 study, RAS-mutant younger patients (age