Background:Spleen tyrosine kinase (SYK) is a nonreceptor cytoplasmic tyrosine kinase primarily expressed in cells of hematopoietic lineage. Constitutive activation of SYK in acute myeloid leukemia (AML) has been reported and targeted inhibition of SYK induced differentiation in vitro and demonstrated anti-leukemia activity in AML mouse models. SYK has also been shown to directly phosphorylate the FLT3 receptor, modulating its activation and possibly promoting its role in leukemogenesis. Entospletinib is an orally bioavailable, selective inhibitor of SYK shown to be clinically active in B-cell malignancies. Here we evaluate the combination of entospletinib in patients with untreated AML using a 14-day window phase to assess single-agent activity, then adding standard intensive chemotherapy. Methods: In this phase 1b/2 study (NCT02343939), patients age 18 to 70 years with previously untreated AML, preserved organ function, and ECOG ≤ 2 were eligible to receive dose escalated entospletinib for 14 days as monotherapy (days -14 to 0) followed by combination with daunorubicin 60 mg/m2/d, cycle 1 day 1 to 3, and cytarabine 100 mg/m2/d, cycle 1 day 1 to 7. All patients received entospletinib monotherapy for up to 14 days prior to starting induction. Chemotherapy could be initiated after 5 days of monotherapy (and entospletinib continued for 4+ weeks) in patients with leukemia-related complications necessitating chemotherapy. Patients enrolled to dose level (DL) 0 and DL 1 received entospletinib 200 mg po BID and 400 mg po BID, respectively. Patients with residual disease two weeks after chemotherapy received a second induction cycle identical to the first. Entospletinib was continued without interruption until remission was assessed at count recovery. Results:Twelve patients enrolled with a median age of 54 (range, 18-69) years. Patients were in the following European LeukemiaNet genetic risk groups: favorable (n=1), intermediate I (n=3), intermediate II (n=2), and adverse (n=4), respectively. Three patients were not evaluable for dose limiting toxicity (DLT) assessment and were replaced (due to detection of CNS disease requiring non-study therapy (n=1), and withdrawal of consent unrelated to drug toxicity (n=2)). Single-agent entospletinib during the window period was well tolerated; toxicities after combination with intensive chemotherapy were common and typical. Among 3 patients treated at 200mg BID, no DLT was observed. Of 3 patients treated at 400mg BID, a patient with documented fungal pneumonia developed grade 3 pneumonitis that was possibly related to entospletinib. Although this did not meet DLT criteria, DL 1 was expanded with 3 additional patients, none of whom experienced DLT. Overall, the most common non hematologic adverse events (inclusive of intensive chemotherapy periods) were febrile neutropenia, nausea, and diarrhea. Based on this clinical experience and compiled pharmacokinetic data demonstrating lack of benefit to further dose escalation, 400 mg BID was selected as the recommended phase 2 dose. Responses were seen at both levels. Among the 3 patients treated at 200 mg BID, two required a second induction but all achieved a complete remission (CR) (3/3; 100%). Of the 6 patients treated at 400mg BID, none required a second induction and the CR rate was also 100%. Remarkably, an 18 year old male with 11q23-rearranged AML achieved morphologic and cytogenetic CR after only the 14 day entospletinib monotherapy window (prior to chemotherapy). Another patient with 11q23-rearranged AML had significant platelet response during the window period (this patient refused disease evaluation by marrow aspiration prior to chemotherapy). Conclusions: Entospletinib appears to have significant clinical activity in AML, and its combination at doses up to 400mg BID with intensive chemotherapy is well tolerated. An extended phase 2 program is now underway. Patients with 11q23-rearranged AML may be uniquely sensitive to SYK inhibition by entospletinib. Detailed molecular analysis of these patients is ongoing and will be presented. Disclosures Walker: Gilead Sciences: Research Funding. Bhatnagar:Karyopharm: Research Funding. Marcondes:Gilead Sciences: Employment, Equity Ownership. DiPaolo:Gilead Sciences: Employment, Equity Ownership. Abella-Dominicis:Gilead Sciences: Employment, Equity Ownership.

This case presents an unusual manifestation of cutaneous chronic graft-vs-host disease (cGVHD) mimicking psoriasis along Blaschko's lines. Such a presentation may pose a particular challenge to providers as it is quite rarely reported, and, therefore, it is possibly misdiagnosed. cGVHD may mimic psoriasis and should be considered in any patient previously transplanted even with a previous history of psoriasis. A Blaschkoid pattern of cGVHD is unusual and may be the manifestation of an immune reaction unveiling a previously masked mosaicism.

Background: Recent advances in the treatment of myelodysplastic syndrome (MDS) have improved patient survival and quality of life (QOL), while reducing transfusion burden. However, allogeneic hematopoietic cell transplantation (HCT), widely used in younger MDS patients, remains the only curative therapy for MDS. While transplantation outcomes among selected older patients with MDS are similar to younger patients with MDS, early transplantation for older patients is infrequently offered since the relative benefits of HCT over non-HCT therapy in have not been well defined in this patient group. We conducted a multi-center, biologic assignment trial in older individuals with high risk MDS to define the benefit of HCT over non-HCT therapy. Methods: The study was a multicenter, biologic assignment trial in subjects aged 50-75 with higher risk de novo MDS (IPSS Intermediate-2 (Int-2) or High) who were candidates for reduced-intensity conditioning (RIC) allogeneic HCT, comparing outcomes of those with a suitable 8/8 HLA-matched donor to those without a donor. The trial was conducted by the Blood and Marrow Transplant Clinical Trials Network (BMT CTN 1102, NCT02016781). Eligible subjects were enrolled prior to a formal donor search, and before or after MDS treatment was initiated. Biological assignment to the Donor or No Donor arm was based on high-resolution HLA typing of eligible family members and a search of the unrelated donor registries. Subjects were initially assigned to the No Donor arm and re-assigned to the Donor arm when a suitable donor was identified. Subjects who died or whose 90-day donor search ended without identifying a suitable donor remained in the No Donor arm. Subjects in the Donor arm were expected to undergo RIC HCT within 6 months of enrollment. Subjects underwent RIC HCT or non-HCT therapy according to institutional standards. The primary analysis compared three-year overall survival (OS) between arms using adjusted survival estimates to account for the potential bias resulting from biological assignment. The sample size was selected to provide at least 80% power to detect a difference of 15% in 3-year OS. Between January 2014 and November 2018, 384 subjects (Donor n=260, No Donor n=124) were enrolled at 34 centers. The study arms were well balanced for age, gender, KPS, IPSS risk, MDS disease duration and responsiveness to hypomethylating therapy (Table). The median follow-up time for surviving patients was 34.2 months (range: 2.3-38 months) in the Donor arm and 26.9 months (range: 2.4-37.2 months) in the No Donor arm. Results: In an intent-to-treat analysis, adjusted OS at 3 years from study enrollment in the Donor arm was 47.9% (95% CI: 41.3%-54.1%) compared with 26.6% (95% CI: 18.4%-35.6%) in the No Donor arm (p=0.0001, absolute difference 21.3%, 95% CI: 10.2%-31.8%)(Figure). A sensitivity analysis excluding subjects assigned to the No Donor arm who died or withdrew prior to the end of the 90-day search window showed no effect on outcome (Adjusted OS: 48.0% vs. 28.1%, p=0.0004). Leukemia-free survival (LFS) at 3 years was greater in the Donor arm (35.8%, 95% CI: 29.8%-41.8%) compared with the No Donor arm (20.6%, 95% CI: 13.3%-29.1%, p=0.003), with no changes in the sensitivity analysis. An OS and LFS benefit was seen across all subgroups tested (Figure). There were no clinically significant differences in QOL between Donor and No Donor arms as measured by the FACT-G, the MOS-SF36 Physical and Mental Component Scores and the EQ-5D utility score at all time points. The overall non-compliance rate for the trial was 26.3%. Reasons for non-compliance included the use of myeloablative conditioning or failure to proceed to RIC transplant in the Donor arm, and the use of alternative donors in the No Donor arm. In an as-treated analysis, comparison of the HCT and No HCT arms demonstrated a significant advantage in 3-year OS (47.4% vs. 16.0%, p<0.0001) and LFS (39.3% vs. 10.9%, p<0.0001) for subjects who underwent HCT. Conclusions: We observed a significant OS advantage in older patients with Int-2 and High IPSS risk de novo MDS who are RIC HCT candidates and have an HLA-matched donor, when compared with those without a donor. The benefit of having a matched donor was seen across subgroups, including those who were of Medicare age (>65) and below. HCT should be offered to all individuals between the ages of 50-75 with Int-2 and High IPSS risk MDS in whom a suitable donor can be identified. Table Disclosures Nakamura: Magenta Therapeutics: Other: Advisory board meeting; Kyowa-Kirin: Other: Support on a meeting presentation; Alexion: Other: Support on a meeting presentation; Merck: Other: advisory board meeting; NapaJen Pharma: Consultancy; Kadmon Corporation: Other: Advisory board meeting; Celgene: Other: Support on seminar; Viracor: Consultancy. Scott:Alexion, Incyte, Novartis, Regeneron: Consultancy; Agios, BMS: Honoraria; BMS, Novartis: Research Funding. Oran:ASTEX: Research Funding; Celgene: Consultancy; Arog Pharmaceuticals: Research Funding. Maziarz:Novartis, Incyte, CRISPR Therapeutics, Artiva Biotherapeutics, and AlloVir: Consultancy; Novartis and Athersys: Other: DSMB participant; Athersys: Patents & Royalties; Incyte, Kite, BMS/Celgene, PACT Pharma, Orca BioSystems, and Omeros: Honoraria; Novartis and Juno: Research Funding. McGuirk:Allo Vir: Consultancy, Honoraria, Research Funding; Gamida Cell: Research Funding; Pluristem Ltd: Research Funding; Bellicum Pharmaceutical: Research Funding; Astellas: Research Funding; Fresenius Biotech: Research Funding; Novartis: Research Funding; Kite Pharmaceuticals: Consultancy, Honoraria, Research Funding, Speakers Bureau; Juno Therapeutics: Consultancy, Honoraria, Research Funding. Sekeres:BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda/Millenium: Consultancy, Membership on an entity's Board of Directors or advisory committees. Cutler:Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees; Kadmon: Consultancy, Membership on an entity's Board of Directors or advisory committees; Jazz: Consultancy, Membership on an entity's Board of Directors or advisory committees; Medsenic: Consultancy, Membership on an entity's Board of Directors or advisory committees; Generon: Consultancy, Membership on an entity's Board of Directors or advisory committees; Mesoblast: Consultancy, Membership on an entity's Board of Directors or advisory committees.

5% respectively. Thirty-nine (17%) patients had adjuvant chemotherapy. With a median follow-up period of 54,5 months (range 1-532), there were 84 (37,1%) relapses including 49 local relapses within median 48 months, 13 regional within 71 months, and 65 metastatic ones within 42 months. At last follow-up, 56% of the patients were alive without disease; and 11% and 29% of the patients were alive or dead with disease, respectively. Of the 62 locoregional relapsing patients, there were 15 (24%) in the irradiated vs 47 (76%) in the nonirradiated patients. Late grade 3 or more toxicity was noted in 3 patients. Conclusion: Extracranial chondrosarcoma is a rare entity but this large database study seems to show that these patients have a better outcome when RT (postoperative or exclusive) is administered.

Background: Patients undergoing allogeneic hematopoietic stem cell transplant with reduced-intensity conditioning (RIC-alloSCT) rely primarily on the graft-versus-tumor (GVT) effect to prevent relapse. Although relapse remains high in this setting, previous data suggest modifications of allograft composition could produce enhanced GVT effect and improve outcomes. Prior retrospective studies suggested higher total nucleated cell (TNC) and CD8 dose correlate with improved overall survival (OS) and a reduction in relapse among all patients undergoing RIC-alloSCT. The aim of our study was to further investigate this association by comparing transplant outcomes with detailed graft immunophenotyping data including T-cell and NK-cell activation and maturation status and CD34 cell doses in patients with AML and MDS undergoing RIC-alloSCT. Methods: We performed a retrospective analysis using data from consecutive patients with AML and MDS who underwent RIC-alloSCT at a single center from 2010-2015 who had graft immunophenotyping data available. We compared transplant outcomes with TNC per kilogram (kg) and dose of CD3, CD4, CD8, CD34, and NK cells along with selected activation and maturation subsets. A competing risk regression analysis was conducted to examine the association between cell dose/kg and risk of relapse and graft versus host disease (GVHD). Overall survival and relapse free survival (RFS) were assessed utilizing the Cox proportional hazard model. Estimates of survival probability were determined by the Kaplan-Meier survival function. The log-rank test was used to compare OS and RFS among patients. Univariable and multivariable regression analyses were performed. Disease Risk Index (DRI) was used to stratify risk among patients. To identify optimal cutoffs (OC) of continuous variables for a specific outcome, a Classification and Regression Tree (CART) algorithm was utilized. Results: Our study included 142 patients who underwent RIC-alloHSCT for AML (n=97, 68%) and MDS (n=45, 32%). The vast majority of patients (98%) received fludarabine and busulfan conditioning with 65% receiving anti-thymocyte globulin. All patients received tacrolimus-based GVHD prophylaxis. Overall relapse rate was 37% at 3 years. Overall survival was 49% with median follow-up of 3.2 years. Total Nucleated Cell Dose: In multivariable analysis controlling for disease, comorbidity index, and performance status, a high infused TNC dose (10.6 - 16.8 x 108 cells/kg) correlated with improved overall survival (HR 0.27, 95% CI [0.12 - 0.59], p=0.001) and relapse free survival (HR 0.31, 95% CI [0.15 - 0.64], p=0.002). However, a very high TNC dose (OC >16.8 x 108 cells/kg) correlated with significantly worse OS (HR 2.84, 95% CI [1.16 - 6.98], p=0.023) and trended toward worse RFS (HR 2.09, 95% CI [0.88 - 4.93], p=0.093). Higher TNC doses were also correlated with an increased risk of chronic GVHD (HR 2.16, 95% CI [1.28 - 3.67], p=0.004, OC 9.8 x 108 cells/kg). Cell Subsets: Very low CD3 cell doses (OC <1.06 x 108 cells/kg) correlated with worse OS (HR 3.30, 95% CI [1.23 - 8.85], p=0.017) and worse RFS (HR 2.64, 95% CI [1.01 - 6.88], p=0.047). High CD3 doses were correlated with an increase in acute GVHD (all grades) (HR 2.41, 95% CI [1.36 - 4.25], p=0.002, OC 4.1 x 108 cells/kg). NK, CD4, CD8, and CD34 cell dose was not associated with relapse, OS, or RFS in multivariable analysis. Utilizing a previously published (Reshef et al, JCO, 2015) cutoff of 7.2 x 108 cells/kg, there was a trend toward a reduction in relapse with higher CD8 cell dose, but this did not reach statistical significance (HR 0.67, 95% CI [0.39 - 1.16], p=0.15). A high dose of late activated T-cells (CD3+/HLA-DR+) correlated with increased risk of acute GVHD (HR 2.31, 95% CI [1.26 - 4.20], p=0.006, OC 2.01 x 107 cells/kg) and chronic GVHD (HR 1.85, 95% CI [1.12 - 3.07], p=0.016, OC 6.6 x 106 cells/kg). Conclusion: Among AML and MDS patients following RIC-alloSCT, higher infused TNC/kg was associated with improved RFS and overall survival, confirming findings from a recent study (Martin et al, Haematologica, 2016). However, very high TNC doses may be deleterious. T-cell activation state influences risk of GVHD. Further research needs to be pursued to corroborate these findings and potentially optimize TNC and T-cell doses. We were unable to identify a significant correlation between CD8 cell dose and relapse or overall survival. Table 1 Table 1. Figure 1 Figure 1. Disclosures Lozanski: Genentech: Research Funding; Boehringer Ingelheim: Research Funding; Stemline Therapeutics Inc.: Research Funding; Beckman Coulter: Research Funding. Andritsos:Hairy Cell Leukemia Foundation: Research Funding.