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11007 Background: Patients (pts) with metastatic sarcoma (SAR) have limited options. Nivolumab(N), a fully human anti-PD-1 mAb and ipilimumab (I), a humanized anti-CTLA-4 mAb, have favorable safety & efficacy in other tumors. Pembrolizumab demonstrated a response rate (RR) of 12% in SAR pts. We evaluated N, independently from N+I, in SAR pts. Methods: This open-label multi-center phase II study enrolled pts failing prior regimens. Randomized (non-comparative) pts received either N3 [N (3 mg/kg q2W)] or N3+I1 [N(3 mg/kg Q3W x4, then Q2W) & [I(1 mg/kg q3W x4)]. Treatment continued beyond progressive disease (PD) in 1st12 weeks. 5 confirmed responses in 38 evaluable pts yielded 90% power (0.05 1-sided alpha) to detect a 20% (vs 5%) confirmed RR. Other endpoints: adverse events (AEs), progression-free, overall survival (PFS, OS), and correlative studies including PD-L1 expression by IHC, mutational burden/neoantigen analysis, TCR clonality and TIL characterization. Results: 85 pts (43 - N3; 42 - N3+I1) were enrolled [mean age 54 yrs (21–81), 52% female). No significant differences in histological subtypes across cohorts: 36% LMS, 4% LPS, 10% UPS/MFH, 6% synovial, 5% bone, 5% Ewing’s, and 34% other. Pts were refractory to 1(20%), 2(22%), and ≥3 (58%) regimens. Grade 3-4 treatment related adverse events (TRAE) occurred in 7% (N3) and 14% (N3+I1) and 0 Gr 5 TRAEs. 8% of pts stopped due to AEs (2% N3, 14% N3+I1). 2/3 confirmed responses on N3, with 2 ongoing (range 1.1-3.2 months). 6/7 confirmed responses (2 complete) on N3+N1, with 5 ongoing (range 6-13 months). Responses occurred in 7 histologies. See Table for pt outcomes. Conclusions: N + I showed acceptable safety and encouraging antitumor activity with most responses ongoing across multiple SAR histologies, passing efficacy criteria. There was minimal activity observed with N alone. Increased TRAEs were observed in N3+I1. Correlative analyses ongoing. NCT02500797. Support: U10CA180821, U10CA180882, Conquer Cancer Foundation, BMS. Clinical trial information: NCT02500797. [Table: see text]

e18560 Background: Myelodysplastic syndromes (MDS) are rare hematological neoplasms typically seen in the elderly. Young MDS (yMDS) patients ( < 50 years old) have been reported to comprise between 3-6% in the Surveillance, Epidemiology and End Results (Ma X et al, Cancer 2007; Rollison R et al, Blood 2008) with a better overall survival (OS). Methods: 1012 MDS patients from 1993 to 2015 were found after IRB approval was obtained. All cases had their bone marrow slides reviewed at our institution. yMDS Patients were included as cohort 1, while the rest as cohort 2. Survival estimates were calculated using Kaplan-Meier curves and univariate and multivariate analyses was based on log-rank testing using JMP software version 10. Results: We found 68 (7%) yMDS patients with a median age of 42 years (range, 18-49). Female gender was more common (43% vs 31%, p = 0.05) while platelets were lower in yMDS (61 vs 102, p < 0.0001). Therapy related MDS (t-MDS) was more frequent (33% vs 17%, p = 0.005), as was transformation to acute myeloid leukemia (AML) in yMDS (28 % vs 11%, p = 0.0004). Allogenic hematopoietic cell transplantation (HCT) was more frequent in yMDS (42% vs 4%, p < 0.0001). Survival outcome: Median OS was longer for cohort 1 vs cohort 2 but did not reach statistical significance (43 vs 21 months, p = 0.1). Median progression free survival (PFS) was shorter for cohort 1 vs cohort 2 but also did not reach statistical significance (8 vs 12 months, p = 0.3). Median OS for cohort 1 based on R-IPSS was 44, 105, 40, 18, and 12 months for very low, low, intermediate, high and very high risk groups, respectively (p = 0.09). Median OS was shorter in t-MDS vs de novo MDS in yMDS (13 vs 47 months, p = 0.04). yMDS patients who transformed to AML had worse median OS (18 vs 93 months, p = 0.001). On multivariate analysis neither t-MDS nor R-IPSS had a statistically significant impact on OS. Conclusions: MDS is rarely diagnosed under the age of 50 with IPSS-R being less powerful in detecting mOS. Among yMDS patients, there was a higher proportion of t-MDS compared to older patients with subsequent higher rates of AML transformation and higher rates of allogeneic HCT. In our study, we did not find an improved OS for yMDS patients compared to older patients.

e18559 Background: Myelodysplastic syndromes (MDS) are a group of myeloid neoplasms defined by ineffective hematopoiesis, dysplastic morphologic features, and variable risks of progression to acute myeloid leukemia (AML). Refractory anemia with ring sideroblasts (RARS) is a subtype of MDS defined by < 5% basts and > 15% ring sideroblasts (per 2008 WHO). Because RARS is a lower risk disease which does not frequently require HMA therapy, very little is known about the effects of HMA on RARS. Methods: A total of 1325 MDS patients’ data from 1993-2016 at Mayo Clinic were reviewed after appropriate IRB approval was obtained. All cases had their bone marrow slides reviewed at our center. Patients were considered for our study if they received HMA for their RARS. Response was identified based on MDS IWG 2006 criteria. Prognostic factors were analyzed by univariate and multivariate analyses. Survival estimates were calculated using Kaplan-Meier curves. Results: 168 of the initial 1325 patient were RARS (14%); only 14 (8%) were treated with HMA. Median age was 72 years (range, 51-85); half were males, with median overall survival of 91.3 months. The median number of ring sideroblasts (RS) at diagnosis was 40% (range 10-85%). Of the 14 patients, 11 (79%) received azacitidine (AZA), 2 (14%) decitabine (DAC) and one received both (7%). The median number of cycles for AZA was 6.5 (range, 2-28) vs 6 cycles for DAC (range, 1-24). Of the 14 patients receiving HMA, only 3 responded (21%) achieving hematologic improvement. All 3 responders received AZA. 6 of the 14 RARS patients (43%) had their bone marrow biopsy repeated after HMA therapy, 3 of whom were among the responders to AZA therapy and 3 were non-responders. In 5 patients, ring sideroblasts decreased after HMA therapy by a median of 15% (range 0-80); they remained the same in 1 patient; one patient who had developed AML had a decrease in RS from 85% to 5%. Conclusions: RARS is a low-risk subtype of MDS that is infrequently treated with HMA (8% in our study). Response rate to HMA (21%) was inferior to known rates in MDS. HMA therapy seems to decrease the number of ring sideroblasts irrespective of response. RARS patients should be treated on clinical trials if available.

e18556 Background: RARS is a subtype of myelodysplastic syndromes (MDS) defined by < 5% blasts and ≥15% ring sideroblasts (WHO 2008). Hereditary hemochromatosis is a disorder characterized by dysregulations in iron absorption, largely associated with C282Y and H63D mutations of the HFE gene. Iron levels are elevated in both disorders and pathophysiologic correlations were suggested. HFE gene mutations were previously found higher in MDS compared to controls (50% vs 36%) ( Nearman et al, Am J Hematol 2007). Methods: A total of 168 RARS patients’ data from 1994 to 2015 at Mayo Clinic were reviewed after appropriate IRB approval was obtained. All cases had their bone marrow slides reviewed at our center. We searched patients’ records retrospectively to Identify those tested for HFE gene (C282Y, H62D, S65C) mutations, done inside or outside our institution. Survival estimates were calculated using Kaplan-Meier curves. Results: Out of the 168 RARS patients, only 17 (10%) were tested for HFE gene mutations. Out of the 17 tested, 11 (65%) were found to have mutations; 2 of which (18%) had homozygous H63D mutation, 1 patient (9%) had double heterozygous H63D and C282Y mutations, 5 (45%) had only one H36D heterozygous mutation vs 3 patients (27%) with only one C282Y heterozygous mutation. Only one patient was tested for the additional S65C mutation and it was not detected. H63D mutation was present in a total of 8 patients (73%) vs C282Y mutation which was present in 4 patients (36%). Bone marrow iron stores were increased in all 17 tested patients, except one who had decreased stores, this patient had one heterozygous C282Y mutation. Median overall survival (mOS) was 117 months in the HFE mutated patients vs 75 months in the non-mutated (p = 0.6). Conclusions: Our study found the HFE gene, when tested, to be mutated in higher frequencies among patients with RARS compared to that reported in the general population (65% vs 36%), with H63D mutation in almost three quarters of all mutated patients. Although it did not reach statistical significance, the longer survival observed among HFE mutated patients compared to the wild-type raises the question whether testing for HFE gene mutations among patients with MDS-RARS should be further explored.

e18514 Background: Standard induction therapy for acute myeloid leukemia (AML) includes “cytarabine and anthracycline”. Anthracyclines are known to cause acute, subacute and chronic cardiac complications ( Lefrak , EA et al, Cancer 1973:32(2):302-314; Singal, PK et al, NEJM 1998;339(13):900-905). It is recommended to do base line cardiac function assessment with echocardiogram prior to induction therapy containing anthracycline. This study was done to find the frequency of changes made in avoiding anthracycline usage following this evaluation. Methods: The Mayo clinic data base was interrogated to identify patients with newly diagnosed AML who underwent echocardiogram prior to anthracycline containing induction chemotherapy. Echocardiogram results, including left ventricular ejection fraction (LVEF), diastolic dysfunction, valvular disease, and any resultant treatment alterations were reviewed. Results: Three hundred twenty six patients were identified. The median (range) age was 61 (17-82) years and 62% were male. The median (range) LVEF was 65% (30-87), and 3 (0.9%) patients had LVEF < 50% (range 30-47%). Of these 3 patients, 1 had 4 vessel CABG a decade ago, his EF was 46% and treated with full dose idarubicin; 2 of them presented with blastic crisis, 1 had EF 46% and improved to 51% after 5 days and then given daunorubicin, the other one had an EF of 30% and treated with 50% dose reduced cytarabine alone. Sixty five (23%) patients had previous chemotherapy or radiation exposure, including 24 (7.4 %) with previous anthracycline, 14 (4.3%) had prior radiation to the chest wall. No patient with previous chemotherapy or radiation exposure had a reduced LVEF. Conclusions: Echocardiography prior to anthracycline therapy rarely detects abnormal LVEF. Screening echo may be helpful in those presented with leukemic blastic crisis or had previous exposure to chemo-radiation.

7058 Background: The 2016 WHO classification includes myelodysplastic/myeloproliferative neoplasms, unclassifiable (MDS/MPN-U), as an MDS/MPN overlap syndrome not meeting criteria for well-defined entities such as CMML. No standard prognostication or treatment guidelines exist for such patients. Methods: We retrospectively identified MDS/MPN-U cases from 1990-2016 through our myeloid malignancies database. All bone marrow reports were reviewed to ensure compliance with 2016 WHO criteria. Clinical & cytogenetic parameters at diagnosis were assessed & compared with treatment outcomes. Results: Eighty nine patients met study criteria, with a median age of 69 years (range: 37-93); 58 (65%) males. Median follow-up was 22.2 months (range: 0-172), with 41 (46%) deaths & 13 (15%) leukemic transformations. Median OS was 24.8 months (range: 0-172). 43 (53%) patients had an abnormal karyotype, with common abnormalities being trisomy 8 (12%), complex karyotype (9%) & del (20q) (6%). Given the fewer types of abnormalities identified, the IPSS cytogenetic stratification was more effective than IPSS-R, with risk categorization including; 45 good (55%), 20 intermediate (25%) & 16 high risk (20%) respectively (8 unavailable). On univariate analysis, increased age (p = 0.05), decreased hemoglobin (p = 0.02), higher ANC (p = 0.03), circulating immature myeloid cells (p = 0.02), higher LDH (p = 0.009), absence of bone marrow ring sideroblasts (p = 0.001) & higher risk (intermediate & high) IPSS cytogenetic categories (p = 0.01) adversely impacted OS. In a multivariate model that included the aforementioned variables, higher risk IPSS cytogenetics retained a negative prognostic impact (p = 0.04). 28 patients received a median of 6 cycles (range: 1-21) of hypomethylating agent therapy (HMA), with an overall response rate of 18% (CR-3, PR-2). All responders had an abnormal karyotype (p = 0.01). However, HMA did not affect either OS or LFS. Conclusions: Intermediate & high risk IPSS cytogenetic categories independently & adversely impact survival in WHO defined MDS/MPN-U patients. HMA use did not impact OS; however, patients with abnormal karyotypes were more likely to respond.

4519 Background: Tandem HDC with carbo/etoposide (CE) is curative for a portion of relapsed GCT pts. However, outcomes of refractory or high-risk relapsed pts remain poor. We tested a new HDC regimen of GemDMC, based on DNA damage repair inhibition. We combined BEV with HDC given their potential synergy and the high vascularity of GCT metastases. Methods: Eligibility: Intermediate (int)/high-risk (Beyer Model), creatinine ≤1.8 mg/dL and adequate organ function. HDC included BEV (5 mg/kg) preceding GemDMC (HDC #1) and ifosfamide/CE (ICE) (HDC #2). Following accrual of 42 pts, we amended the trial omitting BEV. The trial was powered to distinguish a target 50% 2-yr RFS from an expected 25% in this population. Results: We enrolled 69 male pts in cohorts 1 (BEV, N=42) and 2 (no BEV, N=27) (Table). Pts were heavily pretreated and most had refractory tumors. Main AE: mucositis and renal (4 HDC-related deaths in cohort 1, 1 in cohort 2). Tumor markers normalized in 90% pts with active tumors at HDC. After HDC, 19 pts were in CR and 28 in PRm- (of these, 22 had residual lesions resected with no viable tumor found in 20/22, 2 xRT, 4 monitored). Median f/u = 39 (2-105) mo. The 2-yr RFS rates in cohorts 1 and 2 = 52% and 78%, respectively. Their respective 2-yr OS rates = 55% and 81%. Conclusions: Sequential HDC with GemDMC–ICE shows encouraging outcomes in heavily pretreated and refractory GCT, exceeding the anticipated results. Addition of BEV increases toxicity but not tumor control. Clinical trial information: NCT00936936. [Table: see text]

1005 Background: Evidence-based treatments (tx) for metastatic, HER2+ BCBM are limited. We previously found a central nervous system (CNS) objective response rate (ORR) of 8% (95% CI 2-22%) for the irreversible, EGFR/HER2-targeted kinase inhibitor, neratinib. To enhance CNS activity, we evaluated the combination of neratinib + capecitabine in a subsequent cohort, and report results here. Methods: Pts with measurable BCBM (≥ 1 cm in longest dimension) and no prior lapatinib or capecitabine were eligible. All but 3 had CNS progression after local CNS tx. During 21 day cycles, pts received capecitabine 750 mg/m2 twice daily x 14 days followed by 7 days off + neratinib 240 mg orally once daily. Loperamide prophylaxis (16 mg total daily) was recommended during cycle 1. Brain MRI and non-CNS imaging were repeated every 2 cycles until 18 wks, then every 3 cycles. The primary endpoint was composite CNS ORR, requiring all of the following: ≥50% reduction in volumetric sum of target CNS lesions (central review, VORR), no progression of non-target or non-CNS lesions, no new lesions, no escalating steroids, and no progressive neurologic signs/symptoms. We used a two-stage design with hypotheses ORR 15% and 35% (error rates 5% and 20%), responses in ≥5/19 pts to enter 2ndstage; responses in ≥9/35 [26%] pts to be promising. Results: 39 pts enrolled between 4/2014-11/2016 (2 withdrew before tx, 37 analyzed); median age 51, median prior metastatic lines 2 (range 0-6), 65% had prior WBRT. As of 11/15/16, 23 (62%) patients are alive and 7 remain on protocol tx; median number of cycles initiated = 5 (range 1-26). 18 women (49%) had a VORR (95% CI 32-66%, neurologic exams not yet available on all pts). Overall 12-month survival is 63% (95% CI 43%-77%); 4/7 pts still on protocol therapy have not yet reached 6 cycles. No pts had grade 4 toxicity; 18 (49%) had grade 3 toxicity, with diarrhea most common (32%), and 6 pts discontinued tx for toxicity. Conclusions: The combination of neratinib and capecitabine is active for BCBM with VORR in nearly half of pts, supporting further development of the regimen for BCBM. Updated results will be presented at the meeting. Clinical trial information: NCT01494662.