McCullough, Kristen

Abstract Background: AML outcome in elderly patients unfit for intensive chemotherapy continues to be challenging. Hypomethylating agents (HMA) can be effective in these patients but responses are short-lived (Fenaux et al, JCO 2009; Dombret et al Blood 2015). Even though HMAs achieve superior response rates to supportive care alone, complete remissions (CR) are rarely achieved and often quickly lost when they occur. The majority of patients will either have stable disease or progress through therapy. We hereby describe the outcome of these patients at our institution after they fail HMAs. Methods: A total of 56 AML patients' data from Feb 2007 to June 2015 at Mayo Clinic were reviewed after appropriate IRB approval was obtained. All cases had their bone marrow slides reviewed at our institution. Patients were considered for our study if they received HMA as frontline therapy for their AML. Patients who received HMAs after induction chemotherapy failure or for their MDS were excluded. Response was identified based on IWG AML criteria (Cheson et al, JCO 2003). Prognostic factors were analyzed by univariate and multivariate analyses. 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: i) Characteristics at Diagnosis: We identified 56 AML patients treated with HMA as frontline therapy with median age of 76 years (range, 59-91), 68% of which were males. Cases were classified as AML with myelodysplasia related changes in 25%, and therapy related myeloid neoplasm in 2%, and not otherwise specific in 73%. Out of 56 cases, 23% were secondary to MDS, 2% ET (Essential Thrombocytopenia), 5% PV (Polycythemia Vera), 5% MF (Myelofibrosis), 4% from CMML (Chronic Myelomonocytic Leukemia); while 61% were de novo AML. Per cytogenetics data, 2% were considered favorable risk, 62% intermediate, and 36% poor (34% had complex karyotype). ii) Clinical outcome to Frontline HMA: Out of 56 patients, 15(27%) patients received azacitidine (AZA) and 41 (73%) received decitabine (DAC) with a median number of cycles of 4 (range 1-62). Median number of cycles was higher for AZA vs DAC (8 vs 4, p =0.3). CR was found in 10 (18%), CR with incomplete count recovery in 3 (5%), partial remission (PR) in 3 (5%) patients, with overall response of 28% and median response duration of 10 months (range, 1-78 months). Thirteen (81%) out of 16 responders relapsed. Therefore, only 53 patients were included in primary or secondary failure analysis. iii) Clinical outcome to Frontline HMA failure: Out of 53 patients, 12 (23%) received subsequent treatments. Out of the 12 patients, 3 (25%) received another HMA (switch), 2 (17%) subcutaneous low dose cytarabine, 4 (33%) intensive chemotherapy, while 3 (25%) received either therapy on a clinical trial or targeted therapy. None of the 12 patients who got first salvage therapy achieved remission. Five out of the 12 patients received second salvage therapy, 2 (40%) of which achieved CR. Only one patient had third salvage therapy and did not respond. No patient was able to proceed to allogenic hematopoietic cell transplantation. Median overall survival (mOS) for this group was 2 months. Median OS for patients who received subsequent salvage therapies was better than those who did not receive any subsequent therapy after failing HMA (9.5 vs 2 months, p = 0.0009). Conclusions: Elderly patients diagnosed with AML who are unfit for intensive chemotherapy have a poor prognosis. HMA can get some patients into remission but most patients will ultimately fail. Outcome for patients who have primary or secondary (relapse) failure is very poor with a median OS of 2 months. Switch of HMA did not result in any response. Response to salvage therapy continues to be low but offering salvage therapies seem to improve OS. Our study provides historical data for future novel therapies, which are sorely needed for these patients. Figure Figure. Disclosures Al-Kali: Celgene: Research Funding; Onconova Therapeutics, Inc.: Research Funding.

Abstract Background L-asparaginase (LASP) therapy in adults is associated with frequent hepatic and metabolic side effects, often resulting in dose adjustments and omissions. Pegylated asparaginase (PEGASP) substituted for LASP improves convenience of administration with comparable efficacy; however, adverse event (AE) management remains challenging. The incidence and management of LASP- and PEGASP-induced metabolic and hepatic complications in adult ALL patients is not well defined. Methods This single center, retrospective, observational study was approved by the Mayo Clinic Institutional Review Board. Consecutive adult patients with a confirmed diagnosis of ALL receiving LASP or PEGASP containing chemotherapy regimens between January 2000 and October 2012 were evaluated. Patients were followed up to 60 days after the last LASP or PEGASP dose for development of biochemical and clinical pancreatitis, hypertriglyceridemia and hepatotoxicity. Hyperglycemia was not analyzed due to confounding variables, such as concomitant corticosteroid administration. AEs were graded as per the National Cancer Institute Common Terminology Criteria (CTCAE) version 4.03. Analysis was performed using Cox proportional hazard models with odds ratios (with 95% confidence intervals) reported to demonstrate the strength of association between group and AE rate. Results Of 74 adult patients, 54 (73%) met inclusion criteria. History of dyslipidemia, diabetes mellitus, cholelithiasis and coronary artery disease was documented at baseline in 13 (24%), 4 (7%), 4 (7%) and 10 (19%) patients, respectively. Twenty eight (52%) patients received LASP, 22 (41%) received PEGASP and 4 (7%) received both. A total of 399 doses including 335 (84%) LASP and 64 (16%) PEGASP were administered. Distribution based on treatment schedules was as follows; CALGB 9111 (n=20 (37%), Larson et al, 1998), E2993 (n=13 (24%), Goldstone et al, 2008), C10403 (n=9 (17%), NLM: NCT00558519), CCG 1941 (n=7 (13%), Gaynon et al, 2006) and Augmented Hyper-CVAD (n=5 (9%), Faderl et al,2011). Six (11%), 20 (37%), and 53 (98%) patients experienced pancreatic, lipid (hypertriglyceridemia) and hepatic adverse events, respectively. In this group, CTCAE grade 3/4 AEs occurred in 0 (0%), 8 (15%), and 28 (52%) patients, respectively. No deaths were directly related to these complications. Patients receiving PEGASP were more likely to experience AE of any CTCAE grade (OR 11.5, 95% CI 4.4-30.3, p < 0.0001), including grade3/4 AEs (OR 27.9, 95% CI 11.4-68.2, p < 0.0001) in comparison to those receiving LASP. All cases of pancreatitis manifested as biochemical elevation in pancreatic enzymes, and were either grade 1 (n=4, 67%) or grade 2 (n=2, 33%). All patients were managed conservatively. Management of hypertriglyceridemia was heterogeneous across all grades and included observation (n=11, 55%), non-pharmacologic interventions (n=1, 5%), medication management (n=4, 20%) and combined strategies (n=4, 20%). The most common practice was a combination of fibrate derivatives (fenofibrate) and fish oil (n= 5). One patient with a peak triglyceride level of 2285 mg/dL was placed on an insulin/dextrose infusion for 4 days. Hepatic toxicity manifested as CTCAE grade 3/4 transaminitis in 13 (24%) patients, hyperbilirubinemia in 4 (7%) patients and both in 11 (20%) patients. Temporal correlation was used to best distinguish confounding variables including possible hepatoxicity from azole antifungals and other drugs. Management of hepatic toxicity included delay in dosing, subsequent LASP or PEGASP dose reduction and laboratory monitoring until resolution. Overall, deviations in LASP or PEGASP administration were documented in 18 (33%) patients due to metabolic or hepatic AEs. Eight (15%) patients required omission of at least 1 dose, 7 (13%) experienced delays of administration and 7 (13%) needed a dose reduction. Conclusion PEGASP administration resulted in significantly higher AE rates in comparison to LASP and this significance was retained when comparing AEs of CTCAE grade 3 and 4. Given the growing trend of using PEGASP combination chemotherapy in adults with ALL, a detailed analysis looking at the increase in side effects, their consequences (delayed tereatment and dose reductions) and the impact of these factors on disease remission and survival is needed. Disclosures: No relevant conflicts of interest to declare.

Abstract Introduction L-asparaginase therapy results in systemic depletion of antithrombin (AT) and fibrinogen (FG), resulting in thrombotic (TE) and hemorrhagic events (HE). Prophylactic correction of coagulation disturbances have been inconclusive with regard to cost effectiveness, and specifically cost effectiveness of antithrombin concentrate (ATC) replacement has not been evaluated. (Abbott et al, 2009, Mitchell et al, 2003). Currently, AT repletion is recommended for levels less than 60%. (Stock et al, 2012) Several treatment protocols with distinctly different L-asparaginase (LAS) or pegaspargase (PEG) doses complicate the frequency and intensity of ATC replacement. We carried out this study to evaluate the cost effectiveness of ATC replacement, based on our institutional practice. Methods This single center, retrospective, observational study was approved by the Institutional Review Board and conducted at Mayo Clinic, Rochester, MN. Consecutive adult patients with a confirmed diagnosis of ALL receiving LAS or PEG between January 2000 and October 2012 were evaluated. Patients with hereditary or acquired thrombophilias or pre-existing TE or HE, were excluded. Per institutional guidelines, ATC was administered if levels were less than 70%. The Centers for Medicare & Medicaid (CMS) single drug historical pricing guide was utilized for 2000-2004. ATC cost beginning January 1, 2005, was derived from the CMS average sales price, reported quarterly. To adjust for price differences due to regimen utilization trends, each dose was also calculated at the final 2012 cost of 3.05/unit. ATC repletion practices and estimated expenditures were compared between regimens. Results Fifty four patients were treated with LAS or PEG containing regimens. Of these, 47 (87%) received ATC. Twenty-eight patients received LASP, 22 received PEGASP and 4 received both. Distribution across protocols was; CALGB 9111 (n=20, Larson et al, 1998), E2993 (n=13, Goldstone et al, 2008), C10403 (n=9, NLM: NCT00558519), CCG 1941 (n=7, Gaynon et al, 2006) and Augmented HyperCVAD (n=5, Faderl et al, 2005). PEG and LAS dosing schemes are outlined in table 1 . LAS doses were converted to PEG upon specific protocol revision or at discontinuation of LAS availability in 2012. Regimens specified a dose cap with the exception of C10403. A total of 399 LAS and PEG doses resulted in 378 instances of ATC repletion. The reimbursement price of ATC in 2000 was estimated at 1.50/unit U.S. dollars (USD) and 3.04/unit USD by the fourth quarter of 2012. The total estimated average sales price was 2,471,745 USD over the study period. C10403 resulted in the highest median number of PEG doses per patient (n = 5) and a median of 17 ATC doses per dose of PEG. This resulted in C10403 being the most expensive regimen with the median expense for ATC replacement being 118,064 USD (chart 1). This conclusion was also seen after comparing different regimens using the most recent 2012 cost estimates. The overall incidence of TE or HE was 17% and equally distributed between regimens (please see accompanying abstract). Conclusions Repletion of ATC in patients receiving asparaginase containing chemotherapy regimens is very expensive and continues to add to costs at many centers, without clear benefit, especially with regards to TE and HE. A prospective, randomized, multicenter clinical trial looking to answer this question is the need of the hour. Disclosures: No relevant conflicts of interest to declare.

Abstract Background: Acute graft versus host disease (aGVHD) is the leading cause of morbidity and mortality following allogenic hematopoietic cell transplantation (HCT). Corticosteroids are the first line treatment although <50% of patients with severe aGVHD (grades III-IV) achieve durable remissions. Monoclonal antibodies (mAb) are often used as second line agents for steroid refractory aGVHD (SR-aGVHD) (Patriarca et. al.; 2004). However, data regarding their tolerability and efficacy is retrospective and limited. We carried out this study to assess the clinical outcomes related to mAb therapy (Infliximab and Tocilizumab) for SR-aGVHD. Methods: Patients with SR-aGVHD that received therapy with either Infliximab or Tocilizumab between January 2003 and May 2016 were retrospectively identified. Clinical grading of aGVHD was per the Glucksberg criteria (Glucksberg et. al.; 1974). SR-aGVHD was defined as any grade progression within 3 days or failure to achieve at least one grade improvement within 7 days of initiation of systemic steroids. Infliximab and Tocilizumab were administered intravenously at 10mg/kg and 8mg/kg weekly for a total of 4 doses, respectively. Clinical response was evaluated at 4 weeks and 12 weeks post mAb treatment. Complete response (CR) was defined as sustained resolution of all clinical signs of aGVHD; partial response (PR) was defined as overall improvement of 1 or more grades; no response (NR) was defined as neither improvement nor worsening of the overall aGVHD grade. Overall response (OR) was defined as either CR or PR. Overall survival (OS) was calculated from the first day of mAb treatment until death or last available follow up. Results: Forty-three patients (median age 54, range 29-74 years; male 67%) with severe SR- aGVHD were included in the study. Of these, 35 (81%) received Infliximab for a median of 4 (range 1-6) cycles and 8 (19%) received Tocilizumab for a median of 3 (range 1-4) cycles. Both groups were comparable with regards to age, gender, conditioning regimen, graft source, degree of HLA match, ABO blood group, CMV incompatibility, and GVHD prophylaxis regimens. Only differences seen were a higher proportion of unrelated donor (p = 0.004) and cord blood HCT (p = 0.031) in the Tocilizumab group. Twenty (57%) of 35 patients treated with Infliximab and 6 (75%) of 8 patients treated with Tocilizumab had an overall aGVHD grade of IV prior to initiation of mAb therapy (p = 0.44). Organ specific distribution and severity of aGVHD are described in table 1. At 4 weeks post mAb therapy, 17 (40%) patients had an OR, 7 (16%) had no response, and 19 (44%) had died. Twenty-six (60%) patients died at 12 weeks, with OR and no response observed in 9 (21%) and 8 (19%) patients, respectively (table 2). Overall response for Tocilizumab versus Infliximab was comparable at 4 weeks (38% vs. 40%; p = 1.0) and at 12 weeks (38% vs. 17%; p = 0.33). Outcomes per aGVHD grade and gastrointestinal-specific stage at 4 weeks and 12 weeks are shown in figures 1-A and 1-B, with organ specific responses shown in figures 1-C and 1-D, respectively. The estimated median OS was 41 (range 4-3837) days for patients treated with Infliximab and 60 (range 10-756) days for those treated with Tocilizumab (p = 0.48). Disease relapse occurred in 5 (11%) patients treated with Infliximab and in none (0%) treated with Tocilizumab (p = 0.56). Thirty-four (79%) patients had infectious complications during and up to one month after mAb therapy. These included 31 (72%) patients with bacterial blood stream infection and 10 (23%) with invasive fungal infections. Overall, infectious complications were comparable (Infliximab - 83% vs. Tocilizumab - 63%; p = 0.33). CMV reactivation occurred in 11 (31%) and in 2 (25%) patients who were treated with Infliximab and Tocilizumab, respectively (p = 1.0). Given the retrospective nature of the study and the concomitant presence of aGVHD, it was difficult to attribute and grade gastrointestinal and hepatobiliary side effects. Conclusions: The use of anti-inflammatory monoclonal antibody therapy in patients with steroid refractory acute GVHD is associated with significant infectious complications (~80%) and poor response rates (~20% at 12 weeks). Current data, limited by a small sample size, does not show any advantages of using Tocilizumab over Infliximab or vice versa. Prospective clinical trials addressing this question are needed. Disclosures No relevant conflicts of interest to declare.

Outcomes of acute myeloid leukemia (AML) in elderly patients unfit for intensive chemotherapy is challenging. Hypomethylating agents (HMAs) can be effective in these patients but responses are usually short‐lived. The majority of patients will either have stable disease or progress through therapy. We hereby describe the outcome of these patients at our institution after they fail HMAs. The data on 56 AML patients at Mayo Clinic, Rochester were reviewed. Patients were considered for our study if they received HMA as frontline therapy for their AML. Out of 56 patients, 15 (27%) patients received azacitidine (AZA) and 41 (73%) received decitabine. Complete remission was found in 10 (18%), with overall response of 28% and median response duration of 10 months. Thirteen (81%) out of 16 responders relapsed. Therefore 53 patients were included in the primary or secondary failure analysis with a median overall survival (OS) of 2 months after the date of failure. Out of 53 patients, 12 (23%) received subsequent treatments. None of the 12 patients who got first salvage therapy achieved remission. Five out of the 12 patients received second salvage therapy, 2 (40%) of which achieved CR. Median OS for patients who received subsequent salvage therapies was better than those who did not receive any subsequent therapy after failing HMA (9.5 vs. 2 months, P = .0009). Outcome for patients who have primary or secondary failure is very poor. Our study provides important historical data for future novel therapies, which are sorely needed for these patients.

572 Background: There is limited data regarding chemotherapy dosing in obese mCRC patients. Methods: A retrospective, single institution, cohort study of mCRC patients receiving mFOLFOX6 (fluorouracil (5-FU) bolus omitted) was conducted between January 2002 and January 2011. Patients were stratified into: obese (BMI > 30) full dose, obese dose reduced (oxaliplatin (OX) and/or 5-FU), non-obese (BMI 18-29.9) full dose, and non-obese dose reduced. The primary endpoint was incidence of grade 3/4 myelosuppression within the first 12 wks of therapy. Secondary endpoints included incidence of any grade diarrhea and neuropathy, progression free (PFS) and overall survival (OS). Results: Of the 236 patients (72 obese, 164 non-obese), 15 obese and 37 non-obese received a dose reduction. Grade 3/4 myelosuppression occurred in 0 obese OX dose reduced, 3 (7.5%) obese full dose, 1 (8.3%) non-obese dose reduced, and 7 (7.8%) non-obese full dose patients (p=0.93). Grade 3/4 myelosuppression occurred in 0 obese 5-FU dose reduced, 3 (7.5%) obese full dose, 2 (12.5%) non-obese dose reduced, and 6 (7%) non-obese full dose patients (p=0.8). There were no statistically significant differences in the incidence of neuropathy or diarrhea between groups. PFS was longer in OX full dose patients (obese dose reduced, 8.8 mos; obese full dose, 10 mos; non-obese dose reduced, 3.7 mos; non-obese full dose, 10.4 mos; p=0.0094). No difference in PFS was found with 5-FU dosing (p=0.0615). OS favored OX full dose patients (obese dose reduced, 1.6 yrs; obese full dose, 2.4 yrs; non-obese dose reduced, 0.7 yrs; non-obese full dose, 2 yrs; p=0.0006) and 5-FU full dose patients (obese dose reduced, 1.6 yrs; obese full dose, 2.2 yrs; non-obese dose reduced, 1.6 yrs; non-obese full dose, 1.9 yrs; p=0.0287). Conclusions: There is no difference in the incidence of grade 3/4 myelosuppression, diarrhea or neuropathy in obese versus non-obese patients, dose reduced or not. OX dose reductions were associated with reduced PFS and OS. 5-FU dose reductions were associated with reduced OS. Our study supports ASCO recommendations against dose reductions in obese patients receiving chemotherapy.