Litzow, Mark R.

Recent studies have suggested that pediatric-intensive chemotherapy regimens can improve outcomes in adults with acute lymphoblastic leukemia (ALL) up to the age of 45. Above this age, toxicities increase. Monoclonal antibody-based therapies bring the promise of increased response rates without excessive toxicity. The addition of rituximab to combination chemotherapy has shown encouraging results. Newer monoclonal antibody-based therapies linked to cytotoxic agents show promise. These include inotuzumab ozogamicin, an anti-CD22 antibody linked to calicheamicin that has produced significant single-agent responses in relapsed and refractory ALL. Other monoclonal antibodies linked to plant or bacterial toxins are in earlier stages of development. Blinatumomab is a novel bispecific T-cell engaging antibody that combines single chain antibodies to CD19 and CD3 and brings a T cell in close proximity to a leukemic lymphoblast with resulting redirected lysis. This agent has demonstrated encouraging results in both the minimal residual disease setting and the relapsed/refractory setting. Autologous chimeric antigen receptor cells have shown promising responses in indolent B-cell lymphoid malignancies and are being tested in ALL. Many of these agents have the potential to increase response rates in older adults. Trials of many of these monoclonal antibody-based therapies are in various stages of development in the treatment of newly diagnosed ALL.

PURPOSE: Patients with acute myeloid leukemia with high-risk cytogenetics in first complete remission (CR1) achieve better outcomes if they undergo allogeneic hematopoietic cell transplantation (HCT) compared with consolidation chemotherapy alone. However, only approximately 40% of such patients typically proceed to HCT. METHODS: We used a prospective organized approach to rapidly identify donors to improve the allogeneic HCT rate in adults with high-risk acute myeloid leukemia in CR1. Newly diagnosed patients had cytogenetics obtained at enrollment, and those with high-risk cytogenetics underwent expedited HLA typing and were encouraged to be referred for consultation with a transplantation team with the goal of conducting an allogeneic HCT in CR1. RESULTS: Of 738 eligible patients (median age, 49 years; range, 18-60 years of age), 159 (22%) had high-risk cytogenetics and 107 of these patients (67%) achieved CR1. Seventy (65%) of the high-risk patients underwent transplantation in CR1 ( P < .001 compared with the historical rate of 40%). Median time to HCT from CR1 was 77 days (range, 20-356 days). In landmark analysis, overall survival (OS) among patients who underwent transplantation was significantly better compared with that of patients who did not undergo transplantation (2-year OS, 48% v 35%, respectively [ P = .031]). Median relapse-free survival after transplantation in the high-risk cohort who underwent transplantation in CR1 (n = 70) was 11.5 months (range, 4-47 months), and median OS after transplantation was 14 months (range, 4-44 months). CONCLUSION: Early cytogenetic testing with an organized effort to identify a suitable allogeneic HCT donor led to a CR1 transplantation rate of 65% in the high-risk group, which, in turn, led to an improvement in OS when compared with the OS of patients who did not undergo transplantation.

The advent of novel immunotherapies, such as blinatumomab, inotuzumab, and chimeric antigen receptor (CAR) T cell therapy, has revolutionized the therapeutic landscape in the treatment of relapsed/refractory B cell acute lymphoblastic leukemia, but can be associated with specific toxicities. We review unique toxicities of each of these in this article. Blinatumomab, a bispecific T cell engager, has been associated with cytokine release syndrome (CRS) and neurological toxicities, both of which can be prevented and managed with corticosteroids. Inotuzumab is a calicheamicin-conjugated CD22 targeting antibody. The calicheamicin component of the drug is likely associated with the hepatotoxicity seen with inotuzumab, especially sinusoidal obstruction syndrome, which can happen both in the context of the drug alone, and also with allogeneic stem cell transplantation. QT prolongation has also been noted with inotuzumab. CAR T therapy uses genetically modified autologous T cells directed against CD19, a known target on B cells. CRS and neurological symptoms, formally termed as immune-effector-cell-associated neurological syndrome, have been described along with hypogammaglobulinemia, cytopenias, and infections.

Key Points c-KIT activating mutations cause resistance to PARP inhibitor in AML1-ETO–positive leukemias. c-KIT inhibitor avapritinib downregulates BRCA1/2 and DNA-PK catalytic subunit to restore the sensitivity to PARP inhibitor.

Abstract Background: Patients with hematological malignancies are at an increased risk for developing both primary and recurrent Clostridium difficile Infection (RCDI) along with complications such as toxic mega colon and treatment failure likely due to underlying immunosuppression and frequent use of broad spectrum antibiotics that lead to altered gut microbiome. Fecal Microbiota Transplantation (FMT) is an effective treatment for RCDI (Brandt et. al; 2012). However, experience in patients with hematologic malignancies is sparse and most clinical trials exclude these patients due to potential complications. We report the largest case series to date from a single institution evaluating the safety and efficacy of FMT for RCDI in patients with hematologic malignancies. Methods: After IRB approval, a database of 452 RCDI patients treated with FMT between August 2012 and June 2016 was reviewed to identify those with an underlying hematologic malignancy. Data regarding demographics, hematologic disease, C. difficile history, treatments, and outcomes were retrospectively abstracted from the electronic medical record. Results: Sixteen patients (median age 74 years; male 50%) with known hematologic malignancies underwent FMT during the study period. The underlying diagnoses are outlined in Table 1. Five patients had received hematopoietic cell transplantation (3 allogeneic and 2 autologous) prior to FMT. Patients had a median of 4.5 (range 2-9) CDI episodes before FMT, and 4 of them had severe/severe-complicated CDI at some stage. Prior treatments included a median of 3 (range 1-5) standard vancomycin/metronidazole courses, median of 2 (range 0-4) vancomycin taper courses, fidaxomicin in 3 patients, and chronic vancomycin suppression in one patient. Diarrheal symptoms were in remission in all but 3 patients in the week before FMT. FMT was performed via colonoscopy in all patients. At the time of FMT, hematologic malignancies were in complete remission in 9 patients, stable on active treatment in 4, stable off treatment in 2, and relapsed awaiting treatment in 1 patient. Median time from last anti-neoplastic treatment (n = 14) and from last neutropenia (n = 8) to FMT were 10 (range 0-301) and 9.5 (0-68) months, respectively. One patient with hairy cell leukemia was still neutropenic and on prophylactic oral trimethoprim/sulfamethoxazole at the time of FMT. Five patients were on active immunosuppressive medications, including prednisone (n = 2), methotrexate (n = 2), sirolimus (n =1), and cyclosporine (n =1) for related comorbidities at the time of FMT (Table 2). At last follow up (median 12, range 0-32 months), 6 patients had active/relapsed hematological disease, 6 had received additional antineoplastic treatments, and 7 had received additional antibiotics. RCDI developed in two (12%) patients at 8 and 22 months post FMT secondary to exposure to broad spectrum antimicrobials. These patients were successfully treated with a second FMT and with metronidazole, respectively. Severe adverse events included death in one patient that occurred 3 days post FMT due to unexpected cardiac arrest and was deemed unrelated to the procedure. Another patient developed community-acquired pneumonia 15 days post FMT and was treated successfully with oral azithromycin. Minor adverse events within the first two weeks post FMT were noted in 6 (38%) patients (self-limited diarrhea in 3, fecal urgency in 2, abdominal cramps in 2, and constipation in one patient) (Table 3). Only one patient had persistent diarrhea shortly after FMT, with the cause attributed to underlying Crohn's disease. No complications related to the colonoscopy procedure were noted. Conclusion: FMT appears to be a safe and effective therapeutic option for RCDI in patients with hematological malignancies. Considering very few adverse events and particularly no infectious complications in our series, we conclude that immunosuppression should not preclude the use of FMT for treatment of RCDI in this high risk population. These results need prospective validation. Disclosures No relevant conflicts of interest to declare.

Abstract Background : Momelotinib is a JAK1 and JAK2 inhibitor that is currently being evaluated in phase-3 clinical trials for the treatment of myelofibrosis (MF) (NCT01969838, NCT02101268). In a phase-1/2 clinical trial of patients with MF, the drug was shown to improve anemia, reduce spleen size and alleviate symptoms (Leukemia 2013;27:1322). In the current study, we considered 100 consecutive patients from the Mayo Clinic who received momelotinib therapy, in order to identify molecular and cytogenetic predictors of treatment response and survival from the time of study entry. Methods : The study patients constituted part of a phase-1/2 clinical trial (NCT00935987) using momelotinib in MF. Details of the protocol, including inclusion and exclusion criteria were previously published (Leukemia 2013;27:1322). Response was determined by the 2006 response criteria published by the IWG-MRT. Data analysis and interpretation was carried out independent of any influence from the sponsor. Results : 100 patients with MF (median age 66 years; 58% males) were treated at the Mayo Clinic between 11/20/09 and 11/10/10. MF type was primary in 64% of the patients and post-polycythemia vera/essential thrombocythemia in 36%. DIPSS-plus risk distribution was 63% high, 36% intermediate-2 and 1% intermediate-1. Red cell transfusion dependency was documented in 49% and palpable spleen size of >5 cm (median 19 cm) in 92%. All patients were annotated for JAK2/CALR/MPL mutations with respective frequencies of 73%, 16% and 7%. Frequencies for other mutations included 42% for ASXL1 (84 evaluable) and 18% for SRSF2(78 evaluable). All patients were evaluable for karyotype, which was unfavorable in 17%. Previous treatment included other JAK inhibitors in 21 patients, thalidomide/lenalidomide/pomalidomide in 31 and hydroxyurea or other cytoreductive agents in 55. Momelotinib was initiated at 100 mg/day in 3 patients, 150 mg/day in 21, 150 mg twice-daily in 20, 200 mg/day in 3, 300 mg/day in 47 and 400 mg/day in 6. The maximum momelotinib dose was 150 mg/day in 6 patients, 150 mg twice-daily in 20, 300 mg/day in 68 and 400 mg/day in 6. Treatment duration was <6 months in 12 patients, 6-12 months in 22, 12-24 months in 19 and >24 months in 47. Genetic correlates of response to momelotinib : Overall response rate was 57% and included no complete remissions (0%), one (1%) partial remission and 57 (57%) clinical improvements (CI). Response rates for spleen/liver and anemia were 43% (91 evaluable) and 44% (68 evaluable), respectively. Transfusion independency was achieved in 25 (51%) of 49 evaluable cases. Spleen/liver response rate was significantly affected by JAK2/CALR/MPL mutational status (34% vs 73% vs 60%, respectively, and 50% in triple-negative; p=0.04), CALR mutated vs unmutated status (73% vs 37%; p=0.009), and unmutated vs mutated ASXL1 (53% vs 29%; p=0.035). Furthermore, all 8 (100%) patients who were CALR+/ASXL1- responded vs 6 (25%) of 24 CALR-/ASXL1+ vs 3 (50%) of 6 CALR+/ASXL1+ vs 16 (43%) of 37 CALR-/ASXL1- patients (p=0.003). Spleen/liver response rates were not affected by SRSF2 mutations (p=0.93) or karyotype (p=0.41). Anemia response rate was not affected by JAK2/CALR/MPL (p=0.81), ASXL1 (p=0.16), SRSF2 (p=0.12) or CALR/ASXL1 (p=0.42) mutational status or karyotype (p=0.65). The number of informative cases for EZH2, IDH, SF3B1 and U2AF1mutations were not adequate enough to warrant similar analysis. Genetic correlates of survival from time of protocol entry : Median follow-up after the institution of protocol drug therapy was 35 months (range 1-49). During this period, 57 (57%) deaths and 12 (12%) leukemic transformations were documented. On multivariable analysis, shortened survival was predicted by the presence of ASXL1 (p=0.01; HR 2.1, 95% CI 1.2-3.8) or SRSF2 (0.01; HR 2.4, 95% CI 1.2-4.8) mutations and the absence of CALR mutations (p=0.03; HR 3.2, 95% CI 1.1-8.9). Karyotype was significant on univariate (p=0.01) but not in multivariable (p=0.6) analysis that included the aforementioned mutations. The prognostic relevance of each specific mutation was DIPSS-plus independent. Conclusions : We demonstrate significant associations between CALR and ASXL1 mutational status and spleen response to momelotinib therapy in MF. We also show that momelotinib therapy did not overcome the inferior survival associated with the presence of ASXL1 or SRSF2 mutations or the absence of CALR mutations. Disclosures No relevant conflicts of interest to declare.

Abstract Background: Over 10,000 new cases of myelodysplastic syndrome (MDS) are diagnosed in the US annually (MA X, Cancer 2007). Hypomethylating agents (azacitidine and decitabine), immunomodulating drugs (lenalidomide) and erythropoietin stimulating agents (epoetin α and darbepoetin) have been approved for more than a decade for the treatment of MDS. However, changes in overall outcome after the approval of these treatments are unknown. We used the National Cancer Data Base (NCDB), a nationwide oncology registry covering 70% of the US cancer population to answer these questions. Methods: We identified patients with MDS diagnosed from 2004-2013 using ICD-O-3 codes 9980-9983 and 9985-99912. Overall survival (OS) was estimated using the Kaplan-Meier method. We compared OS using the log-rank test according to demographic subgroups (sex, age [<40, 41-65, and ≥65 years], race [White, Black, Native American, Asian/Pacific Islander, and other], and ethnicity) across years of diagnosis (Period 1: 2004-2006, Period 2: 2007-2009, and Period 3: 2010-2013). Results: i) Characteristics: There were 54,953 MDS patients in our study. The median age at diagnosis was 76 years (78.7% older than 65) and 44% were females. White race (88.9%) was the most common, followed by black (7%). Four percent were Hispanics. A third (30.8%) of all patients were treated in academic centers. Three quarters (75.8%) had either Medicaid or Medicare insurance. ii) MDS Subtypes: 5q Syndrome was seen in 2008 cases (3.7%) while the most common subtype was MDS-Unclassifiable (U) (55.6%). Therapy related MDS (t-MDS) was seen in 1125 cases (2%), however coding for t-MDS was discontinued in 2009. Refractory anemia (RA), refractory anemia with ring sideroblasts (RARS), refractory cytopenia with multilineage dysplasia (RCMD), and refractory anemia with excess blasts were seen in 9%, 7.6%, 6%, and15.6%, respectively. iii) OS: Compared to their counterparts, patients who were male, older, had a diagnosis of RAEB, covered by Medicare insurance, and treated at non-academic centers had the worse OS (all P <0.001). Across Periods 1-3, we did not see improvement in OS among demographic subgroups except for those who were <40 years old (P=0.03). Conclusions: In the past decade, the overall outcome of MDS did not improve despite the advent of new therapies. More than half of the cases were classified as MDS-U reflecting the difficulty of subtyping MDS based on World Health Organization classification. We found disparity in outcomes by demographics and type of treatment facility. This is the largest study of MDS outcome to-date and should help in understanding the gaps and areas that need future research. Figure Figure. Disclosures Al-Kali: Onconova Therapeutics, Inc.: Research Funding; Celgene: Research Funding.