Summary Type I interferon (IFN), essential for spontaneous T cell priming against solid tumors, is generated through recognition of tumor DNA by STING. Interestingly, we observe that type I IFN is not elicited in animals with disseminated acute myeloid leukemia (AML). Further, survival of leukemia-bearing animals is not diminished in the absence of type I IFN signaling, suggesting that STING may not be triggered by AML. However, the STING agonist, DMXAA, induces expression of IFN-β and other inflammatory cytokines, promotes dendritic cell (DC) maturation, and results in the striking expansion of leukemia-specific T cells. Systemic DMXAA administration significantly extends survival in two AML models. The therapeutic effect of DMXAA is only partially dependent on host type I IFN signaling, suggesting that other cytokines are important. A synthetic cyclic dinucleotide that also activates human STING provided a similar anti-leukemic effect. These data demonstrate that STING is a promising immunotherapeutic target in AML.

At the intersection between children and older adults, the care of adolescent and young adult (AYA) patients with acute lymphoblastic leukemia (ALL) poses unique challenges and issues beyond those faced by other age groups. Although the survival of AYA patients is inferior to younger children, growing evidence suggests that AYA patients have improved outcomes, with disease-free survival rates of 60% to 70%, when treated with pediatric-based approaches. A holistic approach, incorporating a multidisciplinary team, is a key component of successful treatment of these AYA patients. With the appropriate support and management of toxicities during and following treatment, these regimens are well tolerated in the AYA population. Even with the significant progress that has been made during the last decade, patients with persistence of minimal residual disease (MRD) during intensive therapy still have a poor prognosis. With new insights into disease pathogenesis in AYA ALL and the availability of disease-specific kinase inhibitors and novel targeted antibodies, future studies will focus on individualized therapy to eradicate MRD and result in further improvements in survival. This case-based review will discuss the biology, pharmacology, and psychosocial aspects of AYA patients with ALL, highlighting our current approach to the management of these unique patients. (Blood. 2015;125(24):3702-3710)

The mechanisms through which immune responses are generated against solid cancers are well-characterized, and knowledge of the immune evasion pathways exploited by these malignancies has grown considerably. However, for hematological cancers, which develop and disseminate quite differently than solid tumors, the pathways which regulate immune activation or tolerance are less clear. Growing evidence suggests that, while a number of immune escape pathways are shared between hematological and solid malignancies, there are several unique pathways exploited by leukemia and lymphoma. Below, we discuss immune evasion mechanisms in leukemia and lymphoma, highlighting key differences from solid tumors. A more complete characterization of the mechanisms of immune tolerance in hematological malignancies is critical to inform the development of future immunotherapy approaches.

Purpose The clinical relevance of targeting RAS/RAF/MEK/ERK pathway, activated in 70-80% of acute myeloid leukemia (AML) patients, is unknown. Experimental Design Selumetinib is an oral small molecule inhibitor of MEK1/2 kinase. Forty-seven patients with relapsed/refractory AML or ≥60 years old with untreated AML were enrolled on a phase II study. Patients were stratified by FLT3 ITD mutation status. The primary endpoint was response rate (complete, partial and minor). Leukemia cells were analyzed for ERK and mTOR phosphorylation. Results Common drug-related toxicities were grade I-II diarrhea, fatigue, nausea, vomiting and skin rash. In the FLT3 wild type cohort, 6/36 (17%) patients had a response [1 partial response, 3 minor responses, 2 unconfirmed minor responses (uMR)]. No patient with FLT3 ITD responded. NRAS and KRAS mutations were detected in 7% and 2% patients, respectively. The sole patient with KRAS mutation had uMR with hematologic improvement in platelets. Baseline p-ERK activation was observed in 85% of patients analyzed but did not correlate with a response. A single nucleotide polymorphism (SNP) rs3733542 in exon 18 of KIT gene was detected in significantly higher number of patients with response/stable disease compared with non-responders (60% vs 23%; p=0.027). Conclusion Selumetinib is associated with modest single agent antileukemic activity in advanced AML. However, given its favorable toxicity profile, combination with drugs that target other signaling pathways in AML should be considered. The potential association of SNP rs3733542 in exon 18 of KIT gene with antileukemic activity of selumetinib is intriguing, but will require validation in larger trials.

Blinatumomab, a bispecific T-cell engager (BiTE) associated with improved survival in relapsed or refractory acute lymphoblastic leukemia (ALL), was recently approved for treatment of minimal residual disease (MRD). MRD is an important predictor of survival in ALL, and recent studies suggest that achievement of MRD-negativity with blinatumomab improves outcomes in patients with ALL. However, further research is needed to determine how to optimally incorporate blinatumomab, and other novel therapies, into current therapies for ALL.

BackgroundNovel therapies for patients with acute myeloid leukemia (AML) are imperative, particularly for those with high-risk features. Selinexor, an exportin 1 (XPO1/CRM1) inhibitor, has demonstrated anti-leukemia activity as a single agent, as well as in combination with anthracyclines and/or DNA-damaging agents.MethodsWe report the findings of a phase I dose escalation trial with cohort expansion in 20 patients with newly diagnosed or relapsed/refractory AML that combined selinexor with age-adjusted high-dose cytarabine and mitoxantrone (HiDAC/Mito).ResultsThree (15%) patients received the initial dose of 60 mg of selinexor (~ 35 mg/m2), and 17 (85%) received the target level of 80 mg (~ 50 mg/m2). No dose-limiting toxicities were observed. Common adverse events included febrile neutropenia (70%), diarrhea (40%), anorexia (30%), electrolyte abnormalities (30%), bacteremia (25%), cardiac toxicities (25%), fatigue (25%), and nausea/vomiting (25%). None were unexpected given the HiDAC/Mito regimen. Serious adverse events occurred in 6 (30%) patients; one was fatal. Ten (50%) patients achieved a complete remission (CR), 3 (15%) achieved CR with incomplete recovery (CRi), 1 (5%) achieved partial remission (PR), and 6 (30%) had progressive disease for an overall response rate (ORR) of 70%. Eight of 14 (57%) responders proceeded to allogeneic stem cell transplantation. Correlative studies of WT1 levels showed persistently detectable levels in patients who either did not respond or relapsed quickly after induction.ConclusionThe selinexor/HiDAC/Mito regimen is feasible and tolerable at selinexor doses of 80 mg/day (~ 50 mg/m2/day) twice weekly. The recommended phase II dose is 80 mg and warrants further study in this combination.Trial registrationClinicalTrials.gov, NCT02573363. Registered October 5, 2015

Objectives Chemoradiation therapy (CRT) remains a potentially curative treatment in patients with locally advanced head/neck cancer (LA-HNC). However, survival and other outcomes in older patients with head/neck cancer receiving chemoradiotherapy are not well established. This study was performed to elucidate selected outcomes in this patient population. Materials and Methods Retrospective study of LA-HNC patients ≥70 years of age who had received 5-fluorouracil-hydoxyurea-based CRT with a minimum of 3 years of follow up after therapy initiation was performed. Pre-treatment patient- and cancer-related characteristics were recorded. Survival data in addition to gastrostomy tube utilization, swallowing function, and hematologic toxicity were captured. Results Eighty-nine patients treated between 1997 and 2009 were eligible for analysis (median age, 76 years; range, 70–94; male, 61%; ECOG PS, 0–1 43%; stage IVA/B, 71%). 86 were evaluable for survival analysis. 5-year overall and event-free survival were both at 32% with a median follow-up time of 39.2 months. The majority (86.5%) were able to complete all planned treatment cycles. A significant proportion of patients, however, required gastrostomy tube during CRT (62%) and developed aspiration during swallowing evaluation post-treatment (44%). Several patients required hospice (9%) or skilled nursing facility (13%) referrals during treatment. Conclusion Select older adults with LA-HNC can still experience long-term benefits despite 5-year survival rates lower than those historically reported in younger patients undergoing identical CRT regimens although potentially at higher risk for acute toxicities. Assessment and selection of those who can tolerate more intense combined-modality strategies and their long-term outcomes merit further larger, prospective studies.

Background. Males have a higher incidence of medulloblastoma (MB) than females, but the effect of gender on survival is unclear. Studies have yielded conflicting results, possibly due to small sample sizes or differences in how researchers defined MB. We aimed to determine the effect of gender on survival in MB using a large data set and strict criteria for defining MB. Procedure. A sample of 1,226 subjects (763 males and 463 females) was identified from 1973 to 2002, using the Surveillance Epidemiology and End Results (SEER-9) registry. MB was strictly defined to exclude non-cerebellar embryonal tumors (primitive neuro-ectodermal tumors). Because children <3 years of age are known to have worse survival, patients were stratified by age <3 years at diagnosis (95 males, 82 females) and >3 years (668 males, 381 females). Results. Overall, there was no significant difference in survival between males and females (log rank P ¼ 0.22). However, among subjects >3 years, females had significantly greater survival than males (log rank P ¼ 0.02). In children <3 years, there was a non-significant trend toward poorer survival in females (median survival: males 27 months, females 13 months; log rank P ¼ 0.24). This interaction between age group and gender was statistically significant (P ¼ 0.03). Conclusion. Females with MB have a survival advantage only in subjects >3 years. In children <3 years, females may even have poorer outcome. The effect of gender on survival and incidence in MB warrants additional biologic investigation, and may differ in very young children with MB.