Real-world outcomes with immunosuppressive therapy for aplastic anemia in patients treated at the University of Michigan

Aplastic anemia (AA) is a rare bone marrow failure disorder that is treated with either allogeneic stem cell transplant or immunosuppressive therapy (IST) consisting of antithymocyte globulin (ATG), cyclosporine (CSA), and eltrombopag. While outcomes are favorable in younger patients, older patients (>60) have significantly worse long-term survival. The dose of ATG is often reduced in older patients and those with multiple comorbidities given concerns for tolerability. The efficacy and safety of dose-attenuated IST in this population is largely undescribed. We performed a retrospective review of patients with AA treated with IST. Our analysis was confounded by changes in practice patterns and the introduction of eltrombopag. We identified 53 patients >60 years old, of which, 20 received dose-attenuated IST, with no statistically significant difference in overall survival between full and attenuated dose cohorts. Overall response rates in both cohorts were similar at 6 months at 71% and 68%. There were more documented infectious complications in the full dose cohort (13 vs. 3). This supports the consideration of dose-attenuated IST in older patients with concerns about tolerance of IST. Lastly, our data confirmed favorable outcomes of younger patients receiving IST, especially in combination with eltrombopag.

Tumor lysis syndrome in patients with acute myeloid leukemia treated with venetoclax and hypomethylating agents with or without dose ramp-up

Venetoclax with hypomethylating agents (HMAs) is an important treatment for patients with acute myeloid leukemia (AML) who cannot tolerate intensive chemotherapy. However, there is limited data on the safety of venetoclax without a dose ramp-up in patients with AML. A retrospective cohort analysis of patients with AML treated with HMA/venetoclax (HMA/Ven) with or without a dose ramp-up, or HMA alone from 6/30/2014-8/22/2022 was conducted. The primary endpoint was the incidence of laboratory and/or clinical tumor lysis syndrome (TLS) by day 10. Of 225 patients, 111 patients received HMA alone or HMA/Ven with a dose ramp-up and 114 received HMA/Ven with no dose ramp-up. The incidence of TLS was similar between the control and no dose ramp-up groups, with rates of 5.4% and 5.3% respectively (p = 0.962). TLS incidence was comparable in patients with and without a dose ramp-up, suggesting that a dose ramp-up may not be mandatory in patients with AML.

Multicenter evaluation of the addition of eltrombopag to immunosuppressive therapy for adults with severe aplastic anemia

Eltrombopag has been shown to improve response rates when added to standard therapy in adults with severe aplastic anemia in controlled trial settings. However, outcomes in real-world populations have mostly been examined in small retrospective studies. This robust, multicenter, retrospective cohort study across six academic health systems compared outcomes in patients who received immunosuppressive therapy with or without eltrombopag. The study included 82 patients who received front-line therapy from January 2014 to August 2021. Overall response rates at 6 months did not differ significantly for patients receiving eltrombopag versus immunosuppressive therapy alone (58% v. 65%, p = 0.56). However, complete response rates at 6 and 12 months were over two times higher in the eltrombopag arm (29% v. 12%, p = 0.06 and 48% v. 18%, p = 0.005). Rates of hepatotoxicity were similar across both arms. Eltrombopag addition did not impact overall survival (median not reached in either arm at 2 years, p = 0.86) or disease-free survival (median not reached v. 13.3 months at 2 years, p = 0.20). Eltrombopag may not produce as large of a benefit in real-world settings compared to controlled trial settings but may offer patients deeper responses with similar rates of toxicity to immunosuppressive therapy alone.

Expert consensus guidelines for the prophylaxis and management of tumor lysis syndrome in the United States: Results of a modified Delphi panel

INTRODUCTION

Tumor lysis syndrome (TLS), which occurs spontaneously or in response to anticancer treatment, results in the release of intracellular potassium, phosphorus, and nucleic acids into the bloodstream, which results in secondary clinical complications that may be fatal. Prior TLS guidelines do not take into consideration potent novel oncologic agents or contemporary treatment paradigms with increased risk of TLS. Thus, a modified Delphi panel of experts was convened to provide an update for TLS management guidelines based upon a combination of supporting literature and practice consensus.

METHODS

A three-round modified Delphi process was implemented. For round 1, nine expert panelists completed a web-based questionnaire developed using published literature. In round 2, panelists were asked to reconsider their answers to questions that did not reach consensus (defined as ≥ 66% agreement among voting panelists). Round 3 was an unblinded, moderated virtual meeting to discuss any remaining questions that did not reach consensus.

RESULTS

Detailed recommendations are given for prophylaxis, monitoring, and management of TLS risks and complications, with hydration being a key element of TLS prophylaxis and management. Guidelines for the management of acute effects of TLS and prevention of long-term renal effects include management of hyperkalemia, hypocalcemia, hyperphosphatemia, and hyperuricemia.

DISCUSSION

Although the control of uric acid levels is quite effective with currently available agents, panelists emphasize the importance of monitoring and treating other dangerous electrolyte abnormalities such as hyperkalemia and hyperphosphatemia. Guidelines from this modified Delphi panel should aid clinicians in preventing and managing TLS.

Evaluating the efficacy and toxicity of dose adjusted pegylated L-asparaginase in combination with therapeutic drug monitoring

The incorporation of pediatric-inspired regimens in the adolescent-young-adult (AYA) and adult populations have resulted improved survival outcomes (Stock et al. Blood 133(14):1548-1559 2019; Dunsmore et al. J Clin Oncol 38(28):3282-3293 2020; DeAngelo et al. Leukemia 29(3):526-534 2015). Nonetheless incorporation of such regimens is limited by increased toxicity to asparaginase. Dosing strategies that reduce the weight-based dose of pegylated-L-asparaginase (PEG-asparaginase) utilizing activity monitoring have been shown to result in better tolerability of these regimens. The purpose of this study was to analyze the efficacy and safety of treating adults with Philadelphia chromosome negative (Ph-) ALL with pediatric-inspired regimens that incorporate PEG-asparaginase dose adjustments and asparaginase activity level monitoring. Patients aged 18-65 years initiated on pediatric-inspired regimens utilizing dose-reduced PEG-asparaginase with therapeutic drug monitoring-guided adjustments were included. The screening of 122 patients treated between 2015 and 2021 resulted in the inclusion of 54 patients. The median age of the cohort was 35 years (16-65 years), and median body mass index (BMI) was 30 kg/m2 (18.3-53.4 kg/m2). The 36-month survival estimate was 62.1% (95% CI 48.1-77.7%), and the median overall survival (OS) was 62.2 months (95% CI 35.1-89.3 months). In the AYA cohort, the 36-month survival was 71.2% (95% CI 55.8-91%) and the median overall survival was not reached. Survival was not significantly affected by immunophenotype or BMI. Discontinuation due to toxicity or hypersensitivity reactions was low at 11% and 9% respectively. The encouraging survival outcomes and favorable tolerability of this older population in the real-world setting support the use of individualized PEG-asparaginase dosing with PharmD-guided therapeutic drug monitoring.

Real world outcomes in patients with Philadelphia chromosome positive acute lymphoblastic leukemia undergoing allogeneic stem cell transplantation-A single institution experience

Philadelphia chromosome positive (Ph+) acute lymphoblastic leukemia (ALL) has been associated with a worse prognosis compared to Ph negative ALL. Tyrosine kinase inhibitor (TKI) therapy has led to an improvement in response rates and survival, thus becoming a critical component of therapy. We performed a retrospective cohort study of Ph+ ALL patients treated at the University of Michigan who received TKI therapy pre- and post-allogeneic hematopoietic stem cell transplant (HSCT) from April 2007 to November 2019. The study included 40 patients with Ph+ ALL (47.5% female) with a median age of 54 (24-69) years. Median event-free survival (EFS) was not reached, with a 5-year EFS of 61%. Median overall survival (OS) was not reached, with a 5-year OS of 71%. There was no difference in 2-year EFS or OS for patients on pre-transplant imatinib or dasatinib (p = 0.16, 0.09, respectively), though definitive conclusions are challenging as post-transplant TKI therapy was variable. The incidence of any grade acute graft-versus-host disease (GVHD) was 62.5% (25/40) and any grade chronic GVHD was 77.5% (31/40). Complete molecular remission (CMR) was achieved in 57.5% of patients pre-transplant with no significant difference when stratified by induction TKI (p = 1). Achievement of CMR pre-HSCT showed a trend towards improved 2-year EFS (p=0.0198) but did not significantly change 2-year OS (p = 1). Patients receiving 1^st and 2^nd generation TKIs pre- and post-HSCT seem to have favorable outcomes, although type of TKI (pre-HSCT) did not significantly impact EFS or OS. In addition, attaining a CMR pre-transplant improved EFS, but did not change OS.

Oncology stewardship in acute myeloid leukemia

In recent years, an explosion of novel agents has shifted the treatment paradigm for patients with acute myeloid leukemia. The optimal place in therapy for many of these novel agents remains unknown due to limited guidance from national guidelines and the way these agents were studied prior to entering the market. A critical evaluation of the literature and incorporation of oncology stewardship principles can be helpful in determining an optimal place for these agents while being mindful of the overall cost that is associated with therapies. The purpose of this review is to critically evaluate the efficacy and safety data for five controversial agents and provide examples of the use of stewardship practices in determining their place in the treatment of acute myeloid leukemia.

Identification of variant APL translocations PRKAR1A-RARα and ZBTB16-RARα (PLZF-RARα) through the MI-ONCOSEQ platform

The cornerstone of management in patients with acute promyelocytic leukemia (APL) is early diagnosis and prompt initiation of treatment with an all-trans retinoic acid (ATRA)-based regimen. Identification of the t(15;17)(PML-RARA) chromosomal translocation through conventional cytogenetics fluorescence in-situ hybridization (FISH) or detection of the promyelocytic leukemia-retinoic acid receptor alpha (PML-RARα) fusion through RT-PCR represent the current standard of care for diagnosing APL. However, about 1-2% of patients with APL have a variant translocation involving other fusion partners with RARα besides PML. These patients present a unique diagnostic and clinical challenge in that conventional cytogenetics in addition to FISH and/or RT-PCR for PML-RARα may fail to identify these clinically relevant genetic lesions leading to an inappropriate diagnosis and treatment. We present two cases of patients who had APL with variant translocations whose bone marrow specimens were sent to the University of Michigan for enrollment in the MI-ONCOSEQ study (HUM00067928) after standard testing failed to identify PML-RARα or t(15;17) despite a phenotypic concern for this diagnosis. In these two patients, whole exome and transcriptome profiling via the MI-ONCOSEQ platform identified a PRKAR1A-RARα fusion in one patient and ZBTB16-RARα fusion in another patient. These cases illustrate the utility of whole exome and transcriptome profiling in diagnosing variant translocations in patients in whom there is a high clinical suspicion for APL based on hematopathology review.

Clinical Availability of ATRA for Patients With Suspected Acute Promyelocytic Leukemia: Why Guidelines May Not Be Followed

BACKGROUND

All-trans retinoic acid (ATRA) serves as the backbone of the management of patients with acute promyelocytic leukemia (APL), with guidelines recommending the initiation of ATRA as soon as APL is suspected. As a regional referral center for patients with acute leukemia, those who are suspected of having APL are often transferred to our facility. However, many referring centers are unable to initiate treatment using ATRA. We conducted an exploratory analysis of the clinical availability of ATRA and the factors limiting access to this critical drug.

PATIENTS AND METHODS

The United States was divided into 6 geographic regions: Northwest, Southwest, Central, Southeast, Northeast, and the Great Lakes. Twenty hospitals were randomly selected from states within each of these regions and were surveyed as to whether they typically treated patients with acute leukemia, the availability of ATRA at their institution, and reported reasons for not stocking ATRA (if not available).

RESULTS

Less than one-third of hospitals queried (31%) had ATRA in stock. Neither the size of the hospital nor the hospital's status as academic versus nonacademic (53% vs 31%; P=.08) influenced ATRA availability. Of the hospitals that referred patients with APL, only 14% (7/49) had ATRA readily available. Hospitals that treated patients with APL were more likely to have ATRA available than referring centers (58% vs 14%; P=.000002).

CONCLUSIONS

Nearly two-thirds of the hospitals surveyed that cared for patients with acute leukemia do not have ATRA immediately available. Moreover, the vast majority of hospitals that refer patients to other centers do not have ATRA. These findings should spur investigation into the impact of immediate ATRA availability on the morbidity and mortality of patients with APL. A call by hematologists nationwide to their formulary committees is warranted to ensure that this lifesaving medication is available to patients suspected of having APL.

Late-onset complications with bendamustine versus CHOP or CVP based chemoimmunotherapy in indolent Non-Hodgkin's lymphoma

Bendamustine is a preferred first-line chemoimmunotherapy regimen for indolent non-Hodgkin's lymphoma (iNHL). Emerging evidence suggests an increased incidence of late-onset complications with bendamustine-based regimens compared with CHOP/CVP; however, this evidence is limited. We retrospectively compared late-onset complications from January 2005 to May 2020 in adults with previously untreated iNHL who received rituximab or obinutuzumab with CHOP, CVP, or bendamustine. Forty-six patients received CHOP/CVP; 119 received bendamustine. No difference in incidence of late-onset infections was observed. Bendamustine led to a higher rate of prolonged and unresolved lymphocytopenia and a greater incidence of late-onset neutropenia. Many patients receiving bendamustine did not have lymphocyte recovery even three years following administration. Ongoing infection prophylaxis with bendamustine-based regimens may offset translation of these laboratory findings to late-onset infectious risk.

Real world use of FLT3 inhibitors for treatment of FLT3+ acute myeloid leukemia (AML): A single center, propensity-score matched, retrospective cohort study

BACKGROUND

Patients diagnosed with acute myeloid leukemia with a FLT3 mutation (FLT3+ AML) have historically had poor outcomes. While the addition of the FLT3 inhibitors to induction therapy has been shown to improve survival outcomes in FLT3+ AML, interactions and overlapping toxicities between FLT3 inhibitors and standard of care medications used during induction therapy (e.g. azole antifungals, anthracyclines) and logistical barriers have complicated their use. To avoid these concerns, our institution has opted to defer initiation of midostaurin until after completion of induction therapy. However, to our knowledge no study confirming the effectiveness of this strategy for real world FLT3 inhibitor use has been published.

METHODS

We performed a single center, propensity-score matched, retrospective cohort study characterizing efficacy and safety of our strategy for use of FLT3 inhibitors in the treatment of FLT3+ AML. The primary outcome was median event-free survival (EFS), while secondary endpoints included median overall survival (OS), overall response rate (ORR), 30-day mortality, duration of neutropenia, duration of thrombocytopenia, consolidation cycle delays, documented infections, and all-cause hospital readmission.

RESULTS

A total of 83 FLT3+ AML patients treated with intensive induction therapy were included in the study, of whom 48 were propensity-score matched and analyzed. Baseline characteristics were similar between the patients who received a FLT3 inhibitor after induction therapy and the historical control arm. Median EFS was not significantly different but compared favorably between the FLT3 inhibitor cohort and historical controls (not reached vs 8 months, p = 0.343) with 18-month EFS of 54% and 43% for the two cohorts, respectively. Similarly, no significant differences were noted with regard to median OS (not reached vs 28.7 months, p = 0.752), ORR (79.2% vs 79.2%), or safety outcomes between groups.

CONCLUSION

Compared to historical controls, addition of a FLT3 inhibitor to intensive chemotherapy post-induction may improve EFS or OS in a real world patient cohort with longer follow-up and a larger sample size. The omission of midostaurin in induction allowed for the use of an azole antifungal and the intensification of anthracycline dose may have contributed to high remission rates in both groups.

Multicenter comparison of high-dose cytarabine-based regimens versus liposomal daunorubicin and cytarabine (CPX-351) in patients with secondary acute myeloid leukemia

Liposomal daunorubicin/cytarabine (CPX-351) gained FDA approval for secondary AML after demonstrating improved outcomes over daunorubicin and cytarabine (7 + 3). A number of study limitations prompted a comparison of safety/efficacy of CPX-351 against regimens containing a purine analogue and high-dose cytarabine (HIDAC). This retrospective study compared complete response rates with/without count recovery (CR/CRi) between HIDAC-based regimens and CPX-351 in 169 patients with newly diagnosed sAML. The CR/CRi rate was 62.7% in the HIDAC-based therapy arm vs. 47.9% in the CPX-351 arm (p = 0.002 [one-sided for non-inferiority]). Median time to absolute neutrophil and platelet count recovery was shorter after HIDAC-based therapy (18 and 23 days, respectively) compared to CPX-351 (36 and 38 days; p < 0.001). Median overall survival was 9.8 months in the HIDAC-based group and 9.14 months in the CPX-351 group. 30-day mortality was greater with CPX-351 (8.5%) compared to HIDAC-based (1.3%; p = 0.039). These results reveal comparable efficacy and favorable safety with HIDAC-based regimens.

Utility of methicillin-resistant Staphylococcus aureus (MRSA) nasal screening in patients with acute myeloid leukemia (AML)

BACKGROUND

Current literature has demonstrated the utility of the MRSA nasal screen as a de-escalation tool to decrease unnecessary anti-MRSA antibiotic therapy. However, data on the applicability of this test in patients with hematologic malignancy is lacking.

METHODS

This is a single-center, retrospective cohort study of patients with acute myeloid leukemia (AML) with or without a history of hematopoietic cell transplant (HCT), with pneumonia and MRSA nasal screening with respiratory cultures obtained. The primary outcome was to determine the negative predictive value (NPV) of the MRSA nasal screen for MRSA pneumonia. Secondary outcomes included sensitivity, specificity, positive predictive value (PPV) of the MRSA nasal screen and prevalence of MRSA pneumonia.

RESULTS

Of 98 patients with AML and pneumonia, the prevalence of MRSA pneumonia was 4.1% with confirmed positive MRSA respiratory cultures observed in 4 patient cases. In patients with confirmed MRSA pneumonia, 3 had positive MRSA nasal screens while 1 had a false negative result, possibly due to a long lag time (21 days) between MRSA nasal screen and pneumonia diagnosis. Overall, the MRSA nasal screen demonstrated 75% sensitivity and 100% specificity, with a PPV of 100% and a NPV of 98.9%.

CONCLUSIONS

Given the low prevalence, empiric use of anti-MRSA therapy in those AML and HCT patients with pneumonia may not be warranted in clinically stable patients. For patients in whom empiric anti-MRSA antibiotics are initiated, nasal screening for MRSA may be utilized to de-escalate anti-MRSA antibiotics in patients with AML with or without HCT.

Propensity-score Matched Comparison of Salvage Chemotherapy Regimens in Relapsed/Refractory Acute Myeloid Leukemia

BACKGROUND

Relapsed/refractory acute myeloid leukemia (AML) confers a poor prognosis, and there is no single standard of care first-line salvage regimen. FLAG (fludarabine, cytarabine, and granulocyte colony-stimulating factor) is a common salvage regimen with a favorable toxicity and efficacy profile in poor-risk AML.

MATERIALS AND METHODS

We conducted a single-center, retrospective analysis of first relapse/primary refractory patients with AML that received salvage chemotherapy from January 2009 to July 2019. We propensity-score matched patients 1:1 (based on age at diagnosis, cytogenetic risk group, Charlson comorbidity index, de novo vs. secondary AML, and whether or not they received an allogeneic stem cell transplant in first complete remission) into 2 groups, FLAG (Group 1) or non-FLAG (Group 2) as first-line salvage regimen, with 66 patients in each group. The primary endpoint was overall response rate (complete response and complete response with incomplete hematologic recovery).

RESULTS

The median patient age was 59 years (range, 19-80 years). Patients treated with FLAG had a higher overall response rate (complete response/complete response with incomplete hematologic recovery) (71.2% vs. 50.0%; odds ratio, 2.47; 95% confidence interval [CI], 1.21-5.08; P = .013), longer event-free survival (8.9 vs. 2.1 months; hazard ratio [HR], 0.58; 95% CI, 0.39-0.86; P = .005), and longer overall survival (14.2 vs. 5.9 months; HR, 0.62; 95% CI, 0.41-0.93; P = .019). Patients who received FLAG had a shorter median duration of neutropenia (22 vs. 34 days; HR, 0.43; 95% CI, 0.29-0.64; P < .001).

CONCLUSION

This analysis supports the FLAG regimen as an effective and well-tolerated salvage therapy for patients with relapsed/refractory AML.

Hybrid chemotherapy regimen (FLAG-IDA-vincristine-prednisone) for acute leukemia with mixed-phenotype blasts

BACKGROUND

Acute leukemia with mixed-phenotype blasts is associated with poor outcomes. There are no standard treatment regimens. Due to disease heterogeneity, controversy exists over whether an AML-based, ALL-based, or a combined (hybrid) AML/ALL-based regimen is most appropriate.

MATERIALS AND METHODS

We conducted a single-center, retrospective case series review of patients with acute leukemia with mixed phenotype blasts as described by the European Group for Immunological Characterization of Leukemia (EGIL) or the 2008 WHO classification. Patients were treated from November 2014 and December 2019 with the combination chemotherapy regimen FLAG-idarubicin-vincristine-prednisone with or without rituximab. Outcomes included induction response, time to transplant, time to relapse, overall survival, time to neutrophil or platelet recovery, infection, and duration of hospitalization.

RESULTS

The median age was 68 years (range 21-77). Six patients (87.5 %) had unfavorable/complex cytogenetics. All patients achieved a complete remission (CR) or complete remission with incomplete hematologic recovery (CRi). Estimated 1-year overall survival was 85.7 %. There were no deaths during induction, with a 22 day median duration of hospitalization for induction.

CONCLUSION

The combination of FLAG, idarubicin, vincristine, and prednisone (FLAG-VIPR) demonstrated favorable induction responses in a disease state with historically poor outcomes and should be studied in a prospective clinical trial.

Impact of high dose cytarabine dosing strategies in obese patients with acute myeloid leukemia

High dose cytarabine (HIDAC) consolidation has demonstrated a survival benefit in patients with acute myeloid leukemia (AML). The increasing prevalence of obesity and the toxicity risk with this therapy renders important the quantification of potential risks with weight-based dosing in this patient population. The American Society of Clinical Oncology published recommendations on chemotherapy dosing in obese patients, but patients with leukemia were excluded from analysis. This was a retrospective comparison of safety and efficacy outcomes in obese and non-obese patients with AML who received HIDAC consolidation. Thirty-nine (41.9 %) patients received dose adjusted HIDAC in cycle 1. Nine of the 40 patients in the obese group received HIDAC dose-adjusted for obesity. The combined incidence of cycle delays, febrile neutropenia, or documented infection was 41.5 % in non-obese patients compared to 57.5 % in obese patients (p = 0.127). The median overall survival (OS) and event free survival (EFS) were not reached in both cohorts. The estimated 36-month overall survival was 76.4 % (95 % CI 0.623-0.905) in non-obese patients, compared to 66.1 % (95 % CI 0.472-0.85) in obese patients. There were no significant differences in safety or efficacy outcomes for obese versus non-obese patients who received HIDAC consolidation. For class III obesity, baseline dose-adjustments were more common.

Evaluating the Role of Novel Oncology Agents: Oncology Stewardship in Relapsed/Refractory Diffuse Large B-Cell Lymphoma

Novel treatment strategies have shifted the treatment landscape for patients with diffuse large B-cell lymphoma, particularly for those with relapsed/refractory disease. However, uncertainty remains regarding the therapeutic value of these novel agents compared to existing salvage chemotherapy regimens. In addition, the high cost associated with these agents puts both patients and health systems at risk of financial toxicity, further complicating their use. The development of clinical pathways incorporating oncology stewardship principles are necessary in order to maximize value-based care. This comprehensive review assesses the efficacy and safety data available for novel treatment options in relapsed/refractory diffuse large B-cell lymphoma and applies stewardship principles to evaluate their optimal place in therapy, with the aim of optimizing safe, effective, and financially responsible patient care.

Role of caplacizumab in the treatment of acquired thrombotic thrombocytopenic purpura

Acquired thrombotic thrombocytopenic purpura is a rare blood disorder with a high early mortality rate, if untreated. Standard of care plasma exchange and glucocorticoids have dramatically improved survival. However, additional advancements are necessary to further decrease mortality. Caplacizumab-yhdp (Cablivi®) is the first Food and Drug Administration-approved treatment indicated for adult patients with acquired thrombotic thrombocytopenic purpura, in combination with plasma exchange and immunosuppressive therapy. However, there are considerable risks associated with the use of caplacizumab and they must be weighed against the benefits of the medication.

Contemporary treatment options for a classical disease: Advanced Hodgkin lymphoma

Advanced classical Hodgkin lymphoma (cHL) is a rare lymphoid disease characterized by the presence of Hodgkin and Reed-Sternberg (HRS) cells. Each year, cHL accounts for 0.5% of all new cancer diagnoses and about 80% are diagnosed with advanced stage disease. Given the significant improvement in cure rates, the focus of treatment has shifted towards minimization of acute and long-term toxicities. PET-adapted strategies have largely been adopted as standard of care in the United States in an attempt to balance toxicities with adequate lymphoma control. However, the appropriate upfront chemotherapy regimen (ABVD versus eBEACOPP) remains controversial.

Impact of prophylactic intrathecal chemotherapy on CNS relapse rates in AML patients presenting with hyperleukocytosis

Central nervous system (CNS) relapse in acute myeloid leukemia (AML) confers a poor prognosis. Despite the identification of risk factors for CNS relapse (e.g. hyperleukocytosis), there is no standard practice for CNS relapse risk reduction with intrathecal (IT) chemotherapy in patients. We compared outcomes of 50 patients who did not receive IT chemotherapy with 18 patients who did receive IT chemotherapy with a hyperleukocytosis at diagnosis (defined as white blood cell count ≥100,000 cells/mcL). There were three occurrences of CNS relapse, all within patients who did not receive prophylaxis. There was no difference in the incidence of CNS relapse between the patient cohorts (p = .560). These results highlight the low incidence of CNS relapse in our patient population that received and survived induction chemotherapy despite selecting for a high risk cohort. Furthermore, there is a need for a CNS relapse registry to standardize treatment approaches in this high-risk patient population.

Optimal sequence of daratumumab and elotuzumab in relapsed and refractory multiple myeloma

Daratumumab and elotuzumab have demonstrated improvements in overall response rates (ORR) and progression-free survival (PFS) in relapsed/refractory multiple myeloma (RRMM). There is a lack of comparative clinical trials and an even larger lack of consensus on the optimal integration of these novel agents into the treatment paradigm. Clinical outcomes were compared retrospectively in 37 patients who received daratumumab before elotuzumab (dara-first, n = 23) and patients who received elotuzumab before daratumumab (elo-first, n = 14). ORR to the first monoclonal antibody was not different (dara-first 56.5% vs. elo-first 64.3%, p = .641). ORR to the second antibody differed when daratumumab was given second compared to when elotuzumab was given second (64.3% vs. 34.8%, respectively; p = .081). Cumulative PFS for elo-first was significantly longer than dara-first (22.67 months vs. 10.5 months, respectively; p = .001). Response rates to daratumumab may be preserved irrespective of sequence. However, response rates to elotuzumab may diminish with prior daratumumab exposure.

Lenalidomide Plus Hypomethylating Agent as a Treatment Option in Acute Myeloid Leukemia With Recurrent Genetic Abnormalities-AML With inv(3)(q21.3q26.2) or t(3;3)(q21.3;q26.2); GATA2, MECOM

INTRODUCTION

Acute myeloid leukemia (AML) is a heterogeneous clonal hematopoietic neoplasm. The cytogenetic changes associated with AML affect the response rate and survival and are one of the most important independent prognostic factors. AML with inv(3)(q21.3q26.2) or t(3;3)(q21.3;q26.2); GATA2, MECOM accounts for 1% to 2% of all forms of AML and has been associated with a younger age at diagnosis, a poor response to standard induction chemotherapy, and very poor long-term prognosis.

PATIENTS AND METHODS

We performed a single-center, retrospective cohort study comparing the outcomes with hypomethylating agent (HMA) plus lenalidomide to those with standard intensive induction therapies for newly diagnosed and relapsed/refractory AML with inv(3).

RESULTS

Of the 15 patients, 4 (26.7%) had received lenalidomide and HMA as primary therapy. The overall response rate (ORR) was 100% for the 4 patients who had received lenalidomide with HMA as first-line induction therapy. The ORR was 27.3% (3 of 11) for the patients who had received other induction regimens (P = .0256). The duration of response for first induction therapy was an average of 7.4 months after lenalidomide plus an HMA and a mean of 1.5 months after induction with other chemotherapy regimen (P = .057). The ORR for induction and reinduction therapy was also assessed, with an ORR of 21.4% (6 of 28) for alternative chemotherapy regimens and an ORR of 75% (6 of 8) for induction and reinduction with lenalidomide plus HMA (P = .0046).

CONCLUSIONS

The high ORR and reasonable duration of response could allow for potentially curative allogeneic hematopoietic cell transplantation for these patients with high-risk AML. Our initial data suggest that lenalidomide plus HMA is a promising approach for patients with AML with inv(3).

A single-center multidisciplinary approach to managing the global Erwinia asparaginase shortage

The availability of Erwinia Asparaginase has been limited across the world due to manufacturing shortages or for some countries due to the high acquisition cost, putting patients at risk for inferior outcomes. This manuscript provides guidance on how to manage hypersensitivity reactions and utilize therapeutic drug monitoring (TDM) to conserve and limit Erwinia use. The clinical and financial impact of a multidisciplinary committee are also discussed. Faced with a global Erwinia shortage, a multidisciplinary asparaginase allergy committee was created to review all hypersensitivity reactions to asparaginase therapy, staff education was performed on the management of asparaginase hypersensitivity reactions, an institution-wide premedication policy was mandated, and standardized guidelines were created for TDM. This multidisciplinary approach reduced the PEG-asparaginase to Erwinia switch rate from 21% (35 of 163) to 7% (10 of 134) (p = .0035). A multifaceted approach can safely maintain patients on PEG-asparaginase and conserve Erwinia for patients who need it most.

Incidence and Risk Factors for Breakthrough Invasive Mold Infections in Acute Myeloid Leukemia Patients Receiving Remission Induction Chemotherapy

Background

Despite fungal prophylaxis, invasive mold infections (IMIs) are a significant cause of morbidity and mortality in patients with acute myeloid leukemia (AML) receiving remission induction chemotherapy. The choice of antifungal prophylaxis agent remains controversial, especially in the era of novel targeted therapies. We conducted a retrospective case–control study to determine the incidence of fungal infections and to identify risk factors associated with IMI.

Methods

Adult patients with AML receiving anti-Aspergillus prophylaxis were included to determine the incidence of IMI per 1000 prophylaxis-days. Patients without and with IMI were matched 2:1 based on the day of IMI diagnosis, and multivariable models using logistic regression were constructed to identify risk factors for IMI.

Results

Of the 162 included patients, 28 patients had a possible (n = 22), probable, or proven (n = 6) diagnosis of IMI. The incidence of proven or probable IMI per 1000 prophylaxis-days was not statistically different between anti-Aspergillus azoles and micafungin (1.6 vs 5.4, P = .11). The duration of prophylaxis with each agent did not predict IMI occurrence on regression analysis. Older age (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.004–1.081; P = .03) and relapsed/refractory AML diagnosis (OR, 4.44; 95% CI, 1.56–12.64; P = .003) were associated with IMI on multivariable analysis.

Conclusions

In cases that preclude use of anti-Aspergillus azoles for prophylaxis, micafungin 100 mg once daily may be considered; however, in older patients and those with relapsed/refractory disease, diligent monitoring for IMI is required, irrespective of the agent used for antifungal prophylaxis.

Successful use of blinatumomab in a patient with acute lymphoblastic leukemia and severe hepatic dysfunction

Relapsed/refractory acute lymphoblastic leukemia poses a significant clinical challenge due to its poor prognosis, with survival rates of less than a year, even with novel therapies. Patients frequently experience toxicities from induction chemotherapy such as hepatotoxicity, which can limit therapeutic options upon relapse. Blinatumomab, a novel immunotherapy, has demonstrated excellent efficacy in relapsed/refractory acute lymphoblastic leukemia; however, there are limited data on use of this agent in patients with significant organ dysfunction. In this report, we describe the safe and effective use of blinatumomab in an adult patient with refractory Philadelphia chromosome-negative (Ph-) acute lymphoblastic leukemia in the setting of severe hepatic dysfunction. Blinatumomab may represent a viable option to treat relapsed/refractory acute lymphoblastic leukemia in patients with significant hepatic dysfunction.

Managing liver dysfunction in haematology patients: Switch antifungals, or use the tincture of time?

Liver function test (LFT) abnormalities are a common occurrence in haematology patients receiving antifungal therapies. The cause of elevated LFTs is often multifactorial. Posaconazole is associated with elevated LFTs in approximately 5%-10% of patients. Recently, DiPippo, et al demonstrated that switching to isavuconazole in such cases leads to a reduction in LFTs in the majority of patients. However, the LFTs in such patients may have declined with time while continuing on posaconazole therapy. We retrospectively assessed LFT kinetics in 157 AML patients receiving posaconazole for antifungal prophylaxis and found that in 27 patients who developed grade 2 or higher CTCAE hepatotoxicity, 85% (23/27) had lower LFTs at the end of posaconazole therapy, despite continuation in the setting of hepatotoxicity, and this change from maximum LFTs was statistically significant (P < 0.0001). Thus, the development of LFT abnormalities while on posaconazole therapy may not warrant a switch to an alternative, potentially less effective antifungal, as hepatotoxicity is often multifactorial and generally resolves with time in the majority of patients.

253. Febrile Neutropenia Antibiotic De-escalation Study in Acute Myeloid Leukemia Patients With Prolonged Neutropenia

Background

The IDSA and NCCN guidelines recommend continuing IV anti-pseudomonal (IVPSA) therapy until neutrophil recovery (i.e., an ANC > 500 cells/mm³) in high-risk acute myeloid leukemia (AML) patients with febrile neutropenia (FN). This recommendation is based on expert opinion and the current practice should be re-evaluated given the emergence of multi-drug-resistant organisms and high rates of Clostridium difficile infection (CDI) in this population. The purpose of this study was to evaluate whether IVPSA antibiotics could be safely de-escalated or discontinued in high-risk AML patients with FN following implementation of a guideline.

Methods

This single-center, pre–post quasi-experimental study included patients with AML receiving induction chemotherapy hospitalized between September 2015 to February 2018. Patients in the intervention group were compared with a historical cohort of patients admitted before implementation of the guideline. The primary outcome was the incidence of suspected or documented bacterial infection after antibiotic de-escalation in the intervention group (or meeting criteria for de-escalation in the historical control group). Secondary outcomes included the incidence of CDI, IVPSA Days of Therapy (DOTs), hospital length of stay (LOS), and mortality. Patients in the intervention group were evaluated for antibiotic de-escalation on day 5 of FN and antibiotics were discontinued if patients were afebrile, hemodynamically stable, and without evidence of infection irrespective of their ANC (or de-escalated to fluoroquinolone prophylaxis in relapsed/refractory disease). In clinically stable patients with suspected or documented bacterial infection, antibiotics were continued for a defined duration per indication as outlined in the guideline.

Results

A total of 93 patients were included in the analysis. Baseline demographics were similar between the two groups with the exception of more relapsed/refractory patients in the intervention group. Patients in the intervention group had similar clinical outcomes and lower rates of CDI and IVPSA DOTs (see Figure 1).

Conclusion

In high-risk AML patients with FN, an antibiotic de-escalation guideline reduced the incidence of CDI and IVPSA antibiotic DOTs without adversely affecting clinical outcomes.

Disclosures

All authors: No reported disclosures.

1071. Impact of Standard vs. Prolonged Courses of Antibiotics for the Treatment of Uncomplicated Staphylococcus aureus Bacteremia (SAB) in Patients With Hematologic Malignancies

Background

The optimal treatment duration for uncomplicated SAB (U-SAB) is unknown in patients with hematologic malignancies. The goal of this study was to evaluate the impact of antibiotic duration on outcomes in patients with hematologic malignancies and U-SAB.

Methods

This was a multicenter, retrospective cohort study of adult patients with hematologic malignancies and U-SAB treated with standard (2 weeks) or prolonged (>2 weeks) antibiotic therapy. U-SAB was defined as defervescence and culture clearance within 96 hours of index culture and the absence of: endocarditis, implanted prostheses, metastatic sites of infection, and bone/joint involvement. Patients with SAB therapy <10 days and those with inadequate source control were excluded. The primary outcome was a composite global clinical cure: absence of relapse SAB, absence of SAB progression, and survival at 60 days following index SAB.

Results

Of 89 included patients, 51% received a standard antibiotic duration for U-SAB. The median age of the entire cohort was 56 and majority was male (60%). Neutropenia was present at index culture in 53% of patients, and acute leukemia (48%) and lymphoma (26%) were the most common underlying malignancies. Other baseline characteristics were similar between the two groups except more patients in the standard duration group had relapsed/refractory malignancy (51% vs. 25%, P = 0.016), central-line source (71% vs. 48%, P = 0.032), and antibiotic prophylaxis prior to index SAB (42% vs. 18%, P = 0.021). Median duration of treatment in the standard group was 15 days vs. 28 days in the prolonged duration group. No differences in global clinical cure and other clinical outcomes were seen between groups (Figure 1). On multivariable logistic regression analysis, only relapsed/refractory malignancy was identified as an independent predictor of global clinical failure (odds ratio, OR, 9.43; 95% confidence interval, CI, 1.17–76.9; P = 0.035). Duration of treatment was not associated with global clinical cure (OR, 2.92; 95% CI, 0.51–16.7; P = 0.23).

Conclusion

No differences in clinical outcomes were seen in patients with active hematologic malignancies who received 2 weeks vs. >2 weeks of antibiotic therapy for the treatment of U-SAB, although confirmation of our findings in a larger study is warranted.

Disclosures

All authors: No reported disclosures.

Risk factors for subtherapeutic levels of posaconazole tablet

Background

Posaconazole is the prophylactic antifungal of choice for patients with haematological malignancies at high risk of invasive fungal infections (IFIs). Studies have demonstrated that subtherapeutic concentrations of posaconazole are associated with breakthrough fungal infections and specific risk factors for subtherapeutic troughs associated with the suspension formulation have been identified. However, these risk factors have not been evaluated in a large patient population with the recently approved tablet formulation.

Objectives

To determine the risk factors for subtherapeutic posaconazole troughs associated with the tablet formulation in patients receiving posaconazole as IFI prophylaxis.

Patients and methods

From 1 February 2013 to 31 March 2015 all posaconazole serum trough concentrations were evaluated. A total of 157 patients receiving posaconazole tablet for prophylaxis during induction therapy for haematological malignancies and allogeneic stem cell transplant recipients with graft-versus-host disease were included for analysis.

Results

Overall, 28 patients (18%) had subtherapeutic troughs (<700 ng/mL). Patients were more likely to have subtherapeutic troughs if they had diarrhoea (n = 24; 83%) (P < 0.001), were receiving a proton pump inhibitor (n = 27; 93%) (P = 0.016) and weighed >90 kg (n = 14; 48%) (P = 0.047).

Conclusions

While the posaconazole tablet has provided more consistent therapeutic concentrations when compared with the suspension there may still be a role for therapeutic drug monitoring (TDM). These results may guide us to a specific population in which TDM is necessary to identify subtherapeutic troughs.

The FOSSIL Study: FLAG or standard 7+3 induction therapy in secondary acute myeloid leukemia

Patients with secondary acute myeloid leukemia (sAML) have poor outcomes, with CR/CRi rates of 25-35% with standard 7 + 3 induction chemotherapy, while single center non-comparative analyses suggest promising outcomes with FLAG. We conducted a single-center, retrospective cohort study assessing outcomes in treatment-naïve patients with sAML treated with fludarabine, high-dose cytarabine, and granulocyte colony-stimulating factor (FLAG, n = 40) compared with 7 + 3 (n = 66). Median patient age was 63 years (range: 27-82) in the FLAG group and 60 years (range: 21-76) in the 7 + 3 group (P = 0.968). Patients treated with FLAG achieved higher overall response rates (CR + CRi + MLFS) compared to 7 + 3 (70% vs. 48%, P = 0.043). FLAG was well tolerated, with only one induction death (30-day mortality rate, 3% vs. 8%, P = 0.405) and no cases of cerebellar toxicity. Duration of neutropenia was significantly shorter with FLAG (median 16 vs. 23 days, P < 0.001). Half of the FLAG-treated patients proceeded to consolidative therapy compared with only 27% of those who received 7 + 3 (P = 0.022). Overall survival was comparable between groups (8.5 mos, FLAG vs. 9.1 mos, 7 + 3; P = 0.798). Thus, FLAG may represent a low-cost treatment strategy in sAML that produces higher response rates and promising survival outcomes with minimal treatment-related toxicity. Further studies are required to prospectively compare FLAG to the newly FDA-approved CPX-351 in sAML.

Successful use of cytarabine and bendamustine in a patient with mantle cell lymphoma and acute renal failure using intermittent hemodialysis: A case report

Mantle cell lymphoma is a mature B-cell non-Hodgkin lymphoma characterized by the hallmark (11;14) chromosomal translocation, which often presents with lymphadenopathy and extra-nodal involvement. Young, fit patients are generally treated with chemotherapy approaches that incorporate high-dose cytarabine (e.g. the Nordic regimen) followed by autologous hematopoietic cell transplantation. Because of the significant activity of cytarabine in mantle cell lymphoma, increasingly, high- and intermediate-dose cytarabine are being used in the treatment of elderly mantle cell lymphoma patients. In practice, many patients present with significant organ dysfunction and there is limited data on the use of high- to intermediate-dose cytarabine and bendamustine in this setting. Here, we report a case of a critically ill, elderly patient with mantle cell lymphoma and concomitant acute kidney injury and oliguria who was successfully treated with a cycle of cytarabine (Ara-C) and bendamustine accompanied by intermittent hemodialysis.

Multicentre study of posaconazole delayed-release tablet serum level and association with hepatotoxicity and QTc prolongation

Objectives

The association of posaconazole serum concentrations and toxicity is unclear. An assessment of whether levels obtained with the delayed-release tablet (DRT) formulation are correlated with abnormal liver function test (LFT) results and/or QTc prolongation was undertaken.

Methods

This was a multicentre, retrospective, observational study of adult patients with cancer between 26 November 2013 and 14 November 2014. Patients were included if they received posaconazole DRT with a posaconazole level obtained between days 5 and 14. Clinical data, including demographics, hepatotoxic medications, posaconazole levels, LFTs and QTc intervals, were obtained. Association of factors with changes in LFTs and QTc prolongation was assessed using linear and logistic regression.

Results

One hundred and sixty-six study patients were included. The median posaconazole level was 1250 (range 110-4220) ng/mL and the median time until level was 6 (range 5-14) days. There was a statistically significant increase in AST ( P  <   0.001), ALT ( P  <   0.001), alkaline phosphatase (ALK) ( P  <   0.001), total bilirubin (TBILI) ( P  <   0.001) and QTc ( P  =   0.05) from baseline. Posaconazole levels were not associated with increases in AST [β (SE) = -0.33 (2.2), P  =   0.88], log ALT [β (SE) = -0.02 (0.03), P  =   0.63], ALK [β (SE) = 2.2 (2.9), P  =   0.46] and TBILI [β (SE) = -0.01 (0.04), P  =   0.88]. For each additional hepatotoxic medication, there was a mean change in TBILI of 0.13 mg/dL ( P  =   0.02) and ALK of 7.1 U/L ( P  =   0.09). No statistically significant association between posaconazole level and QTc interval prolongation was found.

Conclusions

We did not identify an association between posaconazole serum concentrations and LFT elevations or QTc prolongation. However, some LFTs were found to increase with more hepatotoxic medications administered.

Pegasparaginase silent inactivation during therapy for NK/T cell lymphoma

Natural Killer/T cell (NK/T cell) lymphoma is a rare, yet aggressive T cell lymphoma, which often displays resistance to traditional chemotherapies. Asparagainse (ASNase), through its unique mechanism of action, has become a vital component in the treatment of NK/T cell lymphoma. However, because ASNase is of bacterial origin, antibody formation can render the therapy ineffective, even in the absence of clinical hypersensitivity, which has been coined 'silent inactivation.' While the phenomenon of silent inactivation of PEG-ASNase is well documented in the treatment of ALL, it has not been described in NK/T cell lymphoma patients. Herein, we report a case series of six patients treated for NK/T cell lymphoma with PEG-ASNase who subsequently developed silent inactivation identified using therapeutic drug monitoring (TDM). The goal of this manuscript is to alert clinicians of this phenomenon, and review the importance of TDM in NK/T cell lymphoma patients receiving ASNase.

Risk factors for cefepime nonsusceptible Gram-negative infections in allogeneic hematopoietic cell transplant recipients

Purpose

Allogeneic hematopoietic cell transplant recipients undergo myelosuppressive chemotherapy to allow engraftment of stem cells and are at particularly high risk for bacterial infections and adverse outcomes. Patients undergoing hematopoietic cell transplant are at increased risk for healthcare-associated infections, including infections with multidrug-resistant pathogens. Cefepime is a commonly prescribed antibiotic for empiric therapy in hematopoietic cell transplant patients, but there is minimal data describing cefepime resistance rates, risk factors for resistance, and clinical outcomes associated with cefepime-resistant infections.

Methods

Adult (≥18 years old) allogeneic hematopoietic cell transplant recipients with a culture positive for a gram-negative rod between January 2010 and January 2016 were spilt into two groups: cefepime susceptible and cefepime nonsusceptible . The primary objective of this study was to identify risk factors for cefepime nonsusceptible through multivariable logistic regression.

Results

A total of 107 patients were included (27 cefepime nonsusceptible, 80 cefepime-susceptible), yielding a 25.2% nonsusceptibility rate. Multivariable analysis yielded age >60 years old, Klebsiella spp. infection, Acinetobacter spp. infection, healthcare exposures within 90 days, acute gastrointestinal graft-vs-host-disease, and chronic graft-vs-host-disease at multiple locations as significant risk factors for cefepime nonsusceptible. The receiver operating characteristic area under the curve of the model was 0.851. Thirty-day all-cause mortality (29.6% versus 16.3%, p = 0.13) and length of hospitalization (19 versus 12.5 days, p = 0.0650) were numerically higher in the cefepime nonsusceptible group.

Conclusions

Hematopoietic cell transplant patients with acute gastrointestinal graft versus host disease, extensive chronic graft-vs-host-disease, advanced age, previous healthcare exposures, or infections with Klebsiella and Acinetobacter are at increased risk for cefepime nonsusceptible. Patients infected with cefepime nonsusceptible pathogens may have higher rates of mortality and length of hospitalization.

PEGging down risk factors for peg-asparaginase hepatotoxicity in patients with acute lymphoblastic leukemia †

Asparaginase is commonly de-emphasized/omitted in adult acute lymphoblastic leukemia regimens due to poor tolerability, including hepatotoxicity (HTX). Adult patients (n = 100) given induction therapy containing pegylated asparaginase (PEG) from January 2008 to February 2016 were evaluated for HTX. Sixteen patients met criteria for HTX (direct bilirubin >3 g/dL). A multivariable model identified body surface area >2m² (OR 7.40; 95% CI: 1.73-31.61, p = .007), albumin <3 mg/dL (OR 4.62; 95% CI: 1.09-19.68, p = .038), and platelet count <50 K/mm³ (OR 9.36; 95% CI: 2.13-41.17, p = .003) as risk factors for HTX. More patients with HTX missed ≥1 dose of intended chemotherapy (75% vs. 8%, p < .001). In patients with HTX, complete response and 30-day mortality rates were 40% and 9% versus 73% and 1% in patients without HTX (p = .02 and p < .001). A risk scoring tool was created to predict risk of toxicity, which should be validated through a prospective evaluation.

A review of CD19-targeted immunotherapies for relapsed or refractory acute lymphoblastic leukemia

Aim Novel immunotherapies have generated high response rates and unique adverse effects among patients with relapsed or refractory acute lymphoblastic leukemia. Therapies engaging endogenous T-cells against acute lymphoblastic leukemia are emerging for children and adults with various poor prognostic factors, thus accurate knowledge of immunotherapies is necessary for their effective implementation in the future. In this review, we evaluate clinical trial data regarding chimeric antigen receptor T-cells and blinatumomab, for the treatment of relapsed or refractory acute lymphoblastic leukemia. Summary In the relapsed or refractory setting, response rates rapidly diminish after subsequent lines of chemotherapy and cumulative toxicities may cause significant patient harm. Immunotherapies provide an approach to improve response rates and minimize traditional toxicities via novel mechanisms of action. Two therapies targeting CD19 antigens expressed on B-cell acute lymphoblastic leukemia lineages, chimeric antigen receptor T-cells, and blinatumomab have induced complete remissions among high-risk patient populations, especially those refractory to multiple therapies. Adverse effects such as cytokine release syndrome and neurologic sequelae remain serious precautions of each therapy. Conclusion Knowledge of immunotherapy mechanisms and clinical outcomes associated with immunotherapies is critical for the optimization of treating patients with relapsed or refractory acute lymphoblastic leukemia. Future use of chimeric antigen receptor T-cells and blinatumomab demands proper assessment of a patient's disease and treatment history in addition to unique monitoring and supportive care interventions.

Daptomycin nonsusceptible vancomycin resistant Enterococcus bloodstream infections in patients with hematological malignancies: risk factors and outcomes

Daptomycin is typically the treatment of choice for vancomycin resistant Enterococcus (VRE) bloodstream infections (BSI) in patients with hematological malignancies, but increasingly daptomycin nonsusceptible VRE are being reported. We reviewed our experience with daptomycin nonsusceptible VRE BSI among patients with hematological malignancies. We compared risk factors and outcomes of 20 patients with daptomycin nonsusceptible VRE BSI (case patients) with 40 matched control patients with daptomycin susceptible VRE BSI. Case patients had more complications (6/20 vs. 2/40, p = .013); all-cause mortality was similar in both groups. By multivariable analysis, only prior daptomycin exposure within 90 days was significantly associated with daptomycin nonsusceptible VRE BSI (odds ratio 26.71; p < .0001). In 25% of case patients, all of whose VRE isolates had an initial minimum inhibitory concentration (MIC) of 4 μg/mL, nonsusceptibility developed during treatment, raising the question of whether higher doses of daptomycin should be used for VRE BSI in hematology patients.