Immunotherapy in Acute Leukemias: Past Success Paves the Way for Future Progress

Immunotherapy as a cancer treatment modality has undergone recent widespread proliferation across all cancer types, especially amongst patients with solid tumors. However, the longest tenured immunotherapy approach to cancer is allogeneic stem cell transplantation (allo-SCT) for two hematologic malignancies: acute myeloid and acute lymphoid leukemia (AML and ALL, respectively). While allo-SCT remains a standard of care for eligible patients, recent advances/applications of monoclonal antibodies, immune checkpoint inhibitors, bispecific T-cell engagers (BiTEs), and CAR T-cell therapy are changing the treatment landscape for these acute leukemias by either direct to tumor immune targeting or through decreased toxicities that expand patient eligibility. Pre-clinical data and clinical trials have shown promising results for novel immunotherapies in acute leukemia, and multiple ongoing trials are investigating these novel approaches. While there have been promising results with these approaches, particularly in the relapsed/refractory setting, there remain challenges in optimizing the use of these therapies, such as managing cytokine release syndrome and other immune-related toxicities. Immunotherapy is a rapidly evolving field in the treatment of acute leukemia and has the potential to significantly impact the management of both AML and ALL. This review highlights the history of immunotherapy in the treatment of acute leukemias, the evolution of immunotherapy into more targeted approaches, the potential benefits and limitations of different immune targeting approaches, and ongoing research and development in the field.

Choice of anticoagulation in patients with low risk antiphospholipid syndrome

Antiphospholipid syndrome (APS) is an acquired hypercoagulable state necessitating long-term anticoagulation for secondary thrombosis prevention. Anticoagulation guidelines are predominantly based on data in high risk, triple positive patients, and favor Vitamin K antagonists over other forms of anticoagulation. The efficacy of alternative anticoagulants for secondary thrombosis prevention in low risk, single and double positive APS remains uncertain. This study aimed to assess the incidence of recurrent thrombosis and major bleeding for patient with low risk APS on long-term anticoagulation. We performed a retrospective cohort study of patients who met revised criteria for thrombotic APS between January, 2001 and April, 2021 and received care through the Lifespan Health System. Primary outcomes included recurrent thrombosis and WHO Grades 3 and 4 major bleeding. A total of 190 patients were followed over a median duration of 3.1 years. At time of APS diagnosis, 89 patients were treated with warfarin and 59 patients with a direct oral anticoagulant (DOAC). There were similar rates of recurrent thrombosis in low risk patients on warfarin versus DOACs (adjusted IRR 6.91; 95% CI 0.90-53.40, p = 0.064). Major bleeding events only occurred in low risk patients on warfarin (n = 8, log-rank p = 0.13). In conclusion, despite the choice of anticoagulation, patients with low risk APS had similar rates of recurrent thrombosis suggesting DOACs may be a potential treatment option for this cohort. There was a non-significant increase in major bleeding rates in low risk patients on warfarin versus DOACs. Study limitations include a retrospective study design and small event numbers.

Ixazomib, Oral Metronomic Cyclophosphamide, and Dexamethasone for First-Line Treatment of Multiple Myeloma: A Phase II Brown University Oncology Group Study

BACKGROUND

Newly diagnosed multiple myeloma patients have many available treatment options. While lenalidomide, bortezomib, and dexamethasone (RVD) is the preferred initial treatment for many patients, several other agents may provide similar efficacy with less toxicity and improved ease of administration.

METHODS

We evaluated the safety and efficacy of the all-oral regimen of ixazomib, cyclophosphamide, and dexamethasone with the use of metronomic cyclophosphamide dosing in the treatment of patients with newly diagnosed multiple myeloma.

RESULTS

The study was stopped prior to planned enrollment due to slow recruitment, with 12 patients available for final analysis. The overall response rate was 58.3% with 2 patients achieving a very good partial response (16.7%) and 5 patients achieving a partial response (41.7%). Median progression-free survival was 16 months, and median overall survival was 43 months. There were no episodes of grade 3 or greater peripheral neuropathy. Grade 3 or greater dermatologic toxicity was experienced in 50% of patients.

CONCLUSION

Although limited enrollment prevented full efficacy evaluation, our data do not support further study of metronomic cyclophosphamide in combination with ixazomib and dexamethasone in the treatment of newly diagnosed multiple myeloma. The activity of this regimen in the relapsed/refractory setting requires further study (ClinicalTrials.gov Identifier: NCT02412228).

Thrombosis in COVID 2022: An Updated Narrative Review of Current Literature and Inpatient Management

Early in the pandemic, it was recognized that infection with COVID-19 was associated with an increased incidence in both venous and arterial thrombotic events leading to poor patient outcomes. Given the rapid rise of the pandemic, anticoagulation strategies were initially based upon retrospective and observational data with few high-quality randomized control trials to help direct strategies regarding the use of thromboprophylaxis during hospitalization, empiric therapeutic anticoagulation, and extended-duration thromboprophylaxis after discharge. Over the past year, several randomized control trials have now been published evaluating these strategies. In this article, we hope to review the current literature surrounding the use of intermediate-dose thromboprophylaxis, empiric therapeutic anticoagulation, and the use of extended-duration thromboprophylaxis for patients hospitalized with COVID-19.

Seroconversion and outcomes after initial and booster COVID-19 vaccination in adults with hematologic malignancies

Background

Patients with hematologic malignancies have impaired humoral immunity secondary to their malignancy and its treatment, placing them at risk of severe coronavirus disease‐19 (COVID‐19) infection and reduced response to vaccination.

Methods

The authors retrospectively analyzed serologic responses to initial and booster COVID‐19 vaccination in 378 patients with hematologic malignancy and subsequently tracked COVID‐19–related outcomes.

Results

Seroconversion occurred in 181 patients (48%) after initial vaccination; patients who had active malignancy or those who were recently treated with a B‐cell–depleting monoclonal antibody had the lowest rates of seroconversion. For initial nonresponders to vaccination, seroconversion after a booster dose occurred in 48 of 85 patients (56%). The seroconversion rate after the booster was similar for patients on (53%) and off (58%) active therapy (p = .82). Thirty‐three patients (8.8%) developed a COVID‐19 infection, and there were three COVID‐19–related deaths (0.8%). Although no significant association was observed between postvaccination seroconversion and the incidence of COVID‐19 infection, no patient with seroconversion died from COVID‐19, and no patient who received tixagevimab/cilgavimab (N = 25) was diagnosed with a COVID‐19 infection.

Conclusions

Booster vaccinations can promote seroconversion in a significant proportion of patients who are seronegative after the initial vaccination course regardless of the specific vaccine or on/off treatment status at the time of revaccination. Although postvaccination seroconversion may not be associated with a decrease in any (including asymptomatic) COVID‐19 infection, the authors' experience suggested that effective vaccination (including a booster), supplemented by passive immunization using tixagevimab/cilgavimab in case of lack of seroconversion, effectively eliminated the risk of COVID‐19 death in the otherwise high‐risk population.

Lay summary

Patients with hematologic malignancy, especially lymphoma, have an impaired response to coronavirus disease 2019 (COVID‐19) vaccination.

In this single‐institution review, less than one half of the patients studied made detectable antibodies.

For those who did not make detectable antibodies after initial vaccination, over one half (65%) were able to produce antibodies after booster vaccination.

By the end of February 2022, 33 of the original 378 patients had a documented COVID‐19 infection.

The only deaths from COVID‐19 were in those who had undetectable antibodies, and no patient who received prophylactic antibody therapy developed a COVID‐19 infection.

Hematologic malignancies and their treatments impaired humoral immunity from coronavirus disease 2019 vaccination, and booster vaccine overcame a lack of initial response in 58% of patients, including 63% those on active therapy. The findings indicated that booster vaccinations should be strongly encouraged; however, even with boosters, many remain unprotected, which should inform infection prevention and treatment strategies.

Phase 1 study of oral azacitidine (CC-486) plus R-CHOP in previously untreated intermediate- to high-risk DLBCL

Resistance to standard immunochemotherapy remains an unmet challenge in diffuse large B-cell lymphoma (DLBCL), and aberrant DNA methylation may contribute to chemoresistance. Promising early-phase results were reported with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) plus subcutaneous azacitidine, a hypomethylating agent. In this phase 1 study, we evaluated CC-486 (oral azacitidine) plus 6 cycles of R-CHOP in patients with previously untreated intermediate- to high-risk DLBCL or grade 3B/transformed follicular lymphoma. CC-486 doses of 100, 150, 200, or 300 mg given 7 days before cycle 1 and on days 8-21 of cycles 1-5 were evaluated; additional patients were enrolled in the expansion phase to examine preliminary efficacy. The primary objectives were to determine the safety and the maximum tolerated dose (MTD) of CC-486 in combination with R-CHOP. The most common grade 3/4 toxicities were hematologic, including neutropenia (62.7%) and febrile neutropenia (25.4%); grade 3/4 nonhematologic toxicities were uncommon (<7%). The MTD was not established; 2 patients had dose-limiting toxicities (1 with grade 4 febrile neutropenia; 1 with grade 4 prolonged neutropenia). The recommended phase 2 dose was established as 300 mg. The overall response rate was 94.9%, with 52 patients (88.1%) achieving complete responses. With a median follow-up of 28.9 months, estimated 1- and 2-year progression-free survival rates were 84.1% and 78.6%, respectively. Overall, epigenetic priming with CC-486 before R-CHOP can be delivered with acceptable safety to patients with previously untreated intermediate- to high-risk DLBCL or grade 3B/transformed follicular lymphoma. ClinicalTrials.gov: NCT02343536.

Tumor lysis syndrome risk in outpatient versus inpatient administration of venetoclax and hypomethlators for acute myeloid leukemia

INTRODUCTION

Venetoclax along with hypomethylating agents (HMAs) is the new standard therapy for older patients with acute myeloid leukemia (AML) not fit for intensive frontline induction chemotherapy. Venetoclax is associated with fatal episodes of tumor lysis syndrome (TLS) in chronic lymphocytic leukemia (CLL), and recommendations are for its initiation for CLL and AML in the inpatient setting with close monitoring. Herein, we evaluated the safety of outpatient venetoclax ramp up when given in addition to HMAs for the treatment of AML.

METHODS

We conducted a retrospective review of patients diagnosed with AML at our institution from 12/1/2016 until 7/1/2020. We identified patients who received HMAs and venetoclax for AML, either as frontline or relapsed/refractory therapy. Records were reviewed for evidence of laboratory or clinical tumor lysis episodes in all patients.

RESULTS

Between 12/1/2016 and 7/1/2020 43, patients at our institution received venetoclax/HMA for the treatment of AML. Thirty-nine patients (91%) had venetoclax initiation and ramp up in the outpatient setting. One episode of laboratory TLS (2.5%) was identified. This patient required admission to the hospital for rasburicase and IV fluids with resolution of the laboratory effects without resultant clinical TLS. There were no episodes of clinical TLS in either group. Thirty-day mortality from venetoclax initiation was 0% in both groups.

CONCLUSION

Our experience with HMAs and venetoclax showed that outpatient ramp up of venetoclax is safe with a very low risk of laboratory TLS (2.5%) and no evidence of clinical TLS within our cohort.

Thrombosis in COVID-19: A Narrative Review of Current Literature and Inpatient Management

COVID-19 infection has been associated with an increased incidence of thrombotic events leading to poor patient outcomes. Given the rapid rise of the COVID-19 pandemic, the ability to conduct prospective trials has been limited and data regarding the use of standard-dose versus intermediate-dose thromboprophylaxis, use of empiric therapeutic anticoagulation, and use of extended-duration thromboprophylaxis after discharge has been largely based upon observational data without any high-quality prospective data guiding their use. In this article, we will review the incidence and frequency of arterial and venous thrombotic events along with the current literature surrounding the use of intermediate-dose thromboprophylaxis, empiric therapeutic anticoagulation, and use of extended-duration thromboprophylaxis for patients hospitalized with COVID-19.

3D tissue engineered plasma cultures support leukemic proliferation and induces drug resistance

Chronic myeloid leukemia (CML), acute myeloid leukemia (AML), and chronic lymphocytic leukemia (CLL) are hematological malignancies that remain incurable despite novel treatments. In order to improve current treatments and clinical efficacy, there remains a need for more complex in vitro models that mimic the intricate human leukemic microenvironment. This study aimed to use 3D tissue engineered plasma cultures (3DTEPC) derived from CML, AML and CLL patients to promote proliferation of leukemic cells for use as a drug screening tool for treatment. 3DTEPC supported the growth of primary CML, AML and CLL cells and also induced significantly more drug resistance in CML, AML and CLL cell lines compared to 2D. The 3DTEPC created a more physiologically relevant environment for leukemia cell proliferation, provided a reliable model for growing leukemia patient samples, and serves as a relevant tool for drug screening and personalized medicine.

Tumor lysis syndrome risk in outpatient versus inpatient administration of venetoclax and hypomethlators for acute myeloid leukemia

INTRODUCTION

Venetoclax along with hypomethylating agents (HMAs) is the new standard therapy for older patients with acute myeloid leukemia (AML) not fit for intensive frontline induction chemotherapy. Venetoclax is associated with fatal episodes of tumor lysis syndrome (TLS) in chronic lymphocytic leukemia (CLL), and recommendations are for its initiation for CLL and AML in the inpatient setting with close monitoring. Herein, we evaluated the safety of outpatient venetoclax ramp up when given in addition to HMAs for the treatment of AML.

METHODS

We conducted a retrospective review of patients diagnosed with AML at our institution from 12/1/2016 until 7/1/2020. We identified patients who received HMAs and venetoclax for AML, either as frontline or relapsed/refractory therapy. Records were reviewed for evidence of laboratory or clinical tumor lysis episodes in all patients.

RESULTS

Between 12/1/2016 and 7/1/2020 43, patients at our institution received venetoclax/HMA for the treatment of AML. Thirty-nine patients (91%) had venetoclax initiation and ramp up in the outpatient setting. One episode of laboratory TLS (2.5%) was identified. This patient required admission to the hospital for rasburicase and IV fluids with resolution of the laboratory effects without resultant clinical TLS. There were no episodes of clinical TLS in either group. Thirty-day mortality from venetoclax initiation was 0% in both groups.

CONCLUSION

Our experience with HMAs and venetoclax showed that outpatient ramp up of venetoclax is safe with a very low risk of laboratory TLS (2.5%) and no evidence of clinical TLS within our cohort.

Outcomes of lenalidomide- or bortezomib-based regimens in older patients with plasma cell myeloma

The "triplet" regimen of lenalidomide, bortezomib, and dexamethasone (RVD) showed survival advantage over lenalidomide-dexamethasone (RD) in clinical trials, but older patients with myeloma often receive doublet regimens (RD or bortezomib-dexamethasone, VD), or VD plus cyclophosphamide (VCD). We compared these first-line regimens using real-world data from Medicare beneficiaries receiving therapy between 2007 and 2015. In each comparative analysis, we balanced confounding characteristics using a propensity score. Outcomes included overall (OS) and event-free survival (EFS, reporting hazard ratios [HR] with 95% confidence intervals [CI]), adverse events, and costs. We identified 6076 patients with median age 76 and median OS of 2.6 years. In the comparison of RVD vs RD/VD doublets, RVD showed significantly better OS (HR = 0.83; 95% CI, 0.72-0.95) and EFS (HR = 0.68; 95% CI, 0.61-0.76). So, RVD was associated with more frequent hospitalizations, anemia, and neuropathy, but no increase in thromboembolism or secondary cancers. Costs were higher with RVD. In the comparison of RD vs VD, RD demonstrated better EFS (HR = 0.74; 95% CI, 0.68-0.81) and marginally better OS (HR = 0.91; 95% CI, 0.83-0.99). And, RD resulted in significantly more thromboembolic events, less neuropathy, and no significant difference in hospitalizations, transfusions, or secondary cancers. In the comparison of VCD vs VD, we observed no significant difference in any outcome. Superior survival favors RVD over doublet regimens, but even in 2015 RVD was applied for only about 25% of Medicare beneficiaries with myeloma. For patients not eligible for RVD due to toxicity, VCD offers no survival benefit over VD. Lenalidomide-dexamethasone may be the preferred line doublet considering its advantage over VD.

Abstract PO-27: Clonotypic cell-free DNA (cfDNA) in the cerebrospinal fluid (CSF) of patients with aggressive lymphomas

Current methods for detection of CNS involvement in lymphoma (CSF cytology, flow cytometry) have very limited sensitivity, particularly in cases of parenchymal brain involvement. Early detection is critical to institute CNS-directed therapy and avert dismal outcomes of overt CNS recurrence. Clonotype-specific cfDNA can be detected in the plasma of patients with lymphoma using next-generation sequencing (NGS), and cfDNA-based minimal residual disease (MRD) assay can predict impending recurrence (Roschewski, Lancet Oncol 2015). cfDNA has not been systematically evaluated in the CSF, yet it may hold promise as a sensitive and specific method to detect CNS invasion. To evaluate the ability of an NGS-MRD assay in CSF to detect CNS invasion, we examined CSF and plasma samples from patients with aggressive lymphomas who either had overt CNS disease or who were without known CNS invasion, but at high clinical risk. Genomic DNA from primary tumors was analyzed for tumor-specific clonotype using NGS of rearranged IGK, IGH (VJ or DJ), or IGL loci (Adaptive Biotechnologies; Carlson, Nat Commun 2013). Tumor-specific clonotypes from each case were selected for subsequent tracking by NGS-MRD in CSF and plasma samples. Clonotype copy numbers are expressed per mL for acellular CSF, and clonotype frequency per all B cells. NGS identified median 3 (range, 2-7) dominant immunoglobulin sequences in each primary lymphoma (N=16), with median dominant clonotype frequency 50.3% (range, 26.8-9.28%). In the CSF, the NGS-MRD assay detected the dominant clonotype in 9 out of 16 samples, including all (N=4) with overt CNS invasion (sensitivity=100%), of which 2 had parenchymal disease only with negative CSF cytology, flow cytometry, or IGH PCR. Median detectable cfDNA clonotype in the CSF was 1,077 copies per mL (range, 2-5,620), with median clonotype frequency of 28.4% (range, 0.1-98.5%). cfDNA copy counts were significantly higher in cases with positive CSF cytology than those with parenchymal or clinically occult disease (P=.0016). We observed no significant correlation between the red blood cell count in the CSF and the cfDNA clonotype concentration (P=0.73) or frequency (P=0.62), suggesting that the presence of cfDNA in the CSF was not due to contamination by blood plasma. There was also no evident correlation between cfDNA in plasma and CSF. Within median 11 months of follow-up, 1 of 4 patients (25%) with a positive CSF NGS-MRD assay and no CNS disease developed a fatal CNS recurrence. Our results suggest that NGS-MRD assay for cfDNA in the CSF can identify intraparenchymal or leptomeningeal CNS invasion with high sensitivity, including cases not identifiable by traditional methods. Prognostic significance of detecting lymphoma-specific cfDNA in the CSF of high-risk patients without overt CNS disease will be explored in a larger sample. Pretreatment NGS-MRD assay could be prospectively tested to predict the risk of CNS recurrence and potentially enable more accurate selection of patients for CNS prophylaxis therapy.

Citation Format: Adam J. Olszewski, Anna Chorzalska, Habibe Kurt, Thomas A. Ollila, Diana O. Treaba, Andrew Hsu, Adam Zayac, John L. Reagan, Ilyas Sahin, William Rafelson, Pamela C. Egan, Jordan Robison, John Vatkevich, Chelsea D. Mullins, Max Petersen, Patrycja M. Dubielecka. Clonotypic cell-free DNA (cfDNA) in the cerebrospinal fluid (CSF) of patients with aggressive lymphomas [abstract]. In: Proceedings of the AACR Virtual Meeting: Advances in Malignant Lymphoma; 2020 Aug 17-19. Philadelphia (PA): AACR; Blood Cancer Discov 2020;1(3_Suppl):Abstract nr PO-27.

Enforcing the "4T": An In-Line Calculator for HIT Antibody Ordering in the Electronic Medical Record

Heparin-induced thrombocytopenia (HIT) remains a difficult clinical diagnosis, even with the under-utilized standardized scoring systems, like the '4T' score, to aid in clinical decision-making. Our quality improvement study sought to assess the use of '4T' score, improve the use of HIT antibody (HITA) testing and improvement management of possible HIT by implementing an in-line calculator with guidance within our electronic medical record (EMR) at our institution. We retrospectively reviewed patient charts between October 2017 and October 2018, assessing practices before and after implementation of the '4T' in-line calculator in April 2018. HITA were ordered inappropriately (for 4T <4) in 141 (67%) of 210 instances (75 before and 66 after). We found no statistically significant difference in positive predictive value (PPV) or 4T documentation in provider notes after its implementation. We were able to identify problematic areas in HIT management, such as the ordering of non-heparin anticoagulants, and implement additional changes addressing these problems.

Intensity of anticoagulation and survival in patients hospitalized with COVID-19 pneumonia

BACKGROUND

SARS-CoV-2 infection has noted derangements in coagulation markers along with significant thrombotic complications. Post-mortem examinations show severe endothelial injury and widespread thrombotic microangiopathy in the pulmonary vasculature. Early reports describing the use of prophylactic anticoagulation demonstrated improved survival, leading to the adoption of prophylactic and therapeutic anticoagulation guided by D-dimer levels. The clinical usefulness of D-dimer values, trends, and more intensive anticoagulation remains an area of clinical interest.

OBJECTIVES

Assess the outcomes and laboratory trends in COVID-19 patients stratified by intensity of anticoagulation at time of admission.

PATIENTS AND METHODS

Retrospectively review the differences in clinical outcomes and laboratory trends in patients hospitalized with COVID-19 in the Lifespan Health System.

RESULTS

Between 27 February and 24 April 2020, 468 patients were hospitalized. Initial use of high-intensity thromboprophylaxis was associated with improved 30-day mortality (adjusted RR 0.26; 95% confidence interval [CI], 0.07-0.97; p = 0.045) without a significant increased rate of bleeding (p = 0.11). In severe COVID-19, D-dimer significantly increased during hospitalization with standard thromboprophylaxis (p < 0.001) but remained stable or decreased with high-intensity prophylaxis or therapeutic anticoagulation.

CONCLUSION

Patients who received high-intensity prophylactic anticoagulation had a downtrend in D-dimer levels and improved 30-day mortality. This suggests a role in anticoagulation in mitigating adverse outcomes associated with COVID-19; however, further randomized, prospective studies are needed.

Adjuvant chemotherapy administration and survival outcomes of lymphoma survivors with common solid tumors: a population-based study†

Using the Surveillance, Epidemiology, and End Results database (2004-2015), we compared adjuvant chemotherapy use and survival for three common solid tumors in patients with and without history of lymphoma (DLBCL: diffuse large B cell, HL: Hodgkin lymphoma). Among patients with breast (n = 531,243), colon (n = 108,196), and lung (n = 23,179) cancers, we identified 361, 134, and 37 DLBCL survivors, and 349, 73, and 25 HL survivors, respectively. We found no significant difference between lymphoma survivors and controls in the use of adjuvant chemotherapy, except HL survivors with colon cancer, who had a lower rate. Among chemotherapy recipients, OS was significantly worse among HL survivors with all three cancers, and DLBCL survivors with breast cancer (hazard ratio [HR] 1.57-2.28). HL survivors had significantly higher mortality from cardiovascular diseases in breast and lung cancers (sub-HR, 7.96-9.64), which suggests that worse survival in this population might be due to late or cumulative toxicities of cancer-directed treatment.

Preliminary findings regarding the use of direct oral anticoagulants in cerebral venous thrombosis

BACKGROUND

Direct oral anticoagulants (DOACs) have entered the treatment paradigms of various conditions based upon large randomized controlled trials. However, use of DOACs for thrombosis at unusual sites, such as cerebral venous thrombosis (CVT), is less clear as the ability to conduct large randomized controlled trials is limited by its rarity. Furthermore, its use in the setting of malignancy or in the elderly remains an area of ongoing research.

OBJECTIVE

Our aim was to assess the outcomes in CVT patients treated with DOACs compared to warfarin. We also sought to elucidate whether its use was safe in the setting of malignancy or in the elderly.

METHODS

Retrospectively assess the differences in clinical outcomes in patients hospitalized with CVT in the Lifespan Health System.

RESULTS

Between 1 July 2004 and 1 March 2020, 46 adult patients with CVT fulfilled inclusion criteria. No significant differences in outcomes were observed between the DOAC (N = 8) and vitamin K antagonist (VKA) (N = 38) cohorts. The use of DOACs did not result in an increased rate of acute complications, recurrent venous thromboembolism (VTE) and/or CVT, World Health Organization (WHO) grade 3 or 4 bleeding rates, or differences in clinical improvement per the modified Rankin scale. Furthermore, in patients with underlying metastatic cancer (N = 2) or in patients > 80 (N = 1) who received a DOAC, there was no increase in adverse events or significant differences in outcome when compared to warfarin.

CONCLUSION

Patients who received a DOAC in the treatment of CVT demonstrated no differences in outcomes when compared to warfarin.

Antifungal prophylaxis during 7 + 3 induction chemotherapy for acute myeloid leukemia is associated with improved survival, in a setting with low incidence of invasive mold infections

Invasive fungal infections (IFIs) are a major cause of morbidity and mortality in patients undergoing induction chemotherapy for acute myeloid leukemia (AML). In this patient population, antifungal prophylaxis (AP) has been associated with decreased incidence of IFIs and better survival. However, some centers have not adopted AP during induction chemotherapy for AML, as it is unclear whether AP improves outcomes in settings where the incidence of invasive mold infections is low. We retrospectively assessed the differences in clinical outcomes and resource utilization in patients undergoing 7 + 3 induction chemotherapy for AML, after implementing a policy of AP as part of a dedicated inpatient malignant hematology service (HS) at Rhode Island Hospital. Between January 1, 2007 and April 1, 2019, 56 patients with AML received AP during 7 + 3 induction chemotherapy and 52 patients did not, without significant differences in their baseline characteristics. Use of AP was associated with less proven or probable IFI (0% vs. 6%, P = 0.1) and lower all-cause in-hospital mortality (7% vs. 21%, P < 0.05), without significant increases in resource utilization or toxicities. Empiric and targeted antifungal therapies were more frequently started in the non-AP group (69%) than changed in the AP group (41%, P < 0.005). Having a dedicated inpatient malignant hematology service was also associated with improved outcomes. However, use of AP was associated with better survival (30-day post-induction survival log-rank P < 0.05), prior to the implementation of this clinical service as well, which is suggestive of an independent benefit from AP.

Outcomes of bendamustine- or cyclophosphamide-based first-line chemotherapy in older patients with indolent B-cell lymphoma

Clinical trials comparing bendamustine/rituximab (BR) with cyclophosphamide-based regimens (RCHOP/RCVP) have pooled various histologies of indolent B-cell lymphomas. We examined real-life outcomes of older patients with follicular (FL), mantle cell (MCL), or marginal zone/lymphoplasmacytic lymphoma (MZL/LPL), treated with these first-line regimens. We identified Medicare beneficiaries with FL, MCL, or MZL/LPL, who received either first-line BR or RCHOP/RCVP in 2009-2016, and matched groups using a propensity score. Outcomes of claims-based event-free survival (EFS), overall survival (OS), toxicity, secondary cancers, and costs were compared in the aggregate cohort (N = 2736), and in separately matched histology-specific subcohorts. In the aggregate cohort, EFS was better with BR than with RCHOP/RCVP (hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.70-0.87). Acute toxicity was lower with BR, including rates of hospitalizations (33% vs 45%), infections (21% vs 30%), cardiovascular events, and transfusions, yet OS did not differ (HR, 1.03; 95% CI, 0.91-1.17) and Medicare spending was higher. There was no difference in the cumulative incidence of secondary cancers (subhazard ratio, 1.11; 95% CI, 0.83-1.48). The EFS advantage of BR was pronounced in MCL (N = 690; HR, 0.64; 95% CI, 0.54-0.76), but less so in FL (N = 1330; HR, 0.83; 95% CI, 0.69-0.98) and absent in MZL/LPL (N = 574; HR, 0.92; 95% CI, 0.73-1.17). Despite improved EFS and lower toxicity, the shift from RCHOP/RCVP to BR in clinical practice did not improve OS for older patients with indolent B-cell lymphomas. Frequent infections and hospitalizations underscore the need for safer treatment approaches in this population. Secondary cancers do not appear to be increased after BR compared with RCHOP/RCVP.

Inflammation-related gene expression profiles of salivary extracellular vesicles in patients with head trauma

At present, there is no reliable biomarker for the diagnosis of traumatic brain injury (TBI). Studies have shown that extracellular vesicles released by damaged cells into biological fluids can be used as potential biomarkers for diagnosis of TBI and evaluation of TBI severity. We hypothesize that the genetic profile of salivary extracellular vesicles in patients with head trauma differs from that in uninjured subjects. Findings from this hypothesis would help investigate the severity of TBI. This study included 19 subjects, consisting of seven healthy controls who denied history of head trauma, six patients diagnosed with concussion injury from an outpatient concussion clinic, and six patients with TBI who received treatment in the emergency department within 24 hours after injury. Real-time PCR analysis of salivary extracellular vesicles in participants was performed using TaqMan Human Inflammation array. Gene expression analysis revealed nine upregulated genes in emergency department patients (LOX5, ANXA3, CASP1, IL2RG, ITGAM, ITGB2, LTA4H, MAPK14, and TNFRSF1A) and 13 upregulated genes in concussion clinic patients compared with healthy participants (ADRB1, ADRB2, BDKRB1, HRH1, HRH2, LTB4R2, LTB4R, PTAFR, CYSLTR1, CES1, KLK1, MC2R, and PTGER3). Each patient group had a unique profile. Comparison between groups showed that 15 inflammation-related genes had significant expression change. Our results indicate that inflammation biomarkers can be used for diagnosis of TBI and evaluation of disease severity. This study was approved by the Institutional Review Board on December 18, 2015 (approval No. 0078-12) and on June 9, 2016 (approval No. 4093-16).

Use of bone-modifying agents and clinical outcomes in older adults with multiple myeloma

Background

Guidelines recommend bone‐modifying agents (BMAs) for all patients initiating treatment for myeloma. We examined adherence to this recommendation, and BMA effectiveness in the era of bortezomib/lenalidomide‐based therapy among Medicare beneficiaries.

Methods

From the linked Surveillance, Epidemiology, and End Results‐Medicare registry, we selected beneficiaries receiving anti‐myeloma chemotherapy in 2007‐2013. We matched BMA recipients (within 90 days of first chemotherapy) to nonrecipients using a propensity score, balancing patient‐, disease‐, and therapy‐related confounders. Cumulative incidence of skeletal‐related events (SREs) and overall survival (OS) was compared in proportional hazard models accounting for competing risks and immortal‐time bias.

Results

Among 4611 patients with median age of 76 years, 51% received BMA. Bone‐modifying agents use remained steady over time (P = .87) and was significantly less frequent for patients who were older, with comorbidities, without prior SRE, and those treated without bortezomib or lenalidomide. In a propensity score‐matched cohort, BMA recipients experienced a lower incidence of SRE (11.0% vs 14.6% at 3 years; subhazard ratio, 0.73; 95% CI, 0.60‐0.89) and better OS (53.3% vs 47.8% at 3 years; hazard ratio, 0.86; 95% CI, 0.77‐0.95). The results were consistent in the subgroup (76%) treated with bortezomib and/or immunomodulatory drugs (IMiDs). The incidence of osteonecrosis of the jaw (ONJ) was 3.2% at 3 years.

Conclusions

In this observational study, the observed benefits of early BMA administration among patients treated with contemporary anti‐myeloma regimens were similar to historical clinical trials. Frequent omission of BMA highlights a remediable deficiency in the quality of supportive care, and suggests that timely administration may be a useful indicator of quality care in myeloma.

Prevalence and Effect on Survival of Pulmonary Hypertension in Myelofibrosis

BACKGROUND

Myelofibrosis (MF), a rare disorder characterized by bone marrow fibrosis, has been implicated as a cause of pulmonary hypertension (PH). To date, studies examining this association have not looked at the impact of PH on survival in MF. We examined the relationship between MF and PH by echocardiogram (echo) using a retrospective patient database and examined the influence of PH on overall survival.

PATIENTS AND METHODS

In this single-center retrospective chart review, we identified 65 patients with biopsy-proven primary and secondary MF, 31 of whom underwent transthoracic echo. After accounting for chronic obstructive pulmonary disease and left-sided or valvular heart dysfunction, which excluded 6 patients, we identified 14 patients (56%) who had echo evidence of group 5 PH (ie, PH due to unclear or multifactorial mechanisms), 8 with primary MF and 6 with secondary MF. MF patients with PH trended toward being predominantly female, being older, and less often having constitutional symptoms compared to the non-PH cohort.

RESULTS

There was no effect of the presence of PH on overall survival in the entire MF cohort or in any subgroup analyzed, including primary MF versus secondary MF and primary MF intermediate risk patients.

CONCLUSION

Given the high prevalence of MF-associated PH, there may be a larger role for routine echo screening in MF patients. Further, the underlying association between PH and MF may signify an endothelial plasticity or increased telomerase activity as part of the pathogenesis of MF.

Clinical features and survival of patients with T-cell/histiocyte-rich large B-cell lymphoma: analysis of the National Cancer Data Base

Using data from the National Cancer Data Base, 2010-2015, we examined characteristics and outcomes of T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL, N = 622) relative to unspecified diffuse large B-cell lymphoma (DLBCL-NOS, N = 91,588) and nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL, N = 2240). Socio-demographic characteristics of patients with THRLBCL resembled more NLPHL than DLBCL-NOS. Five-year overall survival in THRLBCL was 66% (95% confidence interval [CI], 60-71%). Adjusting for clinical and socio-economic covariates, THRLBCL was associated with better survival than DLBCL-NOS (adjusted hazard ratio, 0.80; 95%CI, 0.67-0.94). This association was similar in academic and community hospitals and consistent in a model stratified by the revised International Prognostic Index. Prognostic factors in THRLBCL included age, comorbidity index, and extranodal primary site, but not stage. Adjusted odds of prior NLPHL were 18.2 higher for THRLBCL (95%CI, 7.2-45.7) than DLBCL-NOS. These large-scale epidemiologic data support the relationship between THRLBCL and NLPHL, and suggest improved prognosis with modern rituximab-based immunochemotherapy.

Harnessing alloreactive responses by patient lymphocytes to achieve anti-cancer responses

Potent immune responses are induced by encounter with cells from a different (allogeneic) individual. The increased number of responding alloreactive T cells can be explained by the cross-reactivity exhibited by T cell receptors (TCR). This cross-reactivity also allows these TCR to bind to syngeneic major histocompatibility complex molecules expressing peptides derived from pathogens or cancer cells. Initial studies showed that CD3+ lymphocytes isolated from newly diagnosed leukemic patients were able to lyse syngeneic leukemic cells after stimulation with allogeneic cells in about half of the patients. These findings raise the possibility that manipulating the alloreactive responses by patient lymphocytes could result in enhanced anti-cancer responses. Further studies utilized a mouse acute myeloid leukemic cell line, C1498, derived from a C57BL/6 mouse. C57BL/6 splenocytes stimulated with allogeneic stimulator cells were shown to be able to lyse allogeneic target cells as well as the syngeneic C1498 leukemic cells. The level of lysis of the syngeneic leukemic cells was dependent on the strain from which the allogeneic stimulator cells were obtained. Immunization of C57BL/6 mice with C1498 cells or subcellular antigen enhanced the anti-C1498 response when stimulated with allogeneic cells. Ongoing experiments are defining whether naïve or memory effector cells are responsible for the lysis of the syngeneic leukemic cells as well as the nature of the peptide antigens that allow the syngeneic cancer cells to be recognized. The results of these studies will facilitate the use of protocols which harness alloreactive responses by patient lymphocytes to generate anti-cancer responses.

Potential biomarkers to detect traumatic brain injury by the profiling of salivary extracellular vesicles

Traumatic brain injury (TBI) is a common cause of death and acquired disability in adults and children. Identifying biomarkers for mild TBI (mTBI) that can predict functional impairments on neuropsychiatric and neurocognitive testing after head trauma is yet to be firmly established. Extracellular vesicles (EVs) are known to traffic from the brain to the oral cavity and can be detected in saliva. We hypothesize the genetic profile of salivary EVs in patients who have suffered head trauma will differ from normal healthy controls, thus constituting a unique expression signature for mTBI. We enrolled a total of 54 subjects including for saliva sampling, 23 controls with no history of head traumas, 16 patients enrolled from an outpatient concussion clinic, and 15 patients from the emergency department who had sustained a head trauma within 24 hr. We performed real‐time PCR of the salivary EVs of the 54 subjects profiling 96 genes from the TaqMan Human Alzheimer's disease array. Real‐time PCR analysis revealed 57 (15 genes, p < 0.05) upregulated genes in emergency department patients and 56 (14 genes, p < 0.05) upregulated genes in concussion clinic patients when compared with controls. Three genes were upregulated in both the emergency department patients and concussion clinic patients: CDC2, CSNK1A1, and CTSD ( p < 0.05). Our results demonstrate that salivary EVs gene expression can serve as a viable source of biomarkers for mTBI. This study shows multiple Alzheimer's disease genes present after an mTBI.

The return of gemtuzumab ozogamicin: a humanized anti-CD33 monoclonal antibody-drug conjugate for the treatment of newly diagnosed acute myeloid leukemia

Through the years gemtuzumab ozogamicin (GO) has moved from a panacea in the treatment of acute myeloid leukemia (AML) to a pariah and back again. Early promise of targeted therapy with accelerated approval in the United States in 2000 gave way to fear over increased toxicity in the absence of efficacy, which subsequently resulted in the drug manufacturer voluntarily withdrawing GO from the market in 2010. We outline the history of GO in terms of initial drug development and early clinical trials that ultimately led the way to GO frontline use in AML based on a series of Phase III studies. Among these studies, we discuss the similarities and differences in terms of dosing, frequency, response rates, and toxicities that ultimately led to the re-approval of GO in 2017 based on efficacy, particularly in patients with core-binding factor (CBF) leukemia. Herein, we also review the clinical efficacy of GO in the frontline treatment of acute promyelocytic leukemia, which is based on either initial patient high-risk disease or potential co-morbidities that preclude the use of arsenic trioxide (ATO). Finally, we assess the current evidence for biomarkers aside from initial cytogenetics that may predict a favorable response to GO.

Induction of anti-leukemic responses by stimulation of leukemic CD3+ cells with allogeneic stimulator cells

Background

Immunotherapeutic protocols have focused on identification of stimuli that induce effective anti-leukemic immune responses. One potent immune stimulus is the encounter with allogeneic cells. Our group previously showed that the infusion of haploidentical donor white blood cells (1-2 × 10⁸ CD3+ cells/kg) into patients with refractory hematological malignancies induced responses of varying magnitude in over half of the patients. Because donor cells were eliminated within 2 weeks in these patients, it is presumed that the responses of recipient lymphocytes were critically important in achieving prolonged anti-leukemic responses.

Methods

The role of patient CD3+ cells in anti-leukemic responses was examined by isolating peripheral blood mononuclear cells from newly diagnosed leukemic patients. Immunophenotyping was performed on these peripheral blood mononuclear cells. CD3+ cells were isolated from the peripheral blood mononuclear cells and tested for their ability to proliferate and lyse autologous leukemic cells when stimulated with unrelated allogeneic cells.

Results

Allostimulated CD3+ cells effectively generated cytolytic responses to autologous CD3-cells in 11/21 patients. Increased numbers of CD4+ cells expressing high levels of granzyme A, B and perforin and CD8+CD39+ cells were found in nonresponsive CD3+ cells.

Conclusions

These results indicate that CD3+ cells from leukemic patients are capable of generating anti-leukemic responses when stimulated with unrelated allogeneic cells. This model can be used to identify approaches using alloreactive responses by patient lymphocytes to enhance in vivo anti-leukemic responses.

The next generation of therapy for multiple myeloma: a review of ongoing clinical trials utilizing ClinicalTrials.gov

The therapeutic armamentarium for multiple myeloma has grown significantly over the past decade. We characterized ongoing multiple myeloma clinical trials utilizing ClinicalTrials.gov . A search of ClinicalTrials.gov on 21 April 2017 returned 239 therapeutic interventional trials in multiple myeloma. A majority (84.1%) of trials are early-phase (I/II). Immunotherapies are significantly more likely to be studied in Phase I trials than Phase II trials (p = 0.0049). Primary sponsor (academic, cooperative group, industry) is significantly associated with phase of trial (p = 0.0334). Quality of life assessment is included as a secondary objective in only 10.1% of trials. Areas of need are continued advancement of immunotherapies, late-phase studies utilizing a triplet control group, and an objective focus on quality of life.

Time to treatment is an independent prognostic factor in aggressive non-Hodgkin lymphomas

In aggressive lymphomas, discrepancies in survival reported from experimental and observational studies may reflect selective non-enrolment of high-risk patients in trials. We examined the association between time from diagnosis to chemotherapy and overall survival in diffuse large B-cell (DLBCL), Burkitt (BL), mantle cell (MCL) and peripheral T-cell lymphoma (PTCL), using National Cancer Data Base records of 130 549 patients treated in 2004-2014. Across the histologies, patients who started chemotherapy within 7 days of diagnosis had more often high International Prognostic Index (IPI) or advanced-stage disease. The discrepancy in 3-year survival between groups treated within 7 or >30 days from diagnosis ranged from 14% in BL to 30% in MCL. After adjusting for the IPI, time to treatment was significantly associated with shorter overall survival. Using the group treated >30 days from diagnosis as reference, patients treated within 7 days had a hazard ratio of 1·38 [95% confidence interval (CI), 1·28-1·48] in DLBCL, 1·42 (95% CI, 1·22-1·66) in BL, 2·23 (95% CI, 1·79-2·78) in MCL and 1·46 (95% CI, 1·18-1·81) in PTCL. Time from diagnosis to treatment may reflect high-risk features uncaptured by standard prognostic assessments. Clinical trials should accommodate patients who need urgent therapy to improve external validity and detect treatment effects in high-risk groups.

Pruritic Rash in a Patient with Hodgkin's Lymphoma

Bleomycin-induced flagellate erythema (FE), a skin finding associated with cutaneous deposition of bleomycin, is so called due to its characteristic pattern of whip-like, linear streaks. As bleomycin use in standard chemotherapeutic regimens has decreased, the clinical diagnosis has become increasingly rare. The authors present a case of a 43-year-old female patient with Hodgkin’s lymphoma on her first cycle of adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD) treatment, who subsequently developed a diffuse rash classic for FE. This benign condition is important to recognize to avoid potentially unnecessary and harmful treatment for other dermatologic diagnoses for which it may be mistaken. In severe cases of FE, discontinuation of bleomycin should be considered.

Overexpression of Tpl2 is linked to imatinib resistance and activation of MEK-ERK and NF-κB pathways in a model of chronic myeloid leukemia

The introduction of tyrosine kinase inhibitors (TKI) has transformed chronic myeloid leukemia (CML) into a chronic disease with long-term survival exceeding 85%. However, resistance of CML stem cells to TKI may contribute to the 50% relapse rate observed after TKI discontinuation in molecular remission. We previously described a model of resistance to imatinib mesylate (IM), in which K562 cells cultured in high concentrations of imatinib mesylate showed reduced Bcr-Abl1 protein and activity levels while maintaining proliferative potential. Using quantitative phosphoproteomic analysis of these IM-resistant cells, we have now identified significant upregulation of tumor progression locus (Tpl2), also known as cancer Osaka thyroid (COT1) kinase or Map3k8. Overexpression of Tpl2 in IM-resistant cells was accompanied by elevated activities of Src family kinases (SFKs) and NF-κB, MEK-ERK signaling. CD34+ cells isolated from the bone marrow of patients with CML and exposed to IMin vitro showed increased MAP3K8 transcript levels. Dasatinib (SFK inhibitor), U0126 (MEK inhibitor), and PS-1145 (IκB kinase (IKK) inhibitor) used in combination resulted in elimination of 65% of IM-resistant cells and reduction in the colony-forming capacity of CML CD34+ cells in methylcellulose assays by 80%. In addition, CML CD34+ cells cultured with the combination of inhibitors showed reduced MAP3K8 transcript levels. Overall, our data indicate that elevated Tpl2 protein and transcript levels are associated with resistance to IM and that combined inhibition of SFK, MEK, and NF-κB signaling attenuates the survival of IM-resistant CML cells and CML CD34+ cells. Therefore, combination of SFK, MEK, and NF-κB inhibitors may offer a new therapeutic approach to overcome TKI resistance in CML patients.

Mechanisms of Hypercalcemia in Non-Hodgkin Lymphoma and Associated Outcomes: A Retrospective Review

INTRODUCTION

The etiology of hypercalcemia in non-Hodgkin lymphoma (NHL) has been most often attributed to either elevated serum levels of 1,25-dihydroxycholecalciferol (calcitriol) or parathyroid-related protein (PTHrP). In a single-center retrospective review, we evaluated the incidence of, and outcomes associated with, hypercalcemia in NHL.

PATIENTS AND METHODS

The medical records of patients with a histologically confirmed diagnosis of NHL and ≥ 1 episode of hypercalcemia were evaluated for demographic and lymphoma-specific factors, including the response to therapy and overall survival.

RESULTS

Fifty-four patients with NHL met the inclusion criteria. Most patients (57.4%) had diffuse large B-cell lymphoma, of which, 70% were the nongerminal center subtype. Approximately one half (42.6%) of the included patients had undergone serologic investigation into the etiology of hypercalcemia; however, only 17 patients (31.5%) had both a serum PTHrP and a calcitriol level properly collected. Of the 17 cases for which both a serum calcitriol and a PTHrP were collected, most (61.1%) were found to have neither an elevation of serum calcitriol nor an elevation of PTHrP. The degree of calcitriol elevation correlated with worse progression-free survival (P = .04) but not overall survival.

CONCLUSION

The major mechanism by which NHL patients develop hypercalcemia is not mediated by calcitriol or PTHrP. Hypercalcemia is most prevalent in patients with diffuse large B-cell lymphoma of the nongerminal cell subtype. Patients with calcitriol-mediated hypercalcemia showed a trend toward worse outcomes, suggesting that calcitriol might be a marker of high-grade lymphoma, transformation to such, or a surrogate for more advanced disease.

Extracellular vesicles in leukemia

Extracellular vesicles (EV) are nano-sized membrane enclosed vehicles that are involved in cell-to-cell communication and carry cargo that is representative of the parent cell. Recent studies have highlighted the significant roles leukemia EVs play in tumor progression, and ways in which they can lead to treatment evasion, thus meriting further investigation. Leukemia EVs are involved in crosstalk between the leukemia cell and its surroundings, transforming it into a cancer favorable microenvironment. Due to the diverse biological content found in leukemia EVs, they have an assortment of effects on the cells they interact with and can be harnessed as candidates for diagnostic and therapeutic treatments. This review focuses on EVs in the context of leukemia and the means by which they modulate their microenvironment, hematopoiesis, and the immune system to facilitate malignancy. We will also address current and prospective EV-based therapeutics.

IgM myeloma: A multicenter retrospective study of 134 patients

IgM myeloma is a rare hematologic malignancy for which the clinicopathological features and patient outcomes have not been extensively studied. We carried out a multicenter retrospective study in patients with diagnosis of IgM myeloma defined by >10% marrow involvement by monoclonal plasma cells, presence of an IgM monoclonal paraproteinemia of any size, and anemia, renal dysfunction, hypercalcemia, lytic lesions and/or t(11;14) identified by FISH. A total of 134 patients from 20 centers were included in this analysis. The median age at diagnosis was 65.5 years with a male predominance (68%). Anemia, renal dysfunction, elevated calcium and skeletal lytic lesions were found in 37, 43, 19, and 70%, respectively. The median serum IgM level was 2,895 mg dL^-1 with 19% of patients presenting with levels >6,000 mg dL^-1 . International Staging System (ISS) stages 1, 2, and 3 were seen in 40 (33%), 54 (44%), and 29 (24%) of patients, respectively. The malignant cells expressed CD20 (58%) and cyclin D1 (67%), and t(11;14) was the most common cytogenetic finding (39%). The median overall survival (OS) was 61 months. Higher ISS score was associated with worse survival (P = 0.02). Patients with IgM myeloma present with similar characteristics and outcomes as patients with more common myeloma subtypes.

Clinical Trial Accrual Targeting Genomic Alterations After Next-Generation Sequencing at a Non-National Cancer Institute–Designated Cancer Program

Purpose:

Successful clinical trial accrual targeting uncommon genomic alterations will require broad national participation from both National Cancer Institute (NCI)–designated comprehensive cancer centers and community cancer programs. This report describes the initial experience with clinical trial accrual after next-generation sequencing (NGS) from three affiliated non–NCI-designated cancer programs.

Materials and Methods:

Clinical trial participation was reviewed after enrollment of the first 200 patients undergoing comprehensive genomic profiling by NGS as part of an institutional intuitional review board–approved protocol at three affiliated hospitals in Rhode Island and was compared with published experience from NCI-designated cancer centers.

Results:

Patient characteristics included a median age of 64 years, a median of two lines of prior therapy, and a predominance of GI carcinomas (58%). One hundred sixty-four of 200 patients (82%) had adequate tumor for NGS, 95% had genomic alterations identified, and 100% had variants of unknown significance. Fifteen of 164 patients (9.2%) enrolled in genotype-directed clinical trials, and three patients (1.8%) received commercially available targeted agents off clinical trials. The reasons for nonreceipt of NGS-directed therapy were no locally available matching trial (48.6%), ineligibility (33.6%) because of comorbidities or interim clinical deterioration, physician's choice of a different therapy (6.8%), or stable disease (11%).

Conclusion:

This experience demonstrates that a program enrolling patients in specific targeted agent clinical trials after NGS can be implemented successfully outside of the NCI-designated cancer program network, with comparable accrual rates. This is important because targetable genes have rare mutation rates and clinical trial accrual after NGS is low.

Abstract A14: Cellular immunotherapy for refractory hematological malignancies: Haploidentical donor lymphocyte infusions generate an allogeneic effect that targets leukemia

Background/Objective: Allogeneic stem cell transplantation (allo-SCT) is an effective treatment modality for leukemia and lymphoma that exerts much of its therapeutic benefit via a graft versus tumor response. Its applicability is limited by toxicity from preconditioning chemoradiation and graft versus host disease. We present data from a Phase II IRB and FDA approved clinical trial in which haploidentical allogeneic cells are infused into patients with refractory hematologic malignancies without prior chemotherapy or radiation. The goal is to generate a robust allogeneic response created via donor cell rejection that breaks host tumor tolerance without the toxicity profile seen in allo-SCT.

Methods: Eligible patients have refractory acute leukemias and aggressive systemic lymphomas without curative options. HLA haploidentical donors are identified then undergo leukapheresis without stem cell mobilization. 1-2x108 CD3+ cells/kg are infused unprocessed immediately following collection. Peripheral blood samples collected 1, 24, 48, 72 and 168 hours after infusion are examined for effector cell populations, stimulatory/inhibitory signals, and cytokine release profiles.

Results: Three patients have been infused haploidentical cells. Two developed hyperpyrexia following treatment that persisted for 48 hours. One of three patients demonstrated a decrease in peripheral blood and bone marrow blast counts following therapy (Reduction in peripheral absolute blast count from 3900/uL to 1200/uL and bone marrow blasts from 43% to 21% four weeks post therapy). No Grade 3 or 4 toxicities or durable chimerism was seen. Host T cells demonstrated cytolytic effector molecule expression but little cytolytic activity, possibly secondary to rapid up-regulation of PD-1 and PD-1 ligands by host CD8+ cells and leukemia cells, respectively.

Discussion: Haploidentical donor cellular infusions are well tolerated and demonstrate biological activity in relapsed leukemia. Lab correlative studies suggest potential future mechanisms to augment response involving PD-1 blockade. Our method provides a true bench to bedside approach utilizing adoptive immunotherapy created via a host allogeneic rejection response.

Citation Format: John L. Reagan, Loren D. Fast, Martha Nevola, Andrew Schumacher, Kayla Rosati, Howard Safran, Matt I. Quesenberry, Eric P. Winer, James N. Butera, Peter J. Quesenberry. Cellular immunotherapy for refractory hematological malignancies: Haploidentical donor lymphocyte infusions generate an allogeneic effect that targets leukemia. [abstract]. In: Proceedings of the AACR Special Conference on Hematologic Malignancies: Translating Discoveries to Novel Therapies; Sep 20-23, 2014; Philadelphia, PA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(17 Suppl):Abstract nr A14.

Differences in the clinical course of heparin induced thrombocytopenia before and after the availability of HIT IgG class testing

INTRODUCTION

To determine whether the HIT IgG class platelet factor 4 (PF4) enzyme immunoabsorbant assay (EIA) influenced the duration of parenteral direct thrombin inhibitor (pDTI) therapy or bleeding risk in patients started on pDTI for a presumed diagnosis of HIT.

MATERIALS/METHODS

187 patients started on pDTI for presumed HIT were assessed in two time periods before (period 1, n=88 patients) and after the introduction of an IgG-specific assay (period 2, n=99 patients).

RESULTS

Patients in period 2 were treated with pDTI therapy for a median of 5 days less (p<0.0001) however the incidence of Grade III and IV bleeding episodes was not different. Bleeding was observed to occur early during the hospital course at a median of 2-3 days after initiation of the pDTI. The average pDTI drug acquisition cost was markedly decreased in period 2 when compared to period 1 (p<0.0001).

CONCLUSIONS

Implementation of the IgG class HIT EIA resulted in a decrease in the number of days on a pDTI and a decrease in the average pDTI acquisition cost per patient without an observed change in serious bleeding events.