Citations

Background: Closed-loop control (CLC) has been shown to improve glucose time in range and other glucose metrics; however, randomized trials >3 months comparing CLC with sensor-augmented pump (SAP) therapy are limited. We recently reported glucose control outcomes from the 6-month international Diabetes Closed-Loop (iDCL) trial; we now report patient-reported outcomes (PROs) in this iDCL trial. Methods: Participants were randomized 2:1 to CLC ( N = 112) versus SAP ( N = 56) and completed questionnaires, including Hypoglycemia Fear Survey, Diabetes Distress Scale (DDS), Hypoglycemia Awareness, Hypoglycemia Confidence, Hyperglycemia Avoidance, and Positive Expectancies of CLC (INSPIRE) at baseline, 3, and 6 months. CLC participants also completed Diabetes Technology Expectations and Acceptance and System Usability Scale (SUS). Results: The Hypoglycemia Fear Survey Behavior subscale improved significantly after 6 months of CLC compared with SAP. DDS did not differ except for powerless subscale scores, which worsened at 3 months in SAP. Whereas Hypoglycemia Awareness and Hyperglycemia Avoidance did not differ between groups, CLC participants showed a tendency toward improved confidence in managing hypoglycemia. The INSPIRE questionnaire showed favorable scores in the CLC group for teens and parents, with a similar trend for adults. At baseline and 6 months, CLC participants had high positive expectations for the device with Diabetes Technology Acceptance and SUS showing high benefit and low burden scores. Conclusion: CLC improved some PROs compared with SAP. Participants reported high benefit and low burden with CLC. Clinical Trial Identifier: NCT03563313.

Abstract Lineage-ambiguous leukemias are high-risk malignancies of poorly understood genetic basis. Here, we describe a distinct subgroup of acute leukemia with expression of myeloid, T lymphoid, and stem cell markers driven by aberrant allele-specific deregulation of BCL11B, a master transcription factor responsible for thymic T-lineage commitment and specification. Mechanistically, this deregulation was driven by chromosomal rearrangements that juxtapose BCL11B to superenhancers active in hematopoietic progenitors, or focal amplifications that generate a superenhancer from a noncoding element distal to BCL11B. Chromatin conformation analyses demonstrated long-range interactions of rearranged enhancers with the expressed BCL11B allele and association of BCL11B with activated hematopoietic progenitor cell cis-regulatory elements, suggesting BCL11B is aberrantly co-opted into a gene regulatory network that drives transformation by maintaining a progenitor state. These data support a role for ectopic BCL11B expression in primitive hematopoietic cells mediated by enhancer hijacking as an oncogenic driver of human lineage-ambiguous leukemia. Significance: Lineage-ambiguous leukemias pose significant diagnostic and therapeutic challenges due to a poorly understood molecular and cellular basis. We identify oncogenic deregulation of BCL11B driven by diverse structural alterations, including de novo superenhancer generation, as the driving feature of a subset of lineage-ambiguous leukemias that transcend current diagnostic boundaries. This article is highlighted in the In This Issue feature, p. 2659

Abstract In-stent stenosis has a reported prevalence of 14% to 19% at 1-yr follow-up after carotid stenting and is associated with an increased risk of acute ischemic stroke. 1,2 Risk factors include female sex, diabetes, and dyslipidemia. Cutting balloon angioplasty is a safe and effective treatment modality for the treatment of carotid in-stent stenosis, and alternative treatment options include observation with medical management and placement of another stent. 3,4 The authors present the case of a 61-yr-old man with carotid in-stent restenosis and progressive worsening on serial imaging with ultrasound. The patient had a history of carotid stenting for symptomatic stenosis 6 mo prior and was maintained on aspirin and clopidogrel. In light of the progressive worsening, the in-stent stenosis was confirmed on computed tomography (CT) angiogram. The options were discussed with the patient and he consented for treatment with cutting balloon angioplasty. Final angiogram showed improvement of the luminal diameter with a residual stenosis of 15%. The patient tolerated the procedure well and was discharged home on postoperative day 1. Follow-up ultrasound demonstrated moderate improvement in peak systolic velocities, and the plan is to continue observation with a clinical follow-up and repeat carotid Dopplers at 3 mo.

An automated and computerized system (Automicrobic System [AMS]) for the detection of frequently encountered bacteria in clinical urine specimens was tested in a collaborative study among six laboratories. The sensitivity, specificity, reliability, and reproducibility of the AMS were determined, and the system was compared with conventional detection and identification systems. In this study, pure cultures and mixtures of pure cultures were used to simulate clinical urine specimens. With pure cultures, the sensitivity of the AMS in identifying the nine groups of organisms most commonly found in urine averaged 92.8%. The specificity averaged 99.4%, and the reliability of a positive result averaged 92.1%. The latter value was strongly influenced by a relatively high occurrence of false positive Escherichia coli results. The AMS was capable of detecting growth of most organisms, including those which it was not designed to identify. However, it identified some of these incorrectly as common urinary tract flora. Reproducibility of results, both within laboratories and among different laboratories, was high. Fast-growing organisms, such as E. coli and Klebsiella/Enterobacter species, were detected often at cell populations well below the AMS enumeration threshold of 70,000/ml. In mixed culture studies, high levels of sensitivity and specificity were maintained but when Serratia species were present in mixtures with other organisms, there was often a false positive report of E. coli. The overall performance of the AMS was considered satisfactory under the test conditions used.

11550 Background: RPS often have local recurrence (LR) after surgery. Preoperative radiation (RT) to 50.4 Gy can reduce LR risk but is not uniformly effective, especially after (+) margin resections. Therefore, we conducted a multi-institutional, prospective Phase II study to assess efficacy and tolerability of preop IMPT with selective dose escalation to 63 GyRBE to the posterior RPS margin (clinical target volume [CTV] 2) at high risk for (+) margins to further reduce the risk of LR. This dose was tolerable in a prior phase I study (DeLaney T et al, 2017, PMID:28740917). Methods: Primary RPS patients (pts) >18 years received preop IMPT, 50.4 GyRBE in 28 fractions (fx) of 1.8 GyRBE to CTV1 (tumor plus adjacent tissue at risk of subclinical disease) with SIB to CTV2 to 63.0 GyRBE in 28 fx of 2.25 GyRBE. Pts with high-grade tumors could get chemotherapy(CTX) prior to IMPT. To avoid treatment delay, 11 fx of IMRT x-rays could be substituted for IMPT. Pts had restaging and surgery 4-8 weeks after IMPT. Primary study endpoint was local tumor control. Secondary endpoints included clinical and pathologic response, surgical margin status, and disease-free and overall survival. Results: We accrued 60 pts from January 2016 to February 2021. Histology: 35 liposarcoma(LPS) (19 dediff and 16 well diff), 22 leiomyosarcoma(LMS), and 3 undifferentiated pleomorphic sarcoma. IMPT was delivered per protocol in all pts. 51 pts have had surgery, 5 are awaiting surgery, and 4 had no surgery due to metastases(DM) on preop imaging. 22 pts had (+) margins. 2 pts had > 75% necrosis. With 23-month median (range 1-52 months) follow-up after start of RT, there were two LRs. A dediff LPS pt had a well diff LPS LR 26 months postop, resected, and is disease-free. A renal vein/IVC LMS pt treated with CTX and IMPT had LR and DM 4 months postop and died from disease. Surgical Clavien-Dindo morbidity scores: 0(21), 1(9), 2(8), 3a (4), 3b(4), 4a(2), 4(b)1, 5(2); the periop deaths were from sepsis(pneumonia) and duodenal ulcer. The grade 3-4 periop morbidity included abscess(3), treated by catheter(2) or operative(1) drainage, prolonged hospital stays (2 pts with IVC LMS), small bowel obstruction (1), and late sigmoid colon anastomotic failure (1). Readmissions for lymphopenia(1), pneumoperitoneum (1), and volume overload (1). One late neuropathy was seen in a Type II diabetic pt with transient postop weakness after femoral nerve dissection who later had significant lower extremity weakness 3.75 years postop. Study was amended to reduce IMPT dose in diabetic pts. Conclusions: Preoperative IMPT with selective dose escalation to 63 GyRBE to the high risk posterior RPS margin is feasible. Early local control results with this approach appear promising. Some peri-operative morbidity was noted but appears to be in the expected range for RPS resections. Clinical trial information: NCT01659203.

e20554 Background: The paradigm for locally advanced non-small cell lung cancer has been markedly altered to include maintenance durvalumab (D) post completion of definitive chemoradiation (CRT) following the publication of the Pacific trial in 2018. The toxicity of this treatment has not been well evaluated in the real-world setting. Methods: We identified 42 patients (pts) with Stage IIB-IIIC NSCLC treated at Mayo Clinic Rochester between 6/1/2018 and 10/1/2020 who received definitive CRT followed by maintenance D. Data were abstracted by retrospective chart review under an IRB approved protocol. Results: Median age was 66 yrs (range 47-90) and 62% were women. Primary lung cancer histology included 19 adenocarcinoma, 20 squamous cell, and 3 adenosquamous. The distribution of stages was: IIB (4/42), IIIA (15/42), IIIB (19/42), IIIC (4/42). Approximately half of patients had PDL1 expression > 25% (20/42). With a median follow up of 12.2 months (calculated from first cycle of D; range 4.2-30.5 months), 14 had completed one year of maintenance D, 16 were receiving ongoing D, and 10 stopped D early with 6/12 discontinuing due to disease progression (4/6 local progression, 2/6 distant progression). Other reasons for discontinuation (5/10) included grade 3 colitis, grade 2 hepatitis, aspergillus lung infection, and flare of autoimmune disorders. One quarter of patients experienced grade 2 radiation pneumonitis (RP; 10/42) with median time to development of RP 78 days from end of CRT and 45 days from start of D. RP was determined by multidisciplinary review of imaging and treatment fields. 17/42 patients developed immune related adverse events (see Table for details). There was minimal overlap between the patients who experienced pneumonitis and immune related toxicity; 2/17 had both pneumonitis and immune related toxicity (hepatitis, thyroiditis). Conclusions: In our early experience with the Pacific regimen, 29% of patients did not complete D due to either toxicity or progression during D administration. Pneumonitis was common (10/42 patients) although there were no grade 3 events. Nearly half of the patients developed an immune-related adverse event. Further analysis is needed to evaluate the real-world toxicity of this treatment as well as oncologic outcomes.[Table: see text]

7521 Background: In MCL, outcomes are heterogeneous and the clinical significance of the timing of relapse following autoHCT and its impact on OS is not well defined. Using the CIBMTR database, we evaluate the effect of post-autoHCT time to relapse on OS over time. Methods: Adult MCL pts treated with up to two lines of rituximab-based induction therapy followed by first autoHCT within 1-year of diagnosis were identified between 2000-2018. Primary outcomes included OS and post-relapse OS. A dynamic landmark analysis was performed at 6-month intervals following autoHCT to evaluate the impact of relapse on OS while adjusting for significant patient- and disease-related variables. Post-relapse OS was evaluated in pts who experienced relapse. Results: Of the 461 pts included in the analysis, the median age was 60 years (range 29-78), 57% had a KPS of ≥ 90, 83% had stage III-IV disease at diagnosis, and 76% had extranodal involvement. BEAM was the most common conditioning regimen (58%) and 23% of pts received post-autoHCT maintenance rituximab. With a median follow-up of 67 months, the 5-year progression-free survival was 45.8% with a 5-year OS of 69.6%. On multivariate analysis, age ≥60 years was associated with worse OS (HR= 1.55, 95% CI 1.08-2.24, p=0.0191) at all landmark timepoints. Additionally, the impact of relapse on OS varied with time (p=0.006) and was greatest at the 6-month (HR=7.68), 12-month (HR=6.68), and 18-month (HR=5.81) landmark timepoints. The risk of death for relapsing pts decreased with time and was mirrored by an improvement in adjusted OS for both relapsing and non-relapsing pts. In total, 9.3% of patients relapsed prior to the 18-month landmark timepoint. Relapse at the 6-month, 12-month, and 18-month landmark timepoints correlated with a poor median post-relapse OS of 9 months, 24 months, and 34 months, respectively (Table). Conversely, patients relapsing after the 18-month landmark timepoint experienced a median post-relapse OS ranging from 44-67 months. Conclusions: In MCL, early relapse (< 18-months) following autoHCT defines a high-risk group with inferior post-relapse OS. This population should be considered for clinical trials or novel therapeutic approaches including early utilization of chimeric antigen receptor T-cell therapy.[Table: see text]

e13603 Background: Over half of Americans report favoring access to experimental treatments even if they have yet to be proven either safe or effective, yet only 3-5% are enrolled in clinical trials and a fraction of a percent in expanded access. The Expanded Access (EA) program (aka “compassionate use”) and Right-to-Try (RTT) are parallel federal mechanisms that offer qualifying patients access to off-trial experimental treatments. Our study aimed to capture the views and experiences of oncologists on obtaining eligible medicine using the FDA’s EA and is the first to report findings on physician attitudes toward RTT. Methods: We conducted 21 semi-structured interviews and qualitative analysis of oncologists at a major cancer center with 3 main sites across the U.S. Participants were purposely selected to have experience with EA. Results: Oncologists’ considerations for offering EA options to patients were based on a sound scientific rationale, reasonable risk-benefit ratio, functional status of the patient, and patient motivation. Although oncologists’ experience positively correlated with level of ease in navigating EA, most remained largely unfamiliar with RTT. Only 4 oncologists had experience discussing RTT with patients and none had obtained an experimental therapeutic under this pathway. When informed about RTT, oncologists articulated 3 sets of concerns including limited safety and oversight, unclear structure and lack of requirements to collect and report data, and the potential for inflating patient expectations. Published work by others have shown that patients desire experimental options to be offered and report that physicians do not always offer experimental medicine taking into account factors, such as, reimbursement. Given that oncologists may factor in variables such as patient motivation, and potentially affordability or health literacy, when considering whether experimental medicine is appropriate to offer their patient, there may be a need to develop a conversation aid so that clinically relevant options are presented to patients equitably and patient choice is enhanced. Conclusions: Further research to better understand patient perspectives and potential discordant views between patients and oncologists is needed in order to design shared decision-making tools to inform oncologists about off-trial preapproval pathways and help both oncologists and patients navigate the thorny issues of experimental oncology.

Abstract Atypical teratoid rhabdoid tumor (ATRT) is a central nervous system cancer of infancy and early childhood that may occur anywhere along the neuraxis and is associated with a high rate of mortality. While contemporary multimodal therapeutic approaches have significantly improved overall survival, targeted therapy remains elusive, and treatment is often associated with significant morbidity. ATRT is unique in its genomic stability, with the only recurrent genetic abnormality being bi-allelic loss of the SMARCB1 gene, which encodes a core subunit of the BAF chromatin remodeling complex. The epigenetic mechanisms by which SMARCB1 loss leads to tumorigenesis are not yet well-defined and addressing this gap in understanding is necessary for creating efficacious, targeted therapeutics. To better understand the epigenetic features gained and lost in ATRT, we re-expressed SMARCB1 in a library of patient-derived and established ATRT cell lines of multiple molecular subtypes. SMARCB1 restoration significantly reduced or eliminated the proliferative and clonogenic capacity of each cell line. We performed assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-Seq) and RNA sequencing (RNA-Seq) to define putative transcriptional regulatory networks that are gained and lost in ATRT. SMARCB1 restoration was associated with global changes in chromatin openness consistent with the creation of new regulatory elements throughout the genome, and these were associated with induction of a diverse developmental transcriptional signature. Motif enrichment analysis of regions with increased accessibility defined a small but consistent number of centrally enriched transcription factor motifs across cell lines indicative of putative pioneer factors whose functions may be lost in ATRT. Pertinent chromatin immunoprecipitation with sequencing (ChIP-Seq) data will be discussed in the context of lost and gained transcriptional regulatory networks in ATRT and normal cellular development.