Fetal Heart Rate Deceleration Detection Using a Discrete Cosine Transform Implementation of Singular Spectrum Analysis

Objectives : To develop a singular-spectrum analysis (SSA) based change-point detection algorithm applicable to fetal heart rate (FHR) monitoring to improve the detection of deceleration events.

Methods : We present a method for decomposing a signal into near-orthogonal components via the discrete cosine transform (DCT) and apply this in a novel online manner to change-point detection based on SSA. The SSA technique forms models of the underlying signal that can be compared over time; models that are sufficiently different indicate signal change points. To adapt the algorithm to deceleration detection where many successive similar change events can occur, we modify the standard SSA algorithm to hold the reference model constant under such conditions, an approach that we term “base-hold SSA”. The algorithm is applied to a database of 15 FHR tracings that have been preprocessed to locate candidate decelerations and is compared to the markings of an expert obstetrician.

Results : Of the 528 true and 1285 false decelerations presented to the algorithm, the base-hold approach improved on standard SSA, reducing the number of missed decelerations from 64 to 49 (21.9%) while maintaining the same reduction in false-positives (278).

Conclusions : The standard SSA assumption that changes are infrequent does not apply to FHR analysis where decelerations can occur successively and in close proximity; our base-hold SSA modification improves detection of these types of event series.

Mitigating Water Absorption in Waveguides Made From Unannealed PECVD SiO2

Water absorption was studied in two types of waveguides made from unannealed plasma enhanced chemical vapor deposition (PECVD) SiO₂. Standard rib anti-resonant reflecting optical waveguides (ARROWs) were fabricated with thin films of different intrinsic stress and indices of refraction. Buried ARROWs (bARROWs) with low and high refractive index differences between the core and cladding regions were also fabricated from the same types of PECVD films. All waveguides were subjected to a heated, high humidity environment and their optical throughput was tested over time. Due to water absorption in the SiO₂ films, the optical throughput of all of the ARROWs decreased with time spent in the wet environment. The ARROWs with the lowest stress SiO₂ had the slowest rate of throughput change. High index difference bARROWs showed no decrease in optical throughput after 40 days in the wet environment and are presented as a solution for environmentally stable waveguides made from unannealed PECVD SiO₂.

Abstract P6-12-03: A phase I study of AZD9496, a novel oral, selective estrogen receptor degrader (SERD) in women with estrogen receptor positive, HER-2 negative advanced breast cancer (ABC)

Background AZD9496 is a potent orally bioavailable ER antagonist and degrader that has shown antitumor efficacy in a range of preclinical xenograft models including ESR1wild-type tamoxifen-resistant and long term estrogen deprived models and an ESR1 mutant model.

Methods This is a phase I, open label global multicenter study in women with ER+ HER2–ve BC either metastatic or locoregionally recurrent, not amenable to treatment with curative intent. Patients are post-menopausal, or pre-menopausal women receiving LHRH agonist therapy, with disease progression after ≥6 months endocrine therapy for ER+ BC (no limit on number of prior endocrine therapies; ≤2 prior chemotherapies in advanced setting). The primary objective is to determine the safety and tolerability of AZD9496. Cohorts of 3-6 patients received daily oral therapy and dose limiting toxicities (DLTs) occurring in cycle 1 (28 days) were assessed. Patients are dosed until MTD (defined as ≤1/6 patients with a DLT) or maximum feasible dose (MFD) is reached. Key secondary objectives include determination of single and multiple dose pharmacokinetics (PK), and preliminary antitumor efficacy. ER target modulation by protein and gene expression is evaluated in circulating tumor cells and paired tumor biopsies.

In addition to the dose escalation phase, expansion cohort(s) in patients with or without ESR1 mutations can be enrolled to examine the safety, tolerability, PK and biological activity of AZD9496 further.

Results Preliminary data as of 30th April 2016: 45 patients (median age 62 (range 41-83); 38 post-menopausal, 7 pre/perimenopausal; visceral metastases 76%, prior fulvestrant 25/45) received AZD9496 in 7 dose escalation cohorts: 20mg QD n=4, 40mg BID n=6, 80mg BID n=5, 150mg BID n=6, 250mg BID n=6, 400mg BID n=6, 600mg BID n=6 and also a 250mg BID expansion cohort n=6. The majority of adverse events (AEs) were grade 1 or 2; the most common treatment-related AEs (≥10%) have been diarrhoea (33%), fatigue (27%), nausea (22%), upper abdominal pain (13%) and increased liver function tests (13%). Six patients had treatment-related grade 3 AEs, 5 of which were manageable with dose interruption +/- dose reduction. Specifically, three had DLTs: grade 3 increased AST/ALT/GGT-150mg BID, serious adverse reaction (SAR) leading to withdrawal; grade 3 diarrhoea and grade 3 increased AST/ALT/GGT-400mg BID, SAR, manageable with dose reductions; grade 3 diarrhoea 600mg BID, manageable with dose reduction. The MTD/MFD has not been reached.

Following the first dose up to 400mg the AZD9496 exposure increased in reasonable proportion to increasing dose. At 600mg a more than dose-proportional increase in exposure was observed. Evidence of reduced ER and Ki67 has been observed in on-study biopsies at 150mg BID and above. 10 subjects received treatment for >3-<6 months (5 ongoing, 5 discontinued),4 subjects >6-<12 months (3 ongoing, 1 discontinued), 3 subjects ≥1 year (2 ongoing, 1 discontinued).

Conclusions AZD9496 has a tolerable safety profile, evidence of PD biomarker modulation and prolonged stabilisation of disease in women with heavily pre-treated ER+ve ABC.

Citation Format: Hamilton E, Patel M, Armstrong A, Baird R, Jhaveri K, Hoch M, Morgan S, Dowdall T, Schiavon G, Klinowska T, Weir H, Bujac S, Nash T, Im S-A. A phase I study of AZD9496, a novel oral, selective estrogen receptor degrader (SERD) in women with estrogen receptor positive, HER-2 negative advanced breast cancer (ABC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-12-03.

Abstract OT2-01-08: Phase 2 study of abemaciclib plus tamoxifen or abemaciclib alone in women with previously treated hormone receptor-positive (HR+), HER2- metastatic breast cancer

Background:

Abemaciclib, an oral drug administered twice daily on a continuous schedule, is a specific inhibitor of both CDK4 and CDK6. In MONARCH 1, abemaciclib demonstrated evidence of single-agent activity and an acceptable safety profile in patients with heavily pretreated HR+, HER2- metastatic breast cancer (MBC) whose disease progressed on or after endocrine therapy and chemotherapy; with a confirmed objective response rate of 19.7% and a median duration of response of 8.6 months (Dickler, M. et al. American Society of Clinical Oncology (ASCO), abstr #510 (2016)). This Phase 2 study I3Y-MC-JPCG will evaluate the potential to enhance the risk/benefit profile of abemaciclib in women with previously treated HR+, HER2- MBC, either administered in combination with endocrine therapy or as monotherapy (at the maximum recommended single-agent dose with primary prophylactic antidiarrheal medication or at a lower dose of abemaciclib monotherapy). Such intervention with prophylactic loperamide may increase dose intensity and further optimize the clinical benefit for patients.

Trial design:

Study JPCG (NCT02747004) is a Phase 2 multicenter, randomized, open-label trial with 3 separate treatment arms in patients with HR+, HER2- MBC who have progressed on or after prior endocrine therapy and have received prior treatment with chemotherapy. Patients will be stratified based on presence of liver metastases and prior use of tamoxifen in the advanced/metastatic setting and will be randomized in a 1:1:1 ratio to receive abemaciclib 150 mg Q12H plus tamoxifen 20 mg every day (Arm A) or abemaciclib 150 mg Q12H monotherapy (Arm B); or abemaciclib 200 mg Q12H monotherapy plus primary prophylactic loperamide (Arm C).

Eligibility criteria:

Eligible patients include women with HR+, HER2- MBC with evidence of relapse or disease progression following endocrine therapy who have received prior treatment with at least 2 chemotherapy regimens, of which at least 1 but not more than 2 regimens have been administered in the metastatic setting. Patients are required to have measurable disease, adequate organ function, an ECOG PS of ≤1, and no prior treatment with any CDK4 and CDK6 inhibitor.

Specific aims:

The primary objective of JPCG is to evaluate the progression-free survival per RECIST v1.1, of abemaciclib 150 mg Q12H plus tamoxifen 20 mg QD, abemaciclib 150 mg Q12H monotherapy, and abemaciclib 200 mg Q12H plus prophylactic loperamide in women with HR+, HER2- MBC who have progressed on or after prior endocrine therapy and received prior chemotherapy. Secondary objectives are to evaluate response rates, overall survival, safety, pharmacokinetics, and quality of life. Exploratory objectives include evaluation of the associations between biomarkers relevant to abemaciclib and clinical outcomes.

Statistical methods:

Assuming a hazard ratio of 0.667, the study yields approximately 80% statistical power to detect superiority of Arm A over Arm C at a 1-sided alpha level of 0.10 using a log-rank test. Arms B and C will be compared using an informal non-inferiority rule.

Target accrual:

Approximately 225 patients.

Contact information:

For further information, please contact 1-877-CTLILLY (1-877-285-4559).

Citation Format: Diéras V, Hamilton E, Johnston EL, Forrester T, Martín M. Phase 2 study of abemaciclib plus tamoxifen or abemaciclib alone in women with previously treated hormone receptor-positive (HR+), HER2- metastatic breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT2-01-08.

Population-based cohort study of variation in the use of emergency cholecystectomy for benign gallbladder diseases

Background

The aims of this prospective population-based cohort study were to identify the patient and hospital characteristics associated with emergency cholecystectomy, and the influences of these in determining variations between hospitals.

Methods

Data were collected for consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing the performance of emergency cholecystectomy were analysed by means of multilevel, multivariable logistic regression modelling using a two-level hierarchical structure with patients (level 1) nested within hospitals (level 2).

Results

Data were collected on 4744 cholecystectomies from 165 hospitals. Increasing age, lower ASA fitness grade, biliary colic, the need for further imaging (magnetic retrograde cholangiopancreatography), endoscopic interventions (endoscopic retrograde cholangiopancreatography) and admission to a non-biliary centre significantly reduced the likelihood of an emergency cholecystectomy being performed. The multilevel model was used to calculate the probability of receiving an emergency cholecystectomy for a woman aged 40 years or over with an ASA grade of I or II and a BMI of at least 25·0 kg/m2, who presented with acute cholecystitis with an ultrasound scan showing a thick-walled gallbladder and a normal common bile duct. The mean predicted probability of receiving an emergency cholecystectomy was 0·52 (95 per cent c.i. 0·45 to 0·57). The predicted probabilities ranged from 0·02 to 0·95 across the 165 hospitals, demonstrating significant variation between hospitals.

Conclusion

Patients with similar characteristics presenting to different hospitals with acute gallbladder pathology do not receive comparable care.

Optimization of Y-splitting antiresonant reflecting optical waveguides-based rib waveguides

Antiresonant reflecting optical waveguide power splitters, designed for use around the 635-nm wavelength, are characterized for multiple split angles ranging from 0.5 deg to 9 deg. Theoretical expectations and simulations predict lowest transmission losses at this split junction for the lowest angles. This is confirmed by the experimental structures built in SiO₂ films on silicon substrates. A fabrication nonideality affects the achievable splitting angle. Design considerations are discussed based on tradeoffs between loss and the required length for a Y-splitter.

Abstract OT1-1-13: A phase II study with lead-in safety cohort of cabazitaxel plus lapatinib as therapy for patients with HER2-positive metastatic breast cancer (MBC) and intracranial metastases

Background: HER2-targeted therapy has improved the progress of patients (pts) with HER2-positive breast cancer; however, CNS metastases remain a significant source of morbidity and mortality. It is hypothesized that the inability of drugs like trastuzumab to cross the intact blood-brain barrier (BBB) may render the CNS as a sanctuary site for metastases. Lapatinib is an oral small molecule tyrosine kinase EGFR1/HER2 inhibitor that crosses the BBB and has activity against CNS metastases. Cabazitaxel is a new taxoid that is active in docetaxel- or paclitaxel-resistant breast cancer, and differs from other taxanes in its ability to cross the BBB. The promising systemic activity shown by cabazitaxel in taxane-resistant MBC coupled with the CNS penetrance of both cabazitaxel and lapatinib make this an attractive combination to evaluate in HER2-positive MBC pts with CNS metastases.

Study Objectives: The primary objectives of the study are to determine the safety and CNS objective response rate (ORR = CR+PR) in HER2-positive MBC pts with CNS metastases when treated with cabazitaxel and lapatinib. The secondary objectives include evaluation of the clinical benefit rate (CBR), 3- and 6-month PFS rate for CNS metastases, and response rate and CBR for extra-cranial metastases.

Key eligibility: Pts >18 yrs with HER2-positive (IHC 3+ or FISH/SISH-positive) MBC and unequivocal evidence of brain metastases are eligible. Additional eligibility criteria include: at least one measurable brain lesion >1.0cm in longest dimension on MRI; pts with brain lesions previously treated with WBRT and/or SRS must have at least one intra-cranial lesion >1.0cm not treated with SRS and must have evidence of intra-cranial progressive disease. Pts must have received at least 1 prior HER2-directed therapy in the adjuvant or metastatic setting; pts without prior chemotherapy for MBC are eligible if they progressed during or within 6 months of adjuvant therapy. Otherwise, there is no specific minimum or maximum number of previous chemotherapy regimens for MBC. ECOG performance status 0-2, adequate renal, bone marrow, and hepatic function are required; prior treatment with cabazitaxel or lapatinib (for MBC) not permitted.

Trial design: This is an open-label, non-randomized, phase II study with a lead-in safety cohort. During the lead-in phase, 6-15 pts will be treated in cohorts of 3 with increasing doses of cabazitaxel and lapatinib to determine the tolerability and optimal dose. Once the safety and dose is confirmed, subsequent pts will be treated at the optimal dose of the 2 agents. Each treatment cycle is 3 weeks and restaging will occur systemically and intra-cranially every 2 cycles for the first 8 cycles and every 3 cycles thereafter until progressive disease or unacceptable toxicity.

Statistical methods: We hypothesize that the addition of cabazitaxel will increase the CNS ORR from 6% (expected with single agent lapatinib) to ≥20% in this pt population. Treatment of 27 evaluable pts with the identified phase II doses will detect this difference with a power of 80% and alpha = 10% (one-sided test). Accounting for a 10% inevaluable rate and lead-in pts, a total of 45 pts will be enrolled on the study.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT1-1-13.

The effects of acoustic trauma that can cause tinnitus on spatial performance in rats

Previous studies have shown that acoustic trauma can disrupt the firing of place cells in the hippocampus and also inhibit hippocampal neurogenesis, suggesting that such trauma might impair spatial memory. In this study, we investigated performance in the alternating T maze and Morris water maze of rats exposed to acoustic trauma (16 kHz, 110 dB SPL pure tone for 1 h), who had elevated auditory brainstem response thresholds and the psychophysical attributes of tinnitus (using a conditioned lick suppression task). To our surprise, we found that rats with tinnitus did not perform significantly differently from sham control animals in either the alternating T maze task or any aspect of the reference or working memory versions of the Morris water maze task except for a faster acquisition in T maze alternation. These results suggest that acoustic trauma and tinnitus may not impair spatial memory in rats.