Design of an ultra-low mode volume piezo-optomechanical quantum transducer

Coherent transduction of quantum states from the microwave to the optical domain can play a key role in quantum networking and distributed quantum computing. We present the design of a piezo-optomechanical device formed in a hybrid lithium niobate on silicon platform, that is suitable for microwave-to-optical quantum transduction. Our design is based on acoustic hybridization of an ultra-low mode volume piezoacoustic cavity with an optomechanical crystal cavity. The strong piezoelectric nature of lithium niobate allows us to mediate transduction via an acoustic mode which only minimally interacts with the lithium niobate, and is predominantly silicon-like, with very low electrical and acoustic loss. We estimate that this transducer can realize an intrinsic conversion efficiency of up to 35% with <0.5 added noise quanta when resonantly coupled to a superconducting transmon qubit and operated in pulsed mode at 10 kHz repetition rate. The performance improvement gained in such hybrid lithium niobate-silicon transducers make them suitable for heralded entanglement of qubits between superconducting quantum processors connected by optical fiber links.

Effect of endoscopic sleeve gastroplasty on gastric emptying, motility and hormones: a comparative prospective study

OBJECTIVE

Endoscopic sleeve gastroplasty (ESG) has gained global adoption but our understanding of its mechanism(s) of action and durability of efficacy is limited. We sought to determine changes in gastric emptying (GE), gastric motility (GM), hormones and eating behaviours after ESG.

DESIGN

A priori-designed single-centre substudy of a large US randomised clinical trial, adults with obesity were randomised to ESG or lifestyle interventions (LS) alone. We measured GE, hormones and weight loss and assessed eating behaviours. In a subset of ESG patients, we assessed GM. The primary outcome was the change in T1/2 (min) at 3 months, and secondary outcomes were changes in weight, GE, GM, hormones and eating behaviours. We used t-test analyses and regression to determine the association between GE and weight loss.

RESULTS

36 (ESG=18; LS=18) participated in this substudy. Baseline characteristics were similar between the two groups. At 3 months, T1/2 was delayed in the ESG group (n=17) compared with the LS group (n=17) (152.3±47.3 vs 89.1±27.9; p<0.001). At 12 months, T1/2 remained delayed in the ESG group (n=16) vs control group (n=14) (137±37.4 vs 90.1±23.4; p<0.001). Greater delays in GE at 3 months were associated with greater weight loss. GM was preserved and fasting ghrelin, glucagon-like peptide 1 and polypeptide YY significantly increased 18 months after ESG.

CONCLUSION

ESG promotes weight loss through several key mechanistic pathways involving GE and hormones while preserving GM. These findings further support clinical adoption of this technique for the management of obesity.

TRIAL REGISTRATION NUMBER

NCT03406975.

NMDA receptor-dependent signalling pathways regulate arginine vasopressin expression in the paraventricular nucleus of the rat

The antidiuretic hormone arginine vasopressin (AVP) regulates water homeostasis, blood pressure and a range of stress responses. It is synthesized in the hypothalamus and released from the posterior pituitary into the general circulation upon a range of stimuli. While the mechanisms leading to AVP secretion have been widely investigated, the molecular mechanisms regulating AVP gene expression are mostly unclear. Here we investigated the neurotransmitters and signal transduction pathways that activate AVP gene expression in the paraventricular nucleus (PVN) of the rat using acute brain slices and quantitative real-time PCR. We show that stimulation with l-glutamate robustly induced AVP gene expression in acute hypothalamic brain slices containing the PVN. More specifically, we show that AVP transcription was stimulated by NMDA. Using pharmacological treatments, our data further reveal that the activation of ERK1/2 (PD184352), CaMKII (KN-62) and PI3K (LY294002; 740 Y-P) is involved in the NMDA-induced AVP gene expression in the PVN. Together, this study identifies NMDA-mediated cell signalling pathways that regulate AVP gene expression in the rat PVN.

Abstract P6-18-30: Phase Ib/II study of capecitabine 7/7 schedule with neratinib in patients with HER2-positive metastatic breast cancer (MBC)

Background: Neratinib (N) is a potent irreversible inhibitor of HER1, HER2, and HER4 and has been shown to have antitumor activity in patients (pts) with human epidermal growth factor receptor 2 (HER2) - positive breast cancer. A previous study of combination of neratinib with capecitabine (X) was associated with &gt; G 3 diarrhea in &gt; 20% of patients. Currently, the NALA study is evaluating this combination of N with X at standard schedule against control. X at 7 day on and 7 day off schedule (7/7) has been shown to be well-tolerated with less ≥G3 toxicities. We are conducting a phase Ib/II study of N with X (7/7) in pts with pretreated HER2+ MBC (NCT03377387). Methods: Eligible pts had HER2+ MBC, normal left ventricular ejection fraction (LVEF ≥ 50%); pts can have any and up to 4 prior chemotherapy-based treatments in phase Ib and II portions, respectively. Primary endpoints are to define maximum tolerated dose and efficacy in phase I and phase II portions, respectively. Secondary endpoints include safety and tolerability; exploratory endpoint is to quantify cell-free DNA to correlate with response for phase II portion. There were 4 cohorts for phase Ib with dose level 1 with starting dose of X at 1500 mg BID at 7/7 schedule with N at 240 mg daily. Results: As of July 1, 2018 8 pts have been enrolled in 2 cohorts. The median age is 63y (range: 57-79), and median ECOG is 0 (range: 0-1). 4 patients were treated at dose level 1 and 2 of 4 patients experienced dose-limiting toxicity with G3 diarrhea during cycle 1. Other significant toxicities included G3 hand foot syndrome (n=1), G3 fatigue (n=1) and G3 nausea (n=1). Three pts have now been treated at dose level -1 (X at 1000 mg twice daily 7/7 and N at 240 mg daily) and no ≥ G3 toxicities has been noted. Once MTD is reached, the phase II portion will occur to assess the efficacy and to further establish the safety and tolerability of capecitabine and neratinib at the MTD. Conclusions: The phase Ib/II study combining neratinib and capecitabine 7/7 is ongoing and updated result will be presented.

Citation Format: Wang R, Singh J, Sterlin V, Goldstein M, Lake D, Wong S, Baselga J, Norton L, Dang C. Phase Ib/II study of capecitabine 7/7 schedule with neratinib in patients with HER2-positive metastatic breast cancer (MBC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-30.

Abstract P4-21-34: Phase II study of gemcitabine, trastuzumab, and pertuzumab for HER2-Positive metastatic breast cancer after prior pertuzumab-based therapy

Background: The combination of taxanes with trastuzumab (H) and pertuzumab (P) for first line treatment of HER2-positive metastatic breast cancer (MBC) is associated with improved progression-free survival (PFS) and overall survival (OS). Treatment per physician's choice with anti-HER2 therapy after second line therapy is associated with a median PFS of 3 months. While continued use of H in therapeutic combinations after progression on H-based therapy is common, the efficacy of continuing HP-based treatment after progression on P-based therapy is unknown.

Methods: This is a single arm phase II trial of gemcitabine (G) with HP. Eligible patients had HER2-positive (IHC 3+ or FISH ≥ 2.0) MBC with prior HP-based treatment and ≤ 3 prior chemotherapies. Patients received G (1200 mg/m2) on days 1 and 8 of a q 3 week (w) cycle, and H (8 mg/kg load → 6 mg/kg) and P (840 mg load → 420 mg) q3w. The primary endpoint is PFS at 3 months. Secondary endpoints include OS, safety and tolerability. An exploratory endpoint is to compare PFS by RECIST criteria versus 18-F FDG-PET response criteria. Using a Simon optimal 2-stage design, 21 patients were enrolled in stage 1. The successful 3-month PFS rate for stage 1 was set at 57% to allow accrual to stage 2 for a total of 45 patients. The study therapy will be considered successful if at least 27/45 (60%) patients are progression free at 3 months.

Results: As of June 9, 2016, 28 patients are enrolled; 21 are evaluable at 3 months and 7 have not had 3-month evaluation. At 3 months, 16/21 (76%) are progression free; 5 patients have progressed. The 3 month-PFS results for evaluable patients will be updated. There are no cardiac or febrile neutropenic events to date. Initially, 5 of 22 (23%) patients required G dose reduction (4 due to grade 3 neutropenia and 1 due to grade 3 vomiting) and the study was amended to lower initial G dose to 1000 mg/m2.

Conclusions: The preliminary 3 month-PFS is 76% (95% CI 55% to 89%) in evaluable patients, and updated data will be presented. These findings suggest clinical benefit when P is continued beyond progression.

Citation Format: Iyengar NM, Smyth L, Lake D, Gucalp A, Singh JC, Traina TA, DeFusco P, Dickler MN, Fornier MN, Goldfarb S, Jhaveri K, Modi S, Troso-Sandoval T, Argolo D, Jack K, Ulaner G, Jochelson M, Baselga J, Norton L, Hudis CA, Dang CT. Phase II study of gemcitabine, trastuzumab, and pertuzumab for HER2-Positive metastatic breast cancer after prior pertuzumab-based therapy [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 P4-21-34.

Negative feedback regulation of the ERK1/2 MAPK pathway

The extracellular signal-regulated kinase 1/2 (ERK1/2) mitogen-activated protein kinase (MAPK) signalling pathway regulates many cellular functions, including proliferation, differentiation, and transformation. To reliably convert external stimuli into specific cellular responses and to adapt to environmental circumstances, the pathway must be integrated into the overall signalling activity of the cell. Multiple mechanisms have evolved to perform this role. In this review, we will focus on negative feedback mechanisms and examine how they shape ERK1/2 MAPK signalling. We will first discuss the extensive number of negative feedback loops targeting the different components of the ERK1/2 MAPK cascade, specifically the direct posttranslational modification of pathway components by downstream protein kinases and the induction of de novo gene synthesis of specific pathway inhibitors. We will then evaluate how negative feedback modulates the spatiotemporal signalling dynamics of the ERK1/2 pathway regarding signalling amplitude and duration as well as subcellular localisation. Aberrant ERK1/2 activation results in deregulated proliferation and malignant transformation in model systems and is commonly observed in human tumours. Inhibition of the ERK1/2 pathway thus represents an attractive target for the treatment of malignant tumours with increased ERK1/2 activity. We will, therefore, discuss the effect of ERK1/2 MAPK feedback regulation on cancer treatment and how it contributes to reduced clinical efficacy of therapeutic agents and the development of drug resistance.

Corneal collagen crosslinking for keratoconus or corneal ectasia without epithelial debridement

PURPOSE

Corneal collagen crosslinking (CXL) is a relatively new technique to reduce the progression of keratoconus. The technique can be performed with or without complete debridement of the corneal epithelium. We describe a novel intermediate technique involving mechanical disruption of the epithelium, and evaluate its safety and efficacy.

METHODS

The case notes of 128 eyes with progressive keratoconus or iatrogenic corneal ectasia who had undergone CXL using the epithelial disruption technique were retrospectively reviewed. Thin corneas were treated with hypotonic riboflavin. All others were treated with an isotonic solution. Note was made of preoperative and postoperative parameters, including uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refraction, endothelial cell count, and corneal tomography. Occurrence of procedure-related complications was recorded. Statistical analyses were performed using the paired sample t-test and Wilcoxon signed-rank test, with a level of P<0.05 being accepted as statistically significant.

RESULTS

At 12 months, 41.8% of patients treated with isotonic riboflavin had improved UCVA and 29.7% had improved BSCVA. Only 13.4% lost lines of UCVA and 14.9% lost BSCVA. Of the patients treated with hypotonic riboflavin, at 12 months, 75% demonstrated stability of BSCVA and 25% had stable Kmax. In addition, 25% showed improved visual acuity at 12 months, and 58.3% showed regression of their Kmax. Our rate of short-term complications was comparable to studies using complete epithelial removal.

CONCLUSIONS

CXL with epithelial disruption is a safe and effective treatment for keratoconus or iatrogenic corneal ectasia, and may be better tolerated by patients than the epithelium-off technique.

Endoscopic ultrasonography-guided portal injection chemotherapy for hepatic metastases

INTRODUCTION

We hypothesized that endoscopic ultrasonography-guided portal injection chemotherapy (EPIC) using irinotecan-loaded microbeads may achieve increased intrahepatic concentrations, while decreasing systemic exposure. This may achieve enhanced efficacy for the treatment of diffuse liver metastases, while decreasing systemic toxicities.

MATERIALS AND METHODS

In eight anesthetized 35 kg pigs, EPIC was performed transgastrically using the linear-array echoendoscope and a 22 g fine-needle aspiration. In four animals, irinotecan (100 mg) loaded onto 75-150 micron liquid chromatography (LC) beads was injected. In four animals, saline was injected into the portal vein and unloaded irinotecan (100 mg) was injected into the jugular vein. Plasma (every 15 min), and at 1 h bone marrow, liver and skeletal muscle samples were obtained. Irinotecan and SN-38 (active metabolite) concentrations were assayed by LC/mass spectrometry.

RESULTS

The procedure was performed safely in all eight animals. Compared with systemic administration, EPIC resulted in almost twice the hepatic concentration of irinotecan (6242 vs. 3692 ng/g) and half the systemic concentrations in plasma (1092 vs. 2762 ng/mL), bone marrow (815 vs. 1703 ng/mL) and skeletal muscle (521 vs. 1058 ng/g). SN-38 levels were lower with EPIC (liver: 166 vs. 681 ng/g; plasma: 1.8 vs. 2.4 ng/mL; bone marrow: 0.9 vs. 1.4 ng/mL; muscle 4.6 vs. 9.2 ng/g). Liver histology showed the beads within small portal venules.

CONCLUSIONS

EPIC using irinotecan-loaded microbeads can enhance hepatic exposure to irinotecan, while decreasing systemic concentrations. SN-38 levels were lower with EPIC indicating that a substantial portion of the irinotecan was still loaded onto beads. The microbeads may act as a reservoir resulting in prolonged hepatic drug exposure.

Abstract P5-20-07: Phase II Trial of Dasatinib in Combination With Weekly Paclitaxel for Patients with Metastatic Breast Carcinoma

Background: Src kinase plays an important role in proliferation, survival, angiogenesis and metastasis in several malignancies including breast cancer. Therefore, inhibition of Src and other tyrosine kinases (TKs) represents a novel therapeutic approach. Dasatinib is a potent inhibitor of 5 oncogenic TKs, inhibits VEGF-stimulated proliferation, has potent bone anti-resorptive activity and selectively inhibits basal-type breast cancer growth. Preclinically, the combination of dasatinib and paclitaxel had superior antitumor activity to either agent alone. In a previous phase I study, we determined that, in combination with weekly paclitaxel, the optimum dose of dasatinib was 120mg. Of note, 4/9 (44%) patients treated at or above this dasatinib dose level had objective tumor response. We now present results from the phase II trial of this combination.

Methods: Patients with MBC, ECOG PS 0–1, normal hepatic, renal, marrow function were eligible. Patients had measurable, HER2-negative metastatic breast cancer (MBC), ≤2 prior therapies for MBC. Treatment consisted of weekly paclitaxel 80 mg/m2 IV 3/4 weeks + Dasatinib 120mg orally daily. Response was assessed by RECIST after every 8 weeks of therapy. Simon's two-stage optimal design was used to test the null hypothesis of a 15% response rate (RR) against the alternative of a 30% RR. In stage I, planned enrollment was 23 patients based on Type I and Type II errors of 10%. If 4 or more responses are observed, enrollment will be extended to 55 patients. Exploratory correlative biomarkers of clinical benefit include Src phosphorylation (p-Src) in peripheral blood mononuclear cells, plasma levels of VEGFR2 and collagen Type IV, circulating tumor cells (CTCs) and tumor gene expression profiling.

Results: 21 patients (19 females, 2 male) have enrolled; median age 48 (range 30–79). Patients received a median of 1 prior therapy for MBC (range 0–2). 6 patients are not assessable for response: 1 has received &lt;8 weeks treatment, 5 came off study for toxicity (2 hypersensitivity reaction to paclitaxel, 1 infection, 1 diarrhea/nausea, 1 bleeding likely related to anticoagulation). Among the 15 patients assessable for response, best response to date is as follows: 2 (13%) patients partial response, 11 (73%) patients stable disease (SD) and 2 (13%) patients progression of disease. Of patients with SD, 6/11 (55%) continue on treatment after median of 2 months (range 2–10) and 5/11 (45%) patients have come off study after median of 10 months (range 3–21). Most toxicities have been hematological and low grade. Diarrhea and neuropathy have generally been low grade and no new toxicities related to the combination have occurred since expansion into the phase II. Potential biomarkers of clinical benefit including, p-Src, VEGFR2, collagen Type IV, and CTCs will be presented.

Conclusion: Data from this phase II has demonstrated preliminary evidence of activity for weekly paclitaxel and dasatinib 120mg in patients with MBC. These findings are consistent with data from this dose level in the earlier phase I study. Predictive biomarkers of clinical benefit are under investigation.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-20-07.

Abstract P1-13-11: Adjuvant treatment of early-stage breast cancer with eribulin mesylate following dose-dense doxorubicin and cyclophosphamide: preliminary results from a phase 2, single-arm feasibility study

Background: Despite recent improvements in breast cancer outcomes, patients (pts) with high-risk, early-stage breast cancer continue to experience recurrences and death due to disease. Chemotherapy regimens with the ability to extend survival remain an important drug development goal. Eribulin mesylate has demonstrated antitumor activity and improved overall survival (OS) in pts with heavily pretreated, locally recurrent or metastatic breast cancer when compared to treatment of physician's choice. This study examines the feasibility of eribulin as adjuvant therapy following dose-dense (dd) doxorubicin (A) and cyclophosphamide (C) in patients with early-stage breast cancer.

Methods: Eligible pts have histologically confirmed, HER2-normal, stage I-III invasive breast cancer and adequate bone marrow, liver, and renal function. Treatment consists of dd AC (A 60mg/m2 IV; C 600mg/m2 IV) on Day 1 of each 14-day cycle x4 cycles, followed by eribulin mesylate 1.4mg/m2 IV over 2–5min on Days 1 and 8 every 21 days x4 cycles. Radiation/hormonal therapy were allowed per standard of care. The primary objective of feasibility is defined as the ability to complete 4 cycles of eribulin without a treatment-related dose delay (defined as &gt;2 days) or reduction. Feasibility rates will be reported for pts with and without growth factor use. Secondary/exploratory endpoints include evaluation of the safety via NCI-CTCAEv4 of 4 cycles of AC followed by 4 cycles of eribulin, and 3-year disease-free survival and OS.

Results: As of 5/22/12, 46 of 80 planned pts have been treated; 38 pts have had ≥1 dose of eribulin and are evaluable for eribulin-related toxicity. Pt characteristics are as follows: median age 50 yrs (27–65 yrs); 100% female; ECOG of 0=81.6%; breast cancer stage at study entry: stg 1: 7.5%; stg 2: 72.5%, stg 3: 20%. Select treatment-related AEs are reported as total (all cycles) and eribulin-related events; many AEs overlapped during treatment (Table).

Calculation of shear stiffness in noise dominated magnetic resonance elastography data based on principal frequency estimation

Magnetic resonance elastography (MRE) is a non-invasive phase-contrast-based method for quantifying the shear stiffness of biological tissues. Synchronous application of a shear wave source and motion encoding gradient waveforms within the MRE pulse sequence enable visualization of the propagating shear wave throughout the medium under investigation. Encoded shear wave-induced displacements are then processed to calculate the local shear stiffness of each voxel. An important consideration in local shear stiffness estimates is that the algorithms employed typically calculate shear stiffness using relatively high signal-to-noise ratio (SNR) MRE images and have difficulties at an extremely low SNR. A new method of estimating shear stiffness based on the principal spatial frequency of the shear wave displacement map is presented. Finite element simulations were performed to assess the relative insensitivity of this approach to decreases in SNR. Additionally, ex vivo experiments were conducted on normal rat lungs to assess the robustness of this approach in low SNR biological tissue. Simulation and experimental results indicate that calculation of shear stiffness by the principal frequency method is less sensitive to extremely low SNR than previously reported MRE inversion methods but at the expense of loss of spatial information within the region of interest from which the principal frequency estimate is derived.

Short-Root regulates primary, lateral, and adventitious root development in Arabidopsis

Short-Root (SHR) is a well-characterized regulator of radial patterning and indeterminacy of the Arabidopsis (Arabidopsis thaliana) primary root. However, its role during the elaboration of root system architecture remains unclear. We report that the indeterminate wild-type Arabidopsis root system was transformed into a determinate root system in the shr mutant when growing in soil or agar. The root growth behavior of the shr mutant results from its primary root apical meristem failing to initiate cell division following germination. The inability of shr to reactivate mitotic activity in the root apical meristem is associated with the progressive reduction in the abundance of auxin efflux carriers, PIN-FORMED1 (PIN1), PIN2, PIN3, PIN4, and PIN7. The loss of primary root growth in shr is compensated by the activation of anchor root primordia, whose tissues are radially patterned like the wild type. However, SHR function is not restricted to the primary root but is also required for the initiation and patterning of lateral root primordia. In addition, SHR is necessary to maintain the indeterminate growth of lateral and anchor roots. We conclude that SHR regulates a wide array of Arabidopsis root-related developmental processes.

Abstract P6-12-09: A Phase I-II Trial of Dasatinib (D) in Combination with Weekly (w) Paclitaxel (P) for Patients (Pts) with Metastatic Breast Carcinoma (MBC)

Background: Inhibition of SRC is a novel approach for MBC. D is an inhibitor of multiple tyrosine kinases, including the SRC family. Pre-clinical data show D inhibits multiple breast cancer cell lines, including those of “basal-like” subtype. In preclinical models D + P had superior antitumor activity to either agent alone. We designed this phase I-II study to translate this observation.

Methods: For phase I: pts with MBC, ECOG PS 0-1, normal hepatic, renal, marrow function were eligible. Pts with pleural/pericardial effusions were excluded. For phase II: pts had measurable, HER2-negative MBC, ≥2 prior rx for MBC. Prior taxanes, stable brain metastases and baseline neuropathy grade ≥1 were allowed. Cycle (C) consisted of wP 80 mg/m2 IV 3/4 weeks + D 70mg orally daily; escalating to 100 mg, 120 mg and 150 mg in cohorts of 3pts. Toxicity was assessed by CTCAE v3.0, response by RECIST.

Results: 17 pts enrolled (15 phase I; 2 phase II); median age 54 (range 35-74), median PS=1 (range 0-1). 12 (71%) pts rcvd prior adjuvant chemoRx. Pts rcvd a median of 3 prior rx for MBC (range 0-12). Pts rcvd median of 2 C of D + P (range 1-14). One DLT occurred at 150mg (G3 fatigue); this cohort was expanded with no further DLTs. However 3 pts on this dose level withdrew;1 pt delayed hypersensitivity rash (grade 1), 1 pt febrile neutropenia (grade 3), 1 pt paclitaxel pneumonitis (grade 3). Therefore the phase II dose is D 120mg. Overall the most common toxicities have been hematologic and low G (table). 13 pts are assessable for response; 4 patients (31%) had a PR, including 3 patients previously treated with taxanes. 5 pts (29%) had stable disease.

Toxicities &gt; Grade 1

Conclusion: Treatment with wP and D is feasible in pts with MBC. In the phase I study, 1 DLT occurred at D 150mg but due to cumulative toxicities the recommended dose for the ongoing phase II study is 120mg. Preliminary evidence of activity has been seen in taxane-pretreated pts at the phase II dose. Identification of biomarkers to select appropriate pts for this therapeutic approach is the subject of ongoing correlative studies.

Safety of a novel capecitabine dosing schedule when combined with lapatinib in patients with HER2-positive metastatic breast cancer refractory to trastuzumab

1131

Background: Capecitabine (C) is active in breast cancer and is usually dosed for 14 days (d) followed by a 7d rest (14 - 7). We described a mathematical method which predicts the optimal schedule for C to be 7d followed by a 7d rest (7 - 7) (Norton et al, Amer Assn Can Res. 2005). The MTD of C(7 - 7) is 2,000mg BID (Traina et al, J Clin Oncol. April 2008). Lapatinib (L) improves time to progression when added to C(14 - 7) in patients (pts) with HER-2-positive (+) metastatic breast cancer (MBC) that progressed after trastuzumab (T). To optimize this effective combination, we are testing C(7 - 7) + L in a phase II trial. Methods: Eligible pts have measurable, HER-2(+) MBC that has progressed after T. HER-2(+)=IHC 3+ or FISH>2. Pts have normal LVEF by MUGA, ECOG performance status (PS) <2 and normal organ function. <3 prior chemotherapy (CRx) regimens are permitted. Prior fluoropyrimidine is excluded. Therapy (tx) consists of C (2,000 mg BID, 7 - 7) and L (1,250 mg, daily). Cycle length = 4 wk. Pts are evaluated for toxicity q4 weeks (wk), for response q12wk; LVEF by MUGA q12wk. Primary endpoint: response rate (RR). Secondary endpoints: toxicity, stable disease >6 months, PFS. Using a Simon optimal 2-stage design, with alpha = 10%, power = 90% to discriminate between RR 10% and 25%, 21 pts will be accrued to the first stage. If >2 pts respond, 29 additional pts will be enrolled. If >7/ 40 pts respond, then C(7 - 7) + L will be considered worthy of further study. Results: As of January 5, 2008, 6 pts are enrolled and evaluable. Median (med) age 64 yrs (42–71), med ECOG PS 1 (0–1), ER/PR(+) 3, HER-2(+) 6, sites of MBC: bone (2), viscera (4), soft tissue (5). Med baseline LVEF 62% (51–68%). Prior tx: Adjuvant: CRx (5), hormone tx (3), T (3); MBC: CRx (2), hormone tx (1), T (3). After a med of 3 cycles (1–4), there were no grade 3, 4, or 5 events. Tx-related toxicity is: Gr 2 fatigue (1); Gr 1 AST (4), diarrhea (3), ALT (2), vomiting (1), hand-foot (1), fatigue (1). No withdrawls due to reduced LVEF. Two pts evaluable for response: PR = 1, SD<6 mo = 1. Conclusions: Capecitabine (7 - 7) + lapatinib appears well tolerated compared to C(14 - 7)+L (Geyer et al). Additional safety and efficacy data is anticipated prior to this meeting.

[Table: see text]

Randomized phase II trial of nanoparticle albumin-bound paclitaxel in three dosing schedules with bevacizumab as first-line therapy for HER2-negative metastatic breast cancer (MBC)

1006

Background: Nanoparticle albumin-bound paclitaxel (nab-P) 260 mg/m2 is superior to paclitaxel 175 mg/m2 (P) every 3 weeks (Gradishar et al., J Clin Oncol. 2005). Weekly uninterrupted P is more effective than q3wk P in MBC (Seidman et al., J Clin Oncol. 2008). Bevacizumab (bev) nearly doubles response rate and time to progression (TTP) when added to P as 1st line therapy for MBC (Miller et al., N Engl J Med. 2007). Methods: This open-label, phase II study randomized patients (pts) to nab-P at 260 mg/m2 q3wk (arm A) versus 260 mg/m2 q2wk with filgrastim (arm B) versus 130 mg/m2 weekly uninterrupted, all with bev (15 mg/kg q3wk arm A, 10 mg/kg q2wk arms B and C). Pts were required to have measurable, HER-2-negative MBC and no prior chemotherapy for MBC. The primary endpoints were response rate and toxicity. Results: Accrual is complete, with 25% of pts still on study as of December 1, 2008. Of 208 pts randomized, 202 (72 arm A, 54 arm B, 76 arm C) were treated, with balanced demographics and baseline characteristics. The median age was 56 (range 29–85). 89% had visceral disease and 61% had prior neo-adjuvant or adjuvant chemotherapy. No significant differences in confirmed complete and partial response rates were noted (A: 42%, B: 42%, C: 41%). TTP was longer in arm C (9.2 months) versus both arms B (6.4 months) and A (7.7 months), overall p = 0.028. As per protocol-specified stopping rule, arm B was closed early due to unacceptable safety profile with significantly more grade ≥ 2 fatigue (B:57%, A: 39%, C:39%, p = 0.048) and bone pain (B: 19%, A: 10%, C:4%, p = 0.024). Neurotoxicity grade ≥ 2 was equivalent across all 3 arms (50%); febrile neutropenia occurred in <2% of pts in all arms. Arm C had significantly less arthralgia, myalgia, and nausea compared with arms A and B. Conclusions: Significant antitumor activity was observed in all arms. Weekly nab-P with bev (Arm C) resulted in a significantly longer TTP. Weekly nab-P with bev (Arm C) appears to have the highest therapeutic index, however sensory neuropathy is limiting, suggesting a 3 week on/1 week off schedule could be preferable and should be studied comparatively.

[Table: see text]

Dose-dense (DD) doxorubicin and cyclophosphamide (AC) followed by weekly paclitaxel (P) with trastuzumab (T) and lapatinib (L) in HER2/neu-positive breast cancer is not feasible due to excessive diarrhea: updated results

Abstract #2108

Background: DD q 2 weekly (w) AC → P + T x 1 year (y) has an acceptable safely profile w/ congestive heart failure (CHF) rate of 1/70 pts (Dang, JCO 2008). Lapatinib (L) is effective in HER2 (+) BC. We conducted a pilot study of dd AC → w P + T + L to determine its feasibility and cardiac safety.&#x2028; Methods: Enrolled pts had HER2 (+) BC; LVEF &gt; 50%. Rx consisted of AC at 60/600 mg/m2 x 4 q 2 w (w/ pegfilgrastim 6 mg day 2) → P at 80 mg/m2 x 12 q w + T x 1 y; L (1000 mg daily beginning w/ P + T and continued x 1 y). MUGA is obtained at baseline and at months (mo) 2, 6, 9, and 18. Rx is considered feasible if 1) &gt; 80% pts can complete the PTL phase without a dose delay or reduction and 2) the cardiac event rate (CHF or cardiac death) is &lt; 4%. Pts can remain on-Rx w/ one dose reduction of L (1000 mg → 750 mg) for a G 3 event or &lt; G 3 toxicity (unacceptable).&#x2028; Results: From March 2007 to April 2008, we enrolled 95 pts. Median (med) age was 45 years (range, 28-73). At a med follow-up of 7 months, 90 are evaluable. Of the 90 pts, 34 (37%) withdrew from study during the PTL phase; 29 for a 2nd event of G 3 or unacceptable &lt; G 3 toxicities (15 G 3 diarrhea, 4 G 1/2 diarrhea, 1 G 3 rash, 2 G 2 rash, 1 G 3 dyspnea and also had G 3 diarrhea, 1 G 3 ↑QTc also had G 3 diarrhea, 1 G 3 ↑ALT also had G 3 diarrhea, 1 G 3 paronychia, 1 G 3 pneumonitis, 1 asymptomatic LVEF ↓, 1 myocarditis) and 5 for other reasons (2 personal reason, 1 PCP pneumonia, 1 progression, 1 P hypersensitivity). Overall, 25/90 (27%) pts had G 3 diarrhea and 31/90 (34%) pts required a dose reduction of lapatinib. Med LVEF at baseline is 67% (N=95), at mo 2 is 68% (N=90), at mo 6 is 65% (N=53), and mo 9 is 65% (N=28). To date there are no patient drop-outs due to significant LVEF declines after dd AC; one patient dropped during PTL out due to an asymptomatic LVEF decline.&#x2028; Discussion: L at 1000 mg/day is not feasible combined w/ weekly P and T by protocol stipulation (&gt; 20% pts required L dose reduction) primarily due to excessive G 3 diarrhea. These results have led to the modification of Design 2 (Arm D) of ALTTO. We will report updated results.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2108.

Pharmacokinetics and tolerability of exemestane in combination with raloxifene in postmenopausal women with a history of breast cancer

PURPOSE

Raloxifene is a second-generation selective estrogen receptor modulator that reduces the incidence of breast cancer in postmenopausal women. Exemestane, a steroidal aromatase inhibitor, decreases contralateral new breast cancers in postmenopausal women when taken in the adjuvant setting. Preclinical evidence suggests a rationale for coadministration of these agents to achieve complete estrogen blockade.

EXPERIMENTAL DESIGN

We tested the safety and tolerability of combination exemestane and raloxifene in 11 postmenopausal women with a history of hormone receptor-negative breast cancer. Patients were randomized to either raloxifene (60 mg PO daily) or exemestane (25 mg PO daily) for 2 weeks. Patients then initiated combination therapy at the same dose levels for a minimum of 1 year. Pharmacokinetic and pharmacodynamic data for plasma estrogens, raloxifene, exemestane, and their metabolites were collected at the end of single-agent therapy and during combination therapy.

RESULTS

Plasma concentration-time profiles for each drug were unchanged with monotherapy versus combination therapy. Raloxifene did not affect plasma estrogen levels. Plasma estrogen concentrations were suppressed below the lower limit of detection by exemestane as monotherapy and when administered in combination with raloxifene. The most common adverse events of any grade included arthralgias, hot flashes, vaginal dryness and myalgias.

CONCLUSIONS

In this small study, coadministration of raloxifene and exemestane did not affect the pharmacokinetics or pharmacodynamics of either agent to a significant degree in postmenopausal women. The combination of estrogen receptor blockade and suppression of estrogen synthesis is well tolerated and warrants further investigation.

Phase I study of a novel capecitabine schedule based on Norton-Simon mathematical modeling

1045

Background: We have previously described a mathematical method to optimize chemotherapy dose and schedule (Norton et al, AACR 2005). Capecitabine (C) has activity in breast cancer when conventionally dosed for 14 days (d) q3 weeks (14/7). However, the predicted optimal dosing schedule for C using our model is 7d followed by a 7d rest (biweekly, 7/7). We tested this hypothesis in a Phase I/II study described below. Methods: Eligible patients (pts) have measurable, metastatic breast cancer (MBC), ECOG performance status (PS) =2 and normal organ function. There is no limit to number of prior chemotherapy (CRx) regimens. Pts with prior fluoropyrimidine for MBC are excluded. HER2+ pts must not be candidates for trastuzumab. C is given in divided daily doses for 7d followed by a 7d rest. A standard “3+3” dose escalation scheme employs flat dosing which begins at 1,500mg BID and increases by 500mg/dose level. Primary endpoint is the maximum tolerated dose (MTD), defined as the highest dose for which the incidence of dose-limiting toxicity (DLT) is <33%. Results: 19 pts are now accrued; 17 pts have been treated, 2 withdrew prior to receiving C. Medians: age 47 y (range 34–62 y) and ECOG PS 0 (range 0–2). Sites of MBC: bone 8, viscera 16, soft tissue 11. ER/PR+ 11. HER2+ or unknown 2. Prior adjuvant tx: CRx 17, hormone tx 10. Six pts had adjuvant fluoropyrimidine-based tx. Three pts had 1 prior CRx for MBC; 12 pts received first-line hormone tx for MBC. Fifteen pts had prior anthracycline and taxane. Treatment-related toxicities after a median of 4 cycles (range 1–10) are shown in the table . The MTD has not been reached. Pts continue accrual to the 2500mg/2500mg dose level. Conclusions: Capecitabine 7/7 is well tolerated and allows for safe delivery of higher daily doses than routinely used in practice, as predicted by the mathematical model. Capecitabine 7/7 will be tested in a Phase II program at MSKCC in combination with targeted agents.

[Table: see text]

No significant financial relationships to disclose.

Phase II study of weekly nanoparticle paclitaxel (ABI-007), carboplatin and trastuzumab as first-line therapy of HER2-positive metastatic breast cancer

10650

Background: The combination of carboplatin (C), paclitaxel (P) and trastuzumab (T) is active in HER2+ metastatic breast cancer (MBC) (Robert N et al. Proc ASCO 2003), and safer with weekly administration of all 3 agents (Perez E et al. Proc ASCO 2004). The superiority of nanoparticle paclitaxel (Abraxane, AB) over Cremophor-based paclitaxel (Gradishar W et al. JCO 2005), and the efficacy and safety of weekly AB in MBC (Blum J et al. Proc ASCO 2005) motivated us to conduct this study. Materials/Methods: To date 10 of 50 planned patients (pts) with measurable, HER2+ MBC have entered. After we established the safety of AB at 75 mg/m2 on days 1, 8, and 15 every 28 days (n = 4 pts), all subsequent pts received AB at 100 mg/m2. C was dosed at AUC = 2 on the same schedule, and T was weekly at 2 mg/kg without interruption, after a 4 mg/kg load. Initially, no prophylactic anti-allergy medication was given. Treatment is until disease progression (PD) or prohibitive toxicity. Pts without PD at 6 months may opt to continue T alone. Median age: 42 yrs (29–66), ECOG PS 0/1 (70/30%); 6 pts had prior adjuvant chemotherapy; 1 with anthracycline (A) and 4 with A + taxane (> 1 yr prior). Results: 68 cycles have been delivered to date (median: 8, range 1–9). Dose reductions of AB and C have been necessary in 4 pts (to 80 mg/m2 and AUC of 1.5 weekly), with delays in 4 pts. 3 pts had hypersensitivity reactions (HSR) to C and continued protocol therapy without C (n = 2) or with C and the addition of anti-HSR premeds (n = 1). Grade ¾ toxicities include neutropenia (44/11%) with 1 episode of febrile neutropenia. Grade ¾ anemia or thrombocytopenia has not occurred. Grade ¾ non-hematologic toxicity has been rare: 1 instance of grade 3 neuropathy (2 pts with grade 2). 7 partial responses have been observed in the first 9 evaluable pts (78%, 95% CI 44–93%), in liver, lung, bone and soft tissue sites, including 4 pts with prior adjuvant taxane. The median time to PD is not reached at 9.9+ months (7.3–9.9+). Accrual continues as the trial expands to additional study sites. Conclusions: The weekly administration of AB, C, and T demonstrates promising preliminary efficacy as 1st-line treatment for HER2+ MBC. With the exception of HSRs due to weekly C, a very favorable toxicity profile is observed.

[Table: see text]

Updated cardiac safety results of dose-dense (DD) doxorubicin and cyclophosphamide (AC) followed by paclitaxel (T) with trastuzumab (H) in HER2/neu overexpressed/amplified breast cancer (BCA)

582

Background: DD q 2 weekly (w) AC → T is superior to conventionally scheduled (cs) AC → T and safe w/long follow-up (Hudis et al, SABCS 2005). With q 3 wk AC, adjuvant (adj) H is safe and effective (Romond et al and Perez et al, NEJM 2005). We therefore tested DD q 2 w AC → T + H × 1 year (y) as adj treatment (Rx) of patients (pts) with HER2/neu (+) BCA to determine cardiac safety. Based on the reported cardiac event (CE) rate of ≤ 4% in the randomized trials using cs chemotherapy (CRx) + H, we evaluated DD q 2 w AC → T + H with a 1° endpoint of cardiac safety defined as discontinuation (DC) of H due to 1) cardiac death or 2) congestive heart failure (CHF). The 2° endpoint is time to recurrence and overall survival. Methods: Pts with HER2/Neu IHC 3+ or FISH-amplified BCA were enrolled, regardless of tumor size or nodal status. Rx consisted of AC at 60/600 mg/m2 × 4 → T at 175 mg/m2 × 4 q 2 w w/pegfilgrastim 6 mg on d 2 + H × 1 y. Multi-gated radionuclide angiography scan (MUGA) is obtained at baseline and at months (mo) 2 (after AC × 4), 6 (after T × 4), 9, and 18. Pts w/baseline LVEF of ≥ 55% and w/o cardiac illnesses are eligible. Pts w/significant (sig) asymptomatic (asx) LVEF ↓ after DD AC based on mo 2 MUGA did not receive H, and pts w/sig asx LVEF ↓ during H had it DC’d. If the CE rate is > 4%, Rx is deemed not feasible. Results: From January 4, 2005 to November 1, 2005, 70 pts were enrolled. Median (med) age is 49 years (range, 27–72). Forty one of 70 pts (60%) had node (+) BC and 27/70 pts (40%) had (-) nodes. Med baseline LVEF is 68% (range, 55%-81%). As of January 9, 2005, all pts had mo 2 MUGA after DD AC and there is no sig LVEF ↓ and the med LVEF is 67% (range, 58%-79%). To date 39 pts had mo 6 MUGA w/med LVEF of 66% (range, 56%-75%) and one pt had a sig asx LVEF ↓ from baseline of 74% to 56%; H was DC’d. Twenty-three pts had mo 9 MUGA w/a med LVEF of 64% (range, 57%-69%). One patient had clinical CHF at mo 4 w/EF of 45% and improved sig w/cardiac medications. One had pneumonitis during radiation (RT). One had atrial fibrillation w/pericarditis after completion of RT. Discussion: DD AC → T + H appears to have an acceptable cardiac toxicity profile w/1/70 pts having a CE. Updated cardiac safety data will be presented.

[Table: see text]

Study participants’ perceptions of the process and impact of receiving results of N9831

518

Background: There has been growing interest in providing clinical trial participants with study results. We sought to evaluate the process of sharing results from a large cooperative group trial in an effort to guide clinicians and clinical investigators. Methods: We mailed surveys to a subset of women who participated in NCCTG 9831, Phase III Trial of Adjuvant Chemotherapy with or without Trastuzumab for Women with HER2+ Breast Cancer, after the preliminary study results were mailed to participants. Surveys were sent to all trial participants enrolled through 9 CALGB/ECOG institutions. Results: Of 228 surveys sent, 160 (70%) have been returned. Average age of respondents was 51 years (range 26–76); 84% were white; 61% were college graduates; 4% reported recurrent disease. Women reported receiving results by mail (84%), from a health care provider in person or by phone (43%), and/or from the media (47%); 2% reported that they were not informed of the results. 29% heard the results first from the media; 27% first heard by mail. 35% of women might have preferred to be offered results, with the option of not receiving them, but only 4% of women indicated that they would have declined results had they been offered first. 89% of women found the results information easy to understand; 69% correctly interpreted the results of the study; 31% either had an incorrect interpretation or were unsure of the findings. 81% of women were satisfied with how results were shared; 63% of women felt that learning results had an impact on their lives, 24% were more anxious after learning the results; 36% were less anxious. Multivariable analyses evaluating factors associated with greater satisfaction and increased anxiety will be presented. Conclusions: Sharing results is met with overwhelmingly favorable responses from patients, although a substantial proportion of patients may not initially understand the findings. Some patients desire to be offered results first, but few would decline them. The potential for increased anxiety should be considered, and psychosocial support may be required by some. A plan to share results should be routinely and prospectively included in the design of clinical trials. (Supported in part by an ASCO Career Development Award (AHP)

No significant financial relationships to disclose.

Apparent diffusion coefficients for differentiation of cerebellar tumors in children

BACKGROUND AND PURPOSE

Diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps provide information at MR imaging that may reflect cell attenuation and integrity. We hypothesized that cerebellar tumors in children can be differentiated by their ADC values.

METHODS

Brain MR imaging studies that included ADC maps were retrospectively reviewed in 32 patients with histologically proved cerebellar neoplasm. There were 17 juvenile pilocytic astrocytomas (JPA), 8 medulloblastomas, 5 ependymomas, and 2 rhabdoid (atypical teratoid/rhabdoid tumor [AT/RT]) tumors. Absolute ADC values of contrast-enhancing solid tumor regions and ADC ratios (ADC of solid tumor to ADC of normal-appearing white matter) were compared with the histologic diagnosis. ADC values and ratios of JPAs, medulloblastomas, and ependymomas were compared by using a 2-tailed t test and one-way analysis of variance (ANOVA).

RESULTS

ADC values were significantly higher in pilocytic astrocytomas (1.65 +/- 0.27) (mean +/- SD) than in ependymomas (1.10 +/- 0.11) (P = .0003) and medulloblastomas (0.66 +/- 0.15) (P < .0001). Ependymomas demonstrated significantly higher ADC values than medulloblastomas (P = .0005). The observed differences were statistically significant on ANOVA (P < .001). ADC ratios were also significantly different among these 3 tumor types. AT/RT ADC values were similar to medulloblastoma. The range of ADC values and ratios within JPAs and ependymomas did not overlap with that of medulloblastomas.

CONCLUSION

Assessment of ADC values of enhancing solid tumor is a simple and reliable technique for preoperative differentiation of cerebellar tumors in pediatric patients. Our cutoff values of >1.4 x 10(3) mm(2)/s for JPA and <0.9 x 10(3) mm(2)/s for medulloblastoma were 100% specific.

Comparison and clinical application of frequency domain methods in analysis of neonatal heart rate time series

The frequency content of the heart rate (HR) series contains information regarding the state of the autonomic nervous system. Of particular importance is respiratory sinus arrhythmia (RSA), the high-frequency fluctuation in HR attributable to respiration. The unevenly sampled nature of heart rate data, however, presents a problem for the discrete Fourier transform. Interpolation of the HR series allows even sampling, but filters high-frequency content. The Lomb periodogram (LP) is a regression-based method that addresses these issues. To evaluate the efficacy of the LP and Fourier techniques in detecting RSA, we compared the spectrum of intervals, the spectrum of HR samples, and the LP of simulated and clinical neonatal time series. We found the LP was superior to the spectrum of intervals and the spectrum of HR samples in analysis near the critical frequency of one half the average sampling rate. Applying the LP to clinical data, we found (1) evidence of stochastic resonance, an enhancement of periodicity with the addition of small amounts of noise, and (2) reduced power at all frequencies prior to clinical diagnosis of neonatal sepsis.

Immunologic memory 5 years after meningococcal A/C conjugate vaccination in infancy

Infant vaccination with meningococcal conjugates may provide long-term protection against disease. Antibody levels and immunologic memory were assessed in 5-year-old Gambian children who received meningococcal A/C conjugate vaccination (MenA/C) in infancy. At 2 years, they were randomized to receive a booster of MenA/C (conjugate group), meningococcal A/C polysaccharide (MPS group), or inactivated polio vaccine (IPV group). All groups were revaccinated with 10 microg MPS at 5 years of age, as were 39 previously unvaccinated age-matched control subjects. Before revaccination, titers were higher in the conjugate and MPS groups than in control subjects (P<.001); titers for the IPV group were similar to those for control subjects. Ten days after revaccination, the conjugate and IPV groups had similar serogroup C serum bactericidal antibody titers (3421 vs. 2790, respectively). These levels were significantly higher than those in the MPS (426) and control (485) groups (P<.001). Thus, immunologic memory was sustained for > or =5 years; however, MPS challenge at 2 years interfered with a subsequent memory response.

High-dose chemotherapy and stem cell transplantation for patients with stage IV breast cancer without clinically evident disease: correlation of CD34+ selection to clinical outcome

Forty-five patients with metastatic breast cancer without clinically evident disease were treated with thiotepa 750 mg/m2, mitoxantrone 40 mg/m2 and carboplatin 1000 mg/m2 followed by stem cell transplantation to determine the safety and efficacy of CD34+ selection of peripheral blood stem cells. Of these, 15 patients' (group I) stem cells were processed through Baxter Isolex 300 device for CD34+ selection, whereas 30 patients (group II) received unmanipulated stem cells. Toxicity, progression-free survival and survival were compared between these two groups. There was no difference in transfusion requirements, white cell count and platelet recovery and non-hematologic toxicity between the two groups. The survival of patients in group I was 27 months compared to 38 months in group II (P = 0.8). The progression-free survival was 12 months and 13.5 months for group I and group II patients, respectively (P = 0.6). Our results indicate that while there is no adverse effect, there is also no significant advantage of CD34+ selection in terms of progression-free survival and survival in patients with metastatic breast cancer without clinically evident disease. Bone Marrow Transplantation (2000).

A randomized study comparing standard versus moderately high dose megestrol acetate for patients with advanced prostate carcinoma: cancer and leukemia group B study 9181

BACKGROUND

Megestrol acetate (MA) is a synthetic progestin with reported activity in both hormone-sensitive and hormone-refractory prostate carcinoma (HRPC). Based on limited data suggesting a possible dose-response effect, a trial was initiated to compare standard versus moderately high dose MA in HRPC.

METHODS

One hundred forty-nine men with hormone-refractory prostate carcinoma were randomized to receive oral MA either at 160 mg/day (low dose) or 640 mg/day (high dose). Patients were stratified by performance status and measurable versus evaluable disease. The primary end point was tumor response. Secondary end points were survival, quality-of-life measures, and prostate specific antigen (PSA) decline.

RESULTS

The median survival times of 11.2 months for patients who received the low dose and 12.1 months for patients who received the high dose therapy were not significantly different. Best response was equivalent in the 2 arms: 2 partial responses and 22 patients with stable disease for the 160 mg/day dose, and 1 partial response and 28 patients with stable disease for the 640 mg/day dose. A greater than 50% decline in PSA occurred in 13.8% and 8.8% of patients in the low and high dose treatment arms, respectively. There were no differences in the toxicity or quality-of-life outcomes between the two arms. Poorer performance status (2 vs. 0-1), greater than 5% weight loss, higher baseline PSA, and measurable disease all predicted shorter survival.

CONCLUSIONS

MA has limited activity in hormone-refractory prostate carcinoma, and there is no apparent dose-response correlation.

Confirmation of psaA in all 90 serotypes of Streptococcus pneumoniae by PCR and potential of this assay for identification and diagnosis

The gene encoding the pneumococcal surface adhesin A (PsaA) protein, psaA, was confirmed in all Streptococcus pneumoniae serotypes by a newly developed PCR (psaA PCR) assay. Eighty-nine of the 90 serotypes amplified produced an 838-bp fragment; the exception was a serotype 16F strain acquired from the American Type Culture Collection (ATCC). Analysis of 20 additional 16F strains from the United States and Brazil showed that the gene was amplified in all 16F strains, implying that the serotype 16F ATCC strain must be a variant. The specificity of the assay was verified by the lack of signal from analysis of heterologous bacterial species (n = 30) and genera (n = 14), including viridans group streptococci. The potential of the assay for clinical application was shown by its ability to detect pneumococci in culture-positive nasopharyngeal specimens. Demonstration of psaA in all 90 serotypes and lack of amplification of heterologous organisms suggest that this assay could be a useful tool for detection of pneumococci and diagnosis of disease.

Hand vein responses to noradrenaline in normotensive patients with insulin-dependent diabetes mellitus and microalbuminuria: effects of alpha-adrenoceptor blockade with doxazosin

Nephropathy commonly develops in patients with insulin-dependent (type 1) diabetes. Administration of an antihypertensive agent to type 1 diabetes patients with microalbuminuria, the first clinically detectable stage of nephropathy, can help slow renal deterioration. It is postulated that the exaggerated vasoconstrictor response to noradrenaline seen in these patients may be relevant in the development of microalbuminuria. This open, non-comparative pilot study was designed to investigate the effects of the alpha-adrenoceptor antagonist doxazosin on noradrenaline-induced hand vein vasoconstriction and on albumin excretion in 14 normotensive type 1 diabetes patients with microalbuminuria. After a three-week placebo run-in period, patients received doxazosin (1, 2, and then 4 mg once-daily, at two-week intervals) for six weeks, followed by a two-week placebo washout period. Vasoconstrictor responses to noradrenaline were measured in dorsal hand veins at the end of each two-week period. Hand vein vasoconstrictor responses to noradrenaline decreased significantly, compared with placebo, at 4 mg/day doxazosin (p = 0.006). The mean albumin excretion rate was lower than baseline at all doses of doxazosin, but changes did not reach statistical significance. Doxazosin was generally well-tolerated; four patients (29%) reported mild-to-moderate treatment-related adverse events. This study indicates that alpha 1-adrenoceptor blockade can blunt the exaggerated vascular reactivity to noradrenaline in normotensive type 1 diabetes patients with microalbuminuria, and supports further research into a potential role for doxazosin in preventing the development of diabetic nephropathy.

Phase I clinical and laboratory evaluation of topotecan and cytarabine in patients with acute leukemia

PURPOSE

To determine the maximal-tolerated dose (MTD) of topotecan with cytarabine in acute leukemia patients, and to evaluate leukemia cell apoptosis in these patients.

PATIENTS AND METHODS

Fifty-three patients with acute leukemia not responsive to standard therapy were treated at eight dose levels of topotecan (2.5 mg/m2/d to 7.75 mg/m2/d). Topotecan was given as a 30-minute infusion daily with cytarabine 1 g/m2/d, both for 5 days. Using a flow-cytometric technique, the percent apoptotic cells in blood and bone marrow samples was determined, and the cell cycle distribution of the leukemic cells studied.

RESULTS

Oropharyngeal mucositis was dose-limiting. The MTD of topotecan was 4.75 mg/m2/d for 5 days in high-risk patients and 7.0 mg/m2/d for 5 days in low-risk patients. The mean percent apoptotic cells in the peripheral blood reached a peak of 18.8%, a median of 48 hours following the first dose of topotecan. Patients with higher S-phase fractions, either before treatment or following cytarabine, were more likely to achieve bone marrow aplasia than those with lower S-phase fractions (P = .01 and P < .05, respectively). Clinical responses were seen in four of 39 patients with acute myelogenous leukemia (AML; of whom 32 had received prior high-dose cytarabine), three of six with acute lymphoblastic leukemia (ALL), and one of eight with chronic myelogenous leukemia in blast phase (CML-BP).

CONCLUSION

The recommended phase II dose of topotecan with intermediate-dose cytarabine is 4.75 mg/m2/d for high-risk patients and 7.0 mg/m2/d for low-risk patients. The percentage of cells in S phase was important in determining response to treatment.

A One-Bead One-Peptide Combinatorial Library Method for B-Cell Epitope Mapping

The one-bead one-peptide combinatorial library method represents a powerful approach to the discovery of binding peptides for various macromolecular targets. It involves the synthesis of millions of peptides on beads such that each bead displays only one peptide entity. The peptide-beads that interact with a specific macromolecular target are then isolated for structure determination. We have applied this method to discovering peptide ligands for several murine monoclonal antibodies: (i) anti-beta-endorphin (continuous epitope), (ii) anti-vmos peptide, (iii) anti-human insulin (discontinuous epitope), and (iv) surface immunoglobulins (&mu;kappa) of two murine B-cell lymphoma cell lines (antigen unknown).

Band 3 and its peptides during aging, radiation exposure, and Alzheimer's disease: alterations and self-recognition

An aging antigen, senescent cell antigen, resides on the 911 amino acid membrane protein band 3. It marks cells for removal by initiating specific IgG autoantibody binding. Band 3 is a ubiquitous membrane transport protein found in the plasma membrane of diverse cell types and tissues, and in nuclear, mitochondrial, and golgi membranes. Band 3 in tissues such as brain performs the same functions as it does in red blood cells forming senescent cell antigen. Oxidation is a mechanism for generating senescent cell antigen. The aging antigenic sites reside on human band 3 map residues 538-554, and 812-830. Carbohydrate moieties are not required for the antigenicity or recognition of senescent cell antigen. Anion transport site were mapped to residues 588-594, 822-839, and 869-883. The aging vulnerable site which triggers the antigenic site and the transport sites of band 3 were mapped using overlapping synthetic peptides along the molecule. Naturally occurring autoantibodies to regions of band 3 comprising both senescent cell antigen and B cells producing these antibodies were demonstrated in the sera of normal, healthy individuals. The presence of these antibodies tend to increase with age. Individuals with autoimmune diseases (rheumatoid arthritis and systemic lupus erythematosus) have increased antibodies to senescent cell antigen peptides. Radiation exposure results in an increase in antibodies to peptides 588-602 which lies in a transport region containing the aging vulnerable site. Band 3 ages as cells and tissues age. Our studies, to date, indicate, that the anion transport ability of band 3 decreases in brains and lymphocytes from old mice. This decreased transport ability precedes obvious structural changes such as band 3 degradation and generation of SCA, and is the earliest change thus far detected in band 3 function. Other changes include a decreased efficiency of anion transport (decreased Vmax) in spite of an increase in number of anion binding sites (increased Km), decreased glucose transport, increased phosphorylation, increased degradation to smaller fragments as detected by quantitative binding of antibodies to band 3 breakdown products and residue 812-830, and binding of physiologic IgG autoantibodies in situ. The latter 3 findings indicate that post-translational changes occur. In Alzheimer's Disease (AD), our results indicate that post-translational changes occur in band 3. These include decreased band 3 phosphorylation of a 25-28kD segment, increased degradation of band 3, alterations in band 3 recognized by antibodies, and decreased anion and glucose transport by blood cells. Serum autoantibodies were increased in AD patients compared to controls to band 3 peptide 822-839. This band 3 residue lies in an anion transport/binding region.

IgG autoantibodies to "switch peptide" determinants of TCR alpha/beta in human pregnancy

The fetus is a natural allograft that is protected from immunologic rejection by a complex set of structural and regulatory mechanisms. We determined whether healthy pregnant women differed significantly from healthy non-pregnant controls in their capacity to produce autoantibodies to defined antigenic determinants of the alpha/beta T-cell receptor. Although controls and pregnant women expressed comparable levels of autoantibodies against an intact recombinant T-cell receptor containing the complete V alpha/V beta structures, analysis of comparative reactivity against individual peptide segments of the molecules, indicated enhanced reactivity to regions corresponding to the CDR1 of the alpha chain and to the Fr3 of the variable region of the beta chain. A major difference was noted by increased reactivity of IgG autoantibodies of pregnant women to peptides corresponding to the "switch" region joining the variable and constant domains. This was noted with both the Tcr alpha and beta chains and was directed against highly conserved determinants within these molecules. Antibodies to this region are lacking in the non-pregnant controls. It is possible that autoantibodies directed against conserved regions of the T-cell receptor might function in the suppression of T-cell reactivity of fetal determinants.

Synthetic autoantigens of immunoglobulins and T-cell receptors: their recognition in aging, infection, and autoimmunity

Immunoglobulins and their close relatives, the antigen-specific T-cell receptors, are recognition proteins that express structures which readily serve as self-immunogens. Healthy humans can produce antibodies against variable region-defined recognition structures termed idiotypes, as well as against constant region structures, and the levels of these can increase markedly in autoimmune disease; e.g., rheumatoid factors are autoantibodies directed against a conformational determinant of the gamma heavy chain. More recent analyses employing synthetic peptide technologies and construction of recombinant T-cell receptors document that autoantibodies directed against both variable and constant region markers of the alpha/beta T-cell receptor occur in healthy individuals. Alterations in levels of antibody, usage of IgM or IgG isotypes, and specificity for particular peptide-defined regions vary with natural physiological processes (aging, pregnancy), with artificial allografting, with retroviral infection, and with the inception and progression of autoimmune disease (e.g., rheumatoid arthritis, systemic lupus erythematosus). Two of the major autoimmunogeneic regions of the Tcr alpha/beta are "constitutive" markers inasmuch as all individuals tested produce antibodies against these regions. The most frequently observed autoantibodies are against Tcr V beta CDR1 and Fr3 markers. It is hypothesized that these are normally involved in immunoregulation. Autoantibodies usually are not detected against CDR2 region determinants, or the "private idiotypes" defined by the CDR3 region, or the highly conserved FR4 segment specified by the joining gene segment. However, autoantibodies against the CDR2 of the Tcr alpha chain occur in some SLE patients, and healthy pregnant women produce antibodies against the common peptide determinant expressed by the joining gene and the beginning of the C alpha or C beta domain. Although the precise role of the naturally occurring autoantibodies in immunoregulation remains to be determined, modification of the course of autoimmune diseases in experimental rodent models (experimental allergic encephalomyelitis) has been successfully carried out by immunization with synthetic peptides corresponding to the CDR2 and Fr3/CDR3 segments, and immunization of humans with synthetic V beta CDR2 segments may prove helpful in multiple sclerosis. Moreover, infusion of intravenous immunoglobulins has been successful in the treatment of many autoimmune diseases, including examples where levels of T cells bearing particular V beta gene subsets were elevated. The recent knowledge gained from T-cell receptor structural analysis and antigenic modeling holds promise for determining the roles of particular variable domain structures in antigen recognition MHC-restriction and immunoregulation, and in the development of synthetic and recombinant reagents for modulation of autoimmune and infectious diseases.

Smoking attenuates the vasoconstrictor response to noradrenaline in type I diabetic patients and normal subjects: possible relevance to diabetic nephropathy

Exaggerated vascular reactivity has been implicated in the pathogenesis of diabetic nephropathy, and several studies suggest that smoking accelerates its progression. We therefore assessed the vasoactive effects of smoking by comparing noradrenaline-induced vasoconstriction in dorsal hand-veins between smoking and non-smoking groups of Type I diabetic patients with and without microalbuminuria and in non-diabetic subjects. Smokers had a significantly higher dose causing 50% vasoconstriction (reduced sensitivity to noradrenaline) in all three groups: microalbuminuric diabetic smokers vs. nonsmokers, 20.2(4.6) (SEM) vs. 6.6(2.3) ng min-1 (P = 0.02); normoalbuminuric, 76.9(29.4) vs. 22.8(9.1) ng min-1 (P = 0.03); non-diabetic subjects, 97.8(30.0) vs. 38.0(12.8) ng min-1 (P = 0.01). Both microalbuminuric diabetic groups showed significantly greater sensitivity to noradrenaline-induced vasoconstriction than the other smoking and non-smoking groups, respectively (P < 0.01). Vasoconstrictors responses to noradrenaline are attenuated in smokers, possibly due to alpha-adrenoceptor down-regulation. Smoking could increase urinary albumin losses and accelerate renal damage through catecholamine surges which raise systemic and, perhaps, intraglomerular blood pressure. This hypothesis deserves further consideration.

A 38-year-old female trauma victim of a car bomb

This case profoundly affected prehospital and hospital care providers alike. Most Midwestern areas have small cities and towns, and most of our trauma results from accidents, not deliberate, senseless human acts. There is a quality of life in our community that does not involve doing things like this to others. If our staff was this affected, it is sobering to think of the profound adjustment required of the victim.