A multicenter, randomized phase 2 study to establish combinations of CBP501, cisplatin and nivolumab for ≥3rd-line treatment of patients with advanced pancreatic adenocarcinoma

BACKGROUND

There is no standard of care for ≥ 3rd-line treatment of metastatic pancreatic adenocarcinoma (PDAC). CBP501 is a novel calmodulin-binding peptide that has been shown to enhance the influx of platinum agents into tumor cells and tumor immunogenicity. This study aimed to (1) confirm efficacy of CBP501/cisplatin/nivolumab for metastatic PDAC observed in a previous phase 1 study, (2) identify combinations that yield 35% 3-month progression-free survival rate (3MPFS) and (3) define the contribution of CBP501 to the effects of combination therapy.

METHODS

CBP501 16 or 25 mg/m2 (CBP(16) or CBP(25)) was combined with 60 mg/m2 cisplatin (CDDP) and 240 mg nivolumab (nivo), administered at 3-week intervals. Patients were randomized 1:1:1:1 to (1) CBP(25)/CDDP/nivo, (2) CBP(16)/CDDP/nivo, (3) CBP(25)/CDDP and (4) CDDP/nivo, with randomization stratified by ECOG PS and liver metastases. A Fleming two-stage design was used, yielding a one-sided type I error rate of 2.5% and 80% power when the true 3MPFS is 35%.

RESULTS

Among 36 patients, 3MPFS was 44.4% in arms 1 and 2, 11.1% in arm 3% and 33.3% in arm 4. Two patients achieved a partial response in arm 1 (ORR 22.2%; none in other arms). Median PFS and OS were 2.4, 2.1, 1.5 and 1.5 months and 6.3, 5.3, 3.7 and 4.9 months, respectively. Overall, all treatment combinations were well tolerated. Most treatment-related adverse events were grade 1-2.

CONCLUSIONS

The combination CBP(25)/(16)/CDDP/nivo demonstrated promising signs of efficacy and a manageable safety profile for the treatment of advanced PDAC.

CLINICAL TRIAL REGISTRATION

NCT04953962.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

Lack of phototoxicity potential with delafloxacin in healthy male and female subjects: comparison to lomefloxacin

AIMS

Delafloxacin is a fluoroquinolone antibiotic recently approved by the FDA for treatment of acute bacterial skin and skin structure infections (ABSSSI). Delafloxacin was assessed for phototoxicity potential compared with a known phototoxic fluoroquinolone.

METHODS

A Phase 1, investigator-blind, placebo/active-controlled, randomized, parallel-group study was conducted in 52 healthy male and female volunteers who received 200 or 400 mg of oral delafloxacin, 400 mg oral lomefloxacin or placebo once daily for 6 days. This study evaluated the photosensitizing potential and possible wavelength dependency of delafloxacin by comparing the response of the skin to ultraviolet A (UVA), ultraviolet B (UVB) and visible radiation prior to and during administration of delafloxacin, lomefloxacin as a positive control, or placebo. Adverse events were monitored throughout the study.

RESULTS

Forty-seven subjects completed six days of dosing, and no evidence of phototoxicity was seen with delafloxacin. Delafloxacin at 200 and 400 mg day-1 and placebo did not demonstrate differences in percent change from baseline in minimal erythema dose at all tested wavelengths (295-430 nm) by monochromator and solar simulator. Lomefloxacin, the positive control, had statistically significant differences (p < 0.05) at UVA wavelengths of 335 and 365 ± 30 nm 24 hours after radiation exposure (maximum response). The phototoxic index results were significantly higher for lomefloxacin at 335 nm and 365 nm compared to placebo and delafloxacin.

CONCLUSIONS

200 and 400 mg of delafloxacin administered for 6 days were well tolerated in healthy adult volunteers. Delafloxacin and placebo failed to demonstrate a phototoxic effect but lomefloxacin, the positive control, demonstrated moderate phototoxicity.

Mechanical and physiological examination of barefoot and shod conditions in female runners

Barefoot running and running using minimalist footwear have become increasingly popular in recent years. Footwear choice may affect running mechanics and the metabolic cost of running. To investigate these factors, 8 well-trained, female distance runners (mean age=20.1±1.4 years) were recruited to participate in the study. Following orientation to testing procedures, subjects completed 3 running economy tests on separate days. Treatment order (barefoot, minimalist footwear and running shoe) was counter-balanced. Each testing session consisted of a 5-min warm-up at 2.24 m · s(-1), followed by the 7-min RE test at 3.13 m · s(-1). Biomechanical data were collected at the 3-min mark for 10 s, and expired gases were collected from minutes 5-7. One-way repeated measures ANOVA revealed a statistically significant difference for running economy (p=0.04), expressed as relative oxygen uptake per km in the barefoot condition (running shoe: 204.51±2.84; minimalist footwear: 198.21±3.04; barefoot: 193.26±3.62 ml · kg(-1)· km(-1)) vs. running shoe. The other physiological and biomechanical variables were not statistically significant (p>0.05). However, moderate to large effect sizes suggested there were biomechanical changes that ensured between conditions. It should be further evaluated whether these mechanical adjustments and the running economy trend would translate into improved distance race performance while running barefoot or with minimalist footwear.

Torsional electromechanical systems based on carbon nanotubes

Carbon nanotubes (CNTs) are among the most highly studied nanomaterials due to their unique (and intertwined) mechanical and electrical properties. Recent advances in fabrication have allowed devices to be fabricated that are capable of applying a twisting force to individual CNTs while measuring mechanical and electrical response. Here, we review major results from this emerging field of study, revealing new properties of the material itself and opening possibilities for advances in future devices.

Electron beam induced structural transformations of SWNTs and DWNTs grown on Si3N4/Si substrates

Electron beam induced structural transformations are investigated in single-wall carbon nanotubes (SWNTs), double-wall carbon nanotubes (DWNTs) and crossed nanotube junctions. The nanotubes studied here are synthesized by the chemical vapor deposition method. The response of the nanotubes to an electron beam is found to be influenced by the presence of coatings of amorphous carbon, graphene fragments and structural defects on the tube surface. The dependence of structural modifications on electron beam irradiation dose is measured. While nanotubes with amorphous carbon, graphene fragment coverage and/or defects undergo rapid transformation leading to structure disintegration, those without such coverage or defects are more resistant to beam damage. In addition, it is shown that the amorphous carbon coverage on the double-wall nanotubes can be transformed into graphene layers during electron beam irradiation of coated nanotubes. Finally, the relative stability of nanotube side-wall and end-walls are investigated through sub-threshold energy and above threshold energy irradiation of a model system, C60-filled nanotubes (Peapods). The data indicates that electron beams could be used to join nanotubes end-to-end without damaging the side-walls.

Controlled switching of optical emission energies in semiconducting single-walled carbon nanotubes

We present scanning photoluminescence (PL) microscopy of freely suspended single-walled carbon nanotubes grown by chemically assisted vapor deposition (CVD) across micron-sized open apertures. Scans of the PL emission versus excitation position show unusual "holes"having subwavelength spatial features associated with abrupt blue shifts of the emission energy. By varying the excitation polarization, energy, intensity, and position, we demonstrate that optical switching in some nanotubes is controllable in a highly nonlinear manner by adjusting the nonequilibrium carrier density in the nanotube. Technologically important attributes include large spectral contrast between on/off states at room temperature, a dramatic response to small changes in light intensity near threshold, and the possibility that electrical charge injection could also be used to control emission energies.

A fast, convenient and rugged procedure for characterizing the selectivity of alkyl-silica columns

Previous work has shown that the selectivity of reversed-phase columns for HPLC can be described by means of five column parameters: H (hydrophobicity), S* (steric resistance), A (hydrogen-bond acidity), B (hydrogen-bond basicity) and C (cation-exchange capacity). Values of H, S*, etc. can be determined by carrying out retention measurements for 18 test solutes under standardized conditions. The reproducibility of the latter procedure has been evaluated by comparison testing in four different laboratories and found acceptable. An alternative 10-solute test procedure which is more reproducible and convenient (but somewhat less accurate), requires only 2-3 h per column.

Low proliferative rate of invasive node-negative breast cancer predicts for a favorable outcome: a prospective evaluation of 669 patients

This study was designed to compare outcome in terms of disease-free survival (DFS) in women with histologically negative axillary lymph nodes and documented low proliferative rate cancer to other well-defined prognostic factors including type of adjuvant treatment. Between 1988 and 1998, we studied 669 patients with invasive node-negative breast cancer up to 5 cm in size and low proliferative rate measured by flow cytometry to determine S-phase fraction (SPF) or by histochemistry (Ki67/MIB1). At a median follow-up of 53 months, 5-year DFS for the entire group was 94% and did not differ significantly by type of systemic adjuvant treatment: none (133 patients, 95% DFS), tamoxifen (441 patients, 94% DFS), or chemotherapy with doxorubicin and cyclophosphamide (95 patients, 92% DFS). In a multivariate prognostic factor analysis, only tumor size was significant; 5-year DFS was 96% for T1N0 cancer versus 89% for T2N0 cancer (P = 0.01). We have prospectively confirmed that a low rate of proliferation as measured by SPF or MIB1 determination confers an excellent prognosis in invasive node-negative breast cancer up to 5 cm in size, regardless of adjuvant treatment.

Tunable resistance of a carbon nanotube-graphite interface

The transfer of electrons from one material to another is usually described in terms of energy conservation, with no attention being paid to momentum conservation. Here we present results on the junction resistance between a carbon nanotube and a graphite substrate and show that details of momentum conservation also can change the contact resistance. By changing the angular alignment of the atomic lattices, we found that contact resistance varied by more than an order of magnitude in a controlled and reproducible fashion, indicating that momentum conservation, in addition to energy conservation, can dictate the junction resistance in graphene systems such as carbon nanotube junctions and devices.

The influence of reduced liver blood flow on the pharmacokinetics and pharmacodynamics of recombinant tissue factor pathway inhibitor

OBJECTIVES

Recombinant tissue factor pathway inhibitor (rTFPI) has been shown to be an effective treatment in animal models of sepsis and is under investigation for human use. Reduced liver blood flow during septic shock may substantially alter the pharmacokinetics of rTFPI because clearance of rTFPI approaches liver blood flow. The aim of this study was to examine the effect of exercise-induced reduction in liver blood flow on the pharmacokinetics and pharmacodynamics of rTFPI.

METHODS

This was a two-way, open-label, randomized crossover study in eight healthy male volunteers. The subjects in both treatment groups received a continuous intravenous infusion of rTFPI (0.2 mg/kg/h) concurrently with intravenous sorbitol (50 mg/min) for 4 hours. Sorbitol was used as a biomarker for liver blood flow. The subjects were randomized to remain supine or to exercise on a bicycle ergometer for 30 minutes starting at the beginning of the third hour of the infusion.

RESULTS

Exercise reduced liver blood flow (mean +/- SEM) from 1.44 +/- 0.06 L/min to 0.40 +/- 0.03 L/min. The average clearance of rTFPI decreased from 0.73 +/- 0.04 L/min in the supine position to 0.25 +/- 0.02 L/min during exercise. This decrease in rTFPI clearance resulted in an 80% (95% confidence interval [CI], 60% to 102%) increase in plasma rTFPI levels during exercise. The average maximal prothrombin time and activated partial thromboplastin time values during exercise were 1.4 (95% CI, 0.4 to 2.5) and 4.4 (95% CI, 2.7 to 6.1) seconds higher compared with the supine steady-state level.

CONCLUSIONS

Reduction in liver blood flow by exercise markedly increased rTFPI concentrations and induced a slight but variable prothrombin time and activated partial thromboplastin time increase at the rTFPI dose studied.

Chemoprevention of colon cancer by specific cyclooxygenase-2 inhibitor, celecoxib, administered during different stages of carcinogenesis

Epidemiological observations and laboratory research have suggested that nonsteroidal anti-inflammatory drugs (NSAIDs) reduce the risk of colon cancer and that the inhibition of colon carcinogenesis by NSAIDs is mediated through the modulation of prostaglandin production by rate-limiting enzymes known as cyclooxygenases (COXs). Because traditional NSAIDs inhibit both COX-1 and COX-2, these drugs induce side effects, such as gastrointestinal ulceration and renal toxicity, through the inhibition of the constitutive COX-1. Overexpression of COX-2 has been observed in colon tumors; therefore, specific inhibitors of COX-2 could serve as chemopreventive agents. Our previous study has shown that celecoxib, an inhibitor of COX-2, while sparing COX-1, inhibited azoxymethane (AOM)-induced colon tumorigenesis when administered during both initiation and postinitiation stages, ie., celecoxib administered continuously before, during, and after carcinogen treatment. This study examined the dose-response effect of celecoxib when administered during the initiation and postinitiation stages. In addition, the chemopreventive effects of high-dose celecoxib administered during the promotion/progression stage of colon carcinogenesis, ie., continuous celecoxib administration beginning 14 weeks after the carcinogen treatment, was determined in male F344 rats. We also measured the steady-state levels of celecoxib in the plasma of animals given this inhibitor. Groups of 5-week-old male F344 rats were fed either a control diet or experimental diets containing 500, 1000, or 1500 ppm celecoxib. At 7 and 8 weeks of age, rats scheduled for carcinogen treatment were injected s.c. with AOM at a dose rate of 15 mg/kg body weight/week. Groups of animals destined for the promotion/ progression study and initially receiving the control diet were switched to a diet containing 1500 ppm celecoxib beginning 14 weeks after the second AOM treatment. All rats remained on their respective dietary regimens until the termination of the study, ie., 52 weeks, and were then sacrificed. Colon tumors were evaluated histopathologically. Administration of 500, 1000, or 1500 ppm celecoxib during the initiation and postinitiation stages significantly inhibited the incidence (P < 0.01 to P < 0.0001) as well as the multiplicity (P < 0.01 to P < 0.0001) of adenocarcinomas of the colon in a dose-dependent manner. Importantly, administration of 1500 ppm celecoxib during the promotion/progression stage also significantly suppressed the incidence and multiplicity of adenocarcinomas of the colon (P < 0.01). Also, administration of celecoxib to the rats during the initiation and postinitiation periods and throughout the promotion/progression stage strongly suppressed colon tumor volume (P < 0.0002 to P < 0.001). The steady-state plasma concentration of celecoxib increases somewhat with the dose. Thus, in this model system, the chemopreventive efficacy of celecoxib is dose-dependent when this COX-2 inhibitor is administered during the initiation and postinitiation periods. This study provides the first evidence that celecoxib is also very effective when it is given during the promotion/progression stage of colon carcinogenesis, indicating that the chemopreventive efficacy is achieved during the later stages of colon tumor development. This suggests that celecoxib may potentially be an effective chemopreventive agent for the secondary prevention of colon cancer in patients with familial adenomatous polyposis and sporadic polyps.

Investigation and modification of molecular structures with the nanoManipulator

The nanoManipulator system adds a virtual reality interface to an atomic force microscope (AFM), thus providing a tool that enables the user not only to image but also to manipulate nanometer-sized molecular structures. As the AFM tip scans the surface of these structures, the tip-sample interaction forces are monitored, which in turn provide information about the frictional, mechanical, and topological properties of the sample. Computer graphics are used to reconstruct the surface for the user, with color or contours overlaid to indicate additional data sets. Moreover, by means of a force-feedback pen, which is connected to the scanning tip via software, the user can touch the surface under investigation to feel it and to manipulate objects on it. This system has been used to investigate carbon nanotubes, fibrin, DNA, adenovirus, and tobacco mosaic virus. Nanotubes have been bent, translated, and rotated to understand their mechanical properties and to investigate friction on the molecular level. AFM lithography is being combined with the nanoManipulator to investigate the electromechanical properties of carbon nanotubes. The rupture forces of fibrin and DNA have been measured. This article discusses how some of the graphics and interface features of the nanoManipulator made these novel investigations possible. Visitors have used the system to examine chromosomes, bacterial pili fibers, and nanochain aggregates (NCAs). Investigators are invited to apply to use the system as described on the web at http:@www.cs.unc.edu/Research/nano/doc/biovis it.html.

Nanomanipulation Experiments Exploring Frictional and Mechanical Properties of Carbon Nanotubes

: In many cases in experimental science, the instrument interface becomes a limiting factor in the efficacy of carrying out unusual experiments or prevents the complete understanding of the acquired data. We have developed an advanced interface for scanning probe microscopy (SPM) that allows intuitive rendering of data sets and natural instrument control, all in real time. The interface, called the nanoManipulator, combines a high-performance graphics engine for real-time data rendering with a haptic interface that places the human operator directly into the feedback loop that controls surface manipulations. Using a hand-held stylus, the operator moves the stylus laterally, directing the movement of the SPM tip across the sample. The haptic interface enables the user to "feel" the surface by forcing the stylus to move up and down in response to the surface topography. In this way the user understands the immediate location of the tip on the sample and can quickly and precisely maneuver nanometer-scale objects. We have applied this interface to studies of the mechanical properties of nanotubes and to substrate-nanotube interactions. The mechanical properties of carbon nanotubes have been demonstrated to be extraordinary. They have an elastic modulus rivaling that of the stiffest material known, diamond, while maintaining a remarkable resistance to fracture. We have used atomic-force microscopy (AFM) to manipulate the nanotubes through a series of configuration that reveal buckling behavior and high-strain resilience. Nanotubes also serve as test objects for nanometer-scale contact mechanics. We have found that nanotubes will roll under certain conditions. This has been determined through changes in the images and through the acquisition of lateral force during manipulation. The lateral force data show periodic stick-slip behavior with a periodicity matching the perimeter of the nanotube.

A nonequilibrium radioimmunoassay for angiotensin II

A method for the measurement of angiotensin II levels in dog plasma is described. The method is similar to previously published assays in that in couples gradient high-performance liquid chromatography (HPLC) with radioimmunoassay (RIA) and requires blood sample collection and processing to plasma in the presence of protease inhibitors. The unique feature of the present method is that it utilized a commercially available angiotensin II RIA run under nonequilibrium conditions. Performing the angiotensin II RIA under nonequilibrium conditions increased RIA sensitivity to allow for a minimal detectable limit of 0.75 pg/mL, a limit of detection not achievable with current commercially available RIAs. This lower limit of detection will now allow for the measurement of circulating levels of angiotensin II. Quality control pools of dog plasma fortified with 4.59-50 pg/mL angiotensin II were assayed and analytical recoveries (ARs) and coefficients of variation (CV) of 72.2%-111% and 3.67%-19.0% were observed for the respective pools.

HDO in the Martian atmosphere: implications for the abundance of crustal water

The physical and chemical processes that lead to the preferential escape of hydrogen over deuterium in the Martian atmosphere are studied in detail using a one-dimensional photochemical model. Comparison of our theory with recent observations of HDO suggests that, averaged over the planet, Mars contains 0.2 m of crustal water that is exchangeable with the atmosphere. Our estimate is considerably lower than recent estimates of subsurface water on Mars based on geomorphological analysis of Viking images. The estimate can be reconciled if only a small fraction of crustal water can exchange with the atmosphere.

Large cell lymphomas of the stomach: improved prognosis with complete resection of all intrinsic gastrointestinal disease

Thirty-seven consecutive patients with large cell lymphoma involving the stomach were evaluated between 1974 and 1980. All seven stage IE patients underwent complete resection of the stomach and all patients are alive 21-41 mo after resection. Of 18 stage IIE, 11 underwent complete resection. Two resected patients without postoperative therapy died of their disease. Six patients treated with chemotherapy are alive and well, and two of three patients treated with radiotherapy remain alive without disease. Seven patients had incomplete resection or biopsy, and only one remains alive at 34 mo. Of eight stage IV patients, four had complete resection and chemotherapy without recurrence of their disease. All four patients who were not resected have died of their disease. This study strongly supports the role of early surgery in the management of gastric large cell lymphomas.