A phase I trial of the bombesin/gastrin-releasing peptide (BN/GRP) antagonist RC3095 in patients with advanced solid malignancies

Bombesin/gastrin-releasing peptides (BN/GRP) were shown to bind selectively to cell surface receptors, stimulating the growth of various types of malignancies in murine and human models. The novel BN/GRP synthetic receptor antagonist, RC-3095, was able to produce long-lasting tumor regressions in murine and human tumor models in vitro and in vivo. Animal toxicology studies showed no detectable organ toxicity apart from local irritation at the injection site. The purpose of this study was to determine the safety and feasibility of the administration of RC-3095 by daily subcutaneous injections in patients with advanced and refractory solid malignancies. Twenty-five patients received RC-3095 once or twice-daily at doses ranging from 8 to 96 ug/kg. Dose was escalated in groups of 3-5 patients per dose level. The only toxicity observed was local discomfort in the injection site at the highest doses. A single dose administration of RC-3095 at the highest dose level (96 ug/kg) was tested in a clearly hypergastrinemic individual with the Zollingen-Ellison syndrome and produced a decrease in plasma gastrin down to 50% of basal levels in 6 h. There was no objective tumor responses in patients included in the study. A short-lasting minor tumor response was observed in a patient with a GRP-expressing progressive medullary carcinoma of the thyroid. Due to problems with the analytical method, plasma pharmacokinetic data was obtained only from two patients included at the highest dose level. In these patients, RC-3095 reached plasma concentrations >100 ng/mL for about 8 h, which were within therapeutic levels on the basis of prior data obtained in mice and rats. The plasma elimination half-life was between 8.6-10.9 h. Due to the occurrence of local toxicity at the injection site, the dose escalation procedure could not be fully evaluated up to a maximum tolerated dose. Thus, a recommended dose of RC-3095 for Phase II trials could not be clearly established. Considering the novelty of its mechanism of action and impressive preclinical anti-tumor activity, further studies exploiting new formulations of RC-3095 for human use, such as slow-release preparations, and analogues with a more favorable pharmacokinetics are warranted.

Application of electrokinetic soil flushing to four herbicides: A comparison

In this work, four bench-scale plants containing soil spiked with four herbicides (2,4-Dichlorophenoxyacetic acid (2,4-D), oxyfluorfen, chlorsulfuron and atrazine) undergo treatment consisting of an electrokinetic soil flushing (EKSF). Results clearly demonstrate that efficiency of EKSF depends on the chemical characteristic of the pesticide used. The amount of pesticide collected in the anode well is more significant than that collected in the cathode wells, indicating that the electromigration is much more important than drainage by electro-osmotic flux for this application. After 15 d of treatment, the 2,4-D is the pesticide most efficiently removed (95% of removal), while chlorsulfuron is the pesticide more resilient to the treatment. Additionally, volatilization was found to be a process of the major significance in the application of electrokinetic techniques to soil polluted with herbicides and because of that it should always be taken into account in the future design of full-scale processes.

Zinc and water intake in rats: investigation of adrenergic and opiatergic central mechanisms

We have demonstrated that central administration of zinc in minute amounts induces a significant antidipsogenic action in dehydrated rats as well as in rats under central cholinergic and angiotensinergic stimulation. Here we show that acute third ventricle injections of zinc also block water intake induced by central ss-adrenergic stimulation in Wistar rats (190-250 g). Central inhibition of opioid pathways by naloxone reverses the zinc-induced antidipsogenic effect in dehydrated rats. After 120 min, rats receiving third ventricle injections of isoproterenol (160 nmol/rat) exhibited a significant increase in water intake (5.78 +/- 0.54 ml/100 g body weight) compared to saline-treated controls (0.15 +/- 0.07 ml/100 g body weight). Pretreatment with zinc (3.0, 30.0 and 300.0 pmol/rat, 45 min before isoproterenol injection) blocked water intake in a dose-dependent way. At the highest dose employed a complete blockade was demonstrable (0.54 +/- 0.2 ml/100 g body weight). After 120 min, control (NaAc-treated) dehydrated rats, as expected, exhibited a high water intake (7.36 +/- 0.39 ml/100 g body weight). Central administration of zinc blocked this response (2.5 +/- 0.77 ml/100 g body weight). Naloxone pretreatment (82.5 nmol/rat, 30 min before zinc administration) reverted the water intake to the high levels observed in zinc-free dehydrated animals (7.04 +/- 0.56 ml/100 g body weight). These data indicate that zinc is able to block water intake induced by central ss-adrenergic stimulation and that zinc-induced blockade of water intake in dehydrated rats may be, at least in part, due to stimulation of central opioid peptides.

Coronary inflammation by computed tomography pericoronary fat attenuation in young male anabolic androgenic steroid users

Background

The illicit use of anabolic androgenic steroids (AAS) has been associated with diminished cholesterol efflux mediated by HDL, remarkable decrease in high-density lipoprotein (HDL) plasma concentration and subclinical coronary artery disease (CAD). Inflammation is the key to the atherogenic process associated with atherosclerotic plaque vulnerability. The pericoronary mean fat attenuation (pFAM) has emerged as a marker of coronary inflammation and can predict future cardiovascular events, which is measurable from standard coronary computed tomography angiography (CCTA). However, whether AAS abuse has a role in pFAM in young male AAS users is unknown.

Purpose

The aim of this study was to evaluate whether AAS abuse could leads to higher pFAM and premature coronary inflammation in young male AAS users.

Methods

Twenty strength-trained AAS users (AASU) age 29±5 yr, 20 age-matched strength-trained AAS nonusers (AASNU), and 10 sedentary controls (SC) were enrolled in this study. Coronary inflammation was assessed by pFAM-CCTA in the right coronary artery (RCA), left anterior descending artery (LDA) and left circumflex coronary artery (Cx).

Results

pFAM in the RCA was significantly higher in AASU compared with AASNU and SC (−64.59±9.45 vs. −79.21±6.67 vs. −80.97±7,91 Hounsfield Units (HU), respectively, p<0.001]. Also, the pFAM in the LAD was higher in AASU compared with AASNU and SC (−72.83±7.21 vs. −79.41±6.72 vs. −80.97±7.72 HU, p=0.006). However, no difference to pFAM in the Cx between AASU, AASNU and SC (−74.30±5.85 vs. −79.77±7.13 vs. −78.19±5.82 HU, respectively, p=0.069) was found.

Conclusion

This study indicates that AAS abuse may be associated with higher pFAM and premature coronary inflammation in the RCA and LAD. The higher pFAM may be linked to early development of CAD in young AAS users.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Fundação Zerbini

Abstract P1-16-03: An open-label, multicenter phase 1b trial of radium-223 + paclitaxel in cancer patients with bone metastases: Safety results from the breast cancer patient subgroup

Background: Taxanes have an established role in treating breast cancer (BC), and combination with radium-223 (Ra-223) may be an option in patients (pts) with bone metastases. Both therapies impact hematologic parameters, but myelosuppression risk in combination is unknown. A phase 1b trial (NCT02442063) in cancer pts with bone metastases studied Ra-223+paclitaxel (PTX) safety and mode of interaction regarding myelosuppression; BC subgroup safety results are presented.

Methods: Eligible pts had a malignant solid tumor with ≥2 bone metastases and were PTX candidates. Treatment (tx) was 7 PTX cycles (90 mg/m2/wk IV per local standard of care, 3 wk on/1wk off) + 6 Ra-223 cycles (55 kBq/kg IV; 1 injection q4wk, starting at PTX cycle 2). Primary endpoint was % pts with neutropenia and thrombocytopenia during Ra-223+PTX (cycles 2, 3) vs PTX alone (cycle 1). A dose-exposure-response model describing time course of Ra-223+PTX–induced suppression of absolute neutrophil counts was used to evaluate Ra-223+PTX mode of interaction (additive or synergistic) in the total population.

Results: 15/22 enrolled pts were treated (total population); 7 had BC (BC subgroup). Baseline characteristics of the 2 groups were similar; ECOG PS was better in BC pts (Table). Fewer BC pts had prior taxane therapy (29% vs 53%), but rates of ≥3 prior chemotherapy regimens were similar (43% vs 47%). BC pts, vs total population, had slightly longer median tx duration for Ra-223 (6 vs 5.5 cycles) and PTX (7 vs 6 cycles), and more pts who completed 6 Ra-223 doses (57% vs 47%). Tx discontinuation related to disease progression in 29% of BC pts vs 33% in total population. Table shows TEAEs. In the BC subgroup, all 7 pts completed cycle 3 and Gr 3 neutropenia rates were 43% in cycle 2 and 14% in cycle 3, vs 29% in cycle 1; there was no Gr 4 neutropenia or Gr 3/4 thrombocytopenia. In the total population, 13 pts completing cycle 3 were in the pharmacodynamics analysis. Their Gr 3 neutropenia rates were 31% in cycle 2 and 8% in cycle 3, vs 23% in cycle 1; there was no Gr 4 neutropenia or Gr 3/4 thrombocytopenia. Myelosuppression model for the total population showed an additive effect of Ra-223 to PTX-induced neutropenia, with an additional 10% average decrease in absolute neutrophil count vs PTX alone. BC subgroup modeling was not feasible due to small sample size.

 Total Population n=15BC Subgroup n=7Median age (range), y61(45-76)58(45-68)Tumor type, n (%)  Breast7(47)7(100)Prostate4(27)0Bladder1(7)0Non-small cell lung1(7)0Other2(13)0ECOG score, n (%)  06(40)5(71)18(53)1(14)Prior taxane therapy, n (%)8(53)2(29)≥3 prior chemotherapy regimens, n (%)7(47)3(43)TEAEs, n (%)  Gr 3/49(60)2(29)Serious6(40)2(29)Gr 3/4 TEAEs, n (%)*  Neutrophil count decreased6(40)3(43)White blood cell count decreased4(27)2(29) TEAE=treatment-emergent adverse event.*In >15% of patients.

Conclusions: Ra-223 was well tolerated when combined with PTX in pts with solid tumors and bone metastases. The BC subgroup vs total population had slightly higher hematologic AE rates, but fewer Gr 3/4 and serious TEAEs; more BC pts also completed study tx. The combination should be explored further in pts with bone metastases.

Citation Format: Danson SJ, Perets R, Lopez J, Joensuu H, Peer A, Harris SJ, Souza F, Ploeger B, Pereira KMC, Geva R. An open-label, multicenter phase 1b trial of radium-223 + paclitaxel in cancer patients with bone metastases: Safety results from the breast cancer patient subgroup [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-16-03.

Clinical impact of sex differences and procedural setting in transcatheter aortic valve implantation

BACKGROUND

Transcatheter aortic valve implantation (TAVI) is a well-established treatment for symptomatic patients with aortic stenosis. Yet, the impact of sex differences and public vs. private procedural setting on TAVI outcomes remain uncertain.

METHODS

The RIBAC-NT (Brazilian Registry for Evaluation of Transcatheter Aortic Valve Replacement Outcomes) dataset included 3194 TAVI patients from 2009 to 2021. This retrospective analysis explored disparities in baseline characteristics, procedural and in-hospital outcomes stratifying patients by sex and procedural setting. Temporal trends were also investigated.

RESULTS

We included 1551 (49 %) female and 1643 (51 %) male patients. Women were older (83 [78-87] vs. 81 [75-85] years; p < 0.01) but had a lower prevalence of diabetes mellitus (30.2 % vs. 36.3 %, p < 0.01) and coronary artery disease (39.0 % vs. 52.2 %, p < 0.01). However, women had a 3-fold higher higher risk of life-threatening bleeding (6.1 % vs. 2.4 %, p < 0.01). Women presented higher procedural and in-hospital mortality rates (4.4 % vs. 2.5 % and 7.7 % vs. 4.5 %, all p < 0.01, respectively). Although public hospitals presented ~2-fold higher procedural mortality rate compared with private settings (5.0 % vs. 2.7 %, p < 0.01), after multivariable analysis procedural setting was not independently associated with in-hospital mortality.

CONCLUSIONS

Women had higher procedural and in-hospital mortality rates after TAVI as compared with men, while facing higher life-threatening bleeding and adverse events rates. Although public hospitals exhibited higher mortality rates than private centers, procedural setting was not independently associated with in-hospital mortality.

P–073 High-intensity interval training modulates the effects of hypertension on inflammatory mediators in testis in adult spontaneously hypertensive rats

Study question

Is the high-intensity interval training (HIIT) able to prevent the increase of the inflammatory proteins in the testis of spontaneously hypertensive rats (SHR)?

Summary answer

HIIT for 8 weeks inhibits the increase of the tumor necrosis factor alpha (TNFα) and the interleukin 6 (IL6) in the testis of SHR.

What is known already

Hypertension increases the inflammatory cytokines of the cardiovascular system, causing damage in the microcirculation and in the testes. Hypertension is a cause of low fertility in men and exercises are indicated to decrease blood pressure and improve overall health. HIIT is characterized by short periods of exercise, with an intensity equal to or greater than the anaerobic threshold, separated by recovery periods. HIIT can be indicated for cardiac patients, as this type of training improves the cardiac autonomic nervous system and lipemic control in both hypertensive and normotensive individuals.

Study design, size, duration

Male Wistar-Kyoto rats without hypertension and SHRs were divided into 3 groups (n = 4): WKY (Wistar-Kyoto); SHR; and SHR-HIIT (SHRs that performed HIIT). The HIIT was realized in treadmill for 5 days/week for 8 weeks. HIIT started with 5 times of 4 minutes of 100% of the maximum exhaust speed, with active rest intervals of 3 minutes at 60%. There was an increase of once every week until reaching 7 times each session.

Participants/materials, setting, methods

Samples from testicles were used for immunostainig IL6 and TNFα. After the blocking, the sections were subjected to reaction of specific antibodies IL6 (1:50, E–4, sc–28343) and TNFα (1:50, 52B83, sc–257) at 4ºC overnight, and with secondary antibodies m-IgGK (1:200, IgG-HRP, sc–516) at room temperature for 2 hours. Diaminobenzidine (1:50) was used against Harris stained with Hematoxylin and evaluated in the photomicroscope. Data were analyzed by One-Way ANOVA followed by Tukey post test (P &lt; 0.05).

Main results and the role of chance

The immunostainig of IL6 was higher in SHR (10.23 ± 0.47) than in SHR-HIIT (8.69 ± .44) group (P = 0,0237). From the same perspective, immunoexpression of TNFα was higher in SHR (10.10 ± 0.42) than WKY (8.24 ± 0.24) and SHR-HIIT (7.82 ± 0.39) groups (P = 0.0018).

Limitations, reasons for caution

As a limitation of the study, we have no measurement of fertility parameters to affirm that the HIIT improve the fertility because of the reduction of inflammatory mediators.

Wider implications of the findings: The hypertension drugs have a negative effect on fertility. HIIT can be suggested as a treatment for hypertension as an alternative to medication, since HIIT can inhibit the increase of the inflammatory mediators in testis and its consequences to the reproduction. Financial support by São Paulo Research foundation, FAPESP (2018/22682–0).

Trial registration number

2018/22682–0

Balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension: short- and long-term results from a cohort in Brazil

OBJECTIVE

A significant number of patients with chronic thromboembolic pulmonary hypertension (CTEPH) are not eligible for pulmonary endarterectomy and may be treated with balloon pulmonary angioplasty (BPA). Although BPA programs have recently been developed in Brazil, no results have yet been published. The objective of this study was to assess the clinical and hemodynamic progression of the first patients treated with BPA at our center.

METHODS

This was an observational study of 23 patients with CTEPH enrolled in the BPA program of a specialized center in Brazil between 2015 and 2020.

RESULTS

After a mean of 5.6 ± 1.3 sessions and 11 ± 2.8 treated segments/patient (at a mean of 6.7 ± 2.9 months post-BPA), there was a 26% decrease in mean pulmonary artery pressure (51 ± 11 vs. 38 ± 11 mmHg; p < 0.0001), a 43% decrease in pulmonary vascular resistance (10 ± 3.7 vs. 5.7 ± 3.3 WU; p < 0.0001), and a 22.5% increase in the cardiac index (2.38 ± 0.6 vs. 2.95 ± 0.6 L/min/m2; p < 0.0001). There was an increase in the six-minute walk distance and an improvement in functional class. Acute lung injury with clinical manifestations was observed after 7% of the BPA sessions. None of the patients required intubation. During a mean outpatient follow-up period of 38 ± 22 months, two patients were referred for additional BPA sessions due to clinical worsening and new hospitalizations. Two deaths were recorded (due to CTEPH progression and gastrointestinal bleeding, respectively).

CONCLUSIONS

Among this first group of patients treated with BPA in Brazil, there was significant short- and long-term clinical improvement, together with a low frequency of complications.