Effects of pulsatile intravenous follicle-stimulating hormone treatment on ovarian function in women with obesity

OBJECTIVE

To establish conditions for effective hypothalamic suppression in women with normal and high body mass index (BMI) and test the hypothesis that intravenous (IV) administration of pulsatile recombinant follicle-stimulating hormone (rFSH) can overcome the clinically evident dysfunctional pituitary-ovarian axis in women with obesity.

DESIGN

Prospective interventional study.

SETTING

Academic medical center.

PATIENT(S)

Twenty-seven normal-weight women and 27 women with obesity, who were eumenorrheic and aged 21-39 years.

INTERVENTION(S)

Two-day frequent blood sampling study, in early follicular phase, before and after cetrorelix suppression of gonadotropins and exogenous pulsatile IV rFSH administration.

MAIN OUTCOME MEASURE(S)

Serum inhibin B and estradiol (E2) levels (basal and rFSH stimulated).

RESULT(S)

A modified gonadotropin-releasing hormone antagonism protocol effectively suppressed production of endogenous gonadotropins in women with normal and high BMIs, providing a model to address the functional role of FSH in the hypothalamic-pituitary-ovarian axis. The IV rFSH treatment resulted in equivalent serum levels and pharmacodynamics in normal-weight women and those with obesity. However, women with obesity exhibited reduced basal levels of inhibin B and E2 and a significantly decreased response to FSH stimulation. The BMI was inversely correlated with serum inhibin B and E2. In spite of this observed deficit in ovarian function, pulsatile IV rFSH treatment in women with obesity resulted in E2 and inhibin B levels comparable with those in normal-weight women, in the absence of exogenous FSH stimulation.

CONCLUSION(S)

Despite normalization of FSH levels and pulsatility by exogenous IV administration, women with obesity demonstrate ovarian dysfunction with respect to E2 and inhibin B secretion. Pulsatile FSH can partially correct the relative hypogonadotropic hypogonadism of obesity, thereby providing a potential treatment strategy to mitigate some of the adverse effects of high BMI on fertility, assisted reproduction, and pregnancy outcomes.

CLINICAL TRIAL REGISTRATION NUMBER

ClinicalTrials.gov #NCT02478775.

Fractionated oral dosing and its effect on cyclophosphamide pharmacokinetics in dogs with high-grade multicentric lymphoma

Cyclophosphamide (CP) is an alkylating agent commonly included in multi-drug treatment protocols for canine cancer. As a prodrug, CP requires hepatic metabolism for activation to the intermediate compound 4-hydroxycyclophosphamide (4-OHCP) which then spontaneously forms alkylating phosphoramide mustard. CP is frequently administered in a fractionated manner, with the total dose given over multiple days. CP is reported to cause auto-induction of metabolism in humans, with faster CP clearance and relatively increased 4-OHCP formation following fractionated versus bolus dosing, however canine pharmacokinetic studies of CP dose fractionation are lacking. The study objective was to evaluate the pharmacokinetics of fractionated oral CP dosing at a dose of 200-250 mg/m² over 3 to 4 days in a prospectively identified population of cancer-bearing dogs. Plasma concentrations of CP and 4-OHCP were measured by ultra-high performance liquid chromatography tandem-mass spectrometry in eight dogs following the first and last doses to assess for auto-induction of CP metabolism. No significant difference in the rate of CP elimination between first and last doses were detected (0.73 ± 0.46 vs. 1.22 ± 0.5 h^-1 ; p = .125). Additionally, no significant difference in dose-normalized 4-OHCP exposure was identified between first and last doses (5.9 ± 2.1 vs. 7.9 ± 6.4 h × ng/ml; p = .936). These results suggest that fractionated dosing may not increase exposure to the active metabolite of CP in dogs as it does in humans. As such, standard bolus dosing and fractionated dosing may be equivalent in terms of bio-activation of CP in dogs administered a dose of 200-250 mg/m² .

An Optimized Bioassay for Screening Combined Anticoronaviral Compounds for Efficacy against Feline Infectious Peritonitis Virus with Pharmacokinetic Analyses of GS-441524, Remdesivir, and Molnupiravir in Cats

Feline infectious peritonitis (FIP) is a fatal disease of cats that currently lacks licensed and affordable vaccines or antiviral therapeutics. The disease has a spectrum of clinical presentations including an effusive ("wet") form and non-effusive ("dry") form, both of which may be complicated by neurologic or ocular involvement. The feline coronavirus (FCoV) biotype, termed feline infectious peritonitis virus (FIPV), is the etiologic agent of FIP. The objective of this study was to determine and compare the in vitro antiviral efficacies of the viral protease inhibitors GC376 and nirmatrelvir and the nucleoside analogs remdesivir (RDV), GS-441524, molnupiravir (MPV; EIDD-2801), and β-D-N⁴-hydroxycytidine (NHC; EIDD-1931). These antiviral agents were functionally evaluated using an optimized in vitro bioassay system. Antivirals were assessed as monotherapies against FIPV serotypes I and II and as combined anticoronaviral therapies (CACT) against FIPV serotype II, which provided evidence for synergy for selected combinations. We also determined the pharmacokinetic properties of MPV, GS-441524, and RDV after oral administration to cats in vivo as well as after intravenous administration of RDV. We established that orally administered MPV at 10 mg/kg, GS-441524 and RDV at 25 mg/kg, and intravenously administered RDV at 7 mg/kg achieves plasma levels greater than the established corresponding EC₅₀ values, which are sustained over 24 h for GS-441514 and RDV.

Pharmacokinetic study comparing doxorubicin concentrations after chemoembolization or intravenous administration in dogs with naturally occurring nonresectable hepatic carcinoma

Background

Chemoembolization is a viable treatment option for patients with nonresectable hepatic carcinoma (HC) and may allow delivery of chemotherapeutic drugs with decreased systemic toxicity.

Hypothesis/Objective

Compare the serum concentrations of doxorubicin after chemoembolization or IV administration in the same patient. We hypothesized that locoregional delivery may result in increased tumor chemotherapeutic drug concentrations, reflected by decreased measurable serum drug concentrations. Adverse hematological events were hypothesized to be decreased after locoregional delivery.

Animals

Seventeen client‐owned dogs with incompletely resectable HC.

Methods

Prospective, single‐arm clinical trial. Drug‐eluting bead transarterial chemoembolization was performed to varying levels of blood flow stasis (NO STASIS, STASIS). Intravenous doxorubicin (IVC) subsequently was administered in selected patients. Systemic exposure was quantified by area under the serum doxorubicin concentration time curve (AUC), maximum serum doxorubicin concentration (C_max), and time doxorubicin was last above the limit of quantitation (T_last). Nadir test results after treatments were used to evaluate adverse hematological events.

Results

Thirteen NO STASIS treatments, 15 STASIS treatments, and 9 IVC treatments were performed. Maximum serum doxorubicin concentration, AUC, and T_last were significantly lower when comparing NO STASIS or STASIS to IVC treatments. Of the patients with nadir results available, no adverse hematological events were observed after NO STASIS or STASIS treatments. Two patients developed adverse hematological events after IVC treatment.

Conclusions/Clinical Relevance

Drug‐eluting bead transarterial chemoembolization offers a viable treatment option for patients with incompletely resectable HC with the potential for increased local tumor doxorubicin concentrations, decreased systemic chemotherapeutic exposure, and fewer adverse hematological events.

Pilot study comparing serum chemotherapy levels after intra-arterial and intravenous administration in dogs with naturally occurring urinary tract tumors

The proposed advantages of intra-arterial chemotherapy (IAC) are based on the premises of local dose escalation to the tumor and reduced availability of systemic drugs. There is a lack of objective pharmacokinetic data to confirm the advantage of IAC in dogs with naturally occurring urogenital tumors. The objective of this study was to determine if IAC administration in urogenital tumors would result in decreased systemic drug exposure when compared to intravenous routes. Twenty-two dogs with naturally occurring urogenital tumors were enrolled in this prospective case-controlled study. Mitoxantrone, doxorubicin, or carboplatin were administered by IAC and intravenous routes [intravenous awake (intravenous chemotherapy - IVC) and under general anesthesia (IVGAC)] 3 weeks apart. Serum assays were used to determine the extent of systemic drug exposure. Dose-normalized peak systemic serum concentration (C_max) and area under the serum drug concentration-time curve (AUC) were used to quantify systemic exposure. A total of 26 mitoxantrone treatments were administered to 10 dogs. While there was no significant difference in C_max, the AUC was significantly lower after IAC compared with IVGAC. Ten doxorubicin treatments were administered to 5 dogs. There were no significant differences in C_max or AUC. A total of 14 carboplatin treatments were administered to 7 dogs. The C_max was significantly lower for IAC compared to IVC, while the AUC values were equivocal. This study demonstrates certain lower serum values may be achieved after IAC delivery of carboplatin and mitoxantrone. These chemotherapy agents may have a preferred pharmacological profile for regional chemotherapy delivery in dogs with urogenital tumors.

In vitro and in vivo activity of liposome-encapsulated curcumin for naturally occurring canine cancers

Curcumin has well-established anti-cancer properties in vitro, however, its therapeutic potential has been hindered by its poor bioavailability. Lipocurc is a proprietary liposome-encapsulated curcumin formulation that enables intravenous delivery and has been shown to reach its highest concentration within lung tissue. The goal of this study was to characterize the anti-cancer and anti-angiogenic activity of Lipocurc in vitro, in addition to evaluating Lipocurc infusions in dogs with naturally occurring cancer. We therefore evaluated the effect of Lipocurc, relative to free curcumin, on the viability of canine osteosarcoma, melanoma and mammary carcinoma cell lines, as well as the ability of Lipocurc to inhibit endothelial cell viability, migration and tube formation. We also undertook a pilot clinical trial consisting of four weekly 8-hour Lipocurc infusions in 10 cancer-bearing dogs. Tumour cell proliferation was inhibited by curcumin at concentrations exceeding those achievable in the lung tissue of dogs. Similarly, equivalent high concentrations of Lipocurc and curcumin also inhibited endothelial cell viability, migration and tube formation. Four out of six dogs completing planned infusions of Lipocurc experienced stable disease; however, no radiographic responses were detected.

Abstract 4406: Canine osteosarcoma as a platform to investigate the therapeutic potential of a genetically engineered pre-microRNA prodrug in human osteosarcoma

This study was undertaken to investigate the therapeutic effect of a genetically engineered, human pre-microRNA-34a prodrug in canine osteosarcoma (OS), validating a robust preclinical model for the development of this proposed agent in humans. Although osteosarcoma is the most prevalent primary bone tumor in children and young adults, the low overall incidence presents an obstacle to timely development and testing of new agents. However, the incidence of canine OS is nearly 12 times that in humans, providing a useful preclinical model with spontaneously occurring OS. Despite multimodal therapeutic protocols, up to 40% of human and 90% of dogs will not survive long-term. Therefore, there is a clear need to identify new therapeutic agents for OS treatment. MicroRNAs (miRs) are small, noncoding RNAs that control relevant cellular pathways in tumorigenesis. MiR-34a, a downstream component of the p53 tumor suppressor, is downregulated in OS tumors and its reduced expression linked to poor therapeutic response. Recent evidence in human OS cell lines has shown that a novel genetically engineered human tRNA/miR-34a prodrug has anti-tumor effects following intracellular processing into mature miR-34a. We transfected a panel of canine OS cell lines (D17, HMPOS, Abrams and Gracie) with the human tRNA/miR-34a prodrug and evaluated the downstream effects to validate canine OS as a preclinical model. We measured miR-34a levels following transfection using quantitative real-time PCR. Proliferation was assessed via bioreductive and clonogenic assays. Western blot and immunofluorescence microscopy were used to investigate miR-34a target protein expression. Caspase 3/7 activity and TUNEL staining were used to measure apoptotic effects. In vitro properties associated with metastatic ability were assessed via transwell migration and invasion assays using Boyden chambers. We found significant increases in mature miR-34a levels following transfection, indicating that canine cells effectively process the prodrug. Increased miR-34a was associated with reduced PDGFRα protein expression and dose- and time-dependent inhibition of proliferation. Compared to control and MSA-transfected cells, miR-34a significantly reduced clonogenic cell growth, increased caspase 3/7 activity, and increased TUNEL positivity. We also found a significant inhibition of canine OS cell migration and invasion following transfection with miR-34a prodrug. Taken together, our findings demonstrate the successful internalization and processing of human miR-34a prodrug by canine OS cells. The increased miR-34a levels produce the same anti-tumor effects seen in human OS cells. These results strongly supports the use of canine OS as a preclinical model for the development of this therapy in human OS.

Citation Format: Fernando Alegre Guerra, Kellie Snider, Amanda Ormonde, Ai-Ming Yu, Luke Wittenburg. Canine osteosarcoma as a platform to investigate the therapeutic potential of a genetically engineered pre-microRNA prodrug in human osteosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4406.