OBJECTIVE:Acromegaly is an endocrine disorder caused by the hypersecretion of growth hormone (GH) by a benign tumor of the pituitary that leads to insulin-like growth factor-1 (IGF1) overproduction. In most patients, somatostatin analogs (SSAs), the current first-line medical therapy for acromegaly, do not normalize IGF1 levels. This study aims to investigate the pre-clinical efficacy of ALXN2420, a novel, small peptide antagonist of the growth hormone receptor (GHR), being developed as a combination therapy to SSAs to further suppress and normalize IGF1 levels. DESIGN:In vitro and in vivo experiments were performed to investigate the efficacy of ALXN2420 in antagonizing the GHR and in reducing circulating IGF1 levels. METHODS:The binding affinity of ALXN2420 to GHR was determined by Surface Plasmon Resonance (SPR), and inhibition of GH-induced GHR activation was investigated in vitro in primary hepatocytes. The efficacy of ALXN2420 in suppressing IGF1 levels was evaluated in rats and dogs. The ability of ALXN2420 to reduce growth was determined in the juvenile rat model. Ultimately, the effect of combining ALXN2420 with a SSA in suppressing IGF1 was examined in rats. RESULTS:ALXN2420 bound to the human GHR and inhibited its activation by GH in vitro. In vivo, ALXN2420 administration efficiently reduced IGF1 levels, which was associated with reduced growth in juvenile rats. Importantly, when combined with a SSA, ALXN2420 demonstrated an additive effect on IGF1 reduction. CONCLUSION:These results support the investigation of ALXN2420 as a combination therapy for the treatment of patients with acromegaly inadequately controlled by SSAs.

Objective:This study evaluated the safety, tolerability, pharmacodynamics (PD) and pharmacokinetics (PK) of eneboparatide (AZP-3601), a novel agonist of the PTH receptor 1 developed for the treatment of hypoparathyroidism. Design:This was a randomized, double-blind, placebo-controlled study. One-hundred four healthy volunteers were recruited into seven single ascending dose (SAD) and five multiple ascending dose (MAD) cohorts. Methods:PK parameters were time to peak, Cmax, area under the curve (AUC) and half-life. PD parameters included albumin-adjusted serum calcium (sCa), serum phosphorus (sPh), serum endogenous PTH, 24 hr urinary excretion of calcium (24 h-uCa), fractional excretion of calcium (FECa) and bone turnover markers (s-CTX and P1NP). Results:There were no serious adverse events. All adverse events were of mild-to-moderate intensity. AUC and Cmax of eneboparatide increased with increasing doses. Time to maximum plasma concentration was 5-20 min. SAD showed a dose-dependent increase of sCa and decrease of sPh associated with a reduction of serum endogenous PTH. MAD demonstrated a rapid access to maximal PD effects and maintained levels of sCa throughout the day. Urinary excretion of calcium did not increase as a function of the dose of eneboparatide. P1NP and s-CTX did not change over the treatment period. Conclusion:The PD effects of eneboparatide were prolonged despite the short half-life. These data suggest that eneboparatide may provide sustained control of serum calcium in patients with hypoparathyroidism with once daily dosing. An open-label phase 2 study in patients with hypoparathyroidism has been recently completed and published and a phase 3 study has been initiated. Clinical Trial Registration Number:NCT05239221.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Intracellular signaling involved in the effects observed in response to SST3- agonists.

This supplementary file contains supplementary methods (library screening and statistical analysis) and table S1 (Pharmacological characterization of SST3-selective compounds), table S2 (Relation of functional experiments performed in responsive (RP) and unresponsive (URP) NFPTs), table S3 (Percentage of responsive and unresponsive NFPTs regarding SST3-specific agonists in terms of cell viability), table S4 (Results from Chi-square test of clinical parameters between responsive and unresponsive NFPTs), and table S5 (Clinical data and SST3 mRNA expression levels of individual NFPTs).

Direct effect of BIM-355 at different doses on tumor growth in POMC-KO mice model.

Cell viability in response to SST3-agonists and antagonists in NFPTs primary cell cultures, measured by Alamar-blue reduction.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

mRNA and protein expression pattern of key somatostatin receptors in non- functioning pituitary tumors (NFPTs) and normal pituitaries (NPs).

Representative immunohistochemical staining (400X magnification; scale bar: 20μm) for SST3 measured in responsive and unresponsive NFPAs.

mRNA expression levels of SST3 in different pituitary neuroendocrine tumors (PitNETs) and NPs.

It is the opinion of the World Anti-Doping Agency (WADA) that cannabis should remain a banned substance in sport. The purpose of this editorial is to briefly summarize the elements of the discussion leading to the continued ban in sport. Cannabis availability and its subsequent use, misuse and incidence of use disorder are increasing globally [1], even as the potency of the plant, gauged by delta-9-tetrahydrocannabinol (∆9-THC content), continues to increase [2]. It is not known what proportion of top-level athletes regularly consume cannabis. However, a recent review of self-reports that included more than 46000 athletes suggests that the proportion of athletes using cannabis is no different from the age-matched general population [3]. The World Anti-Doping Agency (WADA) banned cannabis in competition in all sports when the 2004 List of Prohibited Substances and Methods was first released under the World Anti-Doping Code [4]. It has since revisited and updated the cannabinoid category to include synthetic cannabinoids, increase reporting thresholds and to specifically exempt cannabidiol. In response to stakeholder requests, the WADA Executive Committee asked for a review of the status of cannabis. Ad hoc committees conducted a scientific, ethical and medical review of the effects of cannabis, focusing upon the primary psychoactive ingredient, ∆9-THC, among the more than 100 distinct cannabinoids within the cannabis plant. For any substance or method to be considered for inclusion in the Prohibited Substances List as per the World Anti-Doping Code, two of the following three equally-important criteria must be met: (1) it enhances or has the potential to enhance sport performance, (2) it represents an actual or potential risk to the health of the athlete and (3) it violates the spirit of the sport as defined in the Code. In 2022, WADA reviewed more than 2700 articles for the present exercise. Inclusion of a scientific study or review to be further discussed was aided by adherence to scientific principles, where appropriate. This included application of rigorous methods, such as randomization of subjects to treatment groups, use of placebo controls and blinding of both subject and experimenter. Publication in a peer-reviewed scientific journal was required, and greater emphasis was placed upon studies that had results which were independently replicated. This enabled the Expert List, Athletic, Ethical and Health, Medical and Research committees to review the most current science and issue independent opinions on the subject. Finally, as part of the scientific review process, world leading experts on cannabis and addiction behavior were consulted to validate the conclusions of the committees. Perspectives were mixed on the first List inclusion criterion. There were no rigorously conducted studies reviewed that indicated any direct ergogenic effect of cannabis. Nonetheless, a number of reports suggested that other benefits may be conferred by use of the drug, such as reduction in pain or anxiety [5, 6] associated with athletic competition. Some athletes report benefit following athletic performance, by facilitating recovery and reducing pain. Hence, while there may be benefits perceived by some athletes, there were no scientific data to support performance enhancement. There was far more agreement on the second criterion—actual or potential risk to the health of the athlete. There is a comprehensive historical literature as well as a rapidly growing body of contemporary literature supporting the assertion that cannabis use can negatively impact the health, safety or wellbeing of the athlete. Acute intoxication can result in deficits in reaction time, temporal estimation and dexterity [7-11] as well as in psychiatric symptoms [12]. Not all studies detected similar changes; results will vary with the dose, route, subjects' experience and test methods employed. Chronic, frequent use of cannabis is associated with an increased risk of cannabis use disorder, as recently reviewed by Robinson and colleagues [13], as well as potentially other long-term changes [14, 15], including an increased risk of precipitation of severe mental illness [16]. There is a growing body of evidence that cannabis use can affect brain development and anatomy in adolescents and young adults [17-19], although the consequences of these changes are not yet firmly established. The potential of cannabis use to compromise the health and safety of the athlete qualifies the application of this criterion. WADA emphasizes that prohibition of cannabis is in-competition only, which is defined as after 23:59 hours on the day prior to competition. The current decision limit of 180 ng/ml of ∆9-THC-COOH in urine and a cut-off of 150 ng/ml, plus the uncertainty of measurement of 30 ng/ml, takes this into account. Because of these high thresholds, primarily chronic, frequent cannabis users and athletes consuming high doses in-competition will be detected. Therefore, the cut-off generally will not affect the freedom of an athlete who wishes to legally consume cannabis outside of competition. Athletes who have a need for medicinal cannabis treatment should request a therapeutic use exemption (TUE). Marilyn Huestis: Conceptualization (equal); writing—review and editing (equal). Sabina Strano-Rossi: Conceptualization (equal); data curation (equal); writing—review and editing (equal). Yorck-Olaf Schumacher: Conceptualization (equal); validation; writing—review and editing (equal). Peter Harcourt: Conceptualization (supporting). Richard Budgett: Conceptualization (equal); writing—review and editing (equal). Mark Stuart: Conceptualization (equal); writing—review and editing (equal). Justice Tettey: Conceptualization (equal); writing—review and editing (equal). Irene Mazzoni: Conceptualization (equal); data curation (equal); project administration (equal); resources (equal); writing—review and editing (equal). Olivier Rabin: Conceptualization (equal); supervision (equal); writing—review and editing (equal). Anne Danion: Conceptualization (equal); data curation (equal); project administration (equal); resources (supporting); writing—review and editing (equal). Michael Culler: Conceptualization (equal); writing—review and editing (equal). David Handelsman: Conceptualization (equal); writing—review and editing (equal). Mario Thevis: Conceptualization (equal); writing—review and editing (equal). Audrey Kinahan: Conceptualization (equal); project administration (equal); supervision (equal); writing—review and editing (equal). None. No competing interests declared by any author. Data were derived from public domain resources.

Validation by qPCR of SSTR3 gene silencing with two specific siRNAs using the BON-1 cell line.

ROC-curve analyses to determine the accuracy of SSTs expression levels to discriminate between responsive and unresponsive NFPTs.

Abstract   PTH peptides can be effective in normalizing blood calcium (Ca++) levels in cases of hypoparathyroidism (HP), but long-term effects on bone are not well understood. AZP-3601 is a long-acting PTH/PTHrP(1-36) analog currently being investigated as a potential treatment option for HP. As compared to conventional PTH1-34, AZP-3601 binds with higher affinity to the R0 conformation of the PTH receptor and thereby induces more sustained signaling responses in cells as well as more prolonged calcemic responses in vivo, despite having a very short circulating half-life. Using the TPTX rat model of HP, we investigated whether the distinct mode-of-action used by AZP-3601 results in different down-stream effects in bone than those induced by PTH1-34, when the peptides are administered long-term (31 days) either by daily sc injection (AZP-3601 and PTH1-34) or by continuous infusion (PTH1-34), and at doses aimed to optimally normalize blood Ca++ levels. Methods Male TPTX rats (strain S-D, age 9 weeks, and 2 weeks post TPTX surgery) were injected daily with either AZP-3601 at a dose of 0.7 nmol/kg or PTH1-34 at a dose of 50 nmol/kg, or were continuously infused via Alzet mini-pump with PTH1-34 at a dose of 3.0 nmol/kg/day. Vehicle treatments and sham surgery rats were used as controls. Tail-vein blood was collected on days 1, 7 14, 21 and 28 at 6 hours post-injection and analyzed for total Ca++. Rats were euthanized on day 31 (24 hours after last injection) and blood and femurs collected for analysis. Results All peptide-treatments increased serum Ca++ levels on days 7-21 to within or near the normal range (8.8-11.7 mg/dL versus 10.8-11.9 mg/dL in sham-operated rats) and to levels significantly higher than those in vehicle-treated TPTX rats (6.9-7.9 mg/dL, P<0.01). Bone mCT analysis revealed that relative to TPTX-vehicle controls, PTH1-34 continuous infusion significantly decreased (p<0.001) distal femur trabecular bone volume relative to tissue volume (BV/TV), trabecular number (Tb.N) and trabecular thickness (Tb.Th), while PTH1-34 daily injection significantly increased (P<0.001) distal femur BV/TV, Tb.Th and Tb.N, as well as mid-femur cortical thickness (Ct.Th, P<0.001). In contrast, AZP-3601 daily injection caused no change in trabecular or cortical bone parameters. Serum levels of the bone formation marker P1NP were significantly increased by daily injection of PTH1-34 (P<0.001 vs. TPTX-vehicle) but were not changed by other treatments. Conclusion With long-term (31 days) treatment and at doses that similarly normalized serum Ca++ in TPTX rats, effects on bone were catabolic for PTH1-34 by continuous infusion, anabolic for PTH1-34 by daily injection, and neutral for AZP-3601 by daily injection. The distinct MOA used by AZP-3601 may thus result in less of an impact on bone than either daily injection or sustained, continuous delivery of PTH(1-34), when used as a long-term treatment for HP. Presentation: Monday, June 13, 2022 12:15 p.m. - 12:30 p.m.