Novel therapies for acromegaly

Secondary diabetes mellitus in acromegaly: Case report and literature review

RATIONALE

Acromegaly, predominantly resulting from a pituitary adenoma, is marked by excessive secretion of growth hormone (GH) and insulin-like growth factor-1 (IGF-1). However, normalization of blood glucose levels posttreatment is rarely achieved. This case study aims to highlight the diagnostic challenges posed by overlapping symptoms of acromegaly and diabetes, emphasizing the importance of precise diagnosis and effective treatment strategies for optimal patient outcomes.

PATIENT CONCERNS

A 22-year-old male was hospitalized for diabetic ketoacidosis and exhibited classic signs of acromegaly, such as enlarged hands and feet, and distinct facial changes.

DIAGNOSES

The patient's diagnosis of acromegaly, attributed to a pituitary adenoma, was confirmed through clinical observations, laboratory findings (notably raised serum GH and IGF-1 levels, and absence of GH suppression after glucose load during an OGTT), and pituitary MRI scans.

INTERVENTIONS

The patient underwent 2 surgical tumor resections followed by gamma knife radiosurgery (GKRS). After treatment, GH, IGF-1, and blood glucose levels normalized without further need for hypoglycemic intervention.

OUTCOMES

Posttreatment, the patient achieved stable GH, IGF-1, and blood glucose levels. The hyperglycemia was attributed to the GH-secreting tumor, and its resolution followed the tumor's removal.

LESSONS

This case emphasizes the need for comprehensive assessment in patients with acromegaly to address coexisting diabetic complications. Surgical and radiotherapeutic management of acromegaly can lead to significant metabolic improvements, highlighting the importance of interdisciplinary care in managing these complex cases.

Acromegaly in humans and cats: Pathophysiological, clinical and management resemblances and differences

OBJECTIVE

Acromegaly is a disorder associated with excessive levels of growth hormone (GH) and insulin-like growth factor-1 (IGF-1). In general, GH/IGF-1 excess leads to morphologic craniofacial and acral changes as well as cardiometabolic complications, but the phenotypic changes and clinical presentation of acromegaly differ across species. Here, we review the pathophysiology, clinical presentation and management of acromegaly in humans and cats, and we provide a systematic comparison between this disease across these different species.

DESIGN

A comprehensive literature review of pathophysiology, clinical features, diagnosis and management of acromegaly in humans and in cats was performed.

RESULTS

Acromegaly is associated with prominent craniofacial changes in both species: frontal bossing, enlarged nose, ears and lips, and protuberant cheekbones are typically encountered in humans, whereas increased width of the head and skull enlargement are commonly found in cats. Malocclusion, prognathism, dental diastema and upper airway obstruction by soft tissue enlargement are reported in both species, as well as continuous growth and widening of extremities resulting in osteoarticular compromise. Increase of articular joint cartilage thickness, vertebral fractures and spine malalignment is more evident in humans, while arthropathy and spondylosis deformans may also occur in cats. Generalized organomegaly is equally observed in both species. Other similarities between humans and cats with acromegaly include heart failure, ventricular hypertrophy, diabetes mellitus, and an overall increased cardiometabolic risk. In GH-secreting pituitary tumours, local compressive effects and behavioral changes are mostly observed in humans, but also present in cats. Cutis verticis gyrata and skin tags are exclusively found in humans, while palmigrade/plantigrade stance may occur in some acromegalic cats. Serum IGF-1 is used for acromegaly diagnosis in both species, but an oral glucose tolerance test with GH measurement is only useful in humans, as glucose load does not inhibit GH secretion in cats. Imaging studies are regularly performed in both species after biochemical diagnosis of acromegaly. Hypophysectomy is the first line treatment for humans and cats, although not always available in veterinary medicine.

CONCLUSION

Acromegaly in humans and cats has substantial similarities, as a result of common pathophysiological mechanisms, however species-specific features may be found.

Preferences for different treatment options among people living with acromegaly in the US

OBJECTIVE

Acromegaly is a rare hormonal disorder that results in enlargement of the face, hands and feet. It is associated with comorbidities, increased mortality, reduced quality of life and economic burden. Adequate treatment is critical to alleviate symptoms; however, the treatment burden is substantial. To understand how different treatment aspects might ease the burden, this study investigated preferences for treatment options among people with acromegaly in the US, using a choice experiment (CE).

METHODS

An online CE was conducted based on a similar study among the US general population. Respondents were recruited through Acromegaly Community in the US, and all eligible respondents were included. The survey assessed six treatment options that varied according to administration, frequency, storage, treatment setting, needle type and injection pain.

RESULTS

109 adults with acromegaly completed the survey between October and December 2022. On average, the population had lived with symptoms for 15 years, while the average number of years with the diagnosis was eight. Respondents preferred subcutaneous injections every fourth week and preferred them at home rather than at the hospital. Most respondents preferred subcutaneous injections right under the skin administered once every fourth week with a pen at home over oral capsules administered twice daily at home.

CONCLUSION

The results indicate that new treatment options administered as subcutaneous injections right under the skin once every fourth week at home have the potential to lower the treatment burden among people with acromegaly, emphasizing the importance of taking each person's preference into consideration when choosing treatment.

New Treatments for Acromegaly in Development

Acromegaly treatment has greatly evolved in recent decades, but there are still patients whose acromegaly is not controlled with currently available treatments, and there is a need to improve the treatment burden. Fortunately, there are new treatments under development that may increase treatment efficacy and convenience.

Innovative therapeutics in acromegaly

Acromegaly is a systemic disease associated with increased morbidity and mortality that can be prevented with adequate disease control. Three modalities of treatment (surgery, medical treatment, and radiotherapy) are available; however, a significant proportion of patients still maintain disease activity despite treatment. Therefore, there is a need for innovations in the treatment of acromegaly that include changes in the current trial and error approach and the development of new drugs. In this review, we summarize the recent innovations in the treatment of acromegaly and address the future perspectives in this field.

Clinical Management of Acromegaly: Therapeutic Frontiers and New Perspectives for Somatostatin Receptor Ligands (SRLs)

Somatostatin receptor ligands (SRLs) represent a true milestone in the medical therapy for acromegaly. The first-generation SRLs (FG-SRLs), octreotide and lanreotide, have demonstrated good efficacy in disease control and tumor shrinkage, and are still considered first-line medical therapies. The development of long-acting release (LAR) formulations has certainly improved the therapeutic tolerability of these drugs, although many patients still experience therapy-related burden. As such, new formulations have recently been developed to improve adherence and therapeutic efficacy and more solutions are on the way. In the case of FG-SRL-resistant disease, pasireotide, the only second generation SRL currently available, demonstrated superiority in disease control and tumor shrinkage compared to FG-SRLs. However, its use in clinical practice is still limited due to concern for impairment in glucose homeostasis. In this review, we discuss the news about the present and future role of SRLs in acromegaly, exploring the therapeutical frontiers of this drug class. Moreover, we provide practical guidance on the use of pasireotide, based on the data in the literature and our clinical experience.

Prevalence of comorbidities and concomitant medication use in acromegaly: analysis of real-world data from the United States

PURPOSE

Patients receiving treatment for acromegaly often experience significant associated comorbidities for which they are prescribed additional medications. We aimed to determine the real-world prevalence of comorbidities and concomitant medications in patients with acromegaly, and to investigate the association between frequency of comorbidities and number of concomitantly prescribed medications.

METHODS

Administrative claims data were obtained from the IBM® MarketScan® database for a cohort of patients with acromegaly, identified by relevant diagnosis codes and acromegaly treatments, and a matched control cohort of patients without acromegaly from January 2010 through April 2020. Comorbidities were identified based on relevant claims and assessed for both cohorts.

RESULTS

Overall, 1175 patients with acromegaly and 5875 matched patients without acromegaly were included. Patients with acromegaly had significantly more comorbidities and were prescribed concomitant medications more so than patients without acromegaly. In the acromegaly and control cohorts, respectively, 67.6% and 48.4% of patients had cardiovascular disorders, the most prevalent comorbidities, and 89.0% and 68.3% were prescribed > 3 concomitant medications (p < 0.0001). Hypopituitarism and hypothalamic disorders, sleep apnea, malignant neoplasms and cancer, and arthritis and musculoskeletal disorders were also highly prevalent in the acromegaly cohort. A moderate, positive correlation (Spearman correlation coefficient 0.60) was found between number of comorbidities and number of concomitant medications in the acromegaly cohort.

CONCLUSION

Compared with patients without acromegaly, patients with acromegaly have significantly more comorbidities and are prescribed significantly more concomitant medications. Physicians should consider the number and type of ongoing medications for individual patients before prescribing additional acromegaly treatments.

O-GlcNAcylation Is Essential for Rapid Pomc Expression and Cell Proliferation in Corticotropic Tumor Cells

Pituitary adenomas have a staggering 16.7% lifetime prevalence and can be devastating in many patients because of profound endocrine and neurologic dysfunction. To date, no clear genomic or epigenomic markers correlate with their onset or severity. Herein, we investigate the impact of the O-GlcNAc posttranslational modification in their etiology. Found in more than 7000 human proteins to date, O-GlcNAcylation dynamically regulates proteins in critical signaling pathways, and its deregulation is involved in cancer progression and endocrine diseases such as diabetes. In this study, we demonstrated that O-GlcNAc enzymes were upregulated, particularly in aggressive adrenocorticotropin (ACTH)-secreting tumors, suggesting a role for O-GlcNAcylation in pituitary adenoma etiology. In addition to the demonstration that O-GlcNAcylation was essential for their proliferation, we showed that the endocrine function of pituitary adenoma is also dependent on O-GlcNAcylation. In corticotropic tumors, hypersecretion of the proopiomelanocortin (POMC)-derived hormone ACTH leads to Cushing disease, materialized by severe endocrine disruption and increased mortality. We demonstrated that Pomc messenger RNA is stabilized in an O-GlcNAc-dependent manner in response to corticotrophin-releasing hormone (CRH). By affecting Pomc mRNA splicing and stability, O-GlcNAcylation contributes to this new mechanism of fast hormonal response in corticotropes. Thus, this study stresses the essential role of O-GlcNAcylation in ACTH-secreting adenomas' pathophysiology, including cellular proliferation and hypersecretion.

Transient Permeation Enhancer® (TPE®) technology for oral delivery of octreotide: a technological evaluation

INTRODUCTION

The FDA approval of oral semaglutide for type 2 diabetes (2019) and oral octreotide for acromegaly (2020) is evidence that selected niche peptides can be administered orally if formulated with selected intestinal permeation enhancers.

AREAS COVERED

We evaluated the oral octreotide formulation, MYCAPSSA® (Chiasma Pharmaceuticals, Needham, MA, USA). An outline of the current standard of care in acromegaly and the benefits of oral octreotide versus depot injections is provided. We discuss the Transient Permeation Enhancer (TPE®) technology used and detail the safety and efficacy data from animal models and clinical trials.

EXPERT OPINION

TPE® is an oily suspension of octreotide that includes a number of excipients that can transiently alter epithelial barrier integrity by opening of intestinal epithelial tight junctions arising from transcellular perturbation. Phase I studies using 20 mg octreotide capsules yielded a relative oral bioavailability of ~0.7% and primary endpoints were achieved in two Phase III studies. The oral octreotide dose required to achieve these endpoints was over 200 times that of the 0.1 mg immediate-release subcutaneous injection, a reminder of the difficulty in achieving oral absorption of macromolecules. Many acromegaly patients will prefer a convenient twice-daily oral formulation of octreotide compared to monthly depot injections.