Medical Treatment Of Acromegaly Research Articles

Patient diagnosed with acromegaly and pituitary apoplexy after breast carcinoma treatment: challenges in diagnosis and management

The clinical case presented describes a 44-year-old woman with a history of mucinous carcinoma in the right breast, who is diagnosed with a pituitary adenoma. Physical examination revealed signs of acromegaly, such as macroglossia and palmar hyperhidrosis. Hormonal tests were performed and showed elevated levels of insulin-like growth factor type 1 (IGF-1). The patient received GnRH analogues for breast cancer; and started medical treatment with somatostatin analogues for acromegaly, which provided improvement in symptoms. Pituitary bleeding was detected during hormone treatment, which caused the growth of the adenoma, causing it to contact the optic chiasm, although no symptoms of pituitary apoplexy were present. Transsphenoidal endoscopic surgery was performed to remove the adenoma, and the diagnosis of pituitary adenoma was confirmed by pathology. The importance of the evaluation of comorbidities in patients with acromegaly is discussed. Pituitary apoplexy as an uncommon complication of pituitary adenomas, which may be associated with the use of GnRH analogues, is addressed. Pre-surgical medical treatment in acromegaly is also discussed, highlighting the importance of a comprehensive assessment of prognostic factors and appropriate treatment selection to improve clinical outcomes. In conclusion, the importance of a multidisciplinary and personalized approach in the management of patients with GH-producing pituitary adenomas to improve quality of life and clinical outcomes is highlighted.

Predicting Response to Medical Treatment in Acromegaly via Granulation Pattern, Expression of Somatostatin Receptors Type 2 and 5 and E-Cadherin.

Resistance to first-generation somatostatin receptor ligand (fgSRL) treatment in acromegaly is common, making the identification of biomarkers that predict fgSRL response a desired goal. We conducted a retrospective analysis on 21 patients with acromegaly who underwent surgery and subsequent pharmacological treatment. Through immunohistochemistry (IHC), we assessed the expression of the somatostatin receptor subtypes SSTR2 and SSTR5, E-Cadherin, and cytokeratin granulation pattern (sparsely or densely). Patients were divided into responders and non-responders based on their biochemical response to fgSRL and/or the newer agent, Pasireotide, or the GH-blocker, Pegvisomant. Patients resistant to fgSRL (n = 12) exhibited lower SSTR2 and E-Cadherin expressions. Sparsely granulated tumors were more frequent in the non-responder group. SSTR2 (p = 0.024, r = 0.49) and E-Cadherin (p = 0.009, r = 0.64) positively correlated with the Insulin-like Growth Factor 1 (IGF-1) decrease after fgSRL, while SSTR5 (p = 0.107, r = -0.37) showed a trend towards negative correlation. SSTR5 positivity seemed to be associated with Pasireotide response, albeit the number of treated patients was too low (n = 4). No IHC markers correlated with Pegvisomant response. Our findings suggest that densely granulated tumors, with positive SSTR2 and E-Cadherin seem to be associated with favorable fgSRL responses. The strongest predictive value of the studied markers was found for E-Cadherin, which seems to surpass even SSTR2.

Standards of care for medical management of acromegaly in pituitary tumor centers of excellence (PTCOE).

A series of consensus guidelines on medical treatment of acromegaly have been produced in the last two decades. However, little information is available on their application in clinical practice. Furthermore, international standards of acromegaly care have not been published. The aim of our study was to report current standards of care for medical therapy of acromegaly, using results collected through an audit performed to validate criteria for definition of Pituitary Tumor Centers of Excellence (PTCOE). Details of medical treatment approaches to acromegaly were voluntarily provided by nine renowned international centers that participated in this audit. For the period 2018-2020, we assessed overall number of acromegaly patients under medical treatment, distribution of patients on different treatment modalities, overall biochemical control rate with medical therapy, and specific control rates for different medical treatment options. Median number of total patients and median number of new patients with acromegaly managed annually in the endocrinology units of the centers were 206 and 16.3, respectively. Median percentage of acromegaly patients on medical treatment was 48.9%. Among the patients on medical treatment, first-generation somatostatin receptor ligand (SRL) monotherapy was used with a median rate of 48.7%, followed by combination therapies with a median rate of 29.3%. Cabergoline monotherapy was used in 6.9% of patients. Pegvisomant monotherapy was used in 7 centers and pasireotide monotherapy in 5 centers, with median rates of 7.9% and 6.3%, respectively. Current standards of care in PTCOEs include use of first-generation SRLs as the first medical option in about 50% of patients, as recommended by consensus guidelines. However, some patients are kept on this treatment despite inadequate control suggesting that cost-effectiveness, availability, patient preference, side effects, and therapeutic inertia may play a possible role also in PTCOE. Moreover, at odds with consensus guidelines, other monotherapies for acromegaly appear to have a marginal role as compared to combination therapies as extrapolated from PTCOE practice data. Presence of uncontrolled patients in each treatment category suggest that further optimization of medical therapy, as well as use of other therapeutic tools such as radiosurgery may be needed.

Effectiveness of combined first-line medical treatment in acromegaly with prolactin cosecretion.

The aim of this study is to compare the response to first-line medical treatment in treatment-naive acromegaly patients with pure growth hormone (GH)-secreting pituitary adenoma (GH-PA) and those with GH and prolactin cosecreting PA (GH&PRL-PA). This is a retrospective multicentric study of acromegaly patients followed from 2003 to 2023 in 33 tertiary Spanish hospitals with at least 6 months of first-line medical treatment. Baseline characteristics, first-line medical treatment strategies, and outcomes were analyzed. We employed a multiple logistic regression full model to estimate the impact of some baseline characteristics on disease control after each treatment modality. Of the 144 patients included, 72.9% had a GH-PA, and 27.1% had a GH&PRL-PA. Patients with GH&PRL-PA were younger (43.9 ± 15.0 vs 51.9 ± 12.7 years, P < .01) and harboring more frequently macroadenomas (89.7% vs 72.1%, P = .03). First-generation somatostatin receptor ligand (fgSRL) as monotherapy was given to 106 (73.6%) and a combination treatment with fgSRL and cabergoline in the remaining 38 (26.4%). Patients with GH&PRL-PA received more frequently a combination therapy (56.4% vs 15.2%, P < .01). After 6 months of treatment, in the group of patients under fgSRL as monotherapy, those patients with GH&PRL-PA had worse control compared to GH-PAs (29.4% vs 55.1%, P = .04). However, these differences in the rate of disease control between both groups disappeared when both received combination treatment with fgSRL and cabergoline. In GH&PRL-PA, the biochemical control achieved with fgSRL as monotherapy is substantially worse than in patients harboring GH-PA, supporting the inclusion of cabergoline as first-line medical treatment in combination with fgSRLs in these subgroups of patients.

Glucose intolerance in acromegaly is driven by low insulin secretion; results from an intravenous glucose tolerance test.

Insulin sensitivity (Si) and its role in glucose intolerance of acromegaly has been extensively evaluated. However, data on insulin secretion is limited. We aimed to assess stimulated insulin secretion using an intravenous glucose tolerance test (IVGTT) in active acromegaly. We performed an IVGTT in 25 patients with active acromegaly (13 normal glucose tolerance [NGT], 6 impaired glucose tolerance [IGT] and 6 diabetes mellitus [DM]) and 23 controls (8 lean NGT, 8 obese NGT and 7 obese IGT). Serum glucose and insulin were measured at 20 time points along the test to calculate Si and acute insulin response (AIRg). Medical treatment for acromegaly or diabetes was not allowed. In acromegaly, patients with NGT had significantly (p for trend < 0.001) higher AIRg (3383 ± 1082 pmol*min/L) than IGT (1215 ± 1069) and DM (506 ± 600). AIRg was higher in NGT (4764 ± 1180 pmol*min/L) and IGT (3183 ± 3261) controls with obesity than NGT (p = 0.01) or IGT (p = 0.17) acromegaly. Si was not significantly lower in IGT (0.68 [0.37, 0.88] 106*L/pmol*min) and DM (0.60 [0.42, 0.84]) than in NGT (0.81 [0.58, 1.55]) patients with acromegaly. NGT (0.33 [0.30, 0.47] 106*L/pmol*min) and IGT (0.37 [0.21, 0.66]) controls with obesity had lower Si than NGT (p = 0.001) and IGT (p = 0.43) acromegaly. We demonstrated that low insulin secretion is the main driver behind glucose intolerance in acromegaly. Compared to NGT and IGT controls with obesity, patients with NGT or IGT acromegaly had higher Si. Together, these findings suggest that impaired insulin secretion might be a specific mechanism for glucose intolerance in acromegaly.

THU061 Treatment Patterns In Acromegaly: Analysis Of Real-World US Insurance Claims From The MarketScan® Database

Abstract Disclosure: M. Fleseriu: Advisory Board Member; Self; Amryt, Ipsen, Recordati Rare Diseases, Pfizer, Inc. Grant Recipient; Self; Amryt, Crinetics, Ionis Pharmaceuticals Inc. A.L. Barkan: None. T.C. Brue: Advisory Board Member; Self; Advanz Pharma, Debio Pharm, Recordati Rare Diseases. Consulting Fee; Self; Ipsen, Recordati Rare Diseases, Novartis Pharmaceuticals, Pfizer, Inc. Grant Recipient; Self; Pfizer, Inc. Other; Self; Ipsen, Recordati Rare Diseases, Novartis Pharmaceuticals, Pfizer, Inc. E. Duquesne: Employee; Self; Ipsen. A. Houchard: Employee; Self; Ipsen. Stock Owner; Self; Ipsen. M. del Pilar Schneider: Employee; Self; Ipsen. A. Ribeiro-Oliveira Jr.: Employee; Self; Ipsen. Stock Owner; Self; Ipsen. S. Melmed: Advisory Board Member; Self; Ionis Pharmaceuticals Inc., Ipsen, Novo Nordisk, Recordati Rare Diseases. Grant Recipient; Self; Pfizer, Inc. Background: Medical treatment for acromegaly (characterized by excess growth hormone [GH] production) includes somatostatin receptor ligands (SRLs), dopamine agonists (DAs), and GH receptor antagonists (GHRAs). However, there are few real-world treatment evaluations in the US. We present treatment patterns for patients receiving medications for acromegaly (1/1/2010-7/31/2022). Methods: De-identified data were extracted from MarketScan®, a US health insurance claims database. Eligible patients: those receiving monotherapy or combination therapy (≥2 treatments overlapping for &amp;gt;3 months [m]) for ≥90 days without treatment gaps; ≥2 claims associated with acromegaly; data ≥3 m before and ≥6 m after diagnosis/first treatment claim (earlier date); and ≥18 years (y) old at diagnosis. Outcomes were: demographic characteristics; treatment frequency by line of treatment (LOT) and changes between LOTs (Sankey plot); treatment persistence for first LOT (LOT 1) monotherapies (Kaplan-Meier estimator); and treatment up-/downtitration (≥30% dose change, evaluated for octreotide long-acting release [OCT] and lanreotide depot [LAN]). Biochemical control values were unavailable in the database. Results: Of 882 patients, 50.1% were female; mean age at diagnosis was 48.6 y (standard deviation 13.6 y). In the cohort, 59.4% had exactly 1 LOT, 23.1% had exactly 2 LOTs, and 17.5% had exactly 3 LOTs. The most common LOT 1 medication class was first-generation SRLs: OCT (27.7%) and LAN (21.1%). Other LOT 1 classes were Das (cabergoline; 34.5%) and GHRAs (pegvisomant; 10.5%). Only 7 patients received second-generation SRL pasireotide and no patients received oral octreotide in LOT 1. Most patients initiated treatment with monotherapies (94.6%). In monotherapy LOT 1, GHRAs had the longest median persistence (pegvisomant; 24.8 m; 95% confidence interval [CI]: 16.59-32.49 m; n=93), followed by OCT and LAN (20.0 m; 95% CI: 16.98-23.87 m; n=430). Das had the shortest persistence (cabergoline; 14.4 m; 95% CI: 12.23-16.82 m; n=304). Among patients receiving OCT or LAN, 67.6% had ≥1 dose increase and 45.0% had ≥1 dose reduction. Conclusions: Despite guidelines recommending DA monotherapy for few select patients with acromegaly,1 our real-world analysis found that approximately one-third of patients initiated treatment with this class with the shortest treatment persistence. OCT and LAN monotherapies were also commonly used as LOT 1 and had longer persistence. GHRAs, the class with the longest persistence, were not common monotherapy in LOT 1, possibly because they do not target pituitary adenomas directly. Interestingly, only 5% of patients initiated treatment with combination therapies. Recommendations for individualized therapy2 should consider medication persistence and real-world treatment patterns. 1Giustina et al. Rev Endocr Metab Disord. 2020 2Fleseriu et al. Lancet Diabetes Endocrinol. 2022 Presentation: Thursday, June 15, 2023

THU046 Repeated Treatment With AZP-3813, A Bicyclic, 16-Amino Acid Peptide Antagonist Of The Human Growth Hormone Receptor, Induces Enhanced Suppression Of IGF1 In Beagle Dogs

Abstract Disclosure: G. Ravel: None. C. Chalmey: None. C. Berardet: None. D. Duracher: None. H. Kurasaki: None. T. Tomiyama: None. P. Reid: None. M.D. Culler: None. Medical treatment of acromegaly is based on either suppressing pituitary growth hormone (GH) secretion or inhibiting GH action by preventing interaction with its receptor in order to suppress the elevated levels of insulin-like growth factor 1 (IGF1). AZP-3813 is a 16-amino acid, bicyclic peptide antagonist of the GH receptor (GHR) derived from peptide sequences discovered using a unique, cell-free in vitro transcription-translation system screened against the human GHR, and optimized by rational design to increase binding affinity, solubility and half-life. The KD of AZP-3813 for the human GHR is 1.9nM. In previous studies, AZP-3813 was demonstrated to suppress IGF1 secretion in juvenile rats in a dose-related manner, and to maintain IGF1 suppression when given daily for extended periods. Recently, we demonstrated that AZP-3813 is also very effective in suppressing IGF1 in normal Beagle dogs. Dogs receiving a single 0.1, 1 and 10 mg/kg subcutaneous injection of AZP-3813 responded with a dose-related 2.2 + 7.1, 21.4 + 2.7 and 27.8 + 1.5% decrease in IGF1 after 24 hours, respectively, and the decrease in IGF1 attained with a single 10 mg/kg dose was maintained for over 72 hours. The relatively small further increase in IGF1 suppression with 10 versus 1 mg/kg suggests that 10 mg/kg AZP-3813 may induce near maximal GHR antagonism. To examine the effect of repeated and higher dose treatment of dogs with AZP-3813, young adult, non-fasted, Beagle dogs were injected subcutaneously at rotated dorsal sites with AZP-3813 at doses of 10, 30 or 60 mg/kg (n=2, one male and one female) daily for seven days. Blood samples, collected prior to dosing to establish baseline IGF1 levels and 24 hour after the final, seventh AZP-3813 injection, were assayed for total IGF1 content by radioimmunoassay. Baseline IGF1 levels were lower in the female dogs (136.7 + 36.1 ng/ml) than in the male dogs (197.0 + 11.3 ng/ml); however, the percent IGF1 suppression resulting from AZP-3813 treatment was similar for both sexes. AZP-3813, injected for seven days at 10, 30 and 60 mg/kg, induced highly significant 69.0 + 4.0, 70.5 + 9.5 and 75.0 + 1.0% decreases in IGF1, respectively. The similar magnitude of IGF1 suppression attained with the three doses of AZP-3813 implies that maximal GH antagonism is essentially achieved with the 10 mg/kg dose. The substantial increase in IGF1 suppression achieved by repeated 10 mg/kg injection of AZP-3813, compared to the previously observed suppression after a single 10 mg/kg injection, likely represents compound accumulation (under investigation) as well as a progressive effect of maximal GH antagonism on IGF1 production. These results demonstrate that the potent GHR antagonist activity of AZP-3813 translates to a highly effective suppression of IGF1 in normal dogs and further support the development of AZP-3813 as a potential therapy for acromegaly. Presentation: Thursday, June 15, 2023

Transcriptome of GH-producing pituitary neuroendocrine tumours and models are significantly affected by somatostatin analogues

Pituitary neuroendocrine tumours (PitNETs) are neoplasms of the pituitary that overproduce hormones or cause unspecific symptoms due to mass effect. Growth hormone overproducing GH-producing PitNETs cause acromegaly leading to connective tissue, metabolic or oncologic disorders. The medical treatment of acromegaly is somatostatin analogues (SSA) in specific cases combined with dopamine agonists (DA), but almost half of patients display partial or full SSA resistance and potential causes of this are unknown. In this study we investigated transcriptomic landscape of GH-producing PitNETs on several levels and functional models—tumour tissue of patients with and without SSA preoperative treatment, tumour derived pituispheres and GH3 cell line incubated with SSA to study effect of medication on gene expression. MGI sequencing platform was used to sequence total RNA from PitNET tissue, pituispheres, mesenchymal stromal stem-like cells (MSC), and GH3 cell cultures, and data were analysed with Salmon—DeSeq2 pipeline. We observed that the GH-producing PitNETs have distinct changes in growth hormone related pathways related to its functional status alongside inner cell signalling, ion transport, cell adhesion and extracellular matrix characteristic patterns. In pituispheres model, treatment regimens (octreotide and cabergoline) affect specific cell proliferation (MKI67) and core functionality pathways (RYR2, COL8A2, HLA-G, ARFGAP1, TGFBR2). In GH3 cells we observed that medication did not have transcriptomic effects similar to preoperative treatment in PitNET tissue or pituisphere model. This study highlights the importance of correct model system selection for cell transcriptomic profiling and data interpretation that could be achieved in future by incorporating NGS methods and detailed cell omics profiling in PitNET model research.

Preoperative Medical Treatment for Patients With Acromegaly: Yes or No?

Transsphenoidal surgery is the first-line treatment for acromegaly. However, several factors can modify surgical remission rates, such as the initial hormone levels, the size and invasiveness of the tumor, and the degree of experience of the surgeon. Physicians treating patients with acromegaly should thus consider how to improve surgical remission rates. As stated in recent guidelines, the major point is to consider that any patient with acromegaly should be referred to an expert neurosurgeon to maximize the chances of surgical sure. The benefits of presurgical medical treatment, mainly using somatostatin receptor ligands (SRLs), given 3 to 6 months before surgery, remain controversial. By normalizing growth hormone and insulin-like growth factor 1 levels, SRLs may improve the overall condition of the patient, thus decreasing anesthetic and surgical complications. By decreasing the tumor size and modifying the consistency of the tumor, SRLs might also make surgical excision easier. This is however theoretical as published data are contradictory on both points, and only limited data support the use of a systematical presurgical medical treatment. The aim of this review is to analyze the potential benefits and pitfalls of using presurgical medical treatment in acromegaly in view of the contradictory literature data. We also attempt to determine the profile of patients who might most benefit from this presurgical medical treatment approach as an individualized therapeutic management of acromegaly.

Resistance to drug treatment of acromegaly and ways to overcome it

Acromegaly is a severe disabling neuroendocrine disease caused by hypersecretion of growth hormone (GH) and insulin-like growth factor 1 (IGF-1). The problem of resistance to drug therapy in patients with acromegaly is quite common in clinical practice and requires a personalized approach, considering various predictors of sensitivity to the choice of the treatment method. To date, first-generation somatostatin analogues are first-line drugs in the medical treatment of acromegaly, but up to 50% of patients do not achieve biochemical remission of the disease. The prognosis of sensitivity to somatostatin analogues is of great importance and the selection of patients in whom this therapy will be not successful provides invaluable assistance in choosing the optimal treatment approach. This review summarizes potential predictors of sensitivity and resistance to existing drug treatment of acromegaly, discusses possible ways to overcome the resulting resistance to therapy, suggests options for a personalized approach to choosing a treatment strategy in the absence of disease control against the background of monotherapy with somatostatin analogues, including «off-label» combinations. Timely addition of growth hormone receptor antagonist (pegvisomant) avoids repeated neurosurgical intervention, radiation therapy or prescribing excessively high doses of somatostatin analogues. Optimal use of mono- or combination therapy contributes to the achievement of biochemical remission in most resistant patients.

Biliary adverse events in acromegaly during somatostatin receptor ligands: predictors of onset and response to ursodeoxycholic acid treatment

PurposeSomatostatin receptor ligands (SRL) are the first-line medical treatment for acromegaly. Gallbladder alterations are one of most important SRL side effect, but according to some authors growth hormone hypersecretion itself is a risk factor for gallstones. This single center, longitudinal retrospective study evaluated the incidence and the predictors of biliary adverse events (BAE) in acromegaly during SRL therapy and their response to ursodeoxycholic acid (UDCA).Methods91 acromegaly patients with indication to SRL were enrolled. Evaluations of acromegaly activity (GH, IGF-I, IGF-I/ULN) and metabolic profile were collected before starting treatment, yearly during follow-up and at BAE onset. In patients developing BAE we searched for predictors of UDCA effectiveness.Results61.5% of patients developed BAE (58.9% cholelithiasis; 41.1% only sludge). IGF-I and IGF-I/ULN proved to be positive predictor of BAE, which occur about 5 years after SRL starting. None of metabolic markers proved to be associated with BAE. Only five patients (5.5%) underwent cholecystectomy for symptomatic cholelithiasis. 71% of patients started UDCA treatment, achieving regression of BAE in 60% of cases (88% in patients developing only sludge and 30% in patients affected by cholelithiasis, p < 0.001). BMI and obesity were negative predictors of UDCA efficacy. In 50% of the subjects BAE resolved after 36 months of therapy with a lower rate if cholelithiasis was present.ConclusionBiliary stone disease is a frequent SRL adverse event, although it is often symptomless. Ultrasound follow-up mainly in the first 5 years of therapy, early UDCA starting and proper lifestyle represent a valid strategy in their detection and management.

Medical Treatment with Somatostatin Analogues in Acromegaly: Position Statement

Acromegaly is a chronic disorder caused by excessive growth hormone (GH) secretion. In most cases, the excess GH originates from GH-producing pituitary adenomas. Surgery is the preferred first-line treatment for patients with acromegaly, but medical man-agement is considered when the disease persists after surgery or in cases where patients refuse surgery or are poor candidates for surgery. Somatostatin analogues are commonly used to treat acromegaly. The Korean Endocrine Society and the Korean Neuroendocrine Study Group have developed a position statement for the use of somatostatin analogues in the medical treatment of acromegaly. This position statement is based on evidence from the current literature and expert opinions. In the case of discrep-ancies among expert opinions, the experts voted to determine the recommended approach. (Korean J Med 2019;94:485-494)

The position of combined medical treatment in acromegaly.

Advances in combination medical treatment have offer new perspectives for acromegaly patients with persistent disease activity despite receiving the available medical monotherapies. The outcomes of combination medical treatment may reflect both additive and synergistic effects. This review focuses on combination medical treatment and its current position in acromegaly, based on clinical studies evaluating the efficacy and safety of combined medical treatment(s) and our own experiences with combination therapy. Arch Endocrinol Metab. 2019;63(6):646-52.

Current perspectives on the impact of clinical disease and biochemical control on comorbidities and quality of life in acromegaly.

Acromegaly is a rare chronic, systemic disorder caused by excessive growth hormone (GH) secretion from a somatotroph pituitary adenoma. GH hypersecretion leads to overproduction of insulin-like growth factor-1 (IGF-1), which contributes to the somatic overgrowth, physical disfigurement, onset of multiple systemic comorbidities, reduced quality of life (QoL) and premature mortality of uncontrolled patients. Somatostatin receptor ligands, dopamine agonists and a GH receptor antagonist are currently available for medical therapy of acromegaly. The main aim of treatment is biochemical normalisation, defined as age-normalised serum IGF-1 values and random GH levels <1.0μg/L. However, there is an increasing evidence suggesting that achieving biochemical control does not always decrease the burden of disease-related comorbidities and/or improve patients' QoL. This lack of correlation between biochemical and clinical control can be due to both disease duration (late diagnosis) or to the peculiarity of a given comorbidity. Herein we conducted ad hoc literature searches in order to find the most recent and relevant reports on biochemical and clinical disease control during medical treatment of acromegaly. Particularly, we analyse and describe the relationship between biochemical, as well as clinical disease control in patients with acromegaly receiving medical therapy, with a focus on comorbidities and QoL. In conclusion, we found that current literature data seem to indicate that clinical disease control (besides biochemical control), encompassing clinical signs and symptoms, comorbidities and QoL, emerge as a primary focus of acromegaly patient management.

MECHANISMS IN ENDOCRINOLOGY: Clinical and pharmacogenetic aspects of the growth hormone receptor polymorphism.

Pharmacogenetics aims to maximize the beneficial effects of a medical therapy by identifying genetic finger prints from responders and non-responders and, thereby improving safety and efficacy profile of the drug. Most subjects who are deficient in growth hormone (GHD) are candidates for recombinant human GH (rhGH) therapy. To date, it is well established that even after adjustments for several clinical variables, such as age, gender, body composition and the age at onset of the GHD, response to rhGH treatment is highly variable among individuals, part of which is believed to be due to genetic factors within the GH system. As the first genetic variant to potentially influence the individual response to rhGH therapy in children with growth disorders, polymorphism in the GH receptor (GHR) has attracted a great interest as a target for pharmacogenetics. Studies have been conducted to compare the functional and molecular effects of the full-length GHR (fl-GHR) isoform with the exon 3 deleted (d3-GHR) isoform in children and adults treated with rhGH therapy. Additionally, the impact of the GHR polymorphism has been investigated in relation to the clinical status and response to medical treatment in acromegaly, especially to the GHR antagonist drug pegvisomant. We have performed a narrative review of the studies performed to date on the association of GHR polymorphism with rhGH response in children and adults, and its potential influence in the medical management of acromegaly. In addition, data from studies on the general population and in other chronic diseases examining a role of this genetic variant in the regulation of growth and metabolism are summarized.

Somatostatin receptor ligands in the treatment of acromegaly

First-generation somatostatin receptors ligands (SRL) are the mainstay in the medical treatment of acromegaly, however the percentage of patients controlled with these drugs significantly varies in the different studies. Many factors are involved in the resistance to SRL. In this review, we update the physiology of somatostatin and its receptors (sst), the use of SRL in the treatment of acromegaly and the factors involved in the response to these drugs. The SRL act through interaction with the sst, which up to now have been characterized as five subtypes. The first-generation SRL, octreotide and lanreotide, are considered sst2 specific and have biochemical response rates varying from 20 to 70%. Tumor volume reduction can be found in 36-75% of patients. Several factors may determine the response to these drugs, such as sst, AIP, E-cadherin, ZAC1, filamin A and β-arrestin expression in the somatotropinomas. In patients resistant to first-generation SRL, alternative medical treatment options include: SRL high dose regimens, SRL in combination with cabergoline or pegvisomant, or the use of pasireotide. Pasireotide is a next-generation SRL with a broader pattern of interaction with sst. In the light of the recent increase of treatment options in acromegaly and the deeper knowledge of the determinants of response to the current first-line therapy, a shift from a trial-and-error treatment to a personalized one could be possible.

Somatostatin receptor ligands in acromegaly: clinical response and factors predicting resistance.

Somatostatin (SST) receptor ligands (SRL), in particular those of first generation (Octreotide and Lanreotide), are widely used in medical treatment of acromegaly, but they assure biochemical control of disease (and the possibility of an improvement of clinical symptoms and tumor shrinkage), only in a subset of patients. The mechanisms underlying the so called "SRL resistance" are various and involve in particular SST receptor expression and molecular pathways of signal transduction. Different predictors of SRL response have been reported, including clinical and biochemical features (gender, age, growth hormone and insulin-like growth factor-I levels at diagnosis), and tumor characteristic (both at preoperative magnetic resonance imaging study and histopathology) as well as expression of SST receptors. In some cases, only a "partial resistance" to SST can be detected, probably due to the presence of other impaired molecular mechanisms involved in signal transduction, which compromise specific pathways and not others. This may explain some cases of dissociated response between biochemical control and tumor shrinkage.

Medical Treatment for Acromegaly does not Increase the Risk of Central Adrenal Insufficiency: A Long-Term Follow-Up Study.

Central adrenal insufficiency (CAI) in acromegaly may be related to pituitary adenoma or induced by various medical treatments, transsphenoidal neurosurgery (TNS) or radiotherapy (RT), alone or combined. We assessed the role of all available treatments for acromegaly in inducing CAI. We retrospectively studied 97 patients. CAI was diagnosed if morning serum cortisol was <138 nmol/l, or if its response was inadequate in the low-dose short synacthen test. Seventy-four subjects underwent TNS (and 17 of whom also underwent RT), and 23 were on primary medical therapy: overall we diagnosed 21 cases of CAI. Duration of acromegaly, invasion of cavernous sinus, disease control, and type of medical treatment were much the same for patients with and without CAI, which was identified in 18% of patients (10/57) after one TNS, and in 53% (9/17) after RT (p=0.01); repeat surgery increased the risk of CAI (p=0.02). The risk of CAI onset during the follow-up was lower among patients treated with TNS or medical therapy than after RT (p=0.035). Medical treatment did not raise the risk of CAI, whereas a 5- and 4-fold higher risk of CAI was associated with repeat TNS and RT, respectively. Basal or stimulated cortisol levels were similar among acromegalic patients without CAI and matched controls with nonsecreting pituitary lesions. A significant proportion of patients with acromegaly developed CAI over time. While primary or secondary medical treatment did not contribute to the risk of CAI, repeat TNS and RT correlated with pituitary-adrenal axis impairment.

Patient-reported outcomes of parenteral somatostatin analogue injections in 195 patients with acromegaly.

BackgroundLong-acting somatostatin analogues delivered parenterally are the most widely used medical treatment in acromegaly. This patient-reported outcomes survey was designed to assess the impact of chronic injections on subjects with acromegaly.MethodsThe survey was conducted in nine pituitary centres in Germany, UK and The Netherlands. The questionnaire was developed by endocrinologists and covered aspects of acromegaly symptoms, injection-related manifestations, emotional and daily life impact, treatment satisfaction and unmet medical needs.ResultsIn total, 195 patients participated, of which 112 (57%) were on octreotide (Sandostatin LAR) and 83 (43%) on lanreotide (Somatuline Depot). The majority (>70%) of patients reported acromegaly symptoms despite treatment. A total of 52% of patients reported that their symptoms worsen towards the end of the dosing interval. Administration site pain lasting up to a week following injection was the most frequently reported injection-related symptom (70% of patients). Other injection site reactions included nodules (38%), swelling (28%), bruising (16%), scar tissue (8%) and inflammation (7%). Injection burden was similar between octreotide and lanreotide. Only a minority of patients received injections at home (17%) and 5% were self-injecting. Over a third of patients indicated a feeling of loss of independence due to the injections, and 16% reported repeated work loss days. Despite the physical, emotional and daily life impact of injections, patients were satisfied with their treatment, yet reported that modifications that would offer major improvement over current care would be ‘avoiding injections’ and ‘better symptom control’.ConclusionLifelong injections of long-acting somatostatin analogues have significant burden on the functioning, well-being and daily lives of patients with acromegaly.

A paradigm shift in the medical treatment of acromegaly: from a 'trial and error' to a personalized therapeutic decision-making process.

A paradigm shift in the medical treatment of acromegaly: from a 'trial and error' to a personalized therapeutic decision-making process.