How to Position Pasireotide LAR Treatment in Acromegaly

Pasireotide effects on biochemical control and glycometabolic profile in acromegaly patients switched from combination therapies or unconventional dosages of somatostatin analogs

PURPOSE

To evaluate the impact of pasireotide (PAS) therapy on hormonal and glycometabolic outcome in patients with acromegaly previously treated with combination medical therapies or unconventional dosages of first-generation somatostatin receptor ligands (fg-SRLs).

METHODS

Retrospective study carried out in two referral centers for pituitary diseases. Twenty-one acromegalic patients were switched to PAS (12 had biochemical control, 9 were uncontrolled). Data were collected after 3- and 6-months PAS treatment, and at the last available visit (median 35 months).

RESULTS

After switching to PAS therapy, a significant reduction in IGF-1 values was observed [median 39%; 0.79 xULN (IQR 0.5-1.01) vs 1.29 xULN (IQR 1.06-1.83); p = 0.009]. IGF-1 reduction was statistically significant in the 9 patients previously uncontrolled (61%, p = 0.016), and in the 12 controlled subjects (33%, p = 0.037). At last follow-up, the number of patients reaching an acceptable biochemical control (IGF-1 < 1.3 xULN) raised from 57 to 90% (p = 0.032). Mean HbA1c levels increased from 5.7% (5.5-5.9) to 6.0% (5.9-7) (p = 0.002), and the percentage of diabetic patients raised from 14% (3/21) to 67% (14/21) (p = 0.004). At the last evaluation HbA1c was ≥ 7.0% in 5 patients (24%). Antidiabetic drugs were initiated in 9 new patients, and in 7 out of 9 metformin alone was effective. Younger age and male sex were predictors for the maintenance of glucose homeostasis.

CONCLUSION

PAS monotherapy can be effective in acromegalic patients previously treated with combination medical therapies or unconventional dosages of fg-SRLs. Glucose imbalance can be managed in the vast majority of cases by use of lifestyle interventions and metformin.

Management of pasireotide-induced hyperglycemia in patients with acromegaly: An experts' consensus statement

Pasireotide is a somatostatin analogue for the treatment of acromegaly, a chronic condition caused by excess growth hormone. Despite the therapeutic benefits of pasireotide as a second-line treatment for inadequately controlled acromegaly, a major concern is its hyperglycemic side-effect. Here, we provide guidance on how to select appropriate patients with acromegaly for treatment with pasireotide. We summarize baseline characteristics of patients at high risk for pasireotide-associated hyperglycemia and recommend a monitoring strategy based on the risk profile. Self-monitoring of blood glucose levels (SMBG), measurements of fasting plasma glucose (FPG), postprandial plasma glucose (PPG) and regular HbA1c measurements are the foundation of our proposed monitoring approach. The pathophysiology of pasireotide-induced hyperglycemia involves decreased secretion of the incretin hormones GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1). Our expert recommendations address the specific pathophysiology of pasireotide-induced hyperglycemia by recommending the incretin-based therapeutics dipeptidyl peptidase-4 inhibitors (DPP-4i) and glucagon-like peptide-1 receptor agonists (GLP-1 RA) in all appropriate patients as an alternative to first-line monotherapy with metformin. Furthermore, we emphasize the importance of adequate control of acromegaly, excellent diabetes education, nutrition and lifestyle guidance and advise to consult expert diabetologists in case of uncertainty in the management of patients with hyperglycemia under pasireotide.

Efficacy of pasireotide LAR for acromegaly: a prolonged real-world monocentric study

Background

Acromegaly is caused by excessive growth hormone (GH) and insulin-like growth factor 1 (IGF1). Medical therapy plays a role as a treatment option for persistent disease after non-curative surgery or as a first-line therapy when surgery is not feasible. Pasireotide-LAR (Pas-LAR) is recommended for patients with acromegaly as second-line treatment.

Aim

To evaluate the patients characteristics predictive of an adequate response to Pas-LAR and the long-term efficacy and safety of the Pas-LAR treatment.

Methods

Data from 19 patients with active acromegaly, who were and resistant or intolerant to first-line medical therapy and were switched to pas-LAR have been retrospectively collected. We compared the baseline clinical and biochemical characteristics of patients who were found to respond to Pas-LAR therapy (responders, n=14) with those of patients who did not respond (non-responders, n=5). We then evaluated the Pas-LAR efficacy and safety during long-term follow-up in responders.

Results

IGF1 normalization occurred in 71.4% of responders after one injection. IGF1 levels, [median(interquartile range) of the upper limit of the normal range (ULN) fold increase] were higher in non-responders compared to responders within the initial month of therapy [1.40(1.30-2.34) vs 0.70(0.55-1.25), respectively, p=0.009] and after three [1.77(1.74-2.29) vs 0.94(0.82-1.13), respectively, p=0.029] and six months [1.68(1.33-1.72) vs 1.00(0.65 -1.28), respectively, p=0.002]. Out of 6 patients with symptomatic headache (all in responder group), 5 and 1 reported the resolution and improvement of headache, respectively, already after the first injection. Median HbA1c levels tended to increase from baseline to 6 months both in responder (36 mMol/Mol to 42 mMol/Mol) and non-responder patients (45 mMol/Mol to 48 mMol/Mol). During long term follow up, in the responder group 2 new patients developed diabetes. Tumor shrinkage was observed in 6 out of 7 evaluated responders, with no cases of size increase during the long-term follow-up.

Conclusion

Pas-LAR is effective and safe and the early identification of responders is possible just after the first administration.

Real-life data of Pasireotide LAR in acromegaly: a long-term follow-up

OBJECTIVE

Pasireotide LAR (PAS-LAR) was released in Italy in 2017 to treat acromegaly patients resistant to SRLs (Somatostatin Receptors Ligands). The long-term follow-up data of PAS-LAR therapy in Italy are limited. This study aimed to evaluate the efficacy and safety of PAS-LAR in acromegaly.

DESIGN

Patients with acromegaly in PAS-LAR treatment were enrolled in three tertiary Italian endocrinological centers and evaluated by a retrospective observational real-life multicentre study.

METHODS

Patients have been studied before (baseline) and 1, 6, 12, 24 and > 36 months after PAS-LAR start. Clinical, biochemical, and pituitary magnetic resonance data were collected, along with information on adverse events. Acromegaly disease activity was classified according to the IGF-1 index (normal value < 1.0).

RESULTS

Fifty patients (female 23) were enrolled. PAS-LAR treatment (mean follow-up 24 ± 16 months) significantly decreased IGF-1 levels (IGF-1 index baseline vs last visit: 1.9 ± 0.6 vs 1.2 ± 0.6, p < 0.0001). At the last visit, 67% of patients had controlled disease, and 44% showed a decrease in tumor volume. Clinical and biochemical efficacy was observed as early as after 1-month of PAS-LAR treatment (IGF-1 index baseline vs 1-month: 1.9 ± 0.6 vs 1.4 ± 0.7, p < 0.0001). Also, 50% of patients referred headache improvement or disappearance. Fifteen patients discontinued PAS-LAR due to failure of treatment and poor glycaemic control. The prevalence of diabetes increased from 33% at the baseline to 54% at the last visit (p = 0.0072).

CONCLUSION

In real-life settings, PAS-LAR significantly decreases symptoms, IGF-1 levels, and the size of adenoma in patients with acromegaly resistant to SRLs. Beneficial effects may occur early after the first injection.

Position statement on the diagnosis and management of acromegaly: The French National Diagnosis and Treatment Protocol (NDTP)

Acromegaly is a rare disease with prevalence of approximately 60 cases per million, slight female predominance and peak onset in adults in the fourth decade. Clinical diagnosis is often delayed by several years due to the slowly progressive onset of symptoms. There are multiple clinical criteria that define acromegaly: dysmorphic syndrome of insidious onset, symptoms related to the pituitary tumor (headaches, visual disorders), general signs (sweating, carpal tunnel syndrome, joint pain, etc.), complications of the disease (musculoskeletal, cardiovascular, pneumological, dental, metabolic comorbidities, thyroid nodules, colonic polyps, etc.) or sometimes clinical signs of associated prolactin hypersecretion (erectile dysfunction in men or cycle disorder in women) or concomitant mass-induced hypopituitarism (fatigue and other symptoms related to pituitary hormone deficiencies). Biological confirmation is based initially on elevated IGF-I and lack of GH suppression on oral glucose tolerance test or an elevated mean GH on repeated measurements. In confirmed cases, imaging by pituitary MRI identifies the causal tumor, to best determine management. In a minority of cases, acromegaly can be linked to a genetic predisposition, especially when it occurs at a young age or in a familial context. The first-line treatment is most often surgical removal of the somatotroph pituitary tumor, either immediately or after transient medical treatment. Medical treatments are most often proposed in patients not controlled by surgical removal. Conformal or stereotactic radiotherapy may be discussed on a case-by-case basis, especially in case of drug inefficacy or poor tolerance. Acromegaly should be managed by a multidisciplinary team, preferably within an expert center such as a reference or skill center for rare pituitary diseases.

De-escalation treatment with pasireotide for acromegaly: a long-term experience

INTRODUCTION

Pasireotide long-acting release (LAR) is approved for second-line treatment of acromegaly. Starting pasireotide LAR 40 mg every 4 weeks is recommended and then up-titrate to 60 mg monthly in case of IGF-I uncontrolled levels. We present three patients treated with a de-escalation approach with pasireotide LAR. CASE 1: A 61-year-old female diagnosed with resistant acromegaly was treated with pasireotide LAR 60 mg every 28 days. When IGF-I reached the lower age range, therapy was decreased to pasireotide LAR 40 mg and then to 20 mg. In 2021 and 2022, IGF-I value remained within the normal range. CASE 2: A 40-year-old female diagnosed with resistant acromegaly underwent three neurosurgeries. In 2011, she was enrolled in the PAOLA study and assigned to pasireotide LAR 60 mg. Due to IGF-I overcontrol and radiological stability, therapy was downscaled to 40 mg in 2016 and to 20 mg in 2019. The patient developed hyperglycemia, which was treated with metformin. CASE 3: A 37-year-old male diagnosed with resistant acromegaly was treated with pasireotide LAR 60 mg in 2011. In 2018, therapy was decreased to 40 mg due to IGF-I overcontrol and in 2022 to 20 mg. He developed hyperglycemia, but HbA1c values remained under 48 nmol/L for 7 years.

CONCLUSION

De-escalation treatment with pasireotide LAR may allow a greater proportion of patients to achieve control of acromegaly, particularly in selected cases of clinically aggressive acromegaly potentially responsive to pasireotide (high IGF-I values, invasion of the cavernous sinuses, partial resistance to first-line somatostatin analogues and positive expression of somatostatin receptor 5). Another benefit may be IGF-I oversuppression overtime. The major risk seems to be hyperglycemia.

Vertebral Fractures in Acromegaly: A Systematic Review

INTRODUCTION

Acromegaly is characterized by a very particular alteration of bone microarchitecture, leading to increased vertebral fragility. However, due to inconsistent and insufficient evidence, no guidelines are available for the evaluation of this osteopathy.

METHODS

We performed a literature review of studies published between 1968 and January 2022 on the PubMed and SCOPUS databases using the terms "acromegaly" and "vertebral fractures". Twenty-four studies were found eligible for inclusion, published between June 2005 and November 2021. Included studies evaluated acromegaly patients, who were assessed for the presence of vertebral fractures. We excluded case reports, reviews, meta-analyses, letters to the editor, articles not written in English, and research performed on the same set of patients without significant differences in study design. Risk of bias was avoided by following the ROBIS risk of bias recommendations. We executed rigorous data collection, and the results are depicted as a narrative overview, but also, as statistical synthesis. Limitations of the evidence presented in the study include study heterogeneity, small sample sizes, and a small number of prospective studies with short follow-up.

FINDINGS

Data regarding vertebral fractures (VFs) in acromegaly and their influencing factors are variable. Twenty-four studies were included, nine out of which had a prospective design. The smallest group of acromegaly patients had 18 subjects and the largest included 248 patients. Prevalence ranges between 6.5% and 87.1%, although most studies agree that it is significantly higher than in controls. VFs also have a higher incidence (between 5.6% and 42%) and are more frequently multiple (between 46.15% and 71%). Evidence shows that disease activity and active disease duration are influencing factors for the prevalence and incidence of VFs. Nonetheless, hypogonadism does not seem to influence the frequency of VFs. While reports are conflicting regarding the use of bone mineral density in acromegaly, evidence seems to be slightly in favor of it not being associated with VFs. However, trabecular bone score is significantly lower in fractured patients, although no prospective studies are available.

INTERPRETATION

Vertebral fractures evaluation should be performed with regularity in all acromegalic patients, especially in the presence of active disease. Disease activity is an important determinant of vertebral fracture incidence and prevalence, although hypogonadism is less so. To clarify the predictive value of both BMD and TBS for vertebral fractures, additional, larger, prospective studies are necessary.

Impairment in insulin secretion without changes in insulin resistance explains hyperglycemia in patients with acromegaly treated with pasireotide LAR

Objective

Pasireotide is a second-generation somatostatin receptor ligand (SRL) used for treating acromegaly. Its clinical use is limited by adverse effects on glucose homeostasis. The aim of this study was to evaluate longitudinal changes in beta-cell function and insulin sensitivity associated with pasireotide in patients not controlled by first-generation SRLs.

Design

We performed a retrospective study.

Methods

The efficacy (growth hormone (GH)/insulin-like growth factor (IGF-1) concentrations; tumor size) and effect on glucose homeostasis were analyzed in 33 patients. Longitudinal data on oral glucose tolerance tests were available before, shortly (mean ± s.d., 6.1 ± 3.8 months) and long term (24.4 ± 11.1 months) after initiation of pasireotide in 14 patients. Insulin secretion (insulinogenic index; disposition index) and insulin sensitivity were calculated by validated indices.

Results

Pasireotide-induced diabetes occurred in 12 patients (36%). It was mediated by impaired insulin secretion, which occurred shortly after initiation of treatment and then remained stable on long term (insulinogenic index, median (min; max), 80 (12; 542) vs 16 (6.4; 101) vs 25 (3.7; 396) pmol/mmol, respectively; P = 0.028; disposition index, 1.45 (0.42; 4.88) vs 0.53 (0.17; 2.63) vs 0.60 (0.22; 1.71), respectively; P = 0.024). No significant changes in insulin sensitivity were observed, despite a marked reduction of GH/IGF-1 concentrations. Older age and a worse glycemic control at baseline were the strongest predictors for hyperglycemia and the need for antidiabetic treatment.

Conclusion

Worsening of glycemic control during pasireotide therapy is caused by an impaired insulin secretion, whereas insulin sensitivity is not affected. These findings might be important for the choice of antidiabetic treatment for pasireotide-induced hyperglycemia.

Significance statement

Pasireotide, a second-generation SRL used for treating acromegaly, may be associated with glucose metabolism impairment. In a retrospective study of 33 patients, we observed that treatment with pasireotide was associated with normalization of serum IGF-1 in almost 60% of patients, but one-third of patients developed diabetes. In the patients who stopped pasireotide because of hyperglycemia, HbA1c promptly decreased. Longitudinal data in 14 patients show that diabetes is mediated by impaired insulin secretion, which occurred shortly and then remained stable on long term, while no significant changes in insulin sensitivity were observed, despite a marked reduction of GH/IGF-1 concentrations. Older age and a worse glycemic control at baseline were the strongest predictors for hyperglycemia.

Acromegaly: pathogenesis, diagnosis, and management

Growth hormone-secreting pituitary adenomas that cause acromegaly arise as monoclonal expansions of differentiated somatotroph cells and are usually sporadic. They are almost invariably benign, yet they can be locally invasive and show progressive growth despite treatment. Persistent excess of both growth hormone and its target hormone insulin-like growth factor 1 (IGF-1) results in a wide array of cardiovascular, respiratory, metabolic, musculoskeletal, neurological, and neoplastic comorbidities that might not be reversible with disease control. Normalisation of IGF-1 and growth hormone are the primary therapeutic aims; additional treatment goals include tumour shrinkage, relieving symptoms, managing complications, reducing excess morbidity, and improving quality of life. A multimodal approach with surgery, medical therapy, and (more rarely) radiation therapy is required to achieve these goals. In this Review, we examine the epidemiology, pathogenesis, diagnosis, complications, and treatment of acromegaly, with an emphasis on the importance of tailoring management strategies to each patient to optimise outcomes.

Pasireotide-a novel somatostatin receptor ligand after 20 years of use

Pasireotide, a novel multireceptor-targeted somatostatin receptor ligand (SRL) is characterized by a higher affinity to somatostatin receptor type 5 than type 2, unlike first-generation SRLs. Because of the broader binding profile, pasireotide has been suggested to have a greater clinical efficacy in acromegaly than first-generation SRLs and to be efficacious in Cushing's disease. The consequence of this binding profile is the increased blood glucose level in some patients. This results from the inhibition of both insulin secretion and the incretin effect and only a modest suppression of glucagon. A monthly intramuscular formulation of long-acting release pasireotide has been approved for both acromegaly and Cushing's disease treatment. This review presents data on the efficacy and safety of pasireotide treatment mostly in patients with acromegaly and Cushing's disease. Moreover, other possible therapeutic applications of pasireotide are mentioned.

Approach to the Patient With Treatment-resistant Acromegaly

Although most tumors in patients with acromegaly are benign and are cured or controlled by surgery and/or first-generation somatostatin receptor ligands therapy, some can behave more aggressively and are resistant to these standard therapies. Acromegaly, if left untreated, is a rare and chronic disorder, commonly caused by a GH-producing pituitary adenoma and is associated with significant comorbidities and an increased mortality. Transsphenoidal surgery is considered the mainstay of acromegaly management, but medical therapy has an increasingly important role. However, disease activity is not fully controlled in a significant number of patients treated with surgery and/or high-dose first-generation somatostatin receptor ligand monotherapy. In these circumstances, therefore, repeated surgery, second-line medical therapy, and radiotherapy, alone or combined as multimodal therapeutic strategies should be considered, in a patient-centered perspective.

Real-world experience with pasireotide-LAR in resistant acromegaly: a single center 1-year observation

CONTEXT

Pasireotide-LAR, a second-generation somatostatin receptor ligand (SRL), is recommended for patients with acromegaly as second-line treatment. Its efficacy and safety were assessed in clinical trials; however, the real-world evidence is still scarce.

OBJECTIVE

The aim of this study was to evaluate the impact of 1-year treatment with pasireotide-LAR on disease control and glucose metabolism in acromegaly patients resistant to first-generation SRLs.

DESIGN

A single-center prospective study.

METHODS

Twenty-eight patients with active acromegaly or acrogigantism on first-generation SRLs following ineffective pituitary surgery were switched to treatment with pasireotide-LAR 40 or 60 mg i.m. every 28 days. To assess the efficacy of the treatment GH and IGF-1 levels were measured every 3 months. Safety of treatment was carefully evaluated, especially its impact on glucose metabolism.

RESULTS

Complete biochemical control (GH ≤ 1 ng/mL and IGF-1 ≤ 1 × ULN) was achieved in 26.9% of patients and partial + complete response (GH ≤ 2.5 ng/mL and IGF-1 ≤ 1.3 × ULN) in 50.0% of patients. Mean GH level decrease was the largest within first 6 months (P = 0.0001) and mean IGF-1 level decreased rapidly within the first 3 months (P < 0.0001) and they remained reduced during the study. Blood glucose and HbA1c levels increased significantly within 3 months (P = 0.0001) and stayed on stable level thereafter. Otherwise, the treatment was well tolerated and clinical improvement was noticed in majority of patients.

CONCLUSIONS

This real-life study confirmed good effectiveness of pasireotide-LAR in patients resistant to first-generation SRLs. Pasireotide-LAR was overall safe and well tolerated, however significant glucose metabolism worsening was noted.

Personalized Medical Treatment in Patients with Acromegaly: A Review

Acromegaly is associated with significant morbidity and mortality if not appropriately treated. In addition to insulin-like growth factor 1 (IGF-1) and growth hormone (GH) normalization, and tumor shrinkage, treatment goals include symptom relief, managing complications and improving quality of life. Surgical resection is a first-line treatment in most patients, with few being pretreated pre-operatively with medications. Somatostatin receptor ligands (SRLs), injectable and more recently oral capsules, have been the cornerstone of first-line medical therapy for persistent disease. However, several factors, including sparsely granulated adenomas, absent/low somatostatin receptor (SSTR2) status, imaging T2-hyperintensity, young age and aryl hydrocarbon receptor interacting protein mutations could predict first-generation SRL resistance. Patients with these characteristics may be better candidates for the GH receptor antagonist, pegvisomant, or in cases of large tumors the second-generation SRL, pasireotide. Combination therapy should be further pursued in patients who remain biochemically uncontrolled or have high remnant tumor after monotherapy. An efficacious and cost-effective pegvisomant dose-sparing effect of SRLs when used in combination has been demonstrated. With such a wide array of medical treatment options, it is increasingly important to tailor treatment to patients' unique characteristics as well as preferences, with a goal of personalizing management to achieve high quality outcomes.

Acromegaly: Clinical Care in Central and Eastern Europe, Israel, and Kazakhstan

Acromegaly is a rare condition typically caused by benign pituitary adenomas, resulting in excessive production of growth hormone. Clinical manifestations of acromegaly are diverse, varying from the overgrowth of body tissue to cardiovascular, metabolic, and osteoarticular disorders. Symptoms may emerge slowly, overlapping with other diseases and often involve many different healthcare specialists. In the last decade, efforts to provide an accurate and timely diagnosis of acromegaly have improved disease management and clinical experience. Despite this progress, marked differences in the diagnosis, treatment, and management of acromegaly exist from country-to-country. To address these inconsistencies in the region comprising Central and Eastern Europe, Israel, and Kazakhstan, a panel of acromegaly experts from 13 of these countries was convened. Acromegaly experts from each country provided available information on the approaches from their country, including regional treatment centers and multidisciplinary teams, treatment access, reimbursement and availability, and physician education, disease awareness, and patient advocacy. Across several areas of acromegaly management, divergent approaches were identified and discussed, including the provision of multidisciplinary care, approved and available treatments, and disease awareness programs. These were recognized as areas of potential improvement in the management of acromegaly, in addition to participation in national and regional acromegaly registries. Further experience exchange will facilitate the identification of specific strategies that can be adapted in each country, and widespread participation in acromegaly registries will enable their evaluation. It is anticipated that this approach will support the optimization of acromegaly patient care across this region.

Managing pasireotide-associated hyperglycemia: a randomized, open-label, Phase IV study

PURPOSE

Pasireotide is an effective treatment for acromegaly and Cushing's disease, although treatment-emergent hyperglycemia can occur. The objective of this study was to assess incretin-based therapy versus insulin for managing pasireotide-associated hyperglycemia uncontrolled by metformin/other permitted oral antidiabetic drugs.

METHODS

Multicenter, randomized, open-label, Phase IV study comprising a core phase (≤ 16-week pre-randomization period followed by 16-week randomized treatment period) and optional extension (ClinicalTrials.gov ID: NCT02060383). Adults with acromegaly (n = 190) or Cushing's disease (n = 59) received long-acting (starting 40 mg IM/28 days) or subcutaneous pasireotide (starting 600 µg bid), respectively. Patients with increased fasting plasma glucose (≥ 126 mg/dL on three consecutive days) during the 16-week pre-randomization period despite metformin/other oral antidiabetic drugs were randomized 1:1 to open-label incretin-based therapy (sitagliptin followed by liraglutide) or insulin for another 16 weeks. The primary objective was to evaluate the difference in mean change in HbA_1c from randomization to end of core phase between incretin-based therapy and insulin treatment arms.

RESULTS

Eighty-one (32.5%) patients were randomized to incretin-based therapy (n = 38 received sitagliptin, n = 28 subsequently switched to liraglutide; n = 12 received insulin as rescue therapy) or insulin (n = 43). Adjusted mean change in HbA_1c between treatment arms was - 0.28% (95% CI - 0.63, 0.08) in favor of incretin-based therapy. The most common AE other than hyperglycemia was diarrhea (incretin-based therapy, 28.9%; insulin, 30.2%). Forty-six (18.5%) patients were managed on metformin (n = 43)/other OAD (n = 3), 103 (41.4%) patients did not require any oral antidiabetic drugs and 19 patients (7.6%) were receiving insulin at baseline and were not randomized.

CONCLUSION

Many patients receiving pasireotide do not develop hyperglycemia requiring oral antidiabetic drugs. Metformin is an effective initial treatment, followed by incretin-based therapy if needed. ClinicalTrials.gov ID: NCT02060383.

Long-term safety and efficacy of long-acting pasireotide in acromegaly

BACKGROUND

Pasireotide long acting (LAR) can be effective in normalizing insulin-like growth factor (IGF)-1 level in acromegaly patients inadequately controlled by octreotide or lanreotide.

OBJECTIVE

Determine the long-term efficacy and safety of pasireotide, including time to biochemical control and time to best response, and risk for diabetes mellitus.

METHODS

A retrospective multicenter study investigating the efficacy and safety of pasireotide LAR treatment in patients with active acromegaly treated for >12 months.

RESULTS

The study included 19 patients (10 men; mean age ± SD, 48.0 ± 12.9 years) treated with pasireotide for a mean of 50 ± 36 months. During the follow-up, 4 patients discontinued pasireotide treatment. Pasireotide LAR produced a tolerable and long-term significant biochemical response in 15 of 19 patients (79.0%). Mean time to IGF-1 normalization from pasireotide LAR initiation was 13.6 ± 16.9 months with early biochemical normalization (<12 months) evident in 11 (64.7%) patients and delayed IGF-1 normalization in 6 (35.2%) patients. Nadir IGF-1 values were recorded within the first 12 months in 6 patients (35.3%), while in 11 patients (64.7%) lowest values were reported after >12 months of treatment, including 4 of 11 patients with early IGF-1 normalization. New-onset diabetes was documented in 5 of 7 patients with pre-diabetes and in 1 of 5 patients with normal glucose homeostasis at baseline. Among patients with pre-diabetes or diabetes mellitus prior to initiating pasireotide, mean HbA1c increase was 0.56 ± 1.0%.

CONCLUSIONS

The results support the long-term efficacy and safety of pasireotide LAR for acromegaly and support the potential delayed effect of treatment on IGF-1 normalization.

Continuous Glucose Monitoring System in Acromegalic Patients: Possible Role in the Assessment of Glycemia Control

BACKGROUND

Acromegaly is characterized by an insulin resistance condition. There is a significant difference between the different types of therapy in relation to the glycometabolic framework. The blinded continuous glucose monitoring system (CGMS), throughout a period of maximum 6 days for a total of 288 glycemic registrations per day, identifies glycemic excursions and could constitute a valid device to understand the 24-hour glycemic profiles.

AIM OF THE STUDY

To compare the oral glucose tolerance test (OGTT) and CGMS methods in acromegalic patients to evaluate their glycemic profiles, in relation to different treatments for acromegaly.

METHODS

Thirty-five acromegalic patients were divided into 18 somatostatin analogs (SSA), 9 pegvisomant, and 8 successfully surgically treated. A 72-hour CGM was performed and, immediately after, an OGTT.

RESULTS

Results obtained from OGTT: 11/35 impaired fasting glucose, 6/35 impaired glucose tolerance, and 4/35 diabetes mellitus. A positive significant correlation was demonstrated between the OGTT peak and CGM peak in all of the patients, CGM peak of patients treated with SSA and those surgically treated, OGTT average and CGM area under concentration-time curve (AUC) for hyperglycemia of patients treated with SSA and those surgically treated, and CGM AUC for hyperglycemia of patients treated with SSA and those surgically treated.

CONCLUSIONS

Our results show a significantly higher response in terms of mean and peak OGTT in patients treated with SSA, both compared to the CGM study, and compared to the group of patients receiving pegvisomant. The CGM system could represent an instrument for the evaluation of the glycemic trend of acromegalic patients.

Characterization of the ability of a, second-generation SST-DA chimeric molecule, TBR-065, to suppress GH secretion from human GH-secreting adenoma cells

CONTEXT

Somatostatin (SST) and dopamine (DA) inhibit growth hormone (GH) secretion and proliferation of GH-secreting pituitary adenomas (GHomas) through binding to SSTR2 and D2R receptors. Chimeric SST-DA compounds (Dopastatins) display increased potency in inhibiting GH secretion, as compared with individual SST or DA analogs (alone or combined).

OBJECTIVE

To assess the efficacy of a second-generation dopastatin, TBR-065, in suppressing GH secretion from human GH- and GH/prolactin(PRL)-omas.

DESIGN

We compared the ability of TBR-065 to inhibit GH secretion from primary cultures of human GH- or GH/PRLoma cells to that of the first generation dopastatin, TBR-760 (formerly BIM-23A760), octreotide (OCT) and cabergoline (CAB), the later either alone or combined. We investigated whether there was any impact of BIM-133, the metabolite of TBR-065, on the ability of TBR-065 to inhibit GH in these cultures.

METHODS

17 GH- and GH/PRLomas were included in this study. Inhibition of GH secretion by TBR-065, TBR-760, OCT and CAB (0.1 pM to 0.1 µM) was assessed over a period of 8 h.

RESULTS

All tumors expressed SSTR2 and D2R mRNAs. GH suppression was higher with TBR-065 as compared with TBR-760 (E_max = 57 ± 5.6% vs. 41.1 ± 12.5%, respectively, p < 0.001) or with OCT + CAB (E_max = 56.8 ± 7.2% vs. 44.4 ± 9.4%, p < 0.001). BIM-133 did not have any impact on the activity of TBR-065.

CONCLUSION

TBR-065 has significantly improved efficacy in suppressing GH secretion as compared to current available therapies and may represent a new promising option for the treatment of acromegaly.

Somatostatin receptors in normal and acromegalic somatotroph cells: the U-turn of the clinician to immunohistochemistry report - a review

This is a narrative review of literature introducing somatostatin receptors (SSTRs) as part of understanding the somatotroph cells since they are positive in normal cells but also in tumoral cells as seen in somatotropinoma, a growth hormone (GH)-producing neoplasia, which causes acromegaly. They are five subtypes of SSTRs (1 to 5), which are immunohistochemically positive in different proportions in somatotropinomas. SSTR types 2 and 5 are most frequent in GH-secreting adenomas and they are both targeted by medical therapy with somatostatin analogues (SSTAs) like first generation Octreotide and Lanreotide (mainly targeting SSTR2) and second generation Pasireotide (with highest affinity for SSTR5), thus heterogeneous SSTRs configuration into the tumor explains different pattern of response to treatment and it might predict it once the SSTRs immunostaining is performed. Monoclonal antibodies are used for immunohistochemical detection of SSTRs; currently, a lack of standardization is presented, and scoring systems, such as Volante, H-score or human epidermal growth factor receptor 2 (HER2)-score, are applied. Immunoreactive markers like SSTRs are the U-turn in clinical practice regarding somatotropinomas since the configuration of subtypes 2 and 5 explains the responsiveness to medical therapy like SSTA. Further achievement of disease control is imperiously necessary because acromegaly has an increased rate of morbidity and mortality.

Pasireotide in the Personalized Treatment of Acromegaly

The delay in controlling the disease in patients who do not respond to first-line treatment with first generation somatostatin receptor ligands (first-generation SRLs) can be quantified in years, as every modification in the medical therapy requires some months to be fully evaluated. Considering this, acromegaly treatment should benefit from personalized medicine therapeutic approach by using biomarkers identifying drug response. Pasireotide has been positioned mostly as a compound to be used in first-generation SRLs resistant patients and after surgical failure, but sufficient data are now available to indicate it is a first line therapy for patients with certain characteristics. Pasireotide has been proved to be useful in patients in which hyperintensity T2 MRI signal is shown and in those depicting low SST2 and high expression of SST5, low or mutated AIP condition and sparsely granulated immunohistochemical pattern. This combination of clinical and pathological characteristics is unique for certain patients and seems to cluster in the same cases, strongly suggesting an etiopathogenic link. Thus, in this paper we propose to include this clinico-pathologic phenotype in the therapeutic algorithm, which would allow us to use as first line medical treatment those compounds with the highest potential for achieving the fastest control of GH hypersecretion as well as a positive effect upon tumor shrinkage, therefore accelerating the implementation of precision medicine for acromegaly. Moreover, we suggest the development, validation and clinical use of a pasireotide acute test, able to identify patients responsive to pasireotide LAR as the acute octreotide test is able to do for SRLs.

Pasireotide-induced hyperglycemia in a patient with Cushing's disease: Potential use of sodium-glucose cotransporter 2 inhibitor and glucagon-like peptide-1 receptor agonist for treatment

Pasireotide improves hypercortisolemia and induces hyperglycemia via somatostatin receptor type-5 stimulation. GLP-1RA and SGLT2 inhibitor potentially help regulate hyperglycemia in patients with Cushing's disease, especially after pasireotide administration.

Drug treatment strategies for secondary diabetes in patients with acromegaly

INTRODUCTION

Acromegaly is a rare disease due to oversecretion of growth hormone (GH). Even though the disease is often portrayed by its most apparent clinical features, given the abundance of GH receptors throughout the body, it truly is a systemic disease leading to numerous complications and comorbidities. A distinct medical issue in the context of acromegaly is diabetes: It can be a complication as a consequence of GH excess and its mediators, but it can also result from treatment of acromegaly.

AREAS COVERED

This review provides an overview of the effects of acromegaly pathophysiology on glucose homeostasis. Furthermore, it devotes an extensive section on the influence that acromegaly treatment has on glucose metabolism, including approved as well as currently investigated drugs. It also summarizes observations from the use of anti-diabetic medication in patients with acromegaly.

EXPERT OPINION

Glucose imbalance is an important aspect of acromegaly comorbidity and deserves more attention. Even though numerous studies have investigated glucose homeostasis in acromegaly, there is still a clear need for more basic, translational, and also clinical research to advance the understanding of the underlying mechanisms and how to best address them.

Octreotide-Resistant Acromegaly: Challenges and Solutions

Acromegaly is a rare and severe disease caused by an increased and autonomous secretion of growth hormone (GH), thus resulting in high circulating levels of insulin-like growth factor 1 (IGF-1). Comorbidities and mortality rate are closely related to the disease duration. However, in most cases achieving biochemical control means reducing or even normalizing mortality and restoring normal life expectancy. Current treatment for acromegaly includes neurosurgery, radiotherapy and medical therapy. Transsphenoidal surgery often represents the recommended first-line treatment. First-generation somatostatin receptor ligands (SRLs) are the drug of choice in patients with persistent disease after surgery and are suggested as first-line treatment for those ineligible for surgery. However, only about half of patients treated with octreotide (or lanreotide) achieve biochemical control. Other available drugs approved for clinical use are the second-generation SRL pasireotide, the dopamine agonist cabergoline, and the GH-receptor antagonist pegvisomant. In the present paper, we revised the current literature about the management of acromegaly, aiming to highlight the most relevant and recent therapeutic strategies proposed for patients resistant to first-line medical therapy. Furthermore, we discussed the potential molecular mechanisms involved in the variable response to first-generation SRLs. Due to the availability of different medical therapies, the choice for the most appropriate drug can be currently based also on the peculiar clinical characteristics of each patient.

Patient Characteristics, Diagnostic Delays, Treatment Patterns, Treatment Outcomes, Comorbidities, and Treatment Costs of Acromegaly in China: A Nationwide Study

PURPOSE

Acromegaly is a rare, intractable endocrine disease. We aimed to describe the patient characteristics, diagnostic delays, treatment patterns, treatment outcomes, comorbidities and treatment costs of acromegaly in China.

METHODS

This is a nationwide cross-sectional study. Patients diagnosed with and treated for acromegaly between 1996 and 2019 across China were surveyed via the Chinese Association of Patients with Acromegaly platform.

RESULTS

In total, 473 patients (58.8% females, mean age at diagnosis: 39.4±9.5 years) were included. The median disease duration was 3 years. The most common symptoms were extremity enlargement (91.8%) and facial changes (90.1%). Overall, 63.0% of patients experienced diagnostic delays within healthcare systems; 63.8% of the delays were <1 year. The most common first-line therapy was surgery with a transsphenoidal (76.1%) or transcranial approach (3.2%). Somatostatin analogues or dopamine agonists were administered in 20.5% of the patients as first-line therapies and in 41.7% as adjuvant therapies. Radiotherapy was performed in 32.1% of patients, 99.3% of whom received radiotherapy as an adjuvant therapy. After a median 5-year follow-up, 46.2% achieved biochemical control. Comorbidities were reported in 88.2% of the patients at follow-up; memory deterioration and thyroid nodules were the most common. Controlled patients had greater improvements in symptoms and comorbidities during follow-up than uncontrolled patients. The annual per-capita cost-of-treatment was $11013 in 2018, with medical treatments being the largest contributor (67%). Medical insurance covered 47.2% of all treatment costs.

CONCLUSION

This study provides the first comprehensive description of real-world acromegaly data in China, serving as a basis for future population-based studies.

Italian Association of Clinical Endocrinologists (AME) and Italian AACE Chapter Position Statement for Clinical Practice: Acromegaly - Part 2: Therapeutic Issues

Any newly diagnosed patient should be referred to a multidisciplinary team experienced in the treatment of pituitary adenomas. The therapeutic management of acromegaly always requires a personalized strategy. Normal age-matched IGF-I values are the treatment goal. Transsphenoidal surgery by an expert neurosurgeon is the primary treatment modality for most patients, especially if there are neurological complications. In patients with poor clinical conditions or who refuse surgery, primary medical treatment should be offered, firstly with somatostatin analogs (SSAs). In patients who do not reach hormonal targets with first-generation depot SSAs, a second pharmacological option with pasireotide LAR or pegvisomant (alone or combined with SSA) should be offered. Irradiation could be proposed to patients with surgical remnants who would like to be free from long-term medical therapies or those with persistent disease activity or tumor growth despite surgery or medical therapy. Since the therapeutic tools available enable therapeutic targets to be achieved in most cases, the challenge is to focus more on the quality of life.

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.

Pasireotide-LAR in acromegaly patients treated with a combination therapy: a real-life study

PURPOSE

Little data are available regarding the safety and efficacy of switching to Pasireotide-LAR monotherapy in acromegaly patients with partial resistance to first-generation somatostatin agonists (1gSRL) who require combination treatment with cabergoline or pegvisomant.

METHOD

In this monocentric prospective study within a tertiary university hospital, 15 consecutive acromegalic adults partially resistant to 1gSRL treated with octreotide LAR or lanreotide SR, and cabergoline (n = 4, 3.5 mg/week) or pegvisomant (n = 11, median dose 100 mg/week), were switched to Pasireotide-LAR (8 with 40 mg/month; 7 with 60 mg/month). Immunohistochemical expression level of SSTR5 and the granulation pattern of nine somatotroph adenomas were retrospectively determined to test for a correlation with the therapeutic efficacy of Pasireotide-LAR.

RESULTS

Median IGF-1 concentration at the first evaluation (median 3 months) was similar to baseline (1.0 vs 1.1 ULN). 11/15 patients had IGF-1 levels ≤1.3 ULN before and after the switch but individual changes were variable. Hyperglycemia was frequent and greater in diabetic patients. 7/15 patients stopped Pasireotide-LAR due to lack of control of IGF-1 or intolerance. 8/15 patients received Pasireotide-LAR for a median of 29 months with IGF-1 levels ≤1.3 ULN and acceptable glucose tolerance (median HbA1c 6.1%). Two patients required initiation of oral antidiabetic treatment. The intensity of SSTR5 expression and the granulation pattern of adenomas were of limited value for the prediction of Pasireotide-LAR effectiveness.

CONCLUSION

Pasireotide-LAR may represent a suitable therapeutic alternative in a subset of acromegalic patients requiring combination therapy involving a 1gSRL.