Long-term safety of pegvisomant in patients with acromegaly: comprehensive review of 1288 subjects in ACROSTUDY

A Potent Neutralizing Monoclonal Antibody to Human Growth Hormone Suppresses Insulin-Like Growth Factor-1 in Female Rats

Acromegaly and gigantism are disorders caused by hypersecretion of growth hormone (GH), usually from pituitary adenomas. Although somatostatin analogues (SSA), dopamine agonists, and GH receptor antagonists are important therapeutic agents, all of these have issues with their effectiveness, safety, and/or convenience of use. To overcome these, we developed a GH-specific potent neutralizing a mouse monoclonal antibody (mAb) named 13H02. 13H02 selectively bound both to human and monkey GH with high affinity, and strongly inhibited the biological activity of GH in the Nb2 rat lymphoma cell proliferation assay. In hypophysectomized/GH-supplemented rats, a single subcutaneous administration of 13H02 significantly and dose-dependently lowered the serum insulin-like growth factor-1 levels. To pursue the therapeutic potential of this antibody for acromegaly and gigantism, we humanized 13H02 to reduce its immunogenicity and applied a single amino acid mutation in the Fc region to extend its serum half-life. The resulting antibody, Hu-13H02m, also showed GH-specific neutralizing activity, similar to the parental 13H02, and showed improved binding affinity to human FcRn.

Surgical and non-surgical interventions for primary and salvage treatment of growth hormone-secreting pituitary adenomas in adults

BACKGROUND

Growth hormone (GH)-secreting pituitary adenoma is a severe endocrine disease. Surgery is the currently recommended primary therapy for patients with GH-secreting tumours. However, non-surgical therapy (pharmacological therapy and radiation therapy) may be performed as primary therapy or may improve surgical outcomes.

OBJECTIVES

To assess the effects of surgical and non-surgical interventions for primary and salvage treatment of GH-secreting pituitary adenomas in adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, WHO ICTRP, and ClinicalTrials.gov. The date of the last search of all databases was 1 August 2022. We did not apply any language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of more than 12 weeks' duration, reporting on surgical, pharmacological, radiation, and combination interventions for GH-secreting pituitary adenomas in any healthcare setting.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts for relevance, screened for inclusion, completed data extraction, and performed a risk of bias assessment. We assessed studies for overall certainty of the evidence using GRADE. We estimated treatment effects using random-effects meta-analysis. We expressed results as risk ratios (RR) for dichotomous outcomes together with 95% confidence intervals (CI) or mean differences (MD) for continuous outcomes, or in descriptive format when meta-analysis was not possible.

MAIN RESULTS

We included eight RCTs that evaluated 445 adults with GH-secreting pituitary adenomas. Four studies reported that they included participants with macroadenomas, one study included a small number of participants with microadenomas. The remaining studies did not specify tumour subtypes. Studies evaluated surgical therapy alone, pharmacological therapy alone, or combination surgical and pharmacological therapy. Methodological quality varied, with many studies providing insufficient information to compare treatment strategies or accurately judge the risk of bias. We identified two main comparisons, surgery alone versus pharmacological therapy alone, and surgery alone versus pharmacological therapy and surgery combined. Surgical therapy alone versus pharmacological therapy alone Three studies with a total of 164 randomised participants investigated this comparison. Only one study narratively described hyperglycaemia as a disease-related complication. All three studies reported adverse events, yet only one study reported numbers separately for the intervention arms; none of the 11 participants were observed to develop gallbladder stones or sludge on ultrasonography following surgery, while five of 11 participants experienced any biliary problems following pharmacological therapy (RR 0.09, 95% CI 0.01 to 1.47; 1 study, 22 participants; very low-certainty evidence). Health-related quality of life was reported to improve similarly in both intervention arms during follow-up. Surgery alone compared to pharmacological therapy alone may slightly increase the biochemical remission rate from 12 weeks to one year after intervention, but the evidence is very uncertain; 36/78 participants in the surgery-alone group versus 15/66 in the pharmacological therapy group showed biochemical remission. The need for additional surgery or non-surgical therapy for recurrent or persistent disease was described for single study arms only. Surgical therapy alone versus preoperative pharmacological therapy and surgery Five studies with a total of 281 randomised participants provided data for this comparison. Preoperative pharmacological therapy and surgery may have little to no effect on the disease-related complication of a difficult intubation (requiring postponement of surgery) compared to surgery alone, but the evidence is very uncertain (RR 2.00, 95% CI 0.19 to 21.34; 1 study, 98 participants; very low-certainty evidence). Surgery alone may have little to no effect on (transient and persistent) adverse events when compared to preoperative pharmacological therapy and surgery, but again, the evidence is very uncertain (RR 1.23, 95% CI 0.75 to 2.03; 5 studies, 267 participants; very low-certainty evidence). Concerning biochemical remission, surgery alone compared to preoperative pharmacological therapy and surgery may not increase remission rates up until 16 weeks after surgery; 23 of 134 participants in the surgery-alone group versus 51 of 133 in the preoperative pharmacological therapy and surgery group showed biochemical remission. Furthermore, the very low-certainty evidence did not suggest benefit or detriment of preoperative pharmacological therapy and surgery compared to surgery alone for the outcomes 'requiring additional surgery' (RR 0.48, 95% CI 0.05 to 5.06; 1 study, 61 participants; very low-certainty evidence) or 'non-surgical therapy for recurrent or persistent disease' (RR 1.22, 95% CI 0.65 to 2.28; 2 studies, 100 participants; very low-certainty evidence). None of the included studies measured health-related quality of life. None of the eight included studies measured disease recurrence or socioeconomic effects. While three of the eight studies reported no deaths to have occurred, one study mentioned that overall, two participants had died within five years of the start of the study.

AUTHORS' CONCLUSIONS

Within the context of GH-secreting pituitary adenomas, patient-relevant outcomes, such as disease-related complications, adverse events and disease recurrence were not, or only sparsely, reported. When reported, we found that surgery may have little or no effect on the outcomes compared to the comparator treatment. The current evidence is limited by the small number of included studies, as well as the unclear risk of bias in most studies. The high uncertainty of evidence significantly limits the applicability of our findings to clinical practice. Detailed reporting on the burden of recurrent disease is an important knowledge gap to be evaluated in future research studies. It is also crucial that future studies in this area are designed to report on outcomes by tumour subtype (that is, macroadenomas versus microadenomas) so that future subgroup analyses can be conducted. More rigorous and larger studies, powered to address these research questions, are required to assess the merits of neoadjuvant pharmacological therapy or first-line pharmacotherapy.

Efficacy and Safety of Pegvisomant in the Treatment of Acromegaly

Pegvisomant, the first and currently only clinically available growth hormone receptor antagonist, is an effective therapeutic option for the medical treatment of acromegaly, a rare disorder characterized by excessive growth hormone secretion. With now over 20 years of real world experience, its safety and efficacy is well-established. However, several aspects of its clinical use are still controversially discussed. The high cost of pegvisomant has limited its use in several countries, and recent studies have reported a lower efficacy than the initial clinical trials. A reported increase in tumor volume under therapy varies between studies and has been attributed to either actual growth or re-expansion after cessation of somatostatin receptor ligand therapy. Furthermore, different combinations of pegvisomant and other therapeutic agents aiming at reduction of acromegaly disease activity have been proposed to increase or retain effectiveness while lowering side effects and cost. This review aims to assess current clinical data on the safety and efficacy of pegvisomant while also addressing controversies surrounding its use.

A rare form of hyperthyroidism leading to the diagnosis of acromegaly: A case report

Acromegaly is a rare disease, usually caused by a pituitary tumor. It typically exhibits slow evolution and can result in numerous complications. In the present case report, the patient presented with hyperthyroidism associated with ophthalmopathy and right nodular goiter. The laboratory tests revealed persistent high levels of phosphorus without an apparent cause. After ruling out common pathologies associated with this finding, a focus was placed on the clinical aspects associated with acromegaly, a rare cause of hyperphosphatemia. Laboratory tests and MRI confirmed the diagnosis. The patient underwent transsphenoidal surgery, but the disease remained active, thus medical treatment was initiated, to a poor initial response. Associated with acromegaly, two distinct thyroid pathologies were diagnosed: Toxic adenoma and Graves' disease. This case highlights the challenges in diagnosing and managing a rare endocrine pathology.

Practical therapeutic approach in the management of diabetes mellitus secondary to Cushing's syndrome, acromegaly and neuroendocrine tumours

Cushing's syndrome, acromegaly and neuroendocrine disorders are characterized by an excess of counterregulatory hormones, able to induce insulin resistance and glucose metabolism disorders at variable degrees and requiring immediate treatment, until patients are ready to undergo surgery. This review focuses on the management of diabetes mellitus in endocrine disorders related to an excess of counterregulatory hormones. Currently, the landscape of approved agents for treatment of diabetes is dynamic and is mainly patient-centred and not glycaemia-centred. In addition, personalized medicine is more and more required to provide a precise approach to the patient's disease. For this reason, we aimed to define a practical therapeutic algorithm for management of diabetes mellitus in patients with glucagonoma, pheochromocytoma, Cushing's syndrome and acromegaly, based on our practical experience and on the physiopathology of the specific endocrine disease taken into account. This document is addressed to all specialists who approach patients with diabetes mellitus secondary to endocrine disorders characterized by an excess of counterregulatory hormones, in order to take better care of these patients. Care and control of diabetes mellitus should be one of the primary goals in patients with an excess of counterregulatory hormones requiring immediate and aggressive treatment.

Second line treatment of acromegaly: Pasireotide or Pegvisomant?

Acromegaly is a chronic disease with an increased mortality in case of persistently active disease. The treatment of acromegaly is mainly based on the surgical resection of the GH secreting pituitary tumor and, in cases with persistent disease, on the medical therapy with first generation somatostatin analogues (first gen-SSAs). Data from national registries, meta-analysis and epidemiology studies showed that 24%-65% of acromegaly patients treated with first gen-SSA did not reach the control of disease, requiring second line therapies, as the second gen-SSAs and the GH receptor antagonist. According to the high efficacy of these treatments and their molecular mechanisms of action, the choice of second line therapies should be personalized. In this review, we summarize the evidence on clinical, molecular and morphological aspects that may predict the response to second line therapies, in order to integrate and translate in the clinical practice for a patient-tailored therapeutic approach.

Clinical Significance of Transient Asymptomatic Elevations in Aminotransferase (TAEAT) in Oncology

Monitoring for liver injury remains an important aspect of drug safety assessment, including for oncotherapeutics. When present, drug-induced liver injury may limit the use or result in the discontinuation of these agents. Drug-induced liver injury can exhibit with a wide spectrum of clinical and biochemical manifestations, ranging from transient asymptomatic elevations in aminotransferases (TAEAT) to acute liver failure. Numerous oncotherapeutics have been associated with TAEAT, with published reports indicating a phenomenon in which patients may be asymptomatic without overt liver injury despite the presence of grade ≥3 aminotransferase elevations. In this review, we discuss the occurrence of TAEAT in the context of oncology clinical trials and clinical practice, as well as the clinical relevance of this phenomenon as an adverse event in response to oncotherapeutics and the related cellular and molecular mechanisms that may underlie its occurrence. We also identify several gaps in knowledge relevant to the diagnosis and the management of TAEAT in patients receiving oncotherapeutics, and identify areas warranting further study to enable the future development of consensus guidelines to support clinical decision-making.

Are there country-specific differences in the use of pegvisomant for acromegaly in clinical practice? An analysis from ACROSTUDY

OBJECTIVE

A comprehensive picture of pegvisomant use for treating acromegaly in routine clinical practice in different countries is lacking. We aimed, therefore, to document country-specific behaviors in real-life pegvisomant use, and the main safety and effectiveness outcomes in the ACROSTUDY.

DESIGN

ACROSTUDY is an open-label, non-interventional, post-marketing safety surveillance study.

METHODS

A descriptive analysis was performed using data from the six top-recruiter ACROSTUDY countries, i.e., Germany (n = 548 patients), Italy (n = 466), France (n = 312), USA (n = 207), Spain (n = 200) and the Netherlands (n = 175). These nations accounted for > 85% of the ACROSTUDY cases.

RESULTS

The mean pegvisomant dose at treatment start was lowest in the Netherlands (9.4 mg/day), whereas it ranged between 10.9 and 12.6 mg/day in the other countries. At year 5, the mean pegvisomant dose was around 15 mg/day in all countries, except France (18.1 mg/day). At starting pegvisomant, patients treated with monotherapy ranged between 15% in the Netherlands and 72% in Spain. Monotherapy remained lowest over time in the Netherlands. In all countries, the percentage of patients with normal IGF-1 increased steeply from < 20% at baseline to 43-58% at month 6 and 51-67% at year 1. After that, we observed minor changes in the rate of acromegaly control in all countries. The Netherlands peaked in disease control at year 2 (72%). The proportion of patients reporting changes in pituitary tumor size was generally low. Serious treatment-related adverse events were < 5% in all countries.

CONCLUSIONS

Our study provided a detailed summary of real-life use of pegvisomant in the six top-recruiter ACROSTUDY nations.

Past, Present, and Future of Therapies for Pituitary Neuroendocrine Tumors: Need for Omics and Drug Repositioning Guidance

Innovation roadmaps are important, because they encourage the actors in an innovation ecosystem to creatively imagine multiple possible science future(s), while anticipating the prospects and challenges on the innovation trajectory. In this overarching context, this expert review highlights the present unmet need for therapeutic innovations for pituitary neuroendocrine tumors (PitNETs), also known as pituitary adenomas. Although there are many drugs used in practice to treat PitNETs, many of these drugs can have negative side effects and show highly variable outcomes in terms of overall recovery. Building innovation roadmaps for PitNETs' treatments can allow incorporation of systems biology approaches to bring about insights at multiple levels of cell biology, from genes to proteins to metabolites. Using the systems biology techniques, it will then be possible to offer potential therapeutic strategies for the convergence of preventive approaches and patient-centered disease treatment. Here, we first provide a comprehensive overview of the molecular subtypes of PitNETs and therapeutics for these tumors from the past to the present. We then discuss examples of clinical trials and drug repositioning studies and how multi-omics studies can help in discovery and rational development of new therapeutics for PitNETs. Finally, this expert review offers new public health and personalized medicine approaches on cases that are refractory to conventional treatment or recur despite currently used surgical and/or drug therapy.

Pegvisomant in the treatment of acromegaly

Despite improvements in surgical techniques, current radiotherapy options and development of long-acting somatostatin analogues, biochemical control of acromegaly is not achieved in some patients. The failure to achieve optimal serum growth hormone (RH) and insulin-like growth factor-1 (IGF-1) levels means increased morbidity and mortality of acromegaly patients. The RH receptor antagonist pegvisomant (PEG) is a genetically engineered RH analog that prevents of RH receptor dimerization, i.e. a process that is crucial for the action of RH at the cellular level. The effect of the treatment is suppression of IGF-1 production. In pilot studies, normalization of IGF-1 levels was achieved in up to 90 % of patients receiving PEG. However, PEG efficacy in clinical settings is slightly lower (65 to 97 %) than reported in the key studies. A rare side effect of treatment is elevations of liver transaminases. In addition, pituitary tumor growth progression has been reported in several cases. In this review article, we present long-term data on pegvisomant treatment and discuss its associated risks and benefits.

More than a decade of real-world experience of pegvisomant for acromegaly: ACROSTUDY

OBJECTIVE

To report the final long-term safety and efficacy analyses of patients with acromegaly treated with pegvisomant from the ACROSTUDY.

DESIGN

Global (15 countries), multicentre, non-interventional study (2004-2017).

METHODS

The complete ACROSTUDY cohort comprised patients with acromegaly, who were being treated with pegvisomant (PEGV) prior to the study or at enrolment. The main endpoints were long-term safety (comorbidities, adverse events (AEs), pituitary tumour volumes, liver tests) and efficacy (IGF1 changes).

RESULTS

Patients (n = 2221) were treated with PEGV for a median of 9.3 years (range, 0-20.8 years) and followed up for a median of 7.4 years (range, 0-13.9 years). Before PEGV, 96.3% had received other acromegaly treatments (surgery/radiotherapy/medications). Before PEGV treatment, 87.2% of patients reported comorbidities. During ACROSTUDY, 5567 AEs were reported in 56.5% of patients and of these 613 were considered treatment-related (in 16.5% of patients) and led to drug withdrawal in 1.3%. Pituitary imaging showed a tumour size increase in 7.1% of patients; the majority (71.1%) reported no changes. Abnormal AST or ALT liver tests occurred in 3.2% of patients. IGF1 normalization rate improved over time, increasing from 11.4% at PEGV start to 53.7% at year 1, and reaching 75.4% at year 10 with the use of ≥30 mg PEGV/day in an increasing proportion of patients.

CONCLUSION

This comprehensive review of the complete cohort in ACROSTUDY confirmed the overall favourable benefit-to-risk profile and high efficacy of PEGV as mono- and combination therapy in patients with an aggressive course/uncontrolled/active acromegaly requiring long-term medical therapy for control.

Somatostatin Receptor Subtype Expression in Patients with Acromegaly and Complicated Clinical Course

Somatostatin analogues are considered to be the first line of treatment in acromegaly. Somatostatin analogues of the first generation mainly target the somatostatin receptor (SSTR) subtype 2 and have been proven efficient in the majority of patients with acromegaly. Pasireotide was the first somatostatin analogue also substantially targeting the SSTR subtype 5. An efficient drug for Cushing’s disease tailored to suboptimal-responding patients with acromegaly then became available. We immunohistochemically investigated SSTR subtypes expression in pituitary adenomas from operated acromegaly patients with clinical relapse and a complicated clinical course. Patients received pasireotide in the course of their disease. The predictive value of SSTR subtypes immunhistochemical analysis for the therapeutic response is discussed.

Outcomes of Transsphenoidal Surgery in Growth Hormone-Secreting Pituitary Adenomas

Growth hormone (GH)-secreting pituitary adenomas (PA) make up 15 to 20% of total amount of hormonally active adenomas. In addition to acromegaly and gigantism, these tumors cause deep metabolic disturbances. Its systemic impact leads to increased mortality ratio of 1.32 compared with general population. Surgical removal remains the priority treatment option in controlling acromegaly and provides endocrinologic remission in up to 72% patients. A total of 92 patients were included in the study. All surgeries were performed via microscopic transsphenoidal approach (TSA) by the senior author in our institution between December 2009 and October 2019. Only patients who were followed-up with 75 g oral glucose tolerance tests (OGTTs), GH, and insulin-like growth factor I (IFG-I) measurements preoperatively, 1 week, and every 6 months postoperatively were analyzed. Based on standard preoperative 1.5-T MR imaging with contrast enhancement, the adenomas were identified and distributed according to the size and KNOSP classification. The efficacy depends on KNOSP grade, which is directly correlated with invasiveness to cavernous sinus (CS). Grades 3 and 4 are unfavorable factors influencing prognosis. Excluding grade 0 adenomas, as the surgery was not difficult with the excellent outcomes, we reached 75% (36 out of 48) remission in grade 1 to 2 groups. In contrast, only 17% (2 out of 12) had successful outcomes after surgery alone. In conclusion, the study demonstrates the efficiency of TS surgery in patients with confirmed GH-secreting PA.

Pegvisomant in combination or pegvisomant alone after failure of somatostatin analogs in acromegaly patients: an observational French ACROSTUDY cohort study

OBJECTIVE

After surgery, when somatostatin analogs (SAs) do not normalise IGF-I, pegvisomant (PEG) is indicated. Our aim was to define the medical reasons for the treatment of patients with PEG as monotherapy (M) or combined with SA, either as primary bitherapy, PB (PEG is secondarily introduced after SA) or as secondary bitherapy, SB (SAs secondarily introduced after PEG).

METHODS

We retrospectively analysed French data from ACROSTUDY.

RESULTS

167, 88 and 57 patients were treated with M, PB or SB, respectively, during a median time of 80, 42 and 70 months. The median PEG dose was respectively 15, 10 and 20 mg. Before PEG, the mean IGF-I level did not differ between M and PB but the proportion of patients with suprasellar tumour extension was higher in PB group (67.5% vs. 44.4%, P = 0.022). SB regimen was used preferentially in patients with tumour increase and IGF-I level difficult to normalise under PEG. In both secondary regimens, the decrease of the frequency of PEG's injections, compared to monotherapy was confirmed. However, the mean weekly dose of PEG between M and PB remained the same.

CONCLUSIONS

The medical rationale for continuing SAs rather than switching to PEG alone in patients who do not normalise IGF-I under SAs was a tumour concern with suprasellar extension and tumour shrinkage under SA. A potential explanation for introducing SA in association with PEG appears to be a tumour enlargement and difficulties to normalise IGF-I levels under PEG given alone. In both regimens, the prospect of lowering PEG injection frequency favoured the choice.

Effects of growth hormone receptor antagonism and somatostatin analog administration on quality of life in acromegaly

OBJECTIVE

Acromegaly is associated with impaired quality of life (QoL). We investigated the effects of biochemical control of acromegaly by growth hormone receptor antagonism vs somatostatin analog therapy on QoL.

DESIGN

Cross-sectional.

PATIENTS

116 subjects: n = 55 receiving a somatostatin analog (SSA group); n = 29 receiving pegvisomant (PEG group); n = 32 active acromegaly on no medical therapy (ACTIVE group).

MEASUREMENTS

Acromegaly QoL Questionnaire (AcroQoL), Rand 36-Item Short Form Survey (SF-36) and Gastrointestinal QoL Index (GIQLI); fasting glucose, insulin and IGF-1 levels (LC/MS, Quest Diagnostics).

RESULTS

There were no group differences in mean age, BMI or sex [(whole cohort mean ± SD) age 52 ± 14 years, BMI 30 ± 6 kg/m² , and male sex 38%]. Mean IGF-1 Z-scores were higher in ACTIVE (3.9 ± 1.0) vs SSA and PEG, which did not differ from one another (0.5 ± 0.7 and 0.5 ± 0.7, P < .0001 vs ACTIVE). Eighty-three per cent of PEG previously received somatostatin analogs, which had been discontinued due to lack of efficacy (52%) or side effects (41%). There were no differences in the four QoL primary end-points (AcroQoL Global Score, SF-36 Physical Component Summary Score, SF-36 Mental Health Summary Score and GIQLI Global Score) between SSA and PEG. Higher HbA1c, BMI and IGF-1 Z-scores were associated with poorer QoL in several domains.

CONCLUSION

Our data support a comparable QoL in patients receiving pegvisomant vs somatostatin analogs, despite the fact that the vast majority receiving pegvisomant did not respond to or were not able to tolerate somatostatin analogs.

Medical Treatment Landscape for Active Acromegaly in A Pituitary Center in Israel

OBJECTIVE

To evaluate current real-life experience with medical treatment for active acromegaly in a large cohort.

METHODS

Data on demographic parameters, blood tests, imaging studies, and treatments were extracted from the medical records.

RESULTS

The cohort included 87 patients (43 male) with active acromegaly. The mean age at diagnosis was 40.2±11.4 years, and the mean duration of follow-up was 7.9±5.8 years. Seventy patients presented with a macroadenoma. Mean baseline insulin growth factor 1 (IGF-1) (n = 67) was 3.2±1.9 × upper limit of normal (ULN). Surgery and radiotherapy were performed in 75 and 10 patients, respectively. Currently, 38 subjects receive somatostatin analogues, pegvisomant as a monotherapy is given to 8 patients, pasireotide is given to 17 patients, cabegoline to 4 patients, estrogen to 2 females, and SSAs combined with pegvisomant to 10 patients. Eight patients are not being actively treated, including 4 following radiotherapy. Good biochemical control (IGF-1 <1.3 × ULN) was achieved in 76 patients (87%), and 11 patients (13%) are currently uncontrolled (IGF-1 >1.3 × ULN). Seventy-eight percent of controlled patients are being given 1 medication; 11% are on combination therapy; 4 patients are well controlled after radiotherapy and 2 are partially controlled without any treatment. The main adverse effects of treatment were diabetes mellitus in 7 patients (on pasireotide) and symptomatic cholelithiasis in 5 patients.

CONCLUSION

Active acromegaly can be controlled medically in most patients, with a low rate of adverse effects. This study displays the characteristic variety of treatment options available for active acromegaly.

Combined therapy of somatostatin analogues with pegvisomant for the treatment of acromegaly: a meta-analysis of prospective studies

BACKGROUND

Acromegaly is a rare, chronic and severe disease. Drug therapy including somatostatin analogues (SAs), dopamine receptor agonists and growth hormone receptor antagonists (pegvisomant, PEG) are commonly used to treat patients who do not respond to surgery. The use of combination therapy with PEG and SAs has become more common over the last decade. We performed this study to accurately evaluate the effect of combination therapy of SAs with PEG on acromegalic patients.

METHODS

PubMed, EMBASE, The Cochrane Library, ClinicalTrials.gov, Scopus, Web of Science, Chinese Biomedical Literature Database and Trip database were searched for relevant studies. Prospective clinical trials treating acromegaly with the co-administration of SAs and PEG were included. We performed a meta-analysis by using Stata 12.1. Sensitivity analysis was conducted to explore heterogeneity.

RESULTS

Nine studies were included in this meta-analysis. The overall rate of serum insulin-like growth factor 1 (IGF-1) normalization was 66% (95% CI: 52-78%; I² = 62.59%). The combination therapy did not significantly change patients' fasting plasma glucose (ES: 0.011 mmol*L^- 1; 95% CI: - 0.374 to 0.397 mmol*L^- 1; P = 0.954) or glycosylated haemoglobin (ES: - 0.074%; 95% CI: - 0.166 to 0.315%; P = 0.544) while decreasing the fasting plasma insulin (ES: - 21.487 pmol*L^-1; 95% CI: - 35.713 to - 7.260 pmol*L^-1; P = 0.003). Elevation of liver enzyme levels was found in 14% (95% CI: 8 to 21%) of the patients. There was no significant difference for serious adverse events and treatment discontinuation due to adverse event between SAs monotherapy group and combination therapy group.

CONCLUSIONS

Combined therapy of SAs and PEG effectively normalized IGF-1 levels in most of the patients whose IGF-1 level was greater than the upper limit of normal after high dose SAs monotherapy. The therapy also decreased significantly FPI levels with a neutral effect on glucose parameters in acromegaly patients. Moreover, elevated liver enzyme levels were observed in a small number of patients, which suggests a need for liver function monitoring.

TRIAL REGISTRATION

We have our protocol registered in PROSPERO. (Registration number: CRD42019115549 ).

Management of persistent acromegaly following primary therapy: The current landscape in the UK

Acromegaly is the clinical consequence of chronic exposure of the tissues to excess GH and IGF-I. It is almost exclusively the result of a GH-secreting pituitary adenoma. In addition to the somatic features, uncontrolled acromegaly is associated with a number of complications and excess mortality. Management is aimed at control of the tumour; normalization of GH and IGF-I secretion and relief of symptoms. Initial management of GH-secreting pituitary adenoma is widely accepted as endonasal trans-sphenoidal surgery, with second-line therapy where disease is uncontrolled in most cases being somatostatin analogue therapy. With the combination of surgery and somatostatin analogue therapy, control is achieved in around 75% of patients; however, this leaves a significant proportion of patients requiring multimodality therapy to achieve remission. Within the UK, the health system has finite resources, and decisions for management require consideration of efficacy and cost-effectiveness. To add to the complexity, subtle differences exist in availability of high-cost medications used in the treatment of patients with acromegaly across the devolved nations of the UK. In this article, we discuss options for the management of persistent acromegaly following initial surgery and somatostatin analogue therapy, and explore earlier use of dopaminergics and conservative management.

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.

Long-term safety and treatment outcomes of pegvisomant in Japanese patients with acromegaly: results from the post-marketing surveillance

This post-marketing surveillance is to investigate the long-term safety and effectiveness of the growth hormone receptor antagonist pegvisomant, which is used in patients with acromegaly in routine clinical practice. This surveillance included all cases treated with pegvisomant during the study period from the start of marketing (June 5, 2007) to December 2015. Data for 251 patients with acromegaly treated with pegvisomant were collected from 119 institutions nationwide in Japan. Eighty-five patients received pegvisomant monotherapy throughout their treatment, while 165 patients were treated with somatostatin analogue or dopamine agonist in combination with pegvisomant. Mean dose of pegvisomant was 10.6 ± 6.1 mg/day in the entire treatment period (except for initial loading dose). The incidence of adverse drug reactions was 35.6% (89/250). No new safety concerns related to long-term treatment were observed. The major investigation items of incidence of abnormal liver function and tumor enlargement were 16.0% (40/250), and 5.2% (13/250) respectively. Efficacy at the final evaluation point was 96.4% (217/225) based on the overall clinical judgement of attending physicians, and efficacy in each observation period was over 94%. Improvement in IGF-I levels and clinical symptoms scores were also observed by comparing the data at baseline with each observation point during treatment. IGF-I normalization rate was 68.2% at 5 years. Pegvisomant monotherapy showed similar improvement here as well. These results suggest that long-term treatment with pegvisomant is effective in clinical practice.

Hypertension in Acromegaly in Relationship to Biochemical Control and Mortality: Global ACROSTUDY Outcomes

CONTEXT

Hypertension is a major cardiovascular risk factor related to increased mortality in acromegaly. Surgical cure of acromegaly is associated with improvement in blood pressure levels, however little is known about the effect of pegvisomant (PEGV) treatment in patients with hypertension. This analysis evaluates outcomes in patients with hypertension and acromegaly included in ACROSTUDY.

METHODS

ACROSTUDY is a global non-interventional surveillance study of long-term treatment with PEGV, monitoring its safety and efficacy. The cohort was retrospectively divided in two subgroups: patients with and without hypertension. Stepwise logistic regression and Kaplan-Meyer analyses were performed for testing predictors of mortality.

RESULTS

The total cohort included 2,090 patients with acromegaly treated with PEGV who were followed for a median of 6.8 years (range up to 12.1 years). In ACROSTUDY there were 1,344 patients with hypertension (52.3% males). This subgroup was older, had a higher BMI, and higher prevalence of diabetes, hyperlipidemia, and cardiovascular disease (CVD) when compared to patients without hypertension. During ACROSTUDY, 68 deaths were reported in the hypertension cohort, vs 10 in the cohort without hypertension. Both CVD (p<0.0001) and anterior pituitary deficiencies (p=0.0105) at study entry independently predicted mortality in patients with acromegaly and hypertension; Kaplan-Meier analysis confirmed that CVD significantly impairs survival.

CONCLUSIONS

Hypertension is common in patients with acromegaly and significantly increases mortality, especially when there is concomitant CVD. These data suggest that treatment goals should extend beyond IGF-I normalization, and include optimisation of substitution of pituitary deficiencies and scrutinous screening and treatment of CVD.

Safety and efficacy of repeat radiosurgery for acromegaly: an International Multi-Institutional Study

PURPOSE

Surgical resection is the first line treatment for growth hormone (GH) secreting tumors. Stereotactic radiosurgery (SRS) is recommended for patients who do not achieve endocrine remission after resection. The purpose of this study was to evaluate safety and efficacy of repeat radiosurgery for acromegaly.

METHODS

Three hundred and ninety-eight patients with acromegaly treated with the Gamma Knife radiosurgery (Elekta AB, Stockholm) were identified from the International Gamma Knife Research Foundation database. Among these, 21 patients underwent repeated SRS with sufficient endocrine follow-up and 18 patients had sufficient imaging follow-up. Tumor control was defined as lack of adenoma progression on imaging. Endocrine remission was defined as a normal IGF-1 concentration while off medical therapy.

RESULTS

Median time from initial SRS to repeat SRS was 5.0 years. The median imaging and endocrine follow-up duration after repeat SRS was 3.4 and 3.8 years, respectively. The median initial marginal dose was 17 Gy, and the median repeat marginal dose was 23 Gy. Of the 18 patients with adequate imaging follow up, 15 (83.3%) patients had tumor control and of 21 patients with endocrine follow-up, 9 (42.9%) patients had endocrine remission at last follow-up visit. Four patients (19.0%) developed new deficits after repeat radiosurgery. Of these, 3 patients had neurologic deficits and 1 patient had endocrine deficit.

CONCLUSIONS

Repeat radiosurgery for persistent acromegaly offers a reasonable benefit to risk profile for this challenging patient cohort. Further studies are needed to identify patients best suited for this type of approach.

Pegvisomant in acromegaly: a multicenter real-life study in Argentina

OBJECTIVE

To describe the long term safety and efficacy of pegvisomant (PEGV), and the predictors of treatment response in patients with acromegaly in the real life setting.

SUBJECTS AND METHODS

We retrospectively reviewed the clinical, hormonal and radiological data of acromegalic patients treated with PEGV in 17 Argentine centers.

RESULTS

Seventy-five patients (age range 22-77, 51 females) with acromegaly have been treated with PEGV for up to 118 months (median 27 months). Before PEGV, 97.3% of patients had been treated with medical therapy, surgery and/or radiotherapy, two patients had no previous treatment. At that time, all patients had an IGF-1 above the upper normal limit (ULN) (mean 2.4 x ULN ± 0.98, range 1.25-7). At diagnosis of acromegaly 84% presented macroadenomas, prior to PEGV only 23,5% of patients remained with tumor remnant > 1 cm, the remaining showed normal or less than 1 cm images. Disease control (IGF-1 ≤ 1.2 x ULN) was achieved in 62.9% of patients with a mean dose of 11.8 mg/day. Thirty-four patients (45%) received PEGV monotherapy, while 41 (55%) received combined therapy with either somatostatin analogues and/or cabergoline. Adverse events related to PEGV were: local injection site reaction in 5.3%, elevated liver enzymes in 9.3%, and tumor size growth in 9.8%. Pre-PEGV IGF-I level was the only predictor of treatment response: 2.1 x ULN vs 2.8 x ULN in controlled and uncontrolled patients respectively (p < 0.001).

CONCLUSION

this long term experience indicates PEGV treatment was highly effective and safe in our series of Argentine patients with acromegaly refractory to standard therapies. Arch Endocrinol Metab. 2019;63(4):320-7.

Brazilian multicenter study on pegvisomant treatment in acromegaly

OBJECTIVE

Investigate the therapeutic response of acromegaly patients to pegvisomant (PEGV) in a real-life, Brazilian multicenter study.

SUBJECTS AND METHODS

Characteristics of acromegaly patients treated with PEGV were reviewed at diagnosis, just before and during treatment. All patients with at least two IGF-I measurements on PEGV were included. Efficacy was defined as any normal IGF-I measurement during treatment. Safety data were reviewed. Predictors of response were determined by comparing controlled versus uncontrolled patients.

RESULTS

109 patients [61 women; median age at diagnosis 34 years; 95.3% macroadenomas] from 10 Brazilian centers were studied. Previous treatment included surgery (89%), radiotherapy (34%), somatostatin receptor ligands (99%), and cabergoline (67%). Before PEGV, median levels of GH, IGF-I and IGF-I % of upper limit of normal were 4.3 µg/L, 613 ng/mL, and 209%, respectively. Pre-diabetes/diabetes was present in 48.6% and tumor remnant in 71% of patients. Initial dose was 10 mg/day in all except 4 cases, maximum dose was 30 mg/day, and median exposure time was 30.5 months. PEGV was used as monotherapy in 11% of cases. Normal IGF-I levels was obtained in 74.1% of patients. Glycemic control improved in 56.6% of patients with pre-diabetes/diabetes. Exposure time, pre-treatment GH and IGF-I levels were predictors of response. Tumor enlargement occurred in 6.5% and elevation of liver enzymes in 9.2%. PEGV was discontinued in 6 patients and 3 deaths unrelated to the drug were reported.

CONCLUSIONS

In a real-life scenario, PEGV is a highly effective and safe treatment for acromegaly patients not controlled with other therapies.

Functioning Pituitary Adenomas - Current Treatment Options and Emerging Medical Therapies

Pituitary adenomas are benign tumours comprising approximately 16% of all primary cranial neoplasms. Functioning pituitary adenomas (prolactinomas, somatotroph, corticotroph, thyrotroph and rarely gonadotroph adenomas) cause complex clinical syndromes and require prompt treatment to reduce associated morbidity and mortality. Treatment approaches include transsphenoidal surgery, medical therapy and radiation. Medical therapy is the primary therapy for prolactinomas, and surgery by a skilled neurosurgeon is the first-line approach for other functioning pituitary adenomas. A multimodal treatment is frequently necessary to achieve biochemical and clinical control, especially, when surgery is not curative or when medical therapy fails. Several emerging, novel, medical treatments for acromegaly, Cushing's disease and prolactinomas are in phase II and III clinical trials and may become effective additions to the current drug armamentarium. The availability of various management options will allow an individualised treatment approach based on the unique tumour type, clinical situation and patient preference.

First report on persistent remission of acromegaly after withdrawal of long-term pegvisomant monotherapy

The GH-receptor antagonist pegvisomant (PEG) reduces peripheral IGF-1 synthesis and is used to treat acromegaly patients resistant or intolerant to somatostatin analogues (SSA). Medical therapy is generally life-long in patients with acromegaly, since disease remission is very uncommon after SSA discontinuation and has never been reported after PEG withdrawal. Here, we report for the first time the cases of two acromegaly patients treated with PEG monotherapy for many years because of resistance to SSA, who persistently maintained normal serum IGF-1 levels after PEG withdrawal. The first patient autonomously discontinued PEG treatment after 8 years, while in the second case we stopped the treatment after 11 years, because slight hypertransaminasemia occurred. After PEG discontinuation, in both cases IGF-1 values remained persistently normal and GH during OGTT regularly suppressed. To date, both patients are still in remission. Therefore, we suggest that PEG could exert unknown antitumoral effects in pituitary tumor cells and that long-term PEG treatment can induce acromegaly remission in some patients.

Treatment adherence to pegvisomant in patients with acromegaly in Spain: PEGASO study

PURPOSE

The burden of chronic daily subcutaneous administration of pegvisomant on adherence has not been previously studied. This study was aimed to determine the adherence to pegvisomant treatment in acromegaly patients in the real-world clinical practice setting in Spain.

METHODS

Multicenter, observational, descriptive, cross-sectional study in patients with acromegaly treated with pegvisomant for at least 12 months. Patient adherence was indirectly determined by Batalla and Haynes-Sackett questionnaires and directly by prescription record review. Additionally, treatment satisfaction was assessed by the Treatment Satisfaction with Medicines Questionnaire (SATMED-Q) and treatment convenience by an ad-hoc Pegvisomant questionnaire. Errors in reconstitution and administration process were determined by direct observation.

RESULTS

108 patients were included in the analysis. Rates of adherence varied from 60.7 to 92.1% and did not correlate with disease control. Older patient age and alternative schedules other than daily pegvisomant dosing were associated with lower adherence. Treatment satisfaction and convenience was high, with a mean (SD) total SATMED-Q score of 74.6 ± 15.4 over 100 and a total ad-hoc Pegvisomant questionnaire score of 71.2 ± 15.2 over 100. 34.3% of patients made mistakes during the reconstitution /administration process.

CONCLUSIONS

Patient adherence to pegvisomant was high (60.7-92.1%), but more than a third of the patients in the study made mistakes during the administration process, with a potential impact on disease control. Besides dosing compliance, correct administration of medication should be carefully assessed in these patients.

Acromegaly

Acromegaly is characterized by increased release of growth hormone and, consequently, insulin-like growth factor I (IGF1), most often by a pituitary adenoma. Prolonged exposure to excess hormone leads to progressive somatic disfigurement and a wide range of systemic manifestations that are associated with increased mortality. Although considered a rare disease, recent studies have reported an increased incidence of acromegaly owing to better disease awareness, improved diagnostic tools and perhaps a real increase in prevalence. Acromegaly treatment approaches, which include surgery, radiotherapy and medical therapy, have changed considerably over time owing to improved surgical procedures, development of new radiotherapy techniques and availability of new medical therapies. The optimal use of these treatments will reduce mortality in patients with acromegaly to levels in the general population. Medical therapy is currently an important treatment option and can even be the first-line treatment in patients with acromegaly who will not benefit from or are not suitable for first-line neurosurgical treatment. Pharmacological treatments include somatostatin receptor ligands (such as octreotide, lanreotide and pasireotide), dopamine agonists and the growth hormone receptor antagonist pegvisomant. In this Primer, we review the main aspects of acromegaly, including scientific advances that underlie expanding knowledge of disease pathogenesis, improvements in disease management and new medical therapies that are available and in development to improve disease control.

Diabetes in patients with acromegaly treated with pegvisomant: observations from acrostudy

PURPOSE

To explore the effects of pegvisomant (PEGV) on glucose metabolism in patients with acromegaly within ACROSTUDY, an international, observational, prospective safety surveillance study.

METHODS

Patients were retrospectively divided into two cohorts, with (DM group) or without diabetes mellitus (no-DM). Parameters of glucose metabolism and IGF-I values were analyzed yearly both cross-sectionally for 4 years (yrs) and longitudinally at 1 and 4-5 yrs of PEGV treatment.

RESULTS

Among 1762 patients, 510 (28.9%) had DM before PEGV start. At cross-sectional analyses, in the DM group mean blood glucose was 140.0 ± 58.7 mg/dl at baseline, 116.4 ± 44.8 mg/dl at year 1 and 120.0 ± 44.3 mg/dl at yr 4. Mean HbA1c was 6.6 ± 1.2 % at yr 1 vs. 7.0 ± 1.4 % at baseline. HbA1c was above 6.5% in 61.9% at baseline and ranged from 45.4 to 53.8% at subsequent yearly time points. At the 4-yr longitudinal analysis, in the DM group (n = 109), mean blood glucose decreased by 20.2 mg/dl at yr 4, mean HbA1c was 7.0 ± 1.5% at baseline vs. 6.8 ± 1.4%. Patients achieved IGF-I normalization in 52.1% and 57.4% of cases in the DM and no-DM groups, respectively at 1 year. The mean daily PEGV dose (mg/day) was higher in the DM group (18.2 vs. 15.3) while the absolute change of IGF-I values from baseline was similar in both groups. PEGV was well tolerated in both groups without any unexpected AEs.

CONCLUSIONS

Patients with DM had a moderate decrease in mean fasting glucose values during PEGV treatment.

Resistant Paediatric Somatotropinomas due to AIP Mutations: Role of Pegvisomant

BACKGROUND

Somatotropinomas are rare in childhood and frequently associated with genetic mutations. AIP mutations are found in 20-25% cases and cause aggressive somatotropinomas, often resistant to somatostatin analogues.

AIMS

To assess responses to multimodal therapy including pegvisomant in 2 children with sporadic somatotropinomas due to AIP mutations.

CASE DESCRIPTION

We report 2 children, a boy aged 13 and a girl aged 10, with rapid growth, visual impairment, and growth hormone hypersecretion. Magnetic resonance imaging confirmed a pituitary macroadenoma with parasellar extension in both. Despite multiple surgical attempts to debulk tumour mass, residual tumour persisted. Genetic analysis showed two different AIP mutations (patient 1: c.562delC [p.Arg188Glyfs*8]; patient 2: c.140_ 163del24 [p.Gly47_Arg54del8]). They were initially treated with a long-acting somatostatin analogue (octreotide LAR 30 mg/month) and cabergoline as a dopamine agonist, with the later addition of pegvisomant titrated up to 20 mg/day and with radiotherapy for long-term control. Somatostatin analogue was ceased due to patient intolerance and lack of control. Patient 1 had normalization of insulin-like growth factor-1 (IGF-1) after 5 months of combined therapy with pegvisomant and cabergoline. For patient 2, normalization of IGF-1 was achieved after 2 months of cabergoline and pegvisomant.

CONCLUSION

AIP-associated tumours can be resistant to management with somatostatin analogues. Pegvisomant can safely be used, to normalize IGF-1 levels and help control disease.

Systemic Complications of Acromegaly and the Impact of the Current Treatment Landscape: An Update

Acromegaly is a chronic systemic disease with many complications and is associated with increased mortality when not adequately treated. Substantial advances in acromegaly treatment, as well as in the treatment of many of its complications, mainly diabetes mellitus, heart failure, and arterial hypertension, were achieved in the last decades. These developments allowed change in both prevalence and severity of some acromegaly complications and furthermore resulted in a reduction of mortality. Currently, mortality seems to be similar to the general population in adequately treated patients with acromegaly. In this review, we update the knowledge in complications of acromegaly and detail the effects of different acromegaly treatment options on these complications. Incidence of mortality, its correlation with GH (cumulative exposure vs last value), and IGF-I levels and the shift in the main cause of mortality in patients with acromegaly are also addressed.

Effectiveness and safety of pegvisomant: a systematic review and meta-analysis of observational longitudinal studies

PURPOSE

Acromegaly is a rare disease that often requires drug treatment to achieve control, with pegvisomant being one of the most widely used therapies. In the present paper, we aimed to obtain evidence regarding the effectiveness and safety of pegvisomant by reviewing real-world observational longitudinal studies.

METHODS

A systematic review was performed with a meta-analysis of event rates (95% confidence interval (CI)) using a random effects model. Sensitivity and subgroup analyses were performed (comprehensive meta-analysis 2.0). The systematic review was performed in accordance to preferred reporting items for systematic reviews and meta-analyses, meta-analysis of observational studies in epidemiology, and Cochrane recommendations (PROSPERO register CRD 42017059880). PubMed, Scopus, Web of Science, and SciELO were used to search for literature. Observational studies in patients using pegvisomant for the treatment of acromegaly were included.

RESULTS

Initially, 552 papers were retrieved from the databases; and 31 articles were included in the qualitative analysis and 14 in the quantitative analysis. Eight primary meta-analyses were performed. The overall rate of patients with disease control was of 60.9% (51.8-69.3%; 95% CI). When considering patients under monotherapy, the control rate was 71.7% (64.0-78.4%; 95% CI). Tumor growth was estimated in 7.3% (4.7-11.1%; 95% CI) and elevation of transaminases in 3.0% (1.7-5.2%; 95% CI).

CONCLUSIONS

The real-world data showed that the effectiveness of pegvisomant is not as high as reported in interventional studies. Acromegaly appears to be better controlled when pegvisomant is used as a monotherapy. No serious adverse events were associated with the use of pegvisomant; however, given the high cost of this drug, further studies are required.

Evaluation of the Efficacy and Safety of Switching to Pasireotide in Patients With Acromegaly Inadequately Controlled With First-Generation Somatostatin Analogs

Introduction: Acromegaly is a rare, serious endocrine disorder characterized by excess growth hormone (GH) secretion by a pituitary adenoma and overproduction of insulin-like growth factor I (IGF-I). Transsphenoidal surgery is the treatment of choice, although many patients require additional interventions. First-generation somatostatin analogs (SSAs) are the current standard of medical therapy; however, not all patients achieve control of GH and IGF-I. Outcomes from a Phase IIIb open-label study of patients with uncontrolled acromegaly on first-generation SSAs switching to pasireotide are reported. Methods: Adults with uncontrolled acromegaly (mean GH [mGH] ≥1 μg/L from a five-point profile over 2 h, and IGF-I >1.3× upper limit of normal [ULN]) despite ≥3 months' treatment with maximal approved doses of long-acting octreotide/lanreotide received open-label long-acting pasireotide 40 mg/28 days. Pasireotide dose could be increased (maximum: 60 mg/28 days) after week 12 if biochemical control was not achieved, or decreased (minimum: 10 mg/28 days) for tolerability. Patients who completed 36 weeks' treatment could continue receiving pasireotide during an extension (weeks 36-72) when concomitant medication for acromegaly was permitted. Primary endpoint was proportion of patients with mGH <1 μg/L and IGF-I <ULN at week 36. Biochemical control was also assessed during the extension. Safety was assessed throughout. Results: One hundred and twenty-three patients were enrolled and received pasireotide; 88 patients continued into the extension. Overall, 18 [14.6% (95% CI: 8.9-22.1)] patients achieved mGH <1 μg/L and IGF-I <ULN at week 36; biochemical control was achieved in 42.9% with screening mGH 1.0-2.5 μg/L and 6.4% with screening mGH >2.5 μg/L. For patients who entered the extension, 14.8% (95% CI: 8.1-23.9), 12.5% (95% CI: 6.4-21.3), 14.8% (95% CI: 8.1-23.9) and 11.4% (95% CI: 5.6-19.9) had mGH <1 μg/L and IGF-I <ULN at weeks 36, 48, 60, and 72, respectively. During the overall study period, most frequent investigator-reported drug-related adverse events were hyperglycemia (41.5%), diabetes mellitus (23.6%), and diarrhea (11.4%). Conclusions: Switching to long-acting pasireotide provided biochemical control in some patients, which was sustained with continued treatment. Long-term safety and tolerability of long-acting pasireotide was consistent with the known safety profile. These data support long-acting pasireotide for some patients with acromegaly who are uncontrolled on first generation SSAs. Clinical Trial Registration: clinicaltrials.gov, identifier: NCT02354508.

Long-term treatment with pegvisomant: observations from 2090 acromegaly patients in ACROSTUDY

Objectives ACROSTUDY is an international, non-interventional study of acromegaly patients treated with pegvisomant (PEGV), a growth hormone receptor antagonist and has been conducted since 2004 in 15 countries to study the long-term safety and efficacy of PEGV. This report comprises the second interim analysis of 2090 patients as of May 12, 2016. Methods Descriptive analyses of safety, pituitary imaging and outcomes on PEGV treatment up to 12 years were performed. Results Prior to starting PEGV, 96% of patients had reported surgery, radiation, medical therapy or any combinations of those. At start of PEGV, 89% of patients had IGFI levels above the upper limit of normal (ULN). The percentage of patients with normal IGFI levels increased from 53% at year 1 to 73% at year 10, and the average daily dose of PEGV increased from 12.8 mg (year 1) to 18.9 mg (year 10). A total of 4832 adverse events (AEs) were reported in 1137 patients (54.4%), of which 570 were considered treatment related in 337 patients (16.1%). Serious AEs were reported in 22% of patients, of which 2.3% were considered treatment related. Locally reported MRIs showed most patients (72.2%) had no change in tumor size relative to the prior scan; 16.8% had a decrease, 6.8% an increase and 4.3% both. In patients with normal liver tests at PEGV start, an ALT or AST elevation of >3× ULN at any time point during their follow-up was reported in 3%. Conclusions This second interim analysis confirms that long-term use of PEGV is an effective and safe treatment in patients with acromegaly.

Efficacy and safety of long-acting pasireotide in patients with somatostatin-resistant acromegaly: a multicenter study

INTRODUCTION

Pasireotide, a multi-somatostatin receptor (SSTR)-ligand with high affinity for SSTR₅ was recently approved for acromegaly treatment.

PATIENTS AND METHODS

A retrospective multicenter study investigating the efficacy and safety of long-acting (LAR) pasireotide treatment in 35 patients (20 males) with active acromegaly (28 macroadenomas).

RESULTS

Mean baseline insulin-like growth factor-1 (IGF-1) at diagnosis was 3.1 ± 1.3 × ULN. All but five patients have undergone pituitary surgery and six received sellar radiotherapy. All remained with active acromegaly despite first-generation somatostatin analogue (SSA) treatment. Immediately before pasireotide-LAR initiation, eighteen patients were under SSA monotherapy and one with pegvisomant. The remaining patients received combination therapy with SSA and pegvisomant, n = 9 (two received cabergoline also); SSA and cabergoline, n = 4; pegvisomant and cabergoline, n = 1. Two were untreated. Mean IGF-1 was 1.76 ± 0.9 ULN before pasireotide. Pasireotide-LAR starting dose was 40 mg/4 weeks in most patients. IGF-1 normalized in 19 patients, IGF-1 between 1-1.2 × ULN was reached in five, and in additional two patients IGF-1 was significantly suppressed. No effect was seen in nine patients. Pasireotide dose was reduced by 20 mg in six patients with excellent response, with preserved IGF-1 control in five. Severe headaches in six patients disappeared or improved with pasireotide. Side effects consisted of symptomatic cholelithiasis in one patient and deterioration of glucose control in 22 patients, requiring initiation or intensification of antidiabetic treatment in seventeen. One patient developed diabetic ketoacidosis.

CONCLUSIONS

In the real-life scenario ~54% of patients with acromegaly resistant to first-generation SSA, may normalize IGF-1 with pasireotide; however, 63% experienced glucose control deterioration.

Efficacy and Safety of switching to Pasireotide in Acromegaly Patients controlled with Pegvisomant and Somatostatin Analogues: PAPE extension study

OBJECTIVE

to assess the efficacy and safety after 48 weeks of treatment with pasireotide long-acting-release (PAS-LAR) alone or in combination with pegvisomant in patients with acromegaly. In addition, we assessed the relation between insulin secretion and pasireotide-induced hyperglycemia.

DESIGN

The PAPE extension study is a prospective follow-up study until 48 weeks after the core study of 24 weeks.

METHODS

59 out of 61 patients entered the extension study. Efficacy was defined as the percentage of patients achieving IGF-I normalization (≤ 1.2 x the Upper Limit of Normal (ULN)) at 48-weeks through protocol-based adjustment of pegvisomant and PAS-LAR doses. At baseline, insulin secretion was assessed by an oral glucose tolerance test (OGTT).

RESULTS

At the end of the study median IGF-I was 0.98 x ULN, and 77% of patients achieved normal IGF-I levels with a mean pegvisomant dose of 64 mg/week, and an overall cumulative pegvisomant dose reduction of 52%. Frequency of diabetes mellitus increased from 68% at 24 weeks to 77% at 48 weeks, and 9 patients discontinued PAS-LAR treatment, mainly because of severe hyperglycemia. Pasireotide-induced hyperglycemia was inversely correlated with baseline insulin secretion (r = -0.37, P < 0.005).

CONCLUSIONS

PAS-LAR normalizes IGF-I levels in most acromegaly patients, with a fifty percent pegvisomant-sparing effect. However, PAS-LAR treatment coincided with a high incidence of diabetes mellitus. The risk for developing diabetes during PAS-LAR treatment seems inversely related to insulin secretion at baseline.

Updates in Diagnosis and Treatment of Acromegaly

Acromegaly is a rare disease, caused largely by a growth hormone (GH) pituitary adenoma. Incidence is higher than previously thought. Due to increased morbidity and mortality, if not appropriately treated, early diagnosis efforts are essential. Screening is recommended for all patients with clinical features of GH excess. There is increased knowledge that classical diagnostic criteria no longer apply to all, and some patients can have GH excess with normal GH response to glucose. Treatment is multifactorial and personalised therapy is advised.

A Consensus Statement on acromegaly therapeutic outcomes

The 11th Acromegaly Consensus Conference in April 2017 was convened to update recommendations on therapeutic outcomes for patients with acromegaly. Consensus guidelines on the medical management of acromegaly were last published in 2014; since then, new pharmacological agents have been developed and new approaches to treatment sequencing have been considered. Thirty-seven experts in the management of patients with acromegaly reviewed the current literature and assessed changes in drug approvals, clinical practice standards and clinical opinion. They considered current treatment outcome goals with a focus on the impact of current and emerging somatostatin receptor ligands, growth hormone receptor antagonists and dopamine agonists on biochemical, clinical, tumour mass and surgical outcomes. The participants discussed factors that would determine pharmacological choices as well as the proposed place of each agent in the guidelines. We present consensus recommendations highlighting how acromegaly management could be optimized in clinical practice.

A randomised, open-label, parallel group phase 2 study of antisense oligonucleotide therapy in acromegaly

OBJECTIVE

ATL1103 is a second-generation antisense oligomer targeting the human growth hormone (GH) receptor. This phase 2 randomised, open-label, parallel-group study assessed the potential of ATL1103 as a treatment for acromegaly.

DESIGN

Twenty-six patients with active acromegaly (IGF-I >130% upper limit of normal) were randomised to subcutaneous ATL1103 200 mg either once or twice weekly for 13 weeks and monitored for a further 8-week washout period.

METHODS

The primary efficacy measures were change in IGF-I at week 14, compared to baseline and between cohorts. For secondary endpoints (IGFBP3, acid labile subunit (ALS), GH, growth hormone-binding protein (GHBP)), comparison was between baseline and week 14. Safety was assessed by reported adverse events.

RESULTS AND CONCLUSIONS

Baseline median IGF-I was 447 and 649 ng/mL in the once- and twice-weekly groups respectively. Compared to baseline, at week 14, twice-weekly ATL1103 resulted in a median fall in IGF-I of 27.8% (P = 0.0002). Between cohort comparison at week 14 demonstrated the median fall in IGF-I to be 25.8% (P = 0.0012) greater with twice-weekly dosing. In the twice-weekly cohort, IGF-I was still declining at week 14, and remained lower at week 21 than at baseline by a median of 18.7% (P = 0.0005). Compared to baseline, by week 14, IGFBP3 and ALS had declined by a median of 8.9% (P = 0.027) and 16.7% (P = 0.017) with twice-weekly ATL1103; GH had increased by a median of 46% at week 14 (P = 0.001). IGFBP3, ALS and GH did not change with weekly ATL1103. GHBP fell by a median of 23.6% and 48.8% in the once- and twice-weekly cohorts (P = 0.027 and P = 0.005) respectively. ATL1103 was well tolerated, although 84.6% of patients experienced mild-to-moderate injection-site reactions. This study provides proof of concept that ATL1103 is able to significantly lower IGF-I in patients with acromegaly.

Medical Treatments for Acromegaly: A Systematic Review and Network Meta-Analysis

BACKGROUND

Acromegaly results from the hypersecretion of growth hormone. Because of the low incidence rates of this disease worldwide, few clinical trials evaluating drug treatments have been conducted.

OBJECTIVES

To conduct the first network meta-analysis simultaneously comparing all available drugs used in acromegaly treatment so as to provide more robust evidence in this field.

METHODS

A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Cochrane Collaboration recommendations (PROSPERO database under the registration number CRD42017059880). The electronic searches were conducted in PubMed (MEDLINE), Scopus, and Web of Science databases. Randomized controlled trials comparing any drug for the treatment of acromegaly head-to-head or versus placebo were included. Outcomes concerning the efficacy and safety of treatments were evaluated. The statistical analyses were performed using Aggregate Data Drug Information System version 1.16.8 (drugis.org, Groningen, The Netherlands).

RESULTS

The initial search retrieved 2059 articles. Of these, 10 randomized controlled trials were included in a qualitative analysis and 7 in a quantitative analysis. The network meta-analysis for the efficacy outcome (number of patients achieving insulinlike growth factor 1 control) showed that pegvisomant and lanreotide autogel were statistically superior to placebo (odds ratio [95% credible interval] 0.06 [0.00-0.55] and 0.09 [0.01-0.88]). No further differences were found. The probability rank indicated that pegvisomant and pasireotide have the highest probabilities (33% and 34%, respectively) of being the best therapeutic options. No major side effects were noted.

CONCLUSIONS

Pegvisomant is still a good option for acromegaly treatment, but pasireotide seems to be a promising alternative. Nevertheless, other important key factors such as drug costs and effectiveness (real-world results) should be taken into account when selecting acromegaly treatment.

Treatment escape reduces the effectiveness of cabergoline during long-term treatment of acromegaly in monotherapy or in association with first-generation somatostatin receptor ligands

BACKGROUND

Few studies evaluated the use of cabergoline (CAB) for acromegaly treatment in monotherapy or in combination with first-generation somatostatin receptor ligands (SRLs).

AIM

To evaluate the efficacy, predictors of response and safety of CAB treatment in acromegaly both in monotherapy and in combination with SRLs.

METHODS

We retrospectively collected demographic, biochemical, tumour and treatment data. Short-term disease control was defined as random GH level < 1.0 μg/L and normal age-matched IGF-I level after 3-6 months of treatment with the higher dose used. Long-term disease control was defined as maintenance of normal GH and IGF-I levels at the last visit (at least 9 months of treatment).

RESULTS

Eighty-two patients were studied. The median total time of treatment in monotherapy or in combination with SRLs was 14 months (3-124) and 34 months (3-88), respectively. Short-term disease control was observed in 6 (21%) patients in the monotherapy group and in 20 (32%) in the combination group. Treatment escape was observed in 1 patient after 16 months of CAB monotherapy and in 6 (30%) patients with combination therapy (after a median of 38 months), resulting in long-term disease control of 18% and 23%, respectively. Hyperprolactinemia was a predictor of response to monotherapy and pretreatment GH level to combination treatment.

CONCLUSION

We presented the results of the largest single-centre study with CAB in monotherapy and in combination with SRL. The efficacy of CAB in acromegaly seems to be lower than that of other drugs, and treatment escape may occur after a long-term follow-up.

How to improve effectiveness of pegvisomant treatment in acromegalic patients

PURPOSE

Pegvisomant (PEGV) treatment in acromegaly patients resistant to somatostatin analogues is less effective in the real life than in clinical trials. This is a multicenter, observational, retrospective, longitudinal study. The aim was to detect characteristics which improve long-term PEGV effectiveness.

METHODS

87 acromegalic patients treated with PEGV have been enrolled in seven referral Italian centres. PEGV was administered for up to 4 years, at doses up titrated until IGF-1 normalization or to ≥ 30 mg/day. The rate of patients who reached IGF-1 normalization at last visit has been calculated.

RESULTS

IGF-1 was normalized in 75.9% of patients after 1 year and in 89.6% at last visit. Disease control was associated with lower baseline GH, IGF-1 and IGF-1 xULN and was more frequent when baseline IGF-1 was < 2.7 × ULN (p < 0.02). PEGV dose was dependent on baseline IGF-1 > 2.7 × ULN (p < 0.05) and doses > 1.0 mg/BMI/day were administered more frequently when baseline IGF-1 was > 2.0 × ULN (p = 0.03). PEGV resistance was associated with higher BMI (p = 0.006) and was more frequent when BMI was > 30 kg/m² (p = 0.07). There were no significant differences between patients treated with monotherapy or combined treatment. IGF-1 normalization, PEGV dose and rate of associated treatment were similar between males and females. PEGV effectiveness was independent from previous management. Diabetic patients needed higher doses of PEGV than non-diabetic ones.

CONCLUSIONS

PEGV effectiveness improves when up titration is appropriate. Higher PEGV doses at start and a more rapid up-titration are necessary in patients with obesity and/or IGF-1 > 2.7 × ULN.

Increasing frequency of combination medical therapy in the treatment of acromegaly with the GH receptor antagonist pegvisomant

Pegvisomant monotherapy is effective and safe in treatment of acromegaly. However, some clinicians combine pegvisomant with somatostatin analogues (SSA) or dopamine agonist (DA). In this analysis of ACROSTUDY, a long-term non-interventional study, the use of combination regimens was evaluated. Based on their baseline treatment, 2043 patients were retrospectively categorized as: long-acting SSA combined with pegvisomant, 'Combo SSA' 768 patients (38%); DA combined with pegvisomant, 'Combo DA' 123 (6%); pegvisomant monotherapy, 'Peg mono' 1128 (55%). Treatment patterns changed over the 10-year period, with recent patients more likely to receive any combination (20% in 2003 vs 54% in 2012). Combo SSA use varied widely among countries from 22% to 78%. Exposure periods of the three treatment modalities were defined from pegvisomant start until the last visit in ACROSTUDY; patients could switch treatment categories. At year 4, IGF-I was normal in 62% of Combo SSA, 63% of Combo DA and 65% of Peg mono groups. Pegvisomant was initiated as daily injections in 94% of patients in the Peg mono group, 66% of Combo SSA and 91% of Combo DA patients. During 6169 years of treatment exposure, 3424 adverse events (AEs) were reported in 946 (51%) patients, of which 617 (18%) were serious and 401 (12%) were considered treatment related. The reported incidence of serious AEs and treatment-related non-serious AEs were similar among the three treatment modalities. This analysis describes real-world clinical care and shows favorable efficacy and safety for Peg mono and combinations. Novel findings include an increased use of combination therapy over time and variability in treatment modalities between countries.