Multiple facets in the control of acromegaly

Glucose and lipid levels with lanreotide autogel 120 mg in treatment-naïve patients with acromegaly: data from the PRIMARYS study

OBJECTIVE

Impaired glycaemic control, characteristic of acromegaly, can be exacerbated by treatment with somatostatin analogues (SSAs), particularly those with multireceptor activity. We present data from the PRIMARYS study on the impact of the SSA lanreotide, associated with tumour volume and hormonal improvements, on glucose and other metabolic parameters in acromegaly.

DESIGN

PRIMARYS was a 48-week open-label single-arm phase 3b study of lanreotide autogel 120 mg/4 weeks. A priori and post hoc metabolic profile data are reported for the overall population, patients with/without diabetes and patients achieving/not achieving hormonal control.

PATIENTS

Treatment-naïve adults with pituitary macroadenoma, mean growth hormone >1 μg/l and elevated insulin-like growth factor-1 levels (n = 90).

MEASUREMENTS

Glycaemic parameters [glycated haemoglobin (HbA_1c ) and fasting plasma glucose (FPG) levels] assessed at baseline and weeks 12, 24 and 48. Lipid-profile data (triglycerides, total cholesterol, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol) collected at baseline and study end.

RESULTS

In patients with diabetes (n = 24), HbA_1c showed a clinically relevant decrease during treatment [mean change from baseline to week 48, -1·44% (95% CI: -2·52, -0·36)]. In the overall population, in patients without diabetes, or in patients with/without hormonal control, HbA_1c did not significantly change by week 48. Mean FPG levels showed no significant change by week 48 in all populations. Individually, increases and decreases in glycaemic parameters affected some patients in all populations. Glycaemic status as a composite measure of HbA_1c and FPG (classification as normal, mild or diabetic) was stable from baseline to study end in most patients (overall, 70%; patients with diabetes, 50%; patients without diabetes, 76%), but worsened by week 48 in nine (15%) patients [seven (50%) with diabetes at baseline] and improved in nine (15%) patients (none with diabetes). Changes in lipid profiles were not considered clinically meaningful.

CONCLUSIONS

Glucose and lipid levels were not detrimentally affected in most patients, while only a relatively small proportion showed deterioration in glucose control.

Need for improved monitoring in patients with acromegaly

Acromegaly is a rare and insidious disease characterized by the overproduction of growth hormone (GH) and insulin-like growth factor 1 (IGF1) and is most commonly due to a pituitary adenoma. Patients with acromegaly who experience prolonged exposure to elevated levels of GH and IGF1 have an increased mortality risk and progressive worsening of disease-related comorbidities. Multimodal treatment with surgery, medical therapy, and radiotherapy provides biochemical control, defined by recent acromegaly clinical guidelines from the Endocrine Society as a reduction of GH levels to <1.0 ng/ml and normalization of IGF1 levels, to a substantial proportion of patients and is associated with improved clinical outcomes. Patients with acromegaly, even those without clinical symptoms of disease, require long-term monitoring of GH and IGF1 levels if the benefits associated with biochemical control are to be maintained and the risk of developing recurrent disease is to be abated. However, suboptimal monitoring is common in patients with acromegaly, and this can have negative health effects due to delays in detection of recurrent disease and implementation of appropriate treatment. Because of the significant health consequences associated with prolonged exposure to elevated levels of GH and IGF1, optimal monitoring in patients with acromegaly is needed. This review article will discuss the biochemical assessments used for therapeutic monitoring in acromegaly, the importance of monitoring after surgery and medical therapy or radiotherapy, the consequences of suboptimal monitoring, and the need for improved monitoring algorithms for patients with acromegaly.

LIMITATIONS OF CURRENT APPROACHES FOR THE TREATMENT OF ACROMEGALY

OBJECTIVE

Acromegaly is a rare disease characterized by hypersecretion of growth hormone (GH), typically from a benign pituitary somatotroph adenoma, that leads to subsequent hypersecretion of insulin-like growth factor 1 (IGF-1). Patients with acromegaly have an increased risk of mortality and progressive worsening of comorbidities. Surgery, medical therapy, and radiotherapy are currently available treatment approaches for patients with acromegaly, with overall therapeutic goals of lowering GH levels and achieving normal IGF-1 levels, reducing tumor size, improving comorbidities, and minimizing mortality risk. Although surgery can lead to biochemical remission in some patients with acromegaly, many patients will continue to have uncontrolled disease and require additional treatment.

METHODS

We reviewed recently published reports and present a summary of the safety and efficacy of current treatment modalities for patients with acromegaly.

RESULTS

A substantial proportion of patients who receive medical therapy or radiotherapy will have persistently elevated GH and/or IGF-1. Because of the serious health consequences of continued elevation of GH and IGF-1, there is a need to improve therapeutic approaches to optimize biochemical control, particularly in high-need patient populations for whom current treatment options provide limited benefit.

CONCLUSION

This review discusses current treatment options for patients with acromegaly, limitations associated with each treatment approach, and areas within the current treatment algorithm, as well as patient populations for which improved therapeutic options are needed. Novel agents in development were also highlighted, which have the potential to improve management of patients with uncontrolled or persistent acromegaly.

Treatment of acromegaly in the era of personalized and predictive medicine

Acromegaly is a chronic disorder usually diagnosed late in the disease evolution. Such delayed diagnosis, together with the inability to achieve the treatment goals of normalizing biochemical disease markers and controlling tumour mass may result in substantial morbidity and mortality. Somatostatin analogues (SSA) are accepted as first-line medical therapy or as second-line therapy in patients undergoing unsuccessful surgery and are considered a cornerstone in the treatment of acromegaly. However, because a high percentage of patients experience SSA medical treatment failure, the identification of biomarkers associated with a successful or unsuccessful response to all classes of medical therapy would help in the choice of treatment and potentially allow for a quicker normalization of biochemical parameters. The current treatment algorithms for acromegaly are based upon a "trial-and-error" approach with additional treatment options provided when disease is not controlled. In many other diseases, therapeutic algorithms have been evolving towards personalized treatment with the medication that best matches individual disease characteristics, using biomarkers that identify therapeutic response. Additionally, a personalized approach to complementary treatment of comorbidities present in the acromegalic patient is also required. This review will discuss the development of a potential treatment algorithm for acromegaly addressing the biochemical control of the disease as well of its associated comorbidities, under a personalized approach based upon markers of prognostic and predictive significance, such as tumour size, MRI adenoma signal, GH value after acute octreotide test, granular adenoma pattern, Ki-67, somatostatin receptor phenotype, aryl hydrocarbon-interacting protein expression, gsp mutations, RAF kinase activity, E-cadherin and beta-arrestin-1.

A practical approach to acromegaly management in Latin America

INTRODUCTION

Evidence-based treatment guidelines have undoubtedly advanced medical practice and supported optimal management of acromegaly, but their application may be hampered by limited access to the latest treatment options.

METHODS

In this retrospective, narrative review, the authors revisited existing treatment guidelines for acromegaly in Latin America. These were considered in conjunction with published evidence chosen at the authors' discretion.

FINDINGS

In a socially and economically diverse region, such as Latin America, any regional practice guidelines need to appreciate that recommended treatment options, such as surgery by expert pituitary surgical teams and drug therapies, especially somatostatin analogs, are often not available due to limited resources. In these instances, physicians may be obliged to apply less effective therapeutic options.

CONCLUSIONS

The current article looks at the practical aspects of acromegaly management in Latin America and discusses this in the context of existing guidelines. Furthermore, we consider potential strategies to make better use of resources through combination and multimodal approaches to treatment.