Discontinuation of octreotide LAR after long term, successful treatment of patients with acromegaly: is it worth trying?

Atypical Course of a Patient With AIP-Positive Acromegaly: From GH Excess to GH Deficiency and Back to GH Excess

Acromegaly/giantism results from the chronic excess of growth hormone (GH) and insulin-like growth factor-1 (IGF-1), in more than 96% of cases, due to a GH-secreting pituitary adenoma. Primary treatment of choice is transsphenoidal resection of the adenoma. More than 30% to 40% of operated cases require adjunctive forms of treatment, be it pharmacological or radiotherapeutical. The multimodal treatment of acromegaly has resulted in substantial improvements in the quality of life and life expectancy of these patients. We herein present the complex case of a patient with acromegaly due to a mammosomatotrope adenoma, with a germ-line AIP (aryl hydrocarbon receptor-interacting protein) mutation, who had a chronic and protracted course of more than 15 years during which he was treated with surgery, somatostatin receptor ligands, dopamine agonist, and the GH receptor antagonist pegvisomant. At one point, he was able to come off medications and was even found to be transiently GH-deficient, only to develop acromegaly again after a couple of years.

Prescription patterns of somatostatin analogs in patients with acromegaly and neuroendocrine tumors

PURPOSE

Acromegaly and neuroendocrine tumors are rare diseases that, under certain conditions, can be treated with somatostatin analogs. The aim was to determine the prescription patterns of somatostatin analogs in a group of patients with acromegaly and neuroendocrine tumors affiliated with the Colombian Health System.

METHODS

A retrospective study. A cohort of patients from a drug dispensing database that collected all prescriptions of long-acting somatostatin analogs (octreotide, lanreotide, pasireotide). Sociodemographic variables, clinical variables (diagnosis and comorbidities) and pharmacological therapy variables (dose, changes, persistence of use, comedications) were considered.

RESULTS

A total of 213 patients were identified, including 139 (65.3%) with acromegaly and 74 (34.7%) with neuroendocrine tumors. There was a predominance of women (58.7%) and a mean age of 59.7 ± 14.5 years. The most commonly used medications were lanreotide autogel (n = 107; 50.2%), octreotide LAR (n = 102; 47.9%) and pasireotide LAR (n = 4; 1.9%). During follow-up, 11.3% of patients experienced modifications of therapy, with a mean duration from the beginning of treatment to the change in medication of 25 ± 15.9 months. A total of 48.9% of the patients with acromegaly and 87.1% of individuals with neuroendocrine tumors received maximum approved doses of the drug.

CONCLUSION

Patients with acromegaly and neuroendocrine tumors in Colombia are mainly women and are most frequently treated with lanreotide autogel for acromegaly and with octreotide LAR for neuroendocrine tumors. In addition, a high proportion are managed with maximum doses of long-acting somatostatin analogs.

Persistent remission of acromegaly in a patient with GH-secreting pituitary adenoma: Effect of treatment with pasireotide long-acting release and consequence of treatment withdrawal

WHAT IS KNOWN AND OBJECTIVE

Somatostatin analogues (SSAs) have been used for the treatment of acromegaly for several decades. However, a unified conclusion on the duration of SSAs therapy or the possibility of medication withdrawal is still missing. We aimed to report a case of acromegaly cured by pasireotide long-acting release (PAS-LAR) and provide some information on the withdrawal of SSAs after stable regression in acromegalic patients.

CASE SUMMARY

A 55-year-old male patient, who was diagnosed with acromegaly and refused surgery and received PAS-LAR as initial treatment, had maintained stability for ten years under the regular treatment with PAS-LAR. The pituitary microadenoma was also decreased during the treatment. After the PAS-LAR discontinuation for 21 months, no evidence of biochemical or clinical recurrence was found in this patient.

WHAT IS NEW AND CONCLUSION

The use of PAS-LAR in a subset of naive-treatment patients is promising to induce long-term regression. A subgroup of patients with mild and well-controlled acromegaly might hope for perpetual remission after the withdrawal of medication.

Long-term remission of acromegaly after somatostatin analogues withdrawal: a single-centre experience

PURPOSE

A long-lasting remission of acromegaly after somatostatin analogues (SAs) withdrawal has been described in some series. Our aim was to update the disease evolution after SAs withdrawal in a cohort of acromegalic patients.

METHODS

We retrospectively evaluated 21 acromegalic patients previously included in a multicentre study (Ronchi et al. 2008), updating data at the last follow-up. We added further 8 patients selected for SAs withdrawal between 2008-2018. Pituitary irradiation represented an exclusion criterion. The withdrawal was suggested after at least 9 months of clinical and hormonal disease control. Clinical and biochemical data prior and after SAs withdrawal were analysed.

RESULTS

In the whole cohort (29 patients) mean age was 50 ± 14.9 years and 72.4% were females. In 69% pituitary surgery was previously performed. Overall, the median time of treatment before SAs withdrawal was 53 months (IQR = 24-84). At the last follow up in 2019, 23/29 patients (79.3%) had a disease relapse after a median time of 6 months (interquartile range or IQR = 3-12) from the drug suspension, while 6/29 (20.7%) were still on remission after 120 months (IQR = 66-150). IGF-1 levels were significantly lower before withdrawal in patients with persistent remission compared to relapsing ones (IGF-1 SDS: -1.5 ± 0.6 vs -0.11 ± 1, p = 0.01). We did not observe any other difference between patients with and without relapse, including SAs formulation, dosage and treatment duration.

CONCLUSION

A successful withdrawal of SAs is possible in a subset of well-controlled acromegalic patients and it challenges the concept that medical therapy is a lifelong requirement.

Maintenance of Acromegaly Control in Patients Switching From Injectable Somatostatin Receptor Ligands to Oral Octreotide

PURPOSE

The phase 3 CHIASMA OPTIMAL trial (NCT03252353) evaluated efficacy and safety of oral octreotide capsules (OOCs) in patients with acromegaly who previously demonstrated biochemical control while receiving injectable somatostatin receptor ligands (SRLs).

METHODS

In this double-blind study, patients (N = 56) stratified by prior SRL dose were randomly assigned 1:1 to OOC or placebo for 36 weeks. The primary end point was maintenance of biochemical control at the end of treatment (mean insulin-like growth factor 1 [IGF-1] ≤ 1.0 × upper limit of normal [ULN]; weeks 34 and 36). Time to loss of IGF-1 response and proportion requiring reversion to injectable SRLs were assessed as broader control measures.

RESULTS

Mean IGF-1 measurements were 0.80 and 0.97 × ULN for OOC and 0.84 and 1.69 × ULN for placebo, at baseline and end of treatment, respectively. Mean growth hormone (GH) changed from 0.66 to 0.60 ng/mL for OOCs and 0.90 to 2.57 ng/mL for placebo. Normalization of IGF-1 levels (≤ 1.0 × ULN) was maintained in 58.2% for OOCs vs 19.4% for placebo (P = .008); GH levels were maintained (< 2.5 ng/mL) in 77.7% for OOC vs 30.4% for placebo (P = .0007). Median time to loss of response (IGF-1 > 1.0 or ≥ 1.3 × ULN definitions) for patients receiving placebo was 16 weeks; for patients receiving OOCs, it was not reached for both definitions during the 36-week trial (P < .0001). Of the patients in the OOC group, 75% completed the trial on oral therapy. The OOC safety profile was consistent with previous SRL experience.

CONCLUSIONS

OOCs may be an effective therapy for patients with acromegaly who previously were treated with injectable SRLs.

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.

Surgical-pharmacological interactions in the treatment of acromegaly

INTRODUCTION

Acromegaly requires a multimodal treatment approach that includes surgery by an expert pituitary neurosurgeon, pharmacological treatment with one or more of the available drugs and radiation therapy. These treatment alternatives are not mutually exclusive but rather complement each other when properly indicated in the individual patient. In this review, we summarize and analyze the available data concerning the choice of the surgical approach (microscopy vs. endoscopy) and the interactions between medical treatment with somatostatin analogs and pituitary surgery.

AREAS COVERED

Technical aspects, complications and outcome of transsphenoidal surgery (TSS); Advantages and disadvantages of the microscopic and endoscopic approaches; Safety and efficacy of somatostatin analogs (SSA); Primary pharmacological therapy versus primary TSS; Benefits of the preoperative treatment with SSA; and the effect of surgical tumor debulking in the therapeutic response to SSA.

EXPERT COMMENTARY

Continuing efforts at improving surgical techniques and at generating more efficacious pharmacological therapies for acromegaly are likely to improve the outcome of these patients. However, an integral approach of the patient aimed not only at achieving biochemical criteria of cure but also at treating the individual comorbidities is mandatory to improve the quality of life of these patients and to reduce their mortality rate.

How are growth hormone and insulin-like growth factor-1 reported as markers for drug effectiveness in clinical acromegaly research? A comprehensive methodologic review

OBJECTIVE

In rare disease research, most randomized prospective clinical trials can only use limited number of patients and are comprised of highly heterogeneous populations. Therefore, it is crucial to report the results in such a manner that it allows for comparison of treatment effectiveness and biochemical control between studies. The aim of this review was to investigate the current methods that are being applied to measure and report growth hormone (GH) and insulin-like growth factor-1 (IGF-1) as markers for drug effectiveness in clinical acromegaly research.

SEARCH STRATEGY

A systematic search of recent prospective and retrospective studies, published between 2012 and 2017, that studied the effects of somatostatin analogues or dopamine agonists in acromegaly patients was performed. The markers of interest were GH, IGF-1, and the suppression of GH after an oral glucose tolerance test (OGTT). Additionally, the use of pharmacokinetic (PK) measurements in these studies was analyzed. The sampling design, cut-off for biochemical control, reported units, and used summary statistics were summarized.

RESULTS

A total of 49 articles were selected out of the 263 screened abstracts. IGF-1 concentrations were measured in all 49 studies, GH in 45 studies, and an OGTT was performed in 11 studies. A wide range of different cut-off values and sampling designs were used to determine biochemical control in acromegaly patients. The summary statistics were reported in various ways, with the percentage of biochemical control most frequently used. Nine studies sampled the PK at one or more time points. Non-compartmental analyses were commonly performed on the available PK data.

CONCLUSIONS

The way GH and IGF-1 are measured and reported in acromegaly research varies considerably. A consensus on how to report study results would enable better comparisons between studies, thereby improving evidence based decision making to optimize treatment in acromegaly.

Remission of acromegaly after treatment withdrawal in patients controlled by cabergoline alone or in combination with octreotide: results from a multicenter study

PURPOSE

Remission of acromegaly has been reported after somatostatin analogs withdrawal, but not after withdrawal of combination therapy with cabergoline, and only in case reports of patients controlled by cabergoline alone.

METHODS

To establish the remission rates (normal IGF-1 for age/sex: IGF-1 ≤ 1.00 xULN) after withdrawal of combined treatment with octreotide LAR and cabergoline and of cabergoline alone, we prospectively studied 16 patients with acromegaly controlled by those treatments in the preceding 2 years as part of a larger study on remission of acromegaly after withdrawal of different medical treatments.

RESULTS

Among 97 patients with controlled acromegaly included in the entire study, only 16 patients had been on combination therapy (n = 12) or cabergoline alone (n = 4). At 8 weeks after treatment withdrawal, three patients (19%) were in remission (short-term remission). At 60 weeks (long-term remission), IGF-1 levels were still in the normal range in two patients (12.5%) and remained normal up to 108 weeks after treatment withdrawal (last visit). One patient had been treated with cabergoline alone and another one with combination of octreotide and cabergoline before treatment withdrawal.

CONCLUSION

Remission of acromegaly after treatment withdrawal seems to be uncommon in patients controlled by cabergoline, either as monotherapy or in combination with octreotide. In the future, larger studies and/or meta-analysis will be necessary to accurately establish the remission rates of acromegaly after withdrawal of cabergoline with or without somatostatin analogs.

Somatostatin analogues in acromegaly and gastroenteropancreatic neuroendocrine tumours: past, present and future

Acromegaly is a hormonal disorder that arises when the pituitary gland secretes excess growth hormone (GH), which in turn stimulates a concomitant increase in serum insulin-like growth factor 1 (IGF-1) levels. Gastroenteropancreatic neuroendocrine tumours (GEP-NET) constitute a heterogeneous group of tumours that can secrete serotonin and a variety of peptide hormones that may cause characteristic symptoms known as carcinoid syndrome or other symptoms and hormonal hypersecretion syndromes depending on the tumour's site of origin. Current medical therapy for the treatment of acromegaly and GEP-NET involves the administration of somatostatin analogues that effectively suppress excess hormone secretion. After its discovery in 1979, octreotide became the first synthetic biologically stable somatostatin analogue with a short-acting formulation of octreotide introduced into clinical practice in the late 1980s. Lanreotide, another somatostatin analogue, became available in the mid-1990s initially as a prolonged-release formulation administered every 10 or 14 days. Long-acting release formulations of both octreotide (Sandostatin LAR and Novartis) and lanreotide (Somatuline Autogel, Ipsen), based on microparticle and nanoparticle drug-delivery technologies, respectively, were later developed, which allowed for once-monthly administration and improved convenience. First-generation somatostatin analogues remain one of the cornerstones of medical therapy in the management of pituitary and GEP-NET hormone hypersecretion, with octreotide having the longest established efficacy and safety profile of the somatostatin analogue class. More recently, pasireotide (Signifor), a next-generation multireceptor-targeted somatostatin analogue, has emerged as an alternative therapeutic option for the treatment of acromegaly. This review summarizes the development and clinical success of somatostatin analogues.

Active postoperative acromegaly: sustained remission after discontinuation of somatostatin analogues

In patients with active acromegaly after pituitary surgery, somatostatin analogues are effective in controlling the disease and can even be curative in some cases. After treatment discontinuation, the likelihood of disease recurrence is high. However, a small subset of patients remains symptom-free after discontinuation, with normalized growth hormone (GH) and insulin-like growth factor (IGF1) levels. The characteristics of patients most likely to achieve sustained remission after treatment discontinuation are not well understood, although limited evidence suggests that sustained remission is more likely in patients with lower GH and IGF1 levels before treatment withdrawal, in those who respond well to low-dose treatment, in those without evidence of adenoma on an MRI scan and/or in patients who receive long-term treatment. In this report, we describe the case of a 56-year-old female patient treated with lanreotide Autogel for 11 years. Treatment was successfully discontinued, and the patient is currently disease-free on all relevant parameters (clinical, biochemical and tumour status). The successful outcome in this case adds to the small body of literature suggesting that some well-selected patients who receive long-term treatment with somatostatin analogues may achieve sustained remission.

CLINICAL OUTCOMES AND SELF-REPORTED SYMPTOMS IN PATIENTS WITH ACROMEGALY: AN 8-YEAR FOLLOW-UP OF A LANREOTIDE STUDY

OBJECTIVE

The aim of this study was to evaluate the proportion of patients with acromegaly who remained on long-term lanreotide depot after completion of an open-label multicenter phase III clinical trial (SALSA: A Multi Center Open Label Study to Assess the Ability of Subjects With Acromegaly or Their Partners to Administer Somatuline Autogel), compare baseline and long-term follow-up symptoms scores, and correlate scores with individual longitudinal clinical outcomes.

METHODS

Records of all subjects previously enrolled at the Massachusetts General Hospital site of SALSA were reviewed. Those who remained on lanreotide were interviewed and asked to complete a questionnaire that they had filled out in SALSA in 2007 regarding their current symptomatology and injection side effects, as well as to complete the Acromegaly Quality of Life Questionnaire. Furthermore, clinical, biochemical, and radiographic data related to acromegaly and its comorbidities were tracked throughout follow-up.

RESULTS

Six out of 7 patients chose to remain on lanreotide, and 5 of them continued lanreotide depot through last follow-up, for up to 8 years or in 1 case until death. In all cases, lanreotide remained well tolerated, and insulin-like growth factor-1 levels and pituitary imaging remained well controlled on stable doses. While comorbidities persisted or developed, the self-reported symptom score after up to 8 years of therapy showed a significant decrease in frequency or resolution in symptoms that were reported at baseline.

CONCLUSION

This study shows a significant decrease in frequency or resolution in self-reported symptoms in well-controlled patients receiving long-term lanreotide therapy.

ABBREVIATIONS

AcroQoL = Acromegaly Quality of Life Questionnaire GH = growth hormone GI = gastrointestinal IGF-1 = insulin-like growth factor-1 SALSA = A Multi Center Open Label Study to Assess the Ability of Subjects With Acromegaly or Their Partners to Administer Somatuline Autogel.

The Role of Isotretinoin Therapy for Cushing's Disease: Results of a Prospective Study

Objective. This prospective open trial aimed to evaluate the efficacy and safety of isotretinoin (13-cis-retinoic acid) in patients with Cushing's disease (CD). Methods. Sixteen patients with CD and persistent or recurrent hypercortisolism after transsphenoidal surgery were given isotretinoin orally for 6-12 months. The drug was started on 20 mg daily and the dosage was increased up to 80 mg daily if needed and tolerated. Clinical, biochemical, and hormonal parameters were evaluated at baseline and monthly for 6-12 months. Results. Of the 16 subjects, 4% (25%) persisted with normal urinary free cortisol (UFC) levels at the end of the study. UFC reductions of up to 52.1% were found in the rest. Only patients with UFC levels below 2.5-fold of the upper limit of normal achieved sustained UFC normalization. Improvements of clinical and biochemical parameters were also noted mostly in responsive patients. Typical isotretinoin side-effects were experienced by 7 patients (43.7%), though they were mild and mostly transient. We also observed that the combination of isotretinoin with cabergoline, in relatively low doses, may occasionally be more effective than either drug alone. Conclusions. Isotretinoin may be an effective and safe therapy for some CD patients, particularly those with mild hypercortisolism.

Medical Treatment of Acromegaly with Dopamine Agonists or Somatostatin Analogs

Treatment of acromegaly aims to correct (or prevent) tumor compression of surrounding tissues by excising the disease-causing lesion and reduce growth hormone (GH) and IGF-1 levels to normal values. When surgery (the usual first-line treatment) fails to correct GH/IGF-1 hypersecretion, medical treatment with dopamine agonists (DAs; particularly cabergoline) or somatostatin analogs (SAs) can be used. The GH receptor antagonist pegvisomant is helpful in patients who are totally or partially resistant to SAs and can be given in association with both SAs and/or DAs. Thanks to this multistep therapeutic strategy, adequate hormonal disease control is achieved in most patients, giving them normal life expectancy. Comorbidities associated with acromegaly generally improve after treatment, but persistent sequelae may nonetheless impair quality of life.

Recent advances in the management of acromegaly

Acromegaly is a rare condition of GH excess associated with significant morbidities (e.g. hypertension, glucose intolerance or diabetes mellitus, cardiac, cerebrovascular, respiratory disease and arthritis) and, when uncontrolled, high mortality. Surgery, medical treatment and radiotherapy remain our therapeutic tools. Advances in these options during the last years have offered further perspectives in the management of patients and particularly those with challenging tumours; the impact of these on the long-term morbidity and mortality remains to be assessed.

Diagnosis, treatment and clinical perspectives of acromegaly

Acromegaly is an insidious disease of the pituitary caused by a growth hormone-secreting adenoma. Generally, the diagnosis is made rather late in the course of the disease. Currently, acromegaly can be cured in about half of the patients with the disease by expert surgery. The remainder of non-surgically cured patients often can be effectively treated with somatostatin analogs; either with the new generation of dopaminergic drugs or with Pegvisomant, a GH-receptor blocking agent. However, at the time of diagnosis many patients suffer from serious comorbidities, including hypertension, heart disease, arthrosis, sleep apnea and diabetes mellitus. Recent reports have shown that mortality risk can be normalized. Nevertheless, all efforts should be undertaken to treat comorbidities. New strategies for surgery and medical treatment are discussed.

60 YEARS OF NEUROENDOCRINOLOGY: Acromegaly

Acromegaly (ACM) is a chronic, progressive disorder caused by the persistent hypersecretion of GH, in the vast majority of cases secreted by a pituitary adenoma. The consequent increase in IGF1 (a GH-induced liver protein) is responsible for most clinical features and for the systemic complications associated with increased mortality. The clinical diagnosis, based on symptoms related to GH excess or the presence of a pituitary mass, is often delayed many years because of the slow progression of the disease. Initial testing relies on measuring the serum IGF1 concentration. The oral glucose tolerance test with concomitant GH measurement is the gold-standard diagnostic test. The therapeutic options for ACM are surgery, medical treatment, and radiotherapy (RT). The outcome of surgery is very good for microadenomas (80-90% cure rate), but at least half of the macroadenomas (most frequently encountered in ACM patients) are not cured surgically. Somatostatin analogs are mainly indicated after surgical failure. Currently their routine use as primary therapy is not recommended. Dopamine agonists are useful in a minority of cases. Pegvisomant is indicated for patients refractory to surgery and other medical treatments. RT is employed sparingly, in cases of persistent disease activity despite other treatments, due to its long-term side effects. With complex, combined treatment, at least three-quarters of the cases are controlled according to current criteria. With proper control of the disease, the specific complications are partially improved and the mortality rate is close to that of the background population.

Discontinuation of somatostatin analogs while acromegaly is in long-term remission

PURPOSE

We aimed to evaluate the disease activity of medically controlled patients with acromegaly after withdrawal of somatostatin receptor ligands (SRL).

METHODS

Sixteen patients who were on a stable dose of SRL for more than 2 years and had at least 1 year of remission were included in the study. Five patients were on 10 mg, four were on 20 mg and three were on 30 mg of octreotide; whereas for lanreotide, one was on 60 mg, two were on 90 mg, and one was on 120 mg. All patients had received SRL with 28-day intervals. Basal GH, IGF1, glucose-suppressed GH levels were measured with 3-month intervals for a total of 12 months after withdrawal. Sella MRI evaluation was obtained at 6-month intervals. If the nadir GH level after glucose suppression was >1 ng/ml or IGF1 was above the normal limits during the follow-up period, SRL was restarted.

RESULTS

Three months after stopping SRL, 10 (63%) had biochemical disease recurrence. After 12 months of follow-up, in total 13 (81%) of the patients recurred. The final basal GH levels before withdrawal, basal GH at month-3, and glucose suppressed GH levels were significantly lower in patients with sustained remission (p = 0.003, p < 0.001, and p = 0.001). Basal GH and glucose suppressed GH levels at month-3 were correlated with the basal GH levels at month-0 (r = 0.6, p = 0.008 and r = 0.5, p = 0.03).

CONCLUSION

The final GH levels prior to discontinuation of SRL should be taken into consideration in patients with acromegaly in long-term remission. Moreover, the first visit 3 months after withdrawal is critically important for determining the future status of remission.

Octreotide LAR treatment of acromegaly in "real life": long-term outcome at a tertiary care center

OBJECTIVE

To report our day-to day experience with the long-term use of octreotide LAR in the treatment of acromegaly.

PATIENTS AND METHODS

Patients with acromegaly managed between 2003 and 2012 with octreotide LAR for a median of 27 months (interquartile ranges 12-60) and who had not received radiation therapy or concomitant treatment with cabergoline were retrospectively evaluated. Both primarily treated patients (n = 33) and patients who received octreotide after failed pituitary surgery (adjunctive treatment, n = 124) were included. Full biochemical response was defined as the achievement of a GH <2.5 ng/mL and an IGF-1 <1.2 times the upper limit of normal (× ULN); we also evaluated efficacy using a GH cut off of <1 ng/mL.

RESULTS

Over 60% of the patients achieved a GH of <2.5 ng/mL. The combined GH (<2.5 ng/mL) and IGF-1 (<1.2 × ULN) target was achieved by 35.5 and 33.6% of the patients treated primarily and adjunctively, respectively; these figures dropped to 22.6 and 23% when using a GH target of <1 ng/mL. All patients reported a significant improvement in acromegalic symptoms. Lower pretreatment GH and IGF-1 levels were both associated with a higher probability of achieving the composite biochemical target.

CONCLUSION

Currently recommended GH and IGF-1 targets are reached by <36% of patients treated with octreotide LAR in a day-to day practice context. Nevertheless, in most instances a clinical benefit and an improvement in biochemical markers can be clearly documented.

Can we predict long-term remission after somatostatin analog withdrawal in patients with acromegaly? Results from a multicenter prospective trial

Somatostatin analogs (SSAs) represent the mainstay of therapy in acromegaly. One of the potential disadvantages is the expected need to maintain therapy indefinitely in previously non-irradiated patients. The aim of this multicenter prospective open trial was to evaluate the likelihood of successful discontinuation of SSA therapy in well-controlled acromegalic patients who fulfilled very strict criteria: two or more years of treatment with the long-acting SSA octreotide LAR (OCT-LAR), a stable dose and injections interval every 4 weeks or longer for the previous year, GH levels <2.5 ng/ml and normal IGF-1 levels for age, a tumor remnant <10 mm, no history of radiotherapy, and no use of cabergoline or pegvisomant over the previous 6 months. Disease recurrence was defined as an increase of IGF-1 to levels above 1.2-fold the upper limit of normal (ULN). Out of 220 patients, 20 patients (12 women and 8 men; mean age, 48.1 ± 10.3 years; age range, 27-64) treated for 2.74 ± 0.64 years (range, 2.0-4.4) were included in this prospective study and OCT-LAR therapy was stopped. Four patients (20 %) remained without clinical and biochemical/neuroradiological evidence of disease recurrence after 12-18 months of follow-up. Sixteen patients (80 %) relapsed biochemically within 9 months after drug withdrawal and restarted OCT-LAR at the same previous dose. Compared to recurring subjects, non-recurring patients had significantly lower mean IGF-1 (× ULN) levels but there were some overlapping values in both groups. No other characteristic could be identified as a predictor of successful OCT-LAR discontinuation. Our findings demonstrated that OCT-LAR withdrawal, though rare, is possible in well-selected acromegalic patients treated for at least 2 years and considered optimally controlled in hormonal and neuroradiological terms.

Expert consensus document: A consensus on the medical treatment of acromegaly

In March 2013, the Acromegaly Consensus Group met to revise and update guidelines for the medical treatment of acromegaly. The meeting comprised experts skilled in the medical management of acromegaly. The group considered treatment goals covering biochemical, clinical and tumour volume outcomes, and the place in guidelines of somatostatin receptor ligands, growth hormone receptor antagonists and dopamine agonists, and alternative modalities for treatment including combination therapy and novel treatments. This document represents the conclusions of the workshop consensus.

Acromegaly and pregnancy: a prospective study

CONTEXT AND OBJECTIVE

The interaction between pregnancy and acromegaly has been studied only retrospectively. We used prospective data to assess those interactions.

DESIGN

Prospective, interventional, multicentric study.

PATIENTS

TEN PREGNANCIES IN EIGHT ACROMEGALIC PATIENTS WERE INCLUDED ACCORDING TO THE FOLLOWING CRITERIA: previous diagnosis of acromegaly; and active acromegaly before pregnancy. Sellar magnetic resonance image (MRI), GH, and IGF1 measurements were carried out before pregnancy. The exclusion criterion was radiotherapy.

INTERVENTION

Withdrawal of pharmacological treatment (octreotide and/or cabergoline and/or pegvisomant) following pregnancy diagnosis.

MAIN OUTCOME MEASURES

Clinical/biochemical evaluations throughout pregnancy/puerperium and sellar MRI after delivery; and GH and IGF1 measurements before pregnancy. GH was measured by an interference-free IFMA assay during pregnancy and IGF1 by measured by Immulite 2000 assay in patients and 64 control pregnancies.

RESULTS

No tumor growth was observed. Nine deliveries were at term and one at 35 weeks (preeclampsia). All newborns were healthy. Mean IGF1 levels before and during pregnancy were similar, but increased significantly during puerperium. As IGF1 in controls increased after midgestation, the prevalence of controlled IGF1 rose significantly from 2/10 (<20 weeks) to 9/10 (>30 weeks). Diabetes mellitus and hypertension/preeclampsia developed in one patient in each group; both complications were nonsignificantly (P=0.06) associated with IGF1 >1.3 ULN before pregnancy.

CONCLUSIONS

Acromegaly control usually improved and tumor growth was not stimulated during pregnancy in spite of withdrawal of drug treatment. Drug treatment can be discontinued in most patients. Uncontrolled disease before pregnancy may pose a higher risk for diabetes and hypertension.

The role of primary pharmacological therapy in acromegaly

BACKGROUND AND OBJECTIVES

Primary pharmacological therapy may be the only viable treatment option for many patients with acromegaly, especially those presenting with advanced disease with large inoperable tumors. Long-acting somatostatin analogs are currently the first-line treatment of choice in this setting, where they provide biochemical control and reduce tumor size in a significant proportion of patients. We herein present a brief overview of the role of primary pharmacological therapy in the treatment of acromegaly within the context of Latin America and support this with a representative case study.

CASE DESCRIPTION

A 20 year old male presented with clinical and biochemical evidence of acromegaly. The glucose-suppressed growth hormone (GH) was 5.3 μg/L, his insulin-like growth factor-1(IGF-1) was 3.5 times the ULN and serum prolactin greater than 4,000 μg/L. Pituitary MRI revealed a large and invasive mass, extending superiorly into the optic chiasm and laterally into the left cavernous sinus. He was treated with a combination of octreotide and cabergoline with remarkable clinical improvement, normalization of GH and IGF-1 values and striking shrinkage of the adenoma.

CONCLUSION

This case illustrates how effective the pharmacological therapy of acromegaly can be and yet at the same time, raises several important issues such as the need for life-long treatment with costly medications such as the somatostatin analogs. Access to these agents may be limited in regions where resources are restricted and clinicians face challenges in order to make the most efficient use of available options.

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.

Emerging drugs for acromegaly

INTRODUCTION

Acromegaly is a rare disease that severely impacts patients' health all the while, being a slowly progressing illness. In the past decades, advancements in treatment modalities, especially development of new drugs, as well as focused guidelines has improved management of acromegaly. Still, many patients are considered not sufficiently treated and there remains an ongoing need for further development.

AREAS COVERED

This article reviews new medical treatments currently under clinical investigation (such as pasireotide, oral octreotide and somatoprim) and under experimental development (such as octreotide implants, CAM2029 and ATL-1103).

EXPERT OPINION

As it seems unlikely that one single agent may achieve cure in 100% of cases, there is an urgent need for new agents that help patients where current medication fails. Imperatively, this means we have to improve our understanding of the underlying pathogenetic and molecular mechanisms.

Octreotide for acromegaly treatment: a reappraisal

INTRODUCTION

Acromegaly is a rare disorder characterized by excess secretion of growth hormone (GH) generally caused by a pituitary macroadenoma and associated with reduced life expectancy if the disease is untreated. This article covers the recent available evidences published on octreotide , the first somatostatin analog introduced into clinical practice for the medical treatment of acromegaly.

AREAS COVERED

This article discusses i) pharmacology of somatostatin and octreotide; ii) biochemical effects of regular octreotide and long-acting repeatable formulation; iii) tumor shrinkage effects of octreotide in acromegaly; iv) impact of octreotide on acromegalic clinical manifestations and chronic complications; v) safety of octreotide and vi) place of octreotide in the guidelines for acromegaly treatment. Full-text articles in the English language were selected from a PubMed search spanning 1984 - 2013, for keywords including 'octreotide,' 'acromegaly,' 'GH,' 'IGF-I,' and 'tumor shrinkage.' Reference lists in selected papers were also used to broaden the search.

EXPERT OPINION

Octreotide is a mature drug with a consolidated favorable benefit versus risks profile in the treatment of acromegaly.

Acromegaly: Beyond surgery

Acromegaly is characterized by chronic, excess secretion of growth hormone (GH) from a pituitary adenoma, and elevated hepatic insulin-like growth factor 1 (IGF-1) levels. Significant progress has been made in the development of medical therapies to achieve biochemical and symptomatic control in acromegaly. In this review we discuss the three currently available medical therapies, which include somatostatin analogs, dopamine agonists and pegvisomant. We describe a step-wise approach in which a somatostatin analog is followed by the addition of a dopamine agonist, and then if required the addition of or replacement by pegvisomant. New somatostatin agonists such as pasireotide, and the introduction of new orally-acting somatostatin agonists, should increase the therapeutic choices available in the near future.

Acromegalic patients lost to follow-up: a pilot study

Approximately 50 % of all acromegalic patients will require lifelong medical treatment to normalize mortality rates and reduce morbidity. Thus, adherence to therapy is essential to achieve treatment goals. To date, no study has evaluated the frequency and reasons for loss to follow-up in the acromegalic population. The current study aimed at evaluating the frequency of acromegalic patient loss to follow-up in three reference centers and the reasons responsible for their low compliance with treatment. All of the files for the acromegalic patients in the three centers were reviewed. Those patients, who had not followed up with the hospital for more than a year, were contacted via phone and/or mail and invited to participate. Patients who agreed to participate were interviewed, and blood samples were collected. A total of 239 files were reviewed; from these 42 patients (17.6 %) were identified who were lost to follow-up. It was possible to contact 27 of these patients, 10 of whom did not attend the appointments for more than one time and 17 of whom agreed to participate in the study. Fifteen of these 17 patients had active disease (88.2 %), and all of the patients restarted treatment in the original centers. The main reason for loss to follow-up was an absence of symptoms. High-quality follow-up is important in acromegaly to successfully achieve the aims of the treatment. An active search for patients may allow the resumption of treatment in a significant proportion of these cases, contributing to reduced morbidity and mortality in this patient population.

The place of medical treatment of acromegaly: current status and perspectives

INTRODUCTION

Acromegaly is characterized by elevated growth hormone (GH) and insulin-like growth factor-I (IGF-I) levels and by progressive somatic disfigurement and systemic manifestations, which lead to a mortality rate higher than the general population. Therefore, diagnosis and properly treatment should be performed as soon as possible.

AREAS COVERED

This article focuses on the state of the art of acromegaly medical treatment. Somatostatin analogs, dopamine agonists and GH receptor antagonist were reviewed. Somatostatin analogs, the first-choice pharmacotherapy, can be used as primary or pre-operative treatment or as secondary therapy after failed surgery. Dopamine agonists have been used in patients with slightly elevated hormone levels and/or mixed GH/prolactin adenomas. Pegvisomant is indicated for resistant to somatostatin analogs/dopamine agonists. Combined treatment is also an option for resistant cases. Other non-conventional therapies and perspectives of treatment were also been discussed.

EXPERT OPINION

The control of disease activity in acromegaly is of paramount importance. Medical treatment is an important option for cases in which surgery was unsuccessful or not indicated. Despite the achievements in medical treatment, somatotropic tumor aggressiveness and/or resistance to the drugs currently available remain a concern. Therefore, novel therapy targets based on molecular pathogenesis of GH-secreting tumors are currently in development, aiming at fulfilling this important gap.

Octreotide long-acting repeatable for acromegaly

Acromegaly remains a therapeutic challenge for the endocrinologist. Among the available therapeutic options, octreotide long-acting repeatable (Sandostatin(®) LAR(®), Novartis) plays a chief role, both as a primary therapy and as an adjuvant treatment after unsuccessful surgery. A plethora of papers and a meta-analysis have demonstrated its efficacy in: control of clinical picture; achievement of safe growth hormone and normal age-matched IGF-I levels (both factors associated with restoration of normal life expectancy) in 60-70% of patients; control of tumor volume (with real shrinkage in over half of cases); and halt or reversal of most acromegaly-associated comorbidities. Treatment is well tolerated in most patients and can be safely prolonged for many years if required.

[Treatment of acromegaly: a critical analysis of the last ten years]

The ten previous years in terms of acromegaly treatment were essentially characterized by the experience accumulated with new formulations of somatostatin analogues or new drugs such GH-receptor antagonists recently available. Surgery remains the first-line treatment and its results did not change despite the generalization of endoscopy, which mainly seems to decrease local side-effects. The setting of radiotherapy was essentially modified by the increasing use of gamma-knife or stereotactic radiotherapy; however, their results are essentially the same as the classic fractionated, conventional radiotherapy and nobody knows if it will decrease the side-effects of this therapeutic modality. Nevertheless, thanks to a multistep therapeutic strategy, combining the different therapeutic modalities, it has become very rare for acromegaly not to be controlled in a patient.