Pharmacokinetics of a new Autogel formulation of the somatostatin analogue lanreotide after a single subcutaneous dose in healthy volunteers

A microfluidic in vitro method predicting the fate of peptide drugs after subcutaneous administration

For many biopharmaceuticals, subcutaneous (sc) administration is the only viable route. However, there is no in vitro method available accurately predicting the absorption profiles of subcutaneously injected pharmaceuticals. In this work, we show that a recently developed microfluidics method for interaction studies (MIS) has the potential to be useful in this respect. The method utilises the responsiveness of polyelectrolyte microgel networks to oppositely charged molecules as a means to monitor the interaction between peptides and hyaluronic acid (HA), a major constituent of the subcutaneous extracellular matrix. We use the method to determine parameters describing the strength of interaction between peptide and HA as well as the peptide's aggregation tendency and transport properties in HA networks. The results from MIS studies of the peptide drugs exenatide, pramlintide, vancomycin, polymyxin B, lanreotide, MEDI7219 and AZD2820 are compared with results from measurements with the commercially available SCISSOR system and in vivo absorption and bioavailability data from the literature. We show that both MIS and SCISSOR reveal differences in the peptides' diffusivity and tendency to aggregate in the presence of HA. We show that MIS is particularly good at discriminating between peptides forming aggregates stabilised by non-electrostatic forces in the presence of HA, and peptides forming complexes stabilised by electrostatic interactions with HA. The method provides two parameters that can be used to quantify the peptides' aggregation tendency, the one describing the peptide packing density in complexes with HA and the other the apparent diffusivity upon release in a medium of physiological ionic strength and pH. The order of the peptides when ranked by increasing binding strength at pH 7.4 determined with MIS is shown to be in agreement with the order when ranked by the apparent 1st order absorption rate constant (ka) after sc administration in humans: lanreotide (Autogel) < exenatide (IRF) < AZD2820 < pramlintide < lanreotide (IRF) (IRF: Immediate release formulation). A correlation is found between the 1st order release rate constant determined with SCISSOR and ka for lanreotide (Autogel), exenatide and AZD2820. A mechanism relating the magnitude of ka to the peptides' charge is proposed.

Quantitative uptake in 99m Tc-EDDA/HYNIC-TOC somatostatin receptor imaging - the effect of long-acting release somatostatin analogue therapy

PURPOSE

Withdrawal of long-acting release somatostatin analogue (LAR-SSA) treatment before somatostatin receptor imaging is based on empirical reasoning that it may block uptake at receptor sites. This study aims to quantify differences in uptake of 99m Tc-EDDA/HYNIC-TOC between patients receiving LAR-SSA and those who were not.

METHODS

Quantification of 177 patients (55 on LAR-SSA) imaged with 99m Tc-EDDA/HYNIC-TOC was performed, with analysis of pathological tissue and organs with physiological uptake using thresholded volumes of interest. Standardised uptake values (SUVs) and tumour/background (T/B) ratios were calculated and compared between the two patient groups.

RESULTS

SUVs were significantly lower for physiological organ uptake for patients on LAR-SSA (e.g. spleen: SUV max 13.3 ± 5.9 versus 33.9 ± 9.0, P  < 0.001); there was no significant difference for sites of pathological uptake (e.g. nodal metastases: SUV max 19.2 ± 13.0 versus 17.4 ± 11.5, P  = 0.552) apart from bone metastases (SUV max 14.1 ± 13.5 versus 7.7 ± 8.0, P  = 0.017) where it was significantly higher.

CONCLUSION

LAR-SSA has an effect only on physiological organ uptake of 99m Tc-EDDA/HYNIC-TOC, reducing uptake. It has no significant effect on pathological uptake for most sites of primary and metastatic disease. This should be taken into account if making quantitative measurements, calculating T/B ratios or assigning Krenning Scores. There is the potential for improved dosimetric results in Peptide Receptor Radionuclide Therapy by maintaining patients on LAR-SSA.

IGF-I Variability Over Repeated Measures in Patients With Acromegaly Under Long-Acting Somatostatin Receptor Ligands

CONTEXT

In patients with acromegaly on long-term treatment with long-acting somatostatin receptor ligands (SRLs), the time of blood collection for IGF-I measurement after injection is not well defined.

OBJECTIVE

We aimed to assess serum IGF-I dynamics and variability in SRL-treated patients compared with surgically cured patients and healthy controls.

METHODS

Thirty patients under SRLs considered controlled based on a normal previous IGF-I level, 10 patients cured by pituitary surgery, and 7 healthy subjects underwent 4 weekly IGF-I determinations.

RESULTS

In SRL-treated patients, the IGF-I SDS (mean ± SD) was higher just before injection (0.34 ± 0.66) than at Day 7 (-0.33 ± 0.61; P = 0.0041) and Day 14 (-0.23 ± 0.60; P = 0.047) after injection, but it did not significantly vary in cured patients and healthy controls. The IGF-I CV was higher in SRL-treated patients than in cured patients or healthy controls (14.4 ± 7.6% vs 7.9 ± 4.4% and 8.3 ± 3.2%, respectively; P < 0.05 for both). Among SRL-treated patients, IGF-I CV was higher in "nonoptimally controlled patients"-i.e., patients with at least one elevated IGF-I value out of 4 (n = 9) compared with "optimally controlled" patients for whom all 4 IGF-I SDS values were < 2.0 (21.3 ± 9.3 vs 11.6 ± 6.0%; P = 0.0019). The latter did not differ from surgically cured patients and healthy controls. The measurement at the farthest distance from the SRL injection was the most predictive of patients with nonoptimally controlled disease.

CONCLUSION

In patients treated with long-acting SRLs, IGF-I sampling at the farthest distance from SRL injection is the most informative and best predictor of optimal disease control.

The industrial design, translation, and development strategies for long-acting peptide delivery

INTRODUCTION

Peptides are widely recognized as therapeutic agents in the treatment of a wide range of diseases, such as cancer, diabetes etc. However, their use has been limited by their short half-life, due to significant metabolism by exo- and endo-peptidases as well as their inherent poor physical and chemical stability. Research with the aim of improving their half-life in the body, and thus improving patient compliance (by decreasing the frequency of injections) has gained significant attention.

AREAS COVERED

This review outlines the current landscape and industrial approaches to achieve extended peptide exposure and reduce dosing frequency. Emphasis is placed on identifying challenges in drug product manufacturing and desirable critical quality attributes that are essential for activity and safety, providing insights into chemistry and design aspects impacting peptide release, and summarizing important considerations for CMC developability assessments of sustained release peptide drugs.

EXPERT OPINION

Bring the patient and disease perspective early into development. Substantial advances have been made in the field of sustained delivery of peptides despite their complexity. The article will also highlight considerations for early-stage product design and development, providing an industrial perspective on risk mitigation in developing sustained release peptide drug products.

Comparing Somatostatin Analogs in the Treatment of Advanced Gastroenteropancreatic Neuroendocrine Tumors

BACKGROUND

The 2 approved somatostatin analogs (SSAs) in the first-line treatment of advanced, well-differentiated gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are octreotide long-acting release (Sandostatin LAR) and somatuline depot (Lanreotide). The study's objective was to compare progression-free survival (PFS) and overall survival (OS) of patients (pts) with GEP-NETs treated with somatuline or octreotide LAR. Pts and Methods: Pts with advanced well-differentiated GEP-NET who received either SSA at Emory University between 1995 and 2019 were included after institutional review board approval. The primary end point was PFS, defined as time to disease progression (according to the Response Evaluation Criteria in Solid Tumors, version 1.1, or clinical progression) or death. The secondary end point was OS. Kaplan-Meier curves were generated, and log-rank tests were conducted to compare the survival outcomes.

RESULTS

A total of 105 pts were identified. The mean age was 62.1 years (SD ± 11.8). The male-to-female ratio was 51:54. The majority (N = 69, 65.7%) were white. Most pts had grade 2 (G2) disease (N = 44, 41.9%). Primary location was small bowel in 58 (55.2%), pancreas in 27 (25.7%), and other in 20 (19.0%). Functional tumors were defined in 32 pts distributed equally between the 2 groups. Distribution of treatment was similar in the 2 groups, with 54 receiving octreotide LAR and 51 receiving somatuline depot. The median PFS for the octreotide LAR and somatuline depot groups was 12 months (95% CI, 6-18 months) and 10.8 months (95% CI, 6-15.6 months), respectively, and the difference was not statistically significant (p = 0.2665). For pts with G1 disease, the median PFS for the octreotide LAR and somatuline depot was 8.4 versus 32.4 months, respectively, and the difference was not statistically significant (p = 0.159). For G2 disease, the difference in median PFS between octreotide LAR and somutaline depot groups was statistically significant (12 vs. 7.2 months, respectively; p = 0.0372). The mean follow-up time for octreotide LAR was 21.6 months versus 11.3 months for somatuline depot.

CONCLUSIONS

Overall, there was no difference in PFS between octreotide LAR and somatuline depot for pts with well-differentiated, metastatic GEP-NETs. A prospective study is worth designing selecting for G.

How to Position Pasireotide LAR Treatment in Acromegaly

CONTEXT

Pasireotide long-acting release (LAR) is a somatostatin multireceptor ligand, and in the current consensus criteria pasireotide LAR is considered the second-line medical treatment for acromegaly. We present in this article our recommendations to define the position of pasireotide LAR in the treatment of acromegaly and provide recommendations for the management of pasireotide-induced hyperglycemia.

EVIDENCE ACQUISITION

Our recommendations are based on our experiences with the pasireotide LAR and pegvisomant (PEGV) combination study and the available basic or clinical articles published in peer-reviewed international journals on pasireotide LAR and acromegaly.

EVIDENCE SYNTHESIS

In accordance with the current consensus criteria, we recommend pasireotide LAR monotherapy as a second-line therapy in young patients who show tumor growth during first-generation somatostatin receptor ligand (SRL) therapy and in patients who show tumor growth during PEGV therapy. In addition, we recommend pasireotide LAR monotherapy in patients with headache not responsive to first-generation SRL therapy and in patients who experience side effects or are intolerant to PEGV monotherapy. In contrast to the current consensus criteria, we recommend considering combination therapy with pasireotide LAR and PEGV as third-line treatment in patients without diabetes at low PEGV dosages (≤80 mg/week) and in patients with tumor growth or symptoms of active acromegaly during first-generation SRL and PEGV combination therapy. With respect to pasireotide-induced hyperglycemia, we recommend a more liberal strategy of blood glucose monitoring during pasireotide treatment.

CONCLUSIONS

In contrast to the current consensus criteria, we recommend a more reluctant use of pasireotide LAR therapy for the treatment of acromegaly.

Sensitive quantification of the somatostatin analog AP102 in plasma by ultra-high pressure liquid chromatography-tandem mass spectrometry and application to a pharmacokinetic study in rats

AP102 is a di-iodinated octapeptide somatostatin agonist (SSA) designed to treat acromegaly and neuroendocrine tumors. A sensitive and selective method was validated for the quantification of AP102 in plasma following the European Medicines Agency (EMA) and Food and Drug Administration (FDA) guidelines. Sample preparation was performed using solid-phase extraction microplates. Chromatographic separation was achieved on an ultra-high pressure liquid chromatography (UHPLC) C18 column in 6.0 minutes. The compounds were quantified using multiple reaction monitoring on a tandem quadrupole mass spectrometer with ¹³ C,¹⁵ N-labeled AP102 as internal standard. Calibration ranged from 50 to 10000 pg/mL. The lower limit of quantification (LLOQ) was measured at 20 pg/mL, and robust analytical performances were obtained with trueness at 99.2%-100.0%, intra-assay imprecision at 2.5%-4.4%, and inter-assay imprecision at 8.9%-9.7%. The accuracy profiles (total error) built on the 3 concentrations levels showed accuracy within the 70%-130% range. AP102 is remarkably stable since no proteolytic fragments were detected on plasma samples analyzed by Orbitrap-MS. Pharmacokinetic studies were conducted in rats, after single dose (1, 3, and 10 μg/kg, sc) and continuous subcutaneous administration (osmotic minipumps for 28 days, 3.0 or 10.0 μg/kg/h). AP102 showed a rapid absorption by the subcutaneous route (T_max : 15-30 minutes) and a fast elimination (t_1/2 : 33-86 minutes). The PK profile of AP102 exhibited a mean clearance of 1.67 L/h and a mean distribution volume at steady state of 7.16 L/kg, about 10-fold higher than those observed with other SSA or non- and mono-iodinated AP102. LogD_7.4 determination confirmed the lipophilic properties of AP102 that might influence its distribution in tissues.

The Current State of Peptide Drug Discovery: Back to the Future?

Over the past decade, peptide drug discovery has experienced a revival of interest and scientific momentum, as the pharmaceutical industry has come to appreciate the role that peptide therapeutics can play in addressing unmet medical needs and how this class of compounds can be an excellent complement or even preferable alternative to small molecule and biological therapeutics. In this Perspective, we give a concise description of the recent progress in peptide drug discovery in a holistic manner, highlighting enabling technological advances affecting nearly every aspect of this field: from lead discovery, to synthesis and optimization, to peptide drug delivery. An emphasis is placed on describing research efforts to overcome the inherent weaknesses of peptide drugs, in particular their poor pharmacokinetic properties, and how these efforts have been critical to the discovery, design, and subsequent development of novel therapeutics.

Lanreotide Depot: An Antineoplastic Treatment of Carcinoid or Neuroendocrine Tumors

Purpose

Peptide drugs for antineoplastic therapies usually have low oral bioavailability and short in vivo half-lives, requiring less preferred delivery methods. Lanreotide depot is a sustained-release somatostatin analog (SSA) formulation produced via an innovative peptide self-assembly method. Lanreotide is approved in the USA and Europe to improve progression-free survival (PFS) in patients with unresectable gastroenteropancreatic neuroendocrine tumors (GEP-NETs) and also approved in Europe for symptom control in carcinoid syndrome associated with GEP-NETs. This review discusses how the distinct molecule and formulation of lanreotide depot provide advantages to patients and health care providers, as well as the most recent clinical evidence demonstrating the safety and efficacy of lanreotide depot in inhibiting tumor growth and controlling hormonal symptoms in GEP-NETs.

Methodology and Results

The lanreotide depot formulation confers a remarkable pharmacokinetic profile with no excipients, comprised only of lanreotide acetate and water. Of note, lanreotide depot constitutes an example for peptide self-assembly based formulations, providing insights that could help future development of sustained-release formulations of other antineoplastic peptides. Most patients with GEP-NETs will present with inoperable or incurable disease; thus, medical management for symptoms and tumor control plays a crucial role. Recent long-term clinical studies have demonstrated that lanreotide depot is well tolerated, prolongs PFS in GEP-NET patients, and significantly reduces symptoms related to carcinoid syndrome.

Conclusions

The unique depot formulation and delivery method of lanreotide confer advantages in the treatment of metastatic GEP-NETs, contributing to improvements in NET-related symptoms and PFS without reducing quality of life in this patient population.

Neuroendocrine Tumors and Lanreotide Depot: Clinical Considerations and Nurse and Patient Preferences

BACKGROUND

Somatostatin analogs (SSAs) are a mainstay therapy for the treatment of carcinoid syndrome associated with neuroendocrine tumors (NETs). They are effective for a range of gastroenteropancreatic NETs (GEP-NETs). Lanreotide depot (Somatuline®) is an SSA that is approved for the treatment of GEP-NETs to improve progression-free survival (PFS).

OBJECTIVES

The article reviews the efficacy, safety, and administration of lanreotide depot and relates those attributes to considerations and preferences of oncology nurses and their patients.

METHODS

A review of the literature on the use of lanreotide for the treatment of NETs and carcinoid syndrome was conducted. In addition, the literature on drug delivery and routes of administration was surveyed to provide context for comparative studies related to clinical and patient preferences.

FINDINGS

Lanreotide depot prolongs PFS and is well tolerated by patients who expressed satisfaction in the ability to control symptoms related to carcinoid syndrome. Nurses cited several benefits to using lanreotide depot in the clinical setting, including more time saved to address other patient care issues. Attributes of lanreotide depot-including its efficacy, safety and tolerability, dosing and administration, and cost-may contribute to healthcare decisions regarding the treatment and management of NETs.

What is the efficacy of switching to weekly pegvisomant in acromegaly patients well controlled on combination therapy?

CONTEXT

Although combination therapy of acromegaly with long-acting somatostatin analogs (LA-SSAs) and pegvisomant (PEGV) normalizes insulin-like growth factor-1 (IGF1) levels in the majority of patients, it requires long-term adherence. Switching from combination therapy to monotherapy with weekly PEGV could improve patients' comfort, but the efficacy is unknown.

OBJECTIVE

To assess the efficacy of switching to PEGV monotherapy in patients well controlled on combination therapy of LA-SSAs and PEGV.

DESIGN

Single-center, open-label observational pilot study. LA-SSA therapy was discontinued at baseline and all patients were switched to PEGV monotherapy for 12 months. If IGF1 levels exceeded 1.0 times upper limit of normal (ULN), PEGV dose was increased by 20 mg weekly.

SUBJECTS AND METHODS

The study included 15 subjects (eight males), with a median age of 58 years (range 35-80) on combination therapy of high-dose LA-SSAs and weekly PEGV for >6 months, and IGF1 levels within the normal range. Treatment efficacy was assessed by measuring serum IGF1 levels.

RESULTS

After 12 months of weekly PEGV monotherapy, serum IGF1 levels of 73% of the subjects remained controlled. In one patient, LA-SSA had to be restarted due to recurrence of headache. IGF1 levels increased from a baseline level of 0.62 × ULN (range 0.30-0.84) to 0.83 × ULN (0.30-1.75) after 12 months, while the median weekly PEGV dose increased from 60 (30-80) mg to 80 (50-120) mg.

CONCLUSION

Our results suggest that switching from combination therapy of LA-SSAs and PEGV to PEGV monotherapy can be a viable treatment option for acromegaly patients without compromising efficacy.

Lanreotide autogel in acromegaly - a decade on

INTRODUCTION

The novel formulation of lanreotide, lanreotide (LAN) autogel (ATG), has been available in Europe since 2001 and USA from 2006 for the treatment of acromegaly. It is one of only two clinically available somatostatin analogs available for use in acromegaly. Data relating to the use of ATG in acromegaly, specifically relating to comparison to octreotide (OCT) LAR and patient acceptability and preference, have been slow to accumulate.

AREAS COVERED

We performed a comprehensive review of the original literature relating to development, pharmacokinetics, acceptability and clinical efficacy of ATG.

EXPERT OPINION

LAN ATG is a novel formulation of LAN consequent on self-assembly of nanotubules in water. Diffusion between molecules within the nanotubules and surrounding tissue fluid in vivo leads to pseudo first-order pharmacokinetics. Efficacy is equivalent to the alternate long-acting somatostatin analog, OCT LAR, normalizing growth hormone and IGF-I levels in around 60 and 50% respectively. Control of tumor growth is observed in over 95% of patients, with 64% seeing a clinically significant reduction in tumor size. ATG is provided in a prefilled syringe for deep subcutaneous injection, allowing self-injection, and may be administered up to 8 weeks greatly improving convenience for the patient. The data strongly support consideration of ATG as the medical therapy of choice for patients with acromegaly.

Somatostatin analogs therapy in gastroenteropancreatic neuroendocrine tumors: current aspects and new perspectives

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rare tumors that present many clinical features secreting peptides and neuroamines that cause distinct clinical syndromes such as carcinoid syndrome. However most of them are clinically silent until late presentation with mass effects. Surgical resection is the first line treatment for a patient with a GEP-NET while in metastatic disease multiple therapeutic approaches are possible. GEP-NETs are able to express somatostatin receptors (SSTRs) bounded by somatostatin (SST) or its synthetic analogs, although the subtypes and number of SSTRs expressed are very variable. In particular, SST analogs are used frequently to control hormone-related symptoms while their anti-neoplastic activity seems to result prevalently in tumor stabilization. Patients who fail to respond or cease to respond to standard SST analogs treatment seem to have a response to higher doses of these drugs. For this reason, the use of higher doses of SST analogs will probably improve the clinical management of these patients.

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.

Long-Acting Octreotide and Prolonged-Release Lanreotide Formulations Have Different Pharmacokinetic Profiles

Single-dose pharmacokinetic (PK) profiles and multiple-dose PK modeling were compared for long-acting octreotide (20 or 60 mg) and prolonged-release lanreotide (90 or 120 mg) over 91 days; steady-state profiles were simulated. All treatments were well tolerated. Octreotide 20-mg profile showed increased concentration on day 1, lag from days 2 to 6, then prolonged plateau phase (days 11-41); 60-mg PK was dose proportional. Lanreotide 90-mg profile showed C(max) on day 1 then elimination (apparent t1/2 25.5 days); 120-mg profile was underproportional. Steady-state PK of octreotide 20 mg/28 d suggested a C(mean) of 1216 rhog/mL (range, 1065-1585) with low fluctuation index (43%). Steady-state PK of lanreotide 90 mg/28 d suggested a C(mean) of 4455 rhog/mL (range, 2499-9279) with high fluctuation index (152%). Long-acting octreotide had more predictable PK than prolonged-release lanreotide. Simulated steady-state profiles suggest long-acting octreotide could be optimized to meet individual patient needs. In contrast, prolonged-release lanreotide requires exposure constantly above the therapeutic target to enable monthly long-term therapy.

Assessment of real-world usage of lanreotide AUTOGEL 120 in Polish acromegalic patients - results from the prospective 12-month phase of Lanro-Study

Aim of the study

To assess resource utilization and costs of treatment with lanreotide AUTOGEL 120 mg (ATG120) administered as part of routine acromegaly care in Poland.

Material and methods

A multicentre, non-interventional, observational study on resource utilization in Polish acromegalic patients treated with ATG120 at 4 weeks or extended (> 4 weeks) dosing interval. The study recruited adult acromegalic patients treated medically for ≥ 1 year including at least 3 injections of ATG120. Data on dosing interval, aspects of administration, and resource utilization were collected prospectively during 12 months. Costs were calculated in PLN from the public health-care payer perspective for the year 2013.

Results

139 patients were included in the analysis. Changes in dosing regimen were reported in 14 (9.4%) patients. Combined treatment was used in 11 (8%) patients. Seventy patients (50%) received ATG120 at an extended dosing interval; the mean number of days between injections was 35.56 (SD 8.4). ATG120 was predominantly administered in an out-patient setting (77%), by health-care professionals (94%). Mean time needed for preparation and administration was 4.33 and 1.58 min, respectively, mean product wastage – 0.13 mg. Patients were predominantly treated in an out-patient setting with 7.06 physician visits/patient/year. The most common control examinations were magnetic resonance imaging of brain and brain stem (1.36/patient/year), ultrasound of the neck (1.35/patient/year), GH (1.69/patient/year), glycaemia (1.12/patient/year), IGF-1 (0.84/patient/year), pituitary-thyroid axis hormone levels assessment (TSH-0.58/patient/year, T4-0.78/patient/year). There were 0.43 hospitalizations/patient/year. For direct medical costs estimated at PLN 50 692/patient/year the main item was the costs of ATG120 (PLN 4103.87/patient/month; 97%). The mean medical cost, excluding pharmacotherapy, was PLN 1445/patient/year (out-patient care – 49%, hospitalization – 23%, diagnostics/laboratory tests – 28%).

Conclusions

These results represent the current use of ATG120 in the population of Polish acromegalic patients in a realistic clinical setting. Findings that 50% of patients could be treated with dose intervals of longer than 28 days support the potential of ATG120 to reduce the treatment burden.

Clinical experience with lanreotide for the treatment of acromegaly

Acromegaly is a rare disease, characterized in adults by its distinctive appearance of facial dysmorphism and swollen fingers. It is caused by an overproduction of growth hormone (GH) in more than 99% of patients and in nearly all cases is due to a pituitary adenoma. If surgical resection of the adenoma is not effective, medical treatment is usually the next treatment option. The most commonly used medications are the somatostatin analogues octreotide and lanreotide. Lanreotide is a synthetic somatostatin analogue and is available as slow-release microparticle (every 7-14 days) and prolonged-release liquid (autogel, every 28-56 days) formulations. Lanreotide autogel is a supersaturated aqueous formulation for deep subcutaneous injection and is sold in a ready-to-use prefilled syringe. This ease of use allows self or partner administration at home. This article reviews the use of lanreotide in the treatment of acromegaly and its advantages and disadvantages compared with other somatostatin analogues.

Lanreotide depot deep subcutaneous injection: a new method of delivery and its associated benefits

Acromegaly is a rare disease characterized by excessive growth hormone secretion, usually from a pituitary tumor. Treatment options include surgery, medical therapy, and in some cases, radiation therapy. Current medical therapy consists of treatment with somatostatin analog medications or a growth hormone receptor antagonist. There are two somatostatin analogs currently in use, octreotide and lanreotide. Both are supplied in long-acting formulations and are of comparable biochemical efficacy. Lanreotide is supplied in a prefilled syringe and is injected into deep subcutaneous tissue. Studies have been conducted to assess the efficacy of self- or partner administration, and have demonstrated that injection of lanreotide can be accomplished reliably and safely outside a physician's office. For patients who have achieved biochemical control with lanreotide, the FDA has recently approved an extended dosing interval. Selected patients may be able to receive the medication less frequently with injections of 120 mg administered every 6 or 8 weeks. This review focuses on the use of lanreotide in the treatment of acromegaly, the safety and efficacy of the drug, and the benefits afforded to patients because of unique aspects of the delivery of lanreotide.

Resistance to somatostatin analogs in acromegaly

Somatostatin analogs (SA) are widely used in acromegaly, either as first-line or adjuvant treatment after surgery. First-line treatment with these drugs is generally used in the patients with macroadenomas or in those with clinical conditions so severe as to prevent unsafe reactions during anesthesia. Generally, the response to SA takes into account both control of GH and IGF-I excess, with consequent improvement of clinical symptoms directly related to GH and IGF-I excess, and tumor shrinkage. This latter effect is more prominent in the patients treated first-line and bearing large macroadenomas, but it is also observed in patients with microadenomas, even with little clinical implication. Predictors of response are patients' gender, age, initial GH and IGF-I levels, and tumor mass, as well as adequate expression of somatostatin receptor types 2 and 5, those with the highest affinity for octreotide and lanreotide. Only sporadic cases of somatostatin receptor gene mutation or impaired signaling pathways have been described in GH-secreting tumors so far. The response to SA also depends on treatment duration and dosage of the drug used, so that a definition of resistance based on short-term treatments using low doses of long-acting SA is limited. Current data suggest that response to these drugs is better analyzed taking together biochemical and tumoral effects because only the absence of both responses might be considered as a poor response or resistance. This latter evidence seems to occur in 25% of treated patients after 12 months of currently available long-acting SA.

Somatostatin analogues in the treatment of gastroenteropancreatic neuroendocrine tumours, current aspects and new perspectives

Gastroenteropancreatic neuroendocrine tumours (GEP NETs) are rare tumours that present many clinical features.They secrete peptides and neuroamines that cause distinct clinical syndromes, including carcinoid syndrome. However, many are clinically silent until late presentation with mass effects.In 2000 the WHO developed a new classification which gives a better description of the characteristics and biological behaviour of the tumour.Surgical resection is the treatment of first choice for a patient with a GEP NET. In metastatic disease multiple therapeutic approaches are possible. In these cases the goal is to improve quality of life and to extent survival.GEP NETs express somatostatin receptors (SSTRs), which are bound by somatostatin (SST) or its synthetic analogues, although the subtypes and number of SSTRs expressed is very variable.Somatostatin analogues are used frequently to control hormone-related symptoms while their anti-neoplastic activity, even if it has not been widely studied and the regarding data are discordant, seems to result prevalently in tumour stabilisation.A few patients who fail to respond or cease to respond to standard SST analogues treatment seem to have a response to higher doses of these drugs.The use of higher doses of somatostatin analogues or the development of new subtype selective agonists and chimaeric somatostatin analogues, or pan-somatostatin will probably improve the clinical management of these patients.This review provides an update on the use of somatostatin analogues in the management of GEP NETs and discusses novel clinical strategies based on SSTR 2 gene transfer therapy.

Rapid and sustained reduction of serum growth hormone and insulin-like growth factor-1 in patients with acromegaly receiving lanreotide Autogel therapy: a randomized, placebo-controlled, multicenter study with a 52 week open extension

The study was designed to evaluate the long-term efficacy and safety of the 28-day prolonged-release Autogel formulation of the somatostatin analogue lanreotide (Lan-Autogel) in unselected patients with acromegaly. The study comprised four phases: washout; a double-blind comparison with placebo, at a single randomized dose (60, 90 or 120 mg) of Lan-Autogel; a single-blind, fixed-dose phase for four injections (placebo group was re-allocated to active treatment); and eight injections with doses tailored according to biochemical response. Serum samples were assessed for growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels, at weeks 4, 13, 14, 15, 16, 32 and 52. 108 patients were enrolled and 99 completed 52 weeks' treatment. Four weeks after the first injection, serum GH levels decreased by >50% from baseline in 63% of patients receiving Lan-Autogel compared with 0% receiving placebo (P < 0.001). After four injections, 72% of patients had a >50% reduction in GH levels; 49% patients achieved GH levels < or = 2.5 ng/ml; 54% had normalized IGF-1; and 38% achieved the combined criterion of GH level < or = 2.5 ng/ml and normalized IGF-1. The corresponding proportions by week 52 were 82, 54, 59 and 43%, respectively. In patients not requiring dose escalation to 120 mg, 85% achieved biochemical control (combined criterion). Treatment was well tolerated by all patients. In conclusion, Lan-Autogel was effective in controlling GH and IGF-1 hypersecretion in patients with acromegaly and showed a rapid onset of action.

Somatostatin analogues: treatment of pituitary and neuroendocrine tumors

This chapter summarizes the most recent data on the use of the somatostatin analogues (SSAs), octreotide (OCT) and lanreotide for the treatment of patients with pituitary and neuroendocrine tumors (NETs). These two analogues have a high affinity for somatostatin receptor (SSR) sub-types 2 and 5. The major indications of these compounds are GH- and TSH-secreting pituitary adenomas, secreting NETs and non-functioning NETs in progression. Pasireotide is a new analogue, with a receptor pattern different from previous analogues since it binds with high affinity to SSR types 1, 2, 3 and 5. This analogue will be available to treat patients with ACTH-secreting adenomas in a short time. A recent study has also demonstrated a beneficial effect of OCT long-acting release in patients with non-functioning NETs independently from their progression status. These data open the treatment with SSAs in all NET patients.

Cost-effectiveness of lanreotide Autogel in treatment algorithms of acromegaly

The introduction of effective pharmacological treatments has changed the management of acromegaly. However, chronic, life-long treatment with somatostatin analogues and/or growth hormone receptor antagonists is very expensive. We estimated the costs of treatment algorithms to control acromegaly from a Dutch perspective. We used the following assumptions: after the diagnosis of acromegaly there is a mean remaining lifespan of approximately 33 years; the success rates of surgery and somatostatin analogues in controlling the disease are approximately 60%; and the lifelong costs of different algorithms to control acromegaly in 100 patients ranged from 43 million euros (primary surgery and secondary somatostatin analogues) to 57 million euros (primary somatostatin analogues and secondary surgery) and even reached 95 million euros (medical treatment only). In algorithms that include trans-sphenoidal surgery, the lifetime treatment costs are almost 46-59% cheaper per 100 patients than in algorithms with medical treatment but without trans-sphenoidal surgery. Algorithms with primary surgery and secondary somatostatin analogs are 30% cheaper per 100 patients than algorithms with primary somatostatin analogues and secondary surgery. Per 100 patients, algorithms including lanreotide Autogel are 14-34% more expensive than algorithms including octreotide long-acting release. These life-long costs should be taken into consideration when making choices between treatment algorithms.

Significant tumour shrinkage after 12 months of lanreotide Autogel-120 mg treatment given first-line in acromegaly

OBJECTIVE

To evaluate GH and IGF-I control and tumour shrinkage in newly diagnosed patients with acromegaly treated first-line with lanreotide-Autogel (ATG) 120 mg. Design Open, prospective.

PATIENTS

Twenty-six patients (17 women, aged 31-70 years): eight enclosed and 12 extrasellar (eight invasive) macroadenomas and six microadenomas (one invasive). ATG 120 mg initially given every 4 weeks for 12 weeks; then intervals between injections increased to every 6 or 8 weeks if GH levels were <or= 2.5 or < 1 microg/l (equal to 6.5 and 2.6 mU/l), respectively.

RESULTS

Final dosage was ATG 120 mg every 4 weeks in nine patients (34.6%), every 6 weeks in eight patients (30.8%) and every 8 weeks in the remaining nine patients (34.6%). After 12 months, both GH and IGF-I were controlled in 14 patients (53.8%). The mean tumour volume decreased from 1405 +/- 1827 mm(3) at study entry to 960 +/- 1381 mm(3) after 6 months, and 799 +/- 1161 mm(3) after 12 months (P < 0.0001). Overall tumour shrinkage was 35.8 +/- 28.1% after 6 months and 48.4 +/- 27.6% after 12 months. After 12 months, 20 patients (76.9%) achieved > 25% tumour shrinkage: 12 of 14 with controlled disease (85.7%) and 8 of 12 with noncontrolled disease (66.7%; P = 0.49). Hyperhydrosis, paresthesiae and arthralgias significantly reduced after treatment. No patient withdrew from the study because of adverse events.

CONCLUSION

ATG 120 mg in newly diagnosed patients with acromegaly controls GH and IGF-I secretion in 53.8% and induces >or= 25% tumour shrinkage in 76.9% during a 12-month period. The treatment was associated with improvement of clinical symptoms and with a good safety profile.

Lanreotide for the treatment of acromegaly

Lanreotide is an eight-amino acid peptide, which is an analog of the native somatostatin peptide, physiological inhibitor of growth hormone (GH). The drug shows high binding affinity for somatostatin receptors, SSTR2 and SSTR5, which is the primary mechanism considered to be responsible for decreasing GH secretion and GH cell proliferation in acromegaly. Two different formulations of lanreotide are currently available: lanreotide slow release, which requires intramuscular injection every 7-14 days, and lanreotide autogel, which requires deep subcutaneous injection every 4-8 weeks. Several studies have been published to date on the use of lanreotide in acromegaly. Antisecretory efficacy has been reported in 35%-70% of cases; this huge variability is probably explained by different indications (eg, primary or adjunctive postsurgical treatment), or the fact that some studies were based on patients known to be responders to somatostatin analogs. As a primary treatment, antisecretory efficacy was very similar, confirming the possibility of lanreotide as an option in cases of unsuccessful surgery, contraindication, or surgery refusal. Lanreotide also has antitumoral effects as it induces a decrease in tumor volume of [Symbol: see text]25% in 30%-70% of patients. This could be beneficial before transsphenoidal surgery, as a pretreatment, to decrease tumor volume and ease surgery; however, to date, advantages in terms of final remission or uncured status remain a matter of debate. Side effects are rare; the most frequent being gastrointestinal discomfort and increased risk of gallstone formation, and glucose metabolism modifications. Comparison with the other somatostatin analog, octreotide, tends to show identical levels of efficacy between both drugs. Lanreotide thus seems to be an effective treatment in acromegaly. To date, however, lanreotide is still considered as only suspending GH secretion, thus requiring prolonged and costly treatment.

Somatostatin analog lanreotide in the treatment of castration-resistant prostate cancer (CRPC)

Prostate cancer is a common disease affecting males. Despite initial sensitivity to hormone treatment, prostate cancer eventually progresses to a castration-resistant stage (CRPC), which carries an ominous prognosis. Lanreotide is a long-acting somatostatin analog with the same properties with the native peptide. It has been shown to be highly efficacious in treating various hypersecretoty disorders and tumors. Lanreotide has been administered to patients with CRPC within a novel treatment concept, with the aim of targeting not only cancer cells but also various factors secreted in the tumor cell milieu that confer protection from apoptosis. Within this concept, lanreotide has been administered as part of the "antisurvival factor therapy" in combination with dexamethasone and a gonadotropin releasing hormone (GnRH) analog. It has also been given combined with oestrogens in patients with CRPC. The so far published series have documented a clinical response in many patients treated along with significant improvement in parameters related to quality of life. In view of these promising results, large-scale, randomized, controlled trials are warranted to clearly define the exact role of lanreotide and other somatostatin analogs in the treatment of patients with CRPC.

Efficacy of the new long-acting formulation of lanreotide (lanreotide Autogel) in somatostatin analogue-naive patients with acromegaly

OBJECTIVE

To evaluate efficacy and safety of lanreotide autogel (ATG) 120 mg injections every 4-8 weeks in somatostatin analogue-naïve patients with acromegaly.

DESIGN

Open, non-comparative, phase III, multicenter clinical study.

METHODS

Fifty-one patients (28 women, aged 19-78 yr): 39 newly diagnosed (de novo) and 12 who had previously undergone unsuccessful surgery (post-op, 11 macro and 1 micro) were studied. ATG 120 mg was initially given every 8 weeks for 24 weeks and subsequently changed according to GH levels: if <or=2.5 microg/l every 8 weeks (group A, 17 patients); if 2.5-5 microg/l every 6 weeks (group B, 15 patients); and if >5 microg/l every 4 weeks (group C, 19 patients). Treatment duration was 48-52 weeks. The primary objective was to control GH and IGF-I levels (GH<or=2.5 microg/l and IGF-I normalized for age/gender). Secondary objectives were to assess GH, IGF-I, and acid-labile subunit (ALS) decrease, improvement of clinical symptoms and quality of life (QoL).

RESULTS

GH levels normalized in 32 patients (63%), similarly in de novo and post-op patients (72% vs 50%, p=0.48); in 100% of group A, in 73% of group B and in 21% of group C (p<0.0001). IGF-I levels normalized in 19 patients (37%), similarly in the de novo and post-op patients (33% vs 50%, p=0.48): in 65% of group A, 33% of group B, and in 16% of group C. Circulating GH levels decreased by 80+/-17%, IGF-I levels by 44+/-27%, and ALS by 30+/-17%. Symptoms (hyperhidrosis (68.6%), swelling (68.6%), asthenia (58.8%), spine arthralgia (54.9%), and paresthesias (52.9%) and QoL (from 9.1+/-7.9 to 6.1+/-6.6) significantly improved (p<0.001). No patient withdrew from the study because of adverse events (AE). The most frequent AE was diarrhea (76.2% of patients): at study end 16 mild and 1 moderate diarrhea were recorded. Gallstones developed in 12% of patients.

CONCLUSION

ATG 120 mg in somatostatin-naïve patients with acromegaly controls GH secretion in 63% and IGF-I secretion in 37% during a 48-52 week period without any difference between de novo and post-op patients. The treatment was associated with improvement in clinical symptoms and QoL and with a good, safe profile.

Therapeutic options in the management of acromegaly: focus on lanreotide Autogel

BACKGROUND

In acromegaly, expert surgery is curative in only about 60% of patients. Postoperative radiation therapy is associated with a high incidence of hypopituitarism and its effect on growth hormone (GH) production is slow, so that adjuvant medical treatment becomes of importance in the management of many patients.

OBJECTIVE

To delineate the role of lanreotide in the treatment of acromegaly.

METHODS

Search of Medline, Embase, and Web of Science databases for clinical studies of lanreotide in acromegaly.

RESULTS

Treatment with lanreotide slow release and lanreotide Autogel((R)) normalized GH and insulin-like growth factor-I (IGF-I) concentrations in about 50% of patients. The efficacy of 120 mg lanreotide Autogel((R)) on GH and IGF-I levels was comparable with that of 20 mg octreotide LAR. There were no differences in improvement of cardiac function, decrease in pancreatic beta-cell function, or occurrence of side effects, including cholelithiasis, between octreotide LAR and lanreotide Autogel(R). When postoperative treatment with somatostatin analogs does not result in normalization of serum IGF-I and GH levels after noncurative surgery, pegvisomant alone or in combination with somatostatin analogs can control these levels in a substantial number of patients.

A 12-month randomized crossover study on the effects of lanreotide Autogel and octreotide long-acting repeatable on GH and IGF-l in patients with acromegaly

BACKGROUND

Somatostatin analogues have been used successfully for the treatment of acromegaly but no randomized studies have compared the effects of lanreotide Autogel (LAN) and octreotide acetate long-acting repeatable (OCT).

OBJECTIVE

To compare the effect of LAN and OCT for the treatment of acromegaly in a randomized study design.

MATERIAL AND METHODS

Twelve acromegalic patients were included and 10 patients completed treatment with LAN or OCT for 6 months and were then switched to the opposite treatment modality for 6 months without a washout period in a randomized crossover design. GH and IGF-I profiles, clinical and biochemical evaluations were performed at 0, 4, 6, 10 and 12 months.

RESULTS

After 6 months of treatment, five patients had GH levels < 0.38 microg/l during both therapies. The remaining patients had GH levels > 0.38 microg/l during both LAN and OCT treatment. Four patients had normalized IGF-I levels during both treatment regimes. Two patients on LAN and one on OCT had normalized IGF-I levels during one treatment and not during the other. In three patients, IGF-I levels were elevated during both therapies. Four patients developed palpable nodules, two patients on LAN and two patients on OCT. Gastrointestinal complaints were seen in three patients during both therapies, in three patients only during LAN, and in one patient only during OCT. Two patients were withdrawn from the study because of serious adverse effects during LAN. After the study period, four patients preferred LAN and six patients preferred OCT treatment.

CONCLUSION

The effects of LAN and OCT therapy on GH and IGF-I levels were comparable, but 3/10 patients had different treatment efficacies and 6/10 had different side-effect profiles during the LAN and OCT treatment. These results indicate that a change from LAN to OCT or vice versa may be beneficial in some patients with treatment failure or side-effects.

Optimalization and cost management of lanreotide-Autogel therapy in acromegaly

BACKGROUND

Lanreotide-Autogel is a depot formulation of the somatostatin analog lanreotide used in the treatment of acromegaly. We investigated whether prolonging or shortening the interval between injections would offer any benefit.

SUBJECTS AND METHODS

The interval was prolonged from once every 4 weeks to once every 6 weeks when patients (n=9) had normal IGF-I and GH concentrations. When patients (n=12) had still elevated IGF-I or GH on the maximal dose of 120 mg every 4 weeks, the interval was shortened to once every 3 weeks. Serum IGF-I and GH were measured after 12 and 24 weeks to allow for dose adaptation. Symptoms and tumor volume were evaluated at baseline and after 36 weeks.

RESULTS

In seven of the nine subjects with normal IGF-I and GH, the interval could be extended to 6 weeks without loosing efficacy on IGF-I (195 vs 213 microg/l; not significant, NS) and GH concentrations (1.4 vs 1.3 microg/l; NS). The weekly dose could significantly be reduced (from 23.3 to 17.8 mg; P=0.002). In only 1 of the 12 not-controlled patients, reducing the interval to once every 3 weeks induced normalization of IGF-I and GH.

CONCLUSION

In subjects whose acromegaly is well controlled using lanreotide-Autogel, prolonging the time interval between injections can often be increased 4 to 6 weeks without loss of efficacy, thereby improving the subject's comfort and reducing the cost of treatment. On the other hand, in subjects whose acromegaly is not controlled on a dose of 120 mg every 4 weeks, reducing the interval to every 3 weeks is rarely beneficial.

Efficacy of a slow-release formulation of lanreotide (Autogel) 120 mg) in patients with acromegaly previously treated with octreotide long acting release (LAR): an open, multicentre longitudinal study

OBJECTIVE

Lanreotide Autogel 120 mg (ATG120; Ipsen S.p.A, Milan, Italy) is a high-dose, sustained-release aqueous gel formulation, supplied in a prefilled syringe and given by deep subcutaneous injection. The aim of this study was to compare efficacy and tolerability of ATG120 given every 4-8 weeks with those of octreotide LAR (o-LAR) given every 4 weeks. DESIGN PATIENTS AND INTERVENTION: A phase III multicentre Italian open clinical study of 23 acromegalic patients (15 female, 8 male). All patients had received o-LAR for 6-18 months and, after 3 months wash out, ATG120 was given every 6 weeks for a total of four injections (Period 1). Then the interval between ATG120 injections was adjusted according to three different schemes: every 4, 6 or 8 weeks depending on GH levels (GH > 2.5 microg/l; 1 < GH <or= 2.5 microg/l; GH <or= 1 microg/l, respectively). ATG120 was given for a further two to three doses, with a final assessment (Period 2) at Week 34, 36 or 42.

MEASUREMENTS

Hormonal (GH and IGF-I) and clinical efficacy and tolerability.

RESULTS

ATG120 induced a significant GH decrease from 9.9 +/- 11.3 at baseline (Visit 1) to 3.5 +/- 5.7 at the end of Period 1 (P < 0.01) and to 3.8 +/- 5.7 microg/l at the final visit (P < 0.01). IGF-I also decreased from 544 +/- 312 at baseline (Visit 1) to 318 +/- 181 at Period 1 and to 356 +/- 187 microg/l at the final visit (both P < 0.05 vs. baseline). The frequency of ATG120 administrations was adjusted to every 4 weeks in 12 patients, every 6 weeks in 4 patients and every 8 weeks in 6 patients; 1 patient withdrew before the dose adjustment. Serum GH and IGF-I achieved at the end of Period 1 and Period 2 were similar to those reached with o-LAR. The number of patients who achieved GH < 2.5 microg/l was comparable between o-LAR (43%) and ATG120 at Period 1 (48%) and at Period 2 (62%). Normal IGF-I levels were recorded in 8 patients during o-LAR (35%), 11 during ATG Period 1 (48%) and 10 at the final visit (43%). Last, 4 patients showed a better response to ATG120 and 2 to o-LAR.

CONCLUSIONS

Lanreotide Autogel 120 mg is an effective and well-tolerated therapy for acromegaly. In approximately half of patients ATG120 may be administered every 6-8 weeks, instead of every 4 weeks, without lost of efficacy.

The role of lanreotide Autogel® in the treatment of acromegaly

Acromegaly is a rare disease, but all clinicians have to be aware of the diagnosis in order to minimize the negative consequences of increased levels of growth hormone and IGF-I, and the possible impact of a pituitary macroadenoma. Surgery remains the first-line therapy and may alleviate both hormonal excess and symptoms due to tumor mass effects. Postoperatively, however, many patients may need adjunctive therapy. Somatostatin analogs were marketed for clinical use in the 1980s. The depot formulations of the synthetic somatostatin analogs octreotide and lanreotide, octreotide acetate long-acting repeatable and lanreotide sustained release, were developed by incorporating the analogs into microspheres. The advantage of the new formulation of lanreotide, lanreotide Autogel^®, is the prefilled syringe of lanreotide and water. The choice of analog should be individualized for each patient based on level of efficacy, adverse event profile and preferred mode of administration. Approximately a third of acromegalic patients are resistant to the currently available somatostatin analogs. Monotherapy using cabergoline or pegvisomant is clinically available. Adding cabergoline to a somatostatin analog may be advantageous in selected patients and promising data exist regarding combination therapy with pegvisomant. Radiotherapy is still an option; however, although treating comorbidities and avoiding hypopituitarism is very important, radiotherapy should only be used for selected patients where treatment targets cannot be achieved by using the other therapies.

Pharmacokinetic profile of lanreotide Autogel in patients with acromegaly after four deep subcutaneous injections of 60, 90 or 120 mg every 28 days

OBJECTIVE

To investigate the pharmacokinetic profile of a prolonged release, aqueous Autogel formulation of the somatostatin analogue lanreotide (Lan-ATG).

DESIGN

A phase II, randomized, double-blind study, during which patients received 60, 90 or 120 mg Lan-ATG for four fixed administrations at 28-day intervals.

PATIENTS

A total of 18 patients with acromegaly were recruited; six patients were randomized to each treatment.

MEASUREMENTS

Lanreotide minimum concentration (C(min)), maximum serum concentration (C(max)) and area under the concentration-time curve during a dosing interval (AUC(tau)) were assessed after a single dose and at steady state (ss). Serum GH and IGF-1 levels were assessed before each administration and at the end of the study.

RESULTS

After a single administration, dose proportionality for C(min,1), C(max) and AUC(tau) was demonstrated statistically. After repeated administrations, Lan-ATG exhibited linear pharmacokinetics over the dose range and ss values of C(min), C(max) and AUC(tau) increased in a dose-dependent, linear manner. Mean C(max,ss) values were only two- to fourfold greater than C(min,ss) values, and there was good control over the entire release profile. Serum levels of GH and IGF-1 declined over the course of the study and acromegaly symptoms improved. The treatment was well tolerated.

CONCLUSIONS

Lan-ATG showed linear pharmacokinetic profiles over the three dose levels after both single and repeated dosing, no initial burst effect and good control over the entire release profile. Despite the absence of dose adaptation, four injections of Lan-ATG were effective in lowering serum levels of GH and IGF-1.

Modulating the cytokine response to treat Helicobacter gastritis

The conventional view of gastric acid secretion is that a negative feedback mechanism arises in response to high acidity, such that somatostatin keeps G-cells and parietal cells from producing more gastrin and acid, respectively. When the stomach becomes infected, for example with Helicobacter pylori (H. pylori), the feedback mechanism is impaired. In animal models, our laboratory has demonstrated that other types of bacteria besides H. pylori can cause gastritis. For example, under conditions of low acidity, gastritis is secondary to bacterial overgrowth, not production of excessive acid, thus suggesting a new paradigm for the regulation of gastric acid secretion under inflammatory conditions. Cytokines, released during the gastric inflammatory response, including IFN gamma, TNF alpha and IL-1 beta stimulate the G-cell to produce gastrin. Gastrin in turn triggers the release of acid, and hypergastrinemia suppresses somatostatin, the inhibitor of acid. The overall response results in maximal gastric acid output that acts as the stomach's most important anti-microbial agent. The increased acid secretion by the stomach in the presence of H. pylori seems to be part of the innate immune response, in that gastrin and somatostatin are reciprocally regulated by Th1 or Th2 cytokines, respectively. In a mouse model, we showed that octreotide, a somatostatin, analog, is an efficacious treatment for Helicobacter gastritis. In humans, octreotide might accelerate recovery from H. pylori infection, reducing the duration of antibiotic therapy.

Rapid and sustained relief from the symptoms of carcinoid syndrome: results from an open 6-month study of the 28-day prolonged-release formulation of lanreotide

This 6-month, open, non-controlled, multicenter, dose-titration study evaluated the efficacy and safety of 28-day prolonged-release (PR) lanreotide in the treatment of carcinoid syndrome. Eligible patients had a carcinoid tumor with > or =3 stools/day and/or > or =1 moderate/severe flushing episodes/day. Six treatments of 28-day PR lanreotide were administered by deep subcutaneous injection. The dose for the first two injections was 90 mg. Subsequent doses could be titrated (60, 90, 120 mg) according to symptom response. Seventy-one patients were treated. Flushing decreased from a mean of 3.0 at baseline to 2.3 on day 1, and 2.0 on day 2, with a daily mean of 2.1 for the first week post-treatment (p < 0.05). Diarrhea decreased from a mean of 5.0 at baseline to 4.3 on day 1 (p < 0.05), and 4.5 on day 2, with a daily mean of 4.4 for the first week post-treatment (p < 0.001). Symptom frequency decreased further after the second and third injections, and reached a plateau after the fourth injection. By month 6, flushing and diarrhea had significantly decreased from baseline by a mean of 1.3 and 1.1 episodes/day, respectively (both p < or = 0.001); 65% of patients with flushing as the target symptom and 18% of diarrhea-target patients achieved > or =50% reduction from baseline. Median urinary 5-hydroxyindoleacetic acid and chromogranin A levels decreased by 24 and 38%, respectively. Treatment was well tolerated. 28-day PR lanreotide was effective in reducing the symptoms and biochemical markers associated with carcinoid syndrome.