Intramuscular injections of slow-release lanreotide (BIM 23014) in acromegalic patients previously treated with continuous subcutaneous infusion of octreotide (SMS 201-995)

Acromegaly clinical trial methodology impact on reported biochemical efficacy rates of somatostatin receptor ligand treatments: a meta-analysis

INTRODUCTION

Biochemical efficacy of somatostatin receptor ligand (SRL) treatment in acromegaly is defined by metrics for GH and IGF-1 control. Since the earliest therapeutic trials, biochemical control criteria, medical formulations, and assay techniques have evolved.

MATERIALS AND METHODS

We searched PubMed for English-language trials published from 1974 to 2012 evaluating 10 or more patients, with a duration of more than 3 months and biochemical control as a key objective. We used a random-effects model to compare biochemical outcomes for octreotide and lanreotide trials according to study design characteristics.

RESULTS

A total of 4464 patients were enrolled in the analyzed trials; 4125 were treated, and 3787 completed study treatment. Overall achieved control rates were 56% for mean GH and 55% for IGF-1 normalization. Treatment duration was significantly related to both GH (P < .001) and IGF-1 control (P = .02). Prior SRL therapy (P = .01), and year of study publication (P = .03) were related to biochemical control for GH but not IGF-1. No statistically significant differences in GH or IGF-1 response rates were observed for multicenter vs single center, retrospective vs prospective, study drug, and preselection for SRL responsiveness. Dosing scheme, GH response criterion, or switch study design were also not statistically significant in determining GH or IGF-1 response rate.

CONCLUSIONS

Clinical design characteristics anticipated to impart efficacy bias including switching, preselection for SRL responsiveness, and retrospective design had no statistically significant impact on efficacy determination. Later year of publication, study duration, and prior SRL use are significant efficacy determinants for acromegaly trial outcomes.

Comparison of octreotide LAR and lanreotide autogel as post-operative medical treatment in acromegaly

Long-acting somatostatin analogs are frequently used as adjuvant treatment of acromegaly patients after noncurative surgery. This sudy aims to compare the efficacy of octreotide long-acting release (OCT) and lanreotide Autogel (LAN) in acromegaly patients. Sixty-eight patients not cured by transsphenoidal endoscopic or microscopic pituitary surgery between 2003 and 2009 were retrospectively analyzed (25 men; 43 women; mean age 41.1 ± 10.9 years [range 18-65 years]). The patients were assigned randomly to OCT (n = 36) and LAN (n = 32) groups. Evaluations included insulin-like growth factor I (IGF-I) and growth hormone (GH) after oral glucose tolerance test (OGTT) 3, 6, 12 and 18 months after starting medical treatment; pituitary magnetic resonance imaging was performed before treatment and after 3 and 12 months. Patients achieving IGF-I levels within the age and gender normal range and GH level <1 μg/l following OGTT were considered a 'biochemical cure'. Mean IGF-I and GH values and tumor volumes (cm(3)) in the LAN and OCT groups were similar in the post-operative period before initiation of medical treatment. A statistically significant decrease in GH and IGF-I levels was obtained for both treatment groups at each follow-up visit compared to the previous value. Tumor shrinkage after 12 months of treatment was statistically significant in both groups but the percentage tumor shrinkage (28.5% vs. 34.9%, P = 0.166) and rate of patients achieving biochemical cure (63.9 and 78.1%, P = 0.454) were similar between OCT and LAN groups, respectively. OCT and LAN treatment options have similar efficacy for ensuring biochemical cure and tumor shrinkage in acromegaly patients who had noncurative surgery.

Neuroendocrine tumors: a critical appraisal of management strategies

OBJECTIVES

This supplement represents the proceedings of a panel of investigators whose goal was to assess the quality of evidence pertaining to current therapeutic approaches in the management of neuroendocrine tumors (NETs). It will examine the differences in opinions between expert faculty and community physicians.

METHODS

The Neuroendocrine Tumors Summit convened in December 2009 to address 6 statements prepared by panel members that reflect important questions in the management of NETs.

RESULTS

Panel members were polled on their acceptance of each statement, and those results were compared with community-based oncologists, gastroenterologists, and endocrinologists.

CONCLUSIONS

More education regarding the treatment of NETs, including pertinent studies, is needed for physicians. Additional multicenter, prospective, placebo-controlled trials are necessary to demonstrate the benefits of somatostatin analogs, including their ability to control symptoms and affect tumor growth, and their synergistic effect with other therapies. New trials should be reported consistently and include time to tumor progression and progression-free survival as primary or secondary end points.

Effects of lanreotide SR and Autogel on tumor mass in patients with acromegaly: a systematic review

Long-acting somatostatin analogs (SSA) are widely used for the treatment of acromegaly achieving biochemical control of the disease in 50-75% of the patients. One of the goals of the treatment of acromegaly is the control of tumor growth, especially in patients in whom SSAs are used as first-line therapy. Over the recent years, there has been growing evidence that SSAs are able to induce tumor shrinkage in patients with acromegaly. However, most of the data are from patients under treatment with octreotide, either subcutaneously or intramuscularly with long-acting formulation, whereas the data on lanreotide SR or Autogel are very few. Indeed, octreotide and lanreotide, i.e. the two commercially available SSAs, show slight differences in pharmacokinetics and patterns of receptor affinities with potentially different therapeutic effects. We aimed to perform a systematic review of literature data concerning the shrinkage effects of long-acting lanreotide in patients with acromegaly. The analysis was focused on the following issues: differences in shrinkage effects between primary and secondary medical treatment, predictive value of baseline tumor volume and correlation between biochemical control and shrinkage effects. The peer-reviewed medical literature was searched to identify clinical trials studying the effects of lanreotide SR or Autogel on adenoma size in acromegaly. To be included in this analysis, studies had one of the following designs: randomized controlled trial; prospective, nonrandomized trial; retrospective study. Twenty-two studies were found to be eligible for the final analysis, in which tumor size was measured as an end-point for lanreotide treatment. Overall a total of 32.8% of patients experienced a variable degree (from 10 to 77%) of tumor shrinkage during lanreotide SR or Autogel treatment. The analysis showed that tumor shrinkage was more frequent in naïve patients as compared with those previously treated by radiotherapy, surgery or drugs other than lanreotide. The data on the correlation between tumor shrinkage and baseline tumor size were discordant, but when baseline tumor size was specified, more than 80% of patients undergoing shrinkage under lanreotide Autogel had macroadenomas. Finally, with lanreotide Autogel there was no evident correlation between biochemical response and tumor shrinkage. Our systematic review of the literature shows that lanreotide particularly when used as first-line therapy is able to quite frequently induce tumor shrinkage in patients with acromegaly. This finding suggests that this drug may have a role in the primary treatment of acromegaly.

Effectiveness and tolerability of 3-year lanreotide Autogel treatment in patients with acromegaly

OBJECTIVE

During short-term treatment, monthly subcutaneous injections of lanreotide Autogel are effective in controlling GH/IGF-1 hypersecretion and are well tolerated in patients with acromegaly. This study reports the effectiveness and the tolerability of lanreotide Autogel for at least 3 years in acromegalic patients.

PATIENTS

Fourteen patients (nine females, five males) were treated with titrated doses of lanreotide Autogel.

DESIGN

This clinical study was an extension of a previous trial. After three fixed-dose lanreotide Autogel injections, treatment was adjusted according to mean GH and IGF-I levels. After 3 years of treatment, patients were receiving 120 (n=7), 90 (n=2) and 60 mg (n=4) monthly injections of lanreotide Autogel.

MEASUREMENTS

Acromegalic symptoms, GH and IGF-1 concentrations were analysed at the end of lanreotide microparticle treatment, and after 4, 8, 12, 24, 30 and 36 months of lanreotide Autogel therapy. Tolerance and side-effects were monitored throughout the 3-year study. RESULTS Hormonal control (GH <or= 2.5 microg/l and age- and sex-normalized IGF-1) was achieved in six (46%) patients. With the exception of an unrelated death due to pulmonary embolism, no patient withdrew from study. The number of patients reporting digestive adverse events was seven (12 episodes) for the fixed-dose period, and four (eight episodes), two (six episodes) and one (three episodes) at the end of the first, second and third year of treatment, respectively. Persistent induration at the injection sites was reported by two patients, and histological findings were consistent with benign injection-site granulomas. New cholelithiasis or sludge occurred in five (35%) patients during the lanreotide Autogel treatment.

CONCLUSION

This 3-year study shows that lanreotide Autogel is effective in controlling GH/IGF-1 hypersecretion and is well tolerated during long-term treatment of patients with acromegaly.

Limited predictive value of an acute test with subcutaneous octreotide for long-term IGF-I normalization with Sandostatin LAR in acromegaly

OBJECTIVES

To study whether the growth hormone (GH) response after the subcutaneous administration 50 microg of octreotide (acute octreotide test) has any predictive value for long-term IGF-I normalization with Sandostatin LAR.

DESIGN

Twenty four therapy-naive patients with active acromegaly were studied.

RESULTS

> 75% GH decrease in the acute octreotide test predicted long-term IGF-I normalization with Sandostatin LAR in 8/11 (73%) of patients. 3/13 (23%) patients with < 75% GH decrease in the acute octreotide test were long-term biochemically controlled with Sandostatin LAR. Using the > 75% GH reduction criterion, the sensitivity and specificity of this test for predicting long-term normalization of serum IGF-I with Sandostatin LAR treatment were 73% and 77%, respectively (positive and negative predictive values: 73% and 77%, respectively). 6/8 (75%) patients with GH suppression to levels < 1.1 microg/l and 9/16 (56%) patients with GH suppression to levels < 2 microg/l in the acute octreotide test showed normalization of serum IGF-I with long-term Sandostatin LAR treatment. The sensitivity and specificity of GH suppression < 1.1 microg/l for predicting of the long-term normalization of serum IGF-I with Sandostatin LAR therapy were 55% and 85%, respectively (positive and negative predictive values: 75% and 69%, respectively). The sensitivity and specificity of GH suppression < 2 microg/l for predicting of the long-term normalization of serum IGF-I with Sandostatin LAR therapy were 82% and 46%, respectively (positive and negative predictive values: 56% and 75%, respectively).

CONCLUSION

The acute octreotide is not recommended for clinical decision making with regard to long-term treatment using the long-acting somatostatin analog Sandostatin LAR in acromegaly.

One-year follow-up of patients with acromegaly treated with fixed or titrated doses of lanreotide Autogel

OBJECTIVE

Somatostatin analogue treatment is first-line medical therapy for acromegaly. This study compared the efficacy and tolerability of titrated doses of the long-acting somatostatin analogue preparation lanreotide Autogel with fixed doses and with lanreotide prolonged release (PR) 30 mg microparticles.

PATIENTS

Patients entering the initial study had received a diagnosis of active acromegaly within the previous 5 years.

DESIGN

This open, comparative, multicentre study was a 1-year extension of a previous trial during which patients with acromegaly had switched from lanreotide PR 30 mg microparticles injected intramuscularly every 7, 10 or 14 days, for at least 3 months, to one of three fixed doses of lanreotide Autogel (120, 90, or 60 mg every 28 days, respectively). In this extension study, patients continued to receive 60, 90, or 120 mg of lanreotide Autogel by deep subcutaneous injection every 28 days for 1 year. Doses could be titrated at entry or after four or eight injections, according to the GH/IGF-I response (dose increased if GH > 2.5 micro g/l, or decreased if GH < 1 micro g/l with normal IGF-I).

MEASUREMENTS

Mean +/- SEM GH and IGF-I concentrations were analysed and gallbladder echography performed at weeks 0, 16, 32, and 48. Acromegaly symptoms were recorded monthly and tolerance and side-effects were monitored throughout the study.

RESULTS

In total, 130 patients entered this extension phase. After 1 year of treatment with titrated doses of lanreotide Autogel, mean GH (2.4 +/- 0.2 micro g/l) and IGF-I (287 +/- 12 micro g/l) concentrations were significantly lower than with lanreotide microparticles (GH, 2.8 +/- 0.2 micro g/l, P < 0.001; IGF-I, 332 +/- 15 micro g/l, P < 0.01) or with fixed-dose lanreotide Autogel (GH, 3.0 +/- 0.2 micro g/l, P < 0.001; IGF-I, 310 +/- 14 micro g/l, P = 0.02). GH hypersecretion was reduced to </= 2.5 micro g/l in 68% of patients with titrated-dose lanreotide Autogel compared with 49% with microparticles (P < 0.001) and 56% with fixed-dose lanreotide Autogel (P </= 0.005). In the 65 patients who did not require any dose titration, there was no substantial change in serum lanreotide concentration, GH or IGF-I levels over the 12-month study duration. Acromegaly was effectively controlled (GH </= 2.5 micro g/l and normalized IGF-I) in significantly more patients (43%) compared with microparticles (32%; P < 0.05). There was a trend for improved control of acromegalic symptoms with dose titration, whereas the incidence of gastrointestinal symptoms and local tolerance was similar with lanreotide Autogel and lanreotide microparticles. Gallbladder echographies showed new lithiasis in 8% of lanreotide Autogel patients.

CONCLUSION

Dose titration of lanreotide Autogel improved GH and IGF-I control in patients with acromegaly beyond that achieved using fixed doses of lanreotide Autogel or lanreotide microparticles. Titrated long-term lanreotide Autogel treatment is well tolerated.

Sandostatin LAR in acromegaly: a 6-week injection interval suppresses GH secretion as effectively as a 4-week interval

INTRODUCTION

Depot preparations of long-acting somatostatin analogues are being used increasingly in the treatment of GH hypersecretion in patients with acromegaly, either as primary treatment or as secondary treatment following incomplete surgery. In 60% of these patients, Sandostatin long-acting release (LAR), the depot preparation of octreotide, achieves effective suppression of serum GH (< 5 mU/l) and IGF-I levels. The advice is to administer Sandostatin LAR at 4-week intervals. After injection, serum octreotide shows an initial peak and thereafter maximal values between 14 and 42 days. There have been suggestions that the dose interval of this preparation could be increased, resulting in reduced costs, although this concept has not been confirmed by studies.

AIM OF THE STUDY

We performed a prospective, cohort study in patients with active acromegaly but with normal serum GH and IGF-I levels during Sandostatin LAR treatment to assess whether the dose interval could be safely increased from 4 to 6 weeks, without significant effect on serum GH concentrations or other biochemical and clinical markers of GH hypersecretion.

PATIENTS AND METHODS

Fourteen patients (seven males) with GH concentrations below 5 mU/l during Sandostatin LAR treatment entered an 8-week withdrawal study following an injection. Subsequently, during an interval study patients received injections at 6-week intervals (t = 0, 8, 14, 20, 26, 32, 38 and 44 weeks). Study parameters (fasting GH, average GH of eight plasma samples, IGF-I, and octreotide concentrations, symptoms score and quality-of-life score) were assessed 2, 4, 6 and 8 weeks following the first injection (withdrawal) and at 26 and 44 weeks (interval study) before the next injection.

RESULTS

During the withdrawal study, mean serum GH concentration increased significantly from 1.68 +/- 0.3 at 4 weeks to 2.57 +/- 0.5 mU/l at 6 weeks (P = 0.04, 4 vs. 6 weeks) and to 2.89 +/- 0.4 mU/l at 8 weeks (P < 0.001, 4 vs. 8 weeks). Mean serum GH concentration was below 5 mU/l in all patients at all time points, except for one patient at 8 weeks, and IGF-I levels remained normal in all patients. During withdrawal up to 8 weeks there was no significant change in serum IGF-I concentration, symptoms score or quality-of-life score. Mean serum octreotide decreased significantly from 1610 +/- 355 ng/l at 2 weeks to 1045 +/- 272 ng/l at 6 weeks (P = 0.002, 2 and 4 vs. 6 weeks) and to 559 +/- 147 ng/l at 8 weeks. In the interval study, one patient had mean serum GH above 5 mU/l associated with an increase in symptoms at 26 weeks and she was withdrawn from the study. The remaining 13 patients completed the 6-weekly injection study protocol and in the long term no significant changes in mean serum GH concentration, IGF-I concentration or symptom scores were observed (6 vs. 26 and 44 weeks). All patients had a mean serum GH concentration < 5 mU/l and serum IGF-I remained normal in 11 out of 14 patients at 26 weeks and nine out of 13 patients at 44 weeks. Moreover, the mean octreotide concentrations measured 6 weeks after a Sandostatin LAR injection did not decrease in the long term.

CONCLUSION

On the basis of serum GH concentrations, most patients with serum GH levels < 5 mU/l during Sandostatin LAR treatment using a 4-weekly schedule can be effectively treated with 6-weekly injections. However, during long-term treatment with 6-weekly injections, discordant IGF-I and GH results were observed in 30% of the patients and careful clinical monitoring is therefore required.

Efficacy of the new long-acting formulation of lanreotide (lanreotide Autogel) in the management of acromegaly

Lanreotide Autogel is a new long-acting aqueous preparation of lanreotide for the treatment of acromegaly and is administered by deep sc injection from a small volume, prefilled syringe. The aim of this study was to evaluate the efficacy and safety of this new long-acting formulation in a large population of acromegalic patients previously responsive to lanreotide 30 mg, im (sustained release microparticle formulation). Lanreotide Autogel was administered by deep sc injection every 28 d to 107 patients (54 males and 53 females; mean age, 54 +/- 1.2 yr). All patients had been treated with lanreotide (30 mg) for at least 3 months before study entry and had a mean GH level less than 10 ng/ml after at least 4 subsequent im injections every 14 d (48%), 10 d (32%), or 7 d (20%). Treatment was switched from lanreotide 30 mg injected every 14, 10, or 7 d to 60, 90, or 120 mg lanreotide Autogel, respectively, every 28 d. After three fixed dose injections of lanreotide Autogel, mean lanreotide levels were similar to those obtained at steady state with lanreotide 30 mg. During lanreotide Autogel treatment, the control of acromegalic symptoms was comparable with that previously achieved during lanreotide 30 mg treatment. After 3 injections of lanreotide Autogel, mean GH (2.87 +/- 0.22 ng/ml) and IGF-I (317 +/- 15 ng/ml) values were comparable with those recorded at the end of lanreotide 30 mg treatment (GH, 2.82 +/- 0.19 ng/ml; IGF-I, 323 +/- 16 ng/ml). GH levels below 2.5 ng/ml and age-/sex-normalized IGF-I were achieved in 33% and 39% of patients during lanreotide 30 mg and lanreotide Autogel treatment, respectively. Diarrhea, abdominal pain, and nausea were reported by 38%, 22%, and 18% of patients during lanreotide 30 mg treatment and by 29%, 17%, and 9% of patients, respectively, during lanreotide Autogel treatment. In conclusion, this clinical study shows that lanreotide Autogel is at least as efficacious and well tolerated as lanreotide 30 mg. This new long-acting lanreotide formulation, lanreotide Autogel, which is administered from a small volume, prefilled syringe by deep sc injection, is therefore likely to improve the acceptability of medical treatment for patients requiring long-term somatostatin analog therapy.

Growth hormone responses to oral glucose and intravenous thyrotropin-releasing hormone in acromegalic patients treated by slow-release lanreotide

The aim of this study was to assess GH response to oral glucose tolerance test (OGTT) and TRH stimulation test in a group of 10 patients with active post-operative acromegaly before and after long-term slow-release (SR) lanreotide therapy (30 mg im every 10-14 days). Seven patients (2 males, 5 females, 29-71 yr), who during therapy maintained plasma GH and IGF-I concentrations under 5 microg/l and 450 microg/l, respectively, were considered as responders and studied for 24 (1 patient) to 36 months (6 patients). Three patients (1 male, 2 females, 46-61 yr) with levels of GH and IGF-I above those values were studied for 12 months. The OGTT (75 g po) and TRH test (400 microg iv) were repeated before and after 6, 12, 24 and 36 months. The GH response to OGTT was abnormal (nadir: >2 microg/l) at 6 and 12 months in poorly responsive patients. This response was normalized in all responsive patients. Nonetheless, 2 responsive patients showed abnormal GH values after OGTT once each throughout the 36-month study period. The GH response to TRH was characterized by great variability and exhibited unpredictable behavior throughout the study period both in responsive and in poorly responsive patients. Only 2 patients in the responsive group showed persistent normal GH levels (peak: < or =5 microg/l) after TRH for 3 yr. In conclusion, SR lanreotide treatment gave rise to a correct control of GH hypersecretion and to a normalization of GH response to oral glucose in 7 out of 10 patients, although it did not abolish the paradoxical reaction of GH to TRH in all responders. The effect of SR lanreotide on GH response to glucose tolerance test was not paralleled by GH response to TRH.

Optimal dosage interval for depot somatostatin analogue therapy in acromegaly requires individual titration

BACKGROUND

The recent introduction of the depot somatostatin analogues octreotide LAR and lanreotide represent major advances in the medical treatment of acromegaly. However, it is uncertain whether the recommended dose intervals of 4 weeks and 10-14 days, respectively, are applicable to all patients.

AIMS

To determine the optimum intervals between depot injections of either octreotide LAR and lanreotide for the suppression of serum GH and IGF-I in patients with acromegaly. Twenty-seven patients with acromegaly were randomly allocated to receive either three injections at 4 week intervals of octreotide LAR (n = 18) or five injections at 14 day intervals of lanreotide (n = 11); two patients participated in both arms. Prior to the first injection, at 4 and 6 weeks after the last injection of LAR, and at 10, 14 and 21 days after the last injection of lanreotide, serum mean GH and IGF-I levels were measured.

RESULTS

In the LAR-treated group, at 4 and 6 weeks after the third injection 13 patients (72%) and 12 patients (67%), respectively, had a mean GH < 5 mU/l. IGF-I was normalized in 12 and 11 patients at these times. In the lanreotide-treated group, five (45%), four (36%) and three (27%) patients, respectively, had a GH < 5 mU/l at 10, 14 and 21 days after the last injection and eight, six and five patients had a normal serum IGF-I.

CONCLUSION

There is marked variability in individual patient responses to depot somatostatin analogues. The establishment of optimal drug intervals requires careful assessment. For octreotide LAR many patients may be as adequately controlled with 6 weekly injections as with 4 weekly injections. It is important to measure serum GH profiles at intervals after initiating therapy with these drugs to individualize doses for each patient and hence minimize cost.

Time course of GH and IGF-1 levels following withdrawal of long-acting octreotide in acromegaly

AIM

Several studies have demonstrated the efficacy of octreotide LAR administered intramuscularly at 4-week intervals in the treatment of acromegaly. In contrast, few data are available on the time course of GH and IGF-1 plasma levels following octreotide LAR withdrawal. This prompted us to study these parameters for up to 20 weeks following drug withdrawal in a group of 18 acromegalic patients treated for one year.

DESIGN AND PATIENTS

We studied 18 patients treated with octreotide LAR 10 mg (n = 2), 20 mg (n = 15) and 30 mg (n = 1) every 4 weeks for one year. GH (mean level during a 4-hour daily profile) and IGF-1 concentrations were measured at the end of treatment, just before the last injection (baseline) and then 15 +/- 2 weeks (first control) after the last injection. In patients with GH levels below 2.5 micrograms/L and/or normal IGF-1 at the first control, a second control was performed four to eight weeks later.

RESULTS

After one year of treatment with octreotide LAR, the mean plasma GH concentration was 1.91 +/- 1.25 micrograms/L (mean +/- SE) and the mean IGF-1 concentration was 440 +/- 251 micrograms/L. Among the 18 patients, 13 had mean plasma GH concentrations below 2.5 micrograms/L and seven could be considered as well-controlled (normal IGF1 and mean GH levels below 2.5 micrograms/L). After treatment withdrawal, the plasma GH concentration remained below 2.5 micrograms/L at the first and the second controls in 2 of the 13 (15%) patients with suppressed GH levels on baseline. Among the seven well-controlled patients on baseline (GH levels below 2.5 micrograms/L and normal IGF-1), one (15%) remained well-controlled, one (15%) kept GH levels below 2.5 micrograms/L but increased IGF-1 levels, and one (15%) kept normal IGF-1 levels but increased mean GH levels at the first control. This hormonal status remained unchanged at the second control in these 3 patients.

CONCLUSIONS

These results show long-lasting suppression of GH secretion after treatment withdrawal in some acromegalic patients treated for 12 months with octreotide LAR. The duration of GH suppression after treatment withdrawal is variable. Mean GH levels remained below 2.5 micrograms/L in 15% of our patients for up to 21 weeks following withdrawal of octreotide LAR. In practice, it may be preferable to wait several months after long-acting somatostatin analog withdrawal before reassessing hormone status. Owing this long-lasting effect, a dose reduction to 10 mg and/or a longer interval between injections could be considered for very good responders, as this would lead to considerable cost savings without affecting GH or IGF-1 control.

Efficacy and tolerability of the long-acting somatostatin analog lanreotide in acromegaly. A 12-month multicenter study of 58 acromegalic patients. French Multicenter Study Group on Lanreotide in Acromegaly

OBJECTIVE

To determine the effects of the new somatostatin analogue, lanreotide, in its prolonged released form (PR), in patients with acromegaly.

DESIGN

Prospective open multicenter non comparative study.

SETTING

Thirty-three university-affiliated medical centers.

PATIENTS

One hundred sixteen acromegalic patients with active disease, of whom 58 patients complied with the protocol and completed the 12-month period treatment.

INTERVENTION

Lanreotide PR treatment was started at a dose of 30 mg intramuscularly every 14 days. If integrated mean plasma GH levels were not below 5 micrograms/L and/or IGF-I levels were not normalized after one month of treatment, injections were given every 10 days. The duration of the study was 12 months.

RESULTS

After one month of treatment mean plasma GH and IGF-I levels had fallen from 10.7 +/- 11.1 micrograms/L (mean +/- SD; range, 2.6-74.8 micrograms/L; median, 7 micrograms/L) and 718 +/- 270 micrograms/L (range 338-1440 micrograms/L; median, 645 micrograms/L), respectively, to 7.8 +/- 10.1 micrograms/L and 575 +/- 252 micrograms/L, respectively. Thirty patients (22%) had plasma GH levels below 2.5 micrograms/L, and 8 patients (16%) had age-adjusted normal plasma IGF-I levels. At the sixth month of treatment mean plasma GH levels of 2.5 micrograms/L or less, and normal plasma IGF-I levels were observed in 33%, and 33% of patients, respectively. At the twelvth month of treatment, these percentages were 41%, and 41%, respectively. The interval between two injections was shortened (one injection every 10 days) in 8 of the 58 patients (13%) at the second month of treatment, and at the end of the study, 70% of patients required 3 injections per month. The most frequent adverse event elicited by enquiry was transient diarrhea (76% of patients), followed by abdominal pain (62%) and pain at the injection site (59%). Based on the analysis of a subgroup of 46 patients who had at least a measurement of fecal fat content after day 0 of the study, a non significant increase (from 4.2 +/- 3.4 to 5.1 +/- 4.3 g/24 h, p = 0.3) in mean steatorrhea was observed during treatment. Before treatment, steatorrhea was present in 9 (19%) patients. During the study, 15 additional patients (32%) developed persistent steatorrhea, and there was a transient increase in fecal fat content above 6 g/24 h in another 11 patients. After exclusion of the 7 patients (12%) with gallstones at enrollment, new gall-stones were diagnosed in 6 out of 50 patients (12%) during the study.

CONCLUSION

Two or three monthly injections of lanreotide PR decreased GH concentration to less than 2.5 micrograms/L and normalized IGF-I levels in 41% of patients treated during 12 months. The good tolerability of this treatment, and the reduction in the frequency of injections, plus the sustained drug serum concentrations, confirm the usefulness of this new somatostatin analog formulation.

Short-term pre-surgical treatment with somatostatin analogues, octreotide and lanreotide, in acromegaly

Eighteen patients with symptoms of active acromegaly were treated with somatostatin analogues for 4 weeks before surgery. Both before and after the treatment, levels of growth hormone (GH), prolactin (PRL), insulin growth factor -I (IGF-I), luteotropin (LH), folliculostimulin (FSH) and subunit alpha of glycoprotein hormones were estimated. Glucose tolerance test, magnetic resonance imaging (MRI) examination, sight acuity and field of vision tests were also performed. The same tests were performed on ten control patients with clinically and biochemically active acromegaly, subjected to surgery but not treated with somatostatin analogues. In six patients treated with somatostatin analogues GH levels decreased significantly to less than 5 ng/ml and in two patients remained elevated while in 10 patients GH level decreased and ranged from 6.1 to 42.9 ng/ml. In 13 patients we observed a decrease in IGF-I to normal levels (<400 ng/dl) and in 3 patients we noted a decrease to levels slightly higher than normal. There was also a slight decrease in alpha subunit concentration. In the glucose inhibition test 4 patients demonstrated normalized GH levels. In patients with elevated PRL and TSH levels, treatment with somatostatin analogues induced their decrease. No changes were observed in levels of LH and FSH. After therapy MRI examination disclosed a decrease in tumor volume in two patients (by 20 and 25%, respectively) and no changes in tumor size in 16 patients. The two patients with a decreased tumor volume also showed normalized glucose tolerance tests. All patients manifested an improved clinical condition. Neurosurgeons disclosed a decreased tumor consistency which greatly facilitated surgical procedure. Our studies documented favourable effects of somatostatin analogues on the assayed hormone levels, and on the general condition of the patients as well as on the course of the surgical procedure itself.

Comparison of six months therapy with octreotide versus lanreotide in acromegalic patients: a retrospective study

OBJECTIVE

We analysed the effects of 6-months' treatment with octreotide s.c. and lanreotide-SR on circulating GH and IGF-I levels in acromegaly.

DESIGN

Open retrospective study.

PATIENTS

Thirty-eight patients with active acromegaly (plasma IGF-I levels greater than 2 standard deviations for age-matched controls and increased serum GH levels not suppressible by oral glucose load) were studied. All patients received s.c. octreotide at a dose of 150-600 microg/day for six months as first therapy and subsequently, lanreotide i.m., 30-60 mg either at 14 or 10 day intervals, for 6 months. A 3 months' washout was applied before starting lanreotide treatment.

MEASUREMENTS

Mean serum GH levels (from three samples), IGF-I, and clinical examination were performed before and 30, 60, 90 and 180 days after octreotide and lanreotide treatments. Safety tests, HbA1c and, thyroid function were evaluated every three months.

RESULTS

Circulating GH and IGF-I levels were significantly reduced (P < 0.001) after one, three and six months of both octreotide and lanreotide treatment. The absolute values were lower and the percent decrease in serum GH levels obtained after octreotide treatment was significantly greater, at all scheduled assessments, than after lanreotide (P < 0.01). Serum IGF-I levels during octreotide were significantly lower only after the first month of therapy (P < 0.01).

CONCLUSIONS

Our study shows that octreotide s.c. is able to induce an earlier reduction in IGF-I levels and a more marked reduction in GH levels than lanreotide. However, after six months of therapy the number of patients with safe GH levels and normal IGF-I age-matched levels, was similar with both drugs. Therefore we suggest that octreotide treatment be preferentially used in the short-term presurgical treatment, while lanreotide can be used in chronic therapy when better compliance is necessary.

The therapeutic value of somatostatin and its analogues

In this review we discuss the physiological effects of somatostatin, which are mediated by specific receptor subtypes on different tissues. These observations have suggested new therapeutic possibilities for the use of the synthetic somatostatin analogues in the treatment of acromegaly as well as a number of other endocrine and non-endocrine disorders.

Treatment of advanced pancreatic cancer with the long-acting somatostatin analogue lanreotide: in vitro and in vivo results

Fourteen patients with metastatic pancreatic adenocarcinoma were treated with the long-acting somatostatin (SST) analogue lanreotide. No objective response was obtained, and the median survival was 4 months (range 1.8-7 months). Pancreatic cancer could not be visualized by means of SST-receptor (R) scintigraphy in our patients. In vitro data also demonstrated absence of SSTR2 expression, suggesting pancreatic cancer not to be a potential target for treatment with SST analogues.

Successful treatment of an advanced hepatocellular carcinoma with the long-acting somatostatin analog lanreotide

Treatment options for hepatocellular cancer apart from surgical resection are limited because of the drug-refractory nature of this disease. Little is known about the role of somatostatin-receptors in hepatocellular cancer, and somatostatin analogs have not been investigated for treatment of this malignancy. We present the case of a 68-yr-old male, who was successfully treated with the long-acting somatostatin analog lanreotide.

Long-term therapy with long-acting octreotide (Sandostatin-LAR) for the management of acromegaly

OBJECTIVES

To evaluate the efficacy and safety of a long-acting preparation of the somatostatin analogue octreotide, Sandostatin-LAR (SMS-LAR) for the treatment of acromegaly.

DESIGN AND PATIENTS

Thirteen patients with acromegaly received intramuscular injections of SMS-LAR 20-40 mg at 4-6 week intervals for a period of up to 3 years.

MEASUREMENTS

Serial measurement of serum GH and IGF concentrations were obtained. Symptoms related to acromegaly were scored by patients at baseline and following each injection. Serial gallbladder ultrasound and pituitary imaging was performed throughout the study.

RESULTS

One patient was withdrawn from the study after 6 months because of continued gastrointestinal side effects; 4 patients were treated with monthly injections for 12 months and 8 patients with injections at either 1 month or 6-week intervals for 36 months; hence data is presented for n = 12 for up to 12 months; and thereafter n = 8. SMS-LAR significantly reduced serum GH and IGF-1 values: for the whole group GH concentrations fell from 24.8 +/- 4.2 mU/l (mean +/- SE) at baseline to 5.2 +/- 0.8 mU/l at 12 months (P < 0.01, n = 12). In the 8 patients treated for 3 years GH fell from 27.8 +/- 6.1 mU/l at baseline to 4.2 +/- 0.8 mU/l at the end of 3 years (P < 0.01, n = 8). GH fell to < 10 mU/l in all subjects and was < 5 mU/l in 50% after both 1 and 3 years. IGF-1 concentrations fell from 95 +/- 13 nmol/l at baseline to 63 +/- 13 nmol/l after 1 year (P < 0.01, n = 12; reference range < 65 nmol/l). In the 8 patients treated for 3 years IGF-1 concentrations fell from 119 +/- 14 nmol/l at baseline to 60 +/- 13 nmol/l after 3 years (P < 0.001, n = 8). IGF-1 was < 65 nmol/l in 60% of patients after 1 year and 75% after 3 years. Treatment resulted in trends towards improvement in symptoms of acromegaly and statistically significant improvement in sweating. There was no evidence of tachyphylaxis or evidence to suggest development of glucose intolerance. Only 2 patients (15%) developed gallbladder sludge which was asymptomatic; no patient developed gallstones.

CONCLUSIONS

We conclude that SMS-LAR is a safe, effective and well tolerated treatment, making it an important therapeutic option in the management of acromegaly.

Treatment of androgen excess in females: yesterday, today and tomorrow

Hirsutism, acne and androgenic alopecia represent, in females, some of the manifestations of the clinical spectrum of hyperandrogenism. These pictures represent not only cosmetic damage, but also a source of remarkable psychological distress. Often hirsutism is regarded as presumptive evidence of a lack of femininity. The major diagnostic concern is to exclude an ovarian or adrenal androgen-secreting tumor, a congenital hyperplasia or polycystic ovary disease. Ethnic background should be taken into account together with the progression of the symptoms. Following the etiology, surgery and exogenous glucocorticoids or inhibition of gonadotropin secretion have to be carefully chosen in the management of different kinds of hyperandrogenism. Several pharmacologic agents have recently shown the ability to block the androgen receptors at target organ sites, thus allowing a specific antiandrogenic treatment. In some cases cosmetic measures could be of great value. Obesity accompanied by hyperinsulinemia can represent the main cause of ovary androgen hypersecretion; therefore a reduced body weight and muscle activity represent the basis of any treatment. Some other drugs, such as long-acting analogs of somatostatin, could be considered among possible drugs for the future. The aim of this article is to provide an appraisal of what is presently known about the regulation of hair growth, the various causes of excessive androgen secretion and the current methods to solve, safely, this important feminine clinical problem.

Somatostatin analogue treatment of neuroendocrine tumours

The long-acting analogues of somatostatin have an established place in the medical treatment of patients with neuroendocrine tumours. They act through binding with specific, high-affinity membrane receptors. Somatostatin analogue therapy is an effective and safe treatment for most growth hormone and thyrothropin-secreting pituitary adenomas. The potential therapeutic consequences of the presence of somatostatin receptors on clinically 'nonfunctioning' pituitary tumours are still uncertain. Somatostatin analogues are not useful in the treatment of patients with prolactinomas, or adrenocorticotropin (ACTH)-secreting adenomas. However, the somatostatin analogue octreotide suppressed pathological ACTH release in some patients with Nelson's syndrome and ACTH and cortisol secretion in several patients with Cushing's syndrome caused by ectopic ACTH secretion. Somatostatin analogues are effective in the sympatomatic treatment of most (metastatic) pancreatic islet cell tumours and most (metastatic) carcinoids. In some of these patients, they also induce tumour stabilisation or reduction. In some patients with (metastatic) medullary thyroid carcinomas, continuous treatment with very high doses of octreotide can be of temporary relief. The clinical effectiveness of somatostatin analogues in patients with small cell lung cancer is currently under investigation. Long-term therapy with somatostatin analogues of catecholamine-secreting (malignant) paragangliomas and phaeochromocytomas has not shown clinical benefits.