Effectiveness of slow-release lanreotide in previously operated and untreated patients with GH-secreting pituitary macroadenoma

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Improvement in Symptoms and Health-Related Quality of Life in Acromegaly Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Whereas biochemical response is often used as a primary study outcome, improvement in symptoms and health-related quality of life (HRQoL) is the relevant goal for patients to consider treatment successful. We performed a systematic review and meta-analysis to assess the effect of treatment on symptoms and HRQoL in acromegaly.

METHODS

Seven electronic databases were searched for longitudinal studies assessing patient-reported symptoms or HRQoL in acromegaly. Meta-analyses were performed to assess differences during treatment for the Acromegaly Quality of Life Questionnaire (AcroQoL) and Patient-Assessed Acromegaly Symptom Questionnaire (PASQ), and standardized mean difference (SMD) for individual symptoms (interpretation: 0.2 small, 0.5 moderate, and 0.8 large effect). Treatment-naive and previously treated patients were assessed separately.

RESULTS

Forty-six studies with 3301 patients were included; 24 contributed to quantitative analyses. Thirty-six studies used medication as main treatment, 1 transsphenoidal adenomectomy, and 9 various treatments. Symptoms and HRQoL both improved: AcroQoL increased 2.9 points (95% CI, 0.5 to 5.3 points), PASQ decreased -2.3 points (95% CI, -1.3 to -3.3 points), and individual symptom scores decreased for paresthesia -0.9 (95% CI, -0.6 to -1.2), hyperhidrosis -0.4 (95% CI, -0.1 to -0.6), fatigue -0.3 (95% CI, -0.1 to -0.6), arthralgia -0.3 (95% CI, -0.1 to -0.5), headache -0.3 (95% CI, 0.0 to -0.6), and soft-tissue swelling -0.2 (95% CI, 0.0 to -0.4).

CONCLUSION

Symptoms and HRQoL improved during acromegaly treatment. Consensus is needed on which symptoms should be included in a potential core outcome set, taking into account symptom frequency, severity, and sensitivity to change, which can be used in clinical practice and as outcome in trials.

Challenges in the diagnosis and management of acromegaly: a focus on comorbidities

INTRODUCTION

Acromegaly is a rare, insidious disease resulting from the overproduction of growth hormone (GH) and insulin-like growth factor 1 (IGF-1), and is associated with a range of comorbidities. The extent of associated complications and mortality risk is related to length of exposure to the excess GH and IGF-1, thus early diagnosis and treatment is imperative. Unfortunately, acromegaly is often diagnosed late, when patients already have a wide range of comorbidities. The presence of comorbid conditions contributes significantly to patient morbidity/mortality and impaired quality of life.

METHODS

We conducted a retrospective literature review for information relating to the diagnosis of acromegaly, and its associated comorbidities using PubMed. The main aim of this review is to highlight the issues of comorbidities in acromegaly, and to reinforce the importance of early diagnosis and treatment.

FINDINGS AND CONCLUSIONS

Successful management of acromegaly goes beyond treating the disease itself, since many patients are diagnosed late in disease evolution, they present with a range of comorbid conditions, such as cardiovascular disease, diabetes, hypertension, and sleep apnea. It is important that patients are screened carefully at diagnosis (and thereafter), for common associated complications, and that biochemical control does not become the only treatment goal. Mortality and morbidities in acromegaly can be reduced successfully if patients are treated using a multimodal approach with comprehensive comorbidity management.

Preoperative somatostatin analogues versus direct transsphenoidal surgery for newly-diagnosed acromegaly patients: a systematic review and meta-analysis using the GRADE system

Whether the preoperative use of somatostatin analogues (SA) improves surgical outcomes in acromegaly is still a matter of debate.

OBJECTIVE

We conducted a systematic review of randomized, controlled trials that compared the short-term outcomes of preoperative use of SA (Pre-SA) with direct TSS (No-SA) for the treatment of newly diagnosed acromegaly.

METHODS

Embase, Pubmed, Lilacs, and Central Cochrane were used as our data sources. The primary outcomes were no need for any adjuvant treatment 3 months after surgery, based on biochemical results (GH nadir after OGTT <1 μg/L and normal IGF-1 for age and gender), quality of life and mortality. The included trials were analyzed using the Grading of Recommendations Assessment, Development, and Evaluation approach.

RESULTS

A total of 2.099 references were identified and two reviewers independently screened the titles and abstracts. From the 14 potentially eligible studies, four were included and ten were excluded due to lack of randomization or different outcomes. A pool of 261 patients was randomly assigned to Pre-SA or No-SA. Meta-analysis of IGF1 normalization showed a significant difference in favor of Pre-SA (RR 2.47; 95% CI 1.66, 3.77). Adding a GH nadir on OGTT ≤1 μg/L, we found a RR of 2.15 (95% CI 1.39, 3.33). Quality of evidence for no need of adjuvant postoperative treatment was moderate, but for improving quality of life was very low and for mortality was absent.

CONCLUSION

Pre-SA increases the chance of biochemical control of acromegaly 3 months after TSS in patients harboring GH-secreting pituitary macroadenomas.

Preoperative somatostatin analogs treatment in acromegalic patients with macroadenomas. A meta-analysis

BACKGROUND

Several studies have investigated the biochemical remission rate of presurgical somatostatin analogs treatment on acromegaly, but the remission criteria were diversed and the results were contradicting.

OBJECTIVE

Aim of this paper is to provide enhanced evidence for the effectiveness of preoperative SSA treatment to improve on surgical results of macroadenomas in acromegaly.

DATA SOURCE

Literature is cited from the PubMed, Embase and Cochrane Library, dating from December, 1985 to August, 2013.

STUDY ELIGIBILITY CRITERIA

Eligibility criteria included patients with acromegaly caused by GH-secreting pituitary macroadenomas, patients pretreated with somatostatin analogs versus direct surgery and a stricter remission criteria defined as the GH nadir<1μg/l during an oral glucose tolerance test (OGTT) and the age- and sex- adjusted IGF-1 concentration was normal. Primary end points included Short term and long term postoperative biochemical remission.

STUDY APPRAISAL AND SYNTHESIS METHODS

A total of 1421 publications were found by the electronic search. After full-text review, 8 were included in our study. 7 of them focus on the postoperative remission in short term; 3 of them focus on the outcomes in long term. For the analysis of the postoperative biochemical remission, a random effect model was used to account for differences.

RESULTS

The meta analysis shows that patients in the SSA pretreatment groups have had a more significantly cure rate than those in the direct surgery groups (RR=1.72, 95%CI: 1.14-2.60, P=0.009) with a short term follow-up. Subgroup analysis proves benefit from lanreotide pretreated groups (RR=2.27, 95%CI: 1.34-3.84, P=0.002) but not octreotide pretreated groups (RR=1.51, 95%CI: 0.82-2.75, P=0.183). No significant differences appeared between the two groups (RR=1.03, 95%CI: 0.86-1.24, P=0.751) with a long term follow-up.

LIMITATIONS

2 Retrospective trial was included and most of the trials included was designed as single-center study.

CONCLUSIONS

Based on the analysis of this paper, the preoperative SSA treatment was beneficial in the group with short-term follow-up, while it was not advantageous in the group with long-term follow-up. For the limitations in this study, to drawn more solid conclusions, further large, randomized, multi-center, and long-term follow-up trials were required.

Cardiovascular events in acromegaly: distinct role of Agatston and Framingham score in the 5-year prediction

Prediction of ischemic cardiovascular events (ICE) in acromegalic patients stratified accordingly with Framingham (FS) and Agatston score (AS). 32 patients with active (group A (0)) and 20 with controlled (group B (0)) acromegaly have been enrolled. During the 5-year follow-up, 19 out of 32 patients in group A (0) reached disease control. At entry, FS and AS, by an eight-slice MDCT scanner, were calculated in all patients. ICE were diagnosed by autopsy, if lethal, and by electrocardiography and/or echocardiography, if non-lethal. Overall, 9.6 % of patients died for lethal ICE. AS >400, but not high FS at entry, was associated with increased risk of lethal ICE. Lethal ICE had occurred in two patients of group A (0) and three of group B (0) (p NS), while a non-lethal ICE had occurred in two cases of the former and in other two of the latter group (p NS). Either FS or AS was correlated with the risk for ICE overall (p < 0.02), but only AS correlated with that of lethal ICE (p < 0.0003). Survival analysis demonstrated reduced life expectancy in patients with high FS (p < 0.02). In acromegalics, AS >400 is associated with increased risk of lethal ICE, while high FS is associated with reduced life expectancy, regardless of disease control.

HGF/c-met system targeting PI3K/AKT and STAT3/phosphorylated-STAT3 pathways in pituitary adenomas: an immunohistochemical characterization in view of targeted therapies

The ligand/receptor hepatocyte growth factor (HGF)/c-met signaling system promotes cellular growth and angiogenesis through PI3K/phosphor-Akt and STAT3/phosphor-STAT3 downstream effectors. In this study, we have evaluated the expression of molecules of the HGF/c-met pathway in pituitary adenomas (PA). The expression of HGF, c-met, PI3K (p85αsubunit) pAkt, STAT3, and pSTAT3 was analyzed by immunohistochemistry in an archival series of 30 PA (12 non-functioning and 18 functioning; 25 macroadenomas and 5 microadenomas). PAs expressed all six proteins in tumor epithelial cells. The proportion of c-met(+ve) cells was greater than HGF(+ve) cells (49 ± 19 vs 34 ± 17 %, P < 0.01), the pAkt(+ve) cells greater than PI3K(+ve) cells (39 ± 16.0 vs 1.3 ± 0.5 %, P < 0.001), and the STAT3(+ve) cells greater than active pSTAT3(+ve) cells (14 ± 8 vs 7 ± 6 %, P < 0.01). Furthermore, endothelial Akt immunostaining was detected on the vascular surface area of 17 PAs, in macroadenomas more frequently than in microadenomas (82 vs 18 %). The percentage of immunostained endothelial cells was greater in macro than in microadenomas (19 ± 7 and 7 ± 3 %; P < 0.05). In conclusion, HGF and c-met are widely expressed in PA, and correlate with pAkt expression. These data, together with the finding of pAkt immunostaining on microvascular areas related to tumor size, suggest a major role of the pAKT signaling in tumor growth and angiogenesis. There might be practical implications for the targeted therapy of PA.

Complete disappearance of a GH-secreting pituitary macroadenoma in a patient with acromegaly: effect of treatment with lanreotide Autogel and consequence of treatment withdrawal

BACKGROUND

Somatostatin analogs (SA) are the cornerstone in the medical treatment of acromegaly, used as either primary or adjunctive therapy. In particular, SA are effective in inducing the biochemical remission of the disease and tumor shrinkage, although only few cases of complete disappearance of the pituitary tumor in patients treated with SA as long-acting formulations have been reported. SA withdrawal has been demonstrated to keep safe levels of GH and IGF1 at least in a small subset of patients well responsive to SA, although it is generally followed by disease recurrence after several months.

CASE REPORT

A 61-year-old female patient bearing a very large GH-secreting pituitary macroadenoma was treated with 12-month lanreotide Autogel (ATG), at the initial dose of 120 mg/28 days. After 3 months, GH and IGF1 levels were fully normalized, to prolong the administration interval from 28 to 56 days. After 6 months of treatment, a significant tumor shrinkage (90% of baseline size) was observed, whereas GH and IGF1 excess was still well controlled. After 12-month therapy, a complete disappearance of the pituitary tumor was observed, and the hormonal evaluation confirmed the complete biochemical remission of acromegaly. Lanreotide ATG treatment was withdrawn. The clinical, biochemical, and radiological remission of acromegaly was maintained 24 months after lanreotide ATG treatment discontinuation, without evidence of disease recurrence.

CONCLUSIONS

This report represents an exemplary case of the potentiality of treatment with lanreotide ATG in inducing a complete remission of acromegalic disease, persistent after a long period of time from treatment withdrawal.

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.

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.

Effect of gender and gonadal status on the long-term response to somatostatin analogue treatment in acromegaly

:GH and IGF-I secretion is related to gender and age.

OBJECTIVE

To evaluate the impact of gender and gonadal status on the long-term sensitivity to the somatostatin analogues depot octreotide long-acting release (OCT-LAR) and lanreotide (LAN).

PATIENTS

Seventy-three patients with active acromegaly (37 women, median age 34 years; 36 men, median age 38 years) who had not previously been treated with somatostatin analogues were studied: 24 women and 23 men were newly diagnosed; 22 men (61.1%) and 17 women (45.9%) had hypogonadism (P=0.28). Exclusion criteria were age >45 years, follow-up less than 12 months, mixed GH/PRL-secreting adenomas. Study design Observational, analytical, retrospective. Outcome measures (1) Disease control measured as serum GH< 2.5 microg/l and IGF-I normal for age and gender; (2) reduction in tumour volume graded as absent (< 25%), mild (25-50%) and notable (>50%). Results Basal GH, but not IGF-I, levels were higher in women than in men both in the entire series and in 'de novo' patients (97.8+/- 42.2 vs. 71.1+/- 32.6 microg/l, P=0.021). After 12 and 24 months of treatment, respectively, disease control was achieved similarly in men (57.1 and 86.7%) and women (48.6 and 86.7%). Hypogonadal men had longer disease duration than eugonadal men (P=0.022), without any difference in the other parameters. No difference was found between eugonadal and hypogonadal women. Eugonadal men had a smaller tumour volume at baseline than eugonadal women (1396+/- 794 vs. 2896+/- 2871 mm(3), P=0.025). In men undergoing testosterone replacement and withdrawal, there was no change in GH and IGF-I levels after 12 and 24 months of treatment with either LAR or LAN. In the seven women receiving oestro-progestinic replacement, after 24 months of LAR or LAN treatment GH levels were higher during replacement than at withdrawal and IGF-I levels were lower during replacement than withdrawal. Tumour volume decreased significantly in both women and men without any difference between them: the percentage tumour shrinkage in men and women was similar either after 12 (34.4+/-24.4 vs. 40.7+/-22.5%, P=0.38) or 24 months of treatment (58.5+/- 17.4 vs. 56.1+/- 23.6%, P=0.75). Similarly, there was no difference in tumour volume between hypogonadal and eugonadal women and men.

CONCLUSIONS

The results of this study demonstrate that long-term responsiveness to OCT-LAR is similar in women and men. Care should be taken in women with acromegaly and hypogonadism treated with somatostatin analogues and oral oestro-progestinic as in this case GH levels are higher while IGF-I levels are lower than after the somatostatin analogues alone.

Lanreotide 60 mg, a new long-acting formulation: effectiveness in the chronic treatment of acromegaly

Lanreotide (LAN) 60 mg (LAN60), a new long-acting formulation of LAN alleged to suppress GH/IGF-I hypersecretion for 28 d in acromegalic patients, was administered in a prospective open multicenter study to 92 patients with active acromegaly (61 women and 31 men, aged 20-79 yr). LAN60 was given as adjuvant treatment (AT) in 62 patients; the other 30 patients [primary treatment (PT)] were de novo (n = 20) or previously treated only by pharmacotherapy (n = 10). After wash-out from previous treatments, LAN60 was started im every 28 d for 3 injections; the dose was then individually tailored, aiming at lowering GH to less than 2.5 micro g/liter and IGF-I to the normal range. After a median follow-up of 24 months (range, 6-48 months), IGF-I normalized in 65% of patients, decreasing from 199 +/- 8% (expressed as a percentage of the upper limit of normal range; mean +/- SE) to 87 +/- 4% (P < 0.0001). GH fell to less than 2.5 microg/liter in 63% of patients and to less than 1 microg/liter in 25%, decreasing from 20 +/- 3 to 3 +/- 0.4 microg/liter (P < 0.0001). A progressive increase in the rate of IGF-I normalization was observed (from 49% at 1 yr to 77% at 3 yr). The rate of GH/IGF-I normalization was 72% at 36 months by Kaplan-Meier analysis. No tachyphylaxis was observed throughout the study. Shortening the interval between injections to 21 d improved GH/IGF-I suppression. PT and AT patients achieved similar final GH/IGF-I levels and rates of normalization. Tumor shrank in 39% of assessable patients and in 50% of PT. Plasma glucose levels did not change, and high density lipoprotein cholesterol increased (by 19.3 +/- 5.1%; P = 0.0215). Gallstones appeared or worsened in 13% of patients. LAN60 is a new, very effective and long-lasting formulation for the treatment of acromegaly. The persistence of a powerful suppression of GH/IGF-I levels, the progressive increase in the rate of IGF-I normalization, and the similarity in the efficacy achieved in PT and AT patients point to a role for LAN60 in the primary treatment of acromegaly.