A prospective trial on the effect of body mass index and sex on plasma octreotide levels in patients undergoing long-term octreotide LAR therapy

Efficacy and tolerability of somatostatin analogues according to gender in patients with neuroendocrine tumors

As the incidence of neuroendocrine tumors has been rising, gender differences in epidemiology and clinical behavior have emerged, and interest into a gender-driven management of these tumors has grown with the aim to improve survival and quality of life of these patients. Somatostatin Analogues represent the first line of systemic treatment of both functional and non-functional neuroendocrine tumors, through the expression of somatostatin receptors (SSTRs) in the tumor cells, and proved effective in controlling hormonal hypersecretion and inhibiting tumor growth, improving progression-free survival and overall survival of these patients. Aim of the present review is to investigate any differences by gender in efficacy and safety of SSTS-targeted therapies, that represent the mainstay treatment of neuroendocrine tumors, as they emerge from studies of varying design and intent. Although preclinical studies have provided evidence in favor of differences by gender in tumor expression of SSTR, as well as of the role of sex hormones and related receptors in modulating SSTRs expression and function, the clinical studies conducted so far have not shown substantial differences between males and females in either efficacy or toxicity of SSTR-targeted therapies, even if with sometimes inconsistent results. Moreover, in most studies gender was not a predictor of response to treatment. Studies specifically designed to address this issue are needed to develop gender-specific therapeutic algorithms, improving patients' prognosis and quality of life.

Octreotide LAR Dosage and Survival Among Elderly Patients With Distant-Stage Neuroendocrine Tumors

INTRODUCTION

Octreotide long-acting repeatable (LAR) is approved for the management of carcinoid syndromes and may improve progression-free survival of patients with well-differentiated neuroendocrine tumors (NETs). It is unknown whether the dosage of octreotide LAR affects survival. This paper evaluates the association between initial octreotide LAR dosage and overall survival of elderly patients with NETs.

PATIENTS AND METHODS

Patients with distant-stage NET diagnosed between January 1999 and December 2009 who received octreotide LAR treatment within 12 months of diagnosis were identified from the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. Those under age 65 years, enrolled in health maintenance organizations, or without continuous enrollment in Medicare Parts A and B were excluded. We compared the 5-year survival of patients with NET based on dose per 28 days averaged over the initial 3 months: low (≤20 mg); medium (21-30 mg); high (>30 mg). Kaplan-Meier estimations and Cox proportional hazard modeling were used to examine the association between octreotide LAR dose and survival.

RESULTS

Among 222 patients with distant-stage NET who received octreotide LAR treatment, 81 (36%) received a low dosage, 82 (37%) received a medium dosage, and only 59 (27%) received a high dosage. Multivariate analysis showed that compared with a medium octreotide LAR dose, a low dosage was associated with significantly worse survival (hazard ratio [HR]: 2.00; p = .001), whereas a high initial dosage (HR: 1.09; p = .719) did not show additional survival benefits over that observed with a medium dosage.

CONCLUSION

This population-based study suggests potential survival benefits for octreotide LAR provided within 12 months of diagnosis at a dosage of 21-30 mg among elderly patients with distant-stage NET.

Efficacy and safety of an octreotide implant in the treatment of patients with acromegaly

CONTEXT

Acromegaly is caused by excessive GH secretion and IGF-I overproduction. The goals of treatment are to reduce GH and IGF-I values to normal and relieve the associated symptoms.

OBJECTIVE

The purpose of this article was to demonstrate that an octreotide implant (84 mg) is safe and efficacious in patients with acromegaly who were responsive to prior monthly octreotide long-acting release (LAR) injections.

DESIGN

This was a phase 3, open-label study. Before treatment, subjects received a stable monthly dose of octreotide LAR injections (10-40 mg) for ≥ 3 months. Randomization was in a 3:1 ratio to either a 6-month octreotide implant or monthly octreotide LAR injections.

SETTING

This was a multicenter, international study conducted in private or institutional practices.

SUBJECTS

Enrollment included 163 subjects (aged ≥ 18 years) with acromegaly.

MAIN OUTCOME MEASURE

The efficacy, safety, and tolerability of the octreotide implant during 24 weeks of treatment was evaluated.

RESULTS

After 24 weeks, the success rate of the implant for maintenance of IGF-I and GH levels was 86% (95% confidence interval, 80.3%) compared with a rate of 84% (95% confidence interval, 73.8%) for octreotide LAR. Serum octreotide concentrations after implant insertion increased within 8 days and peaked between days 14 and 28. The overall safety of the octreotide implant and octreotide LAR were similar. Diarrhea and headache were more frequent with the implant, whereas cholecystitis and hypertension were more frequent with octreotide LAR.

CONCLUSIONS

In this pivotal phase 3 study, the octreotide implant maintained reduced blood levels of GH and IGF-I with continuous octreotide release over 6 months, which was well tolerated.

Pancreatic endocrine tumors

Pancreatic endocrine tumours are rare tumours, and arise from the types of pancreatic cells that produce hormones. These tumours may or may not secrete hormones themselves and may or may not be cancerous (malignant). Functioning tumours secrete a particular hormones which may cause various syndromes. The present article reviews the latest reports on the pancreatic endocrine tumours.

Evaluating the characteristics and the management of patients with neuroendocrine tumors receiving octreotide LAR during a 6-year period

OBJECTIVE

This retrospective study evaluated physician practice patterns in the medical management of patients with neuroendocrine tumors (NETs) treated with octreotide LAR.

METHODS

Data were collected from the medical charts of 392 patients diagnosed with NET and treated with octreotide LAR for 4 months or longer.

RESULTS

Approximately 72% (n = 284) of patients had metastatic disease with carcinoid syndrome (CS). Of these, 92% (n = 260) had CS at diagnosis and 8% (n = 24) developed CS after diagnosis. Of the patients studied, 89% received octreotide LAR, and the most common octreotide LAR doses were 30 mg (45% of all regimens), 20 mg (32%), and 40 mg (11%). After 12 months of treatment with octreotide LAR, symptom resolution or improvement was seen in 60%, 48%, 48%, and 30% of patients with flushing, diarrhea, bronchoconstriction, and carcinoid heart disease, respectively. Approximately 57% of patients treated with octreotide LAR demonstrated stable disease; with rates of 57% at 20 mg, 57% at 30 mg, 55% at 40 mg, and 50% at 60 mg.

CONCLUSIONS

This retrospective study has added to the wealth of evidence demonstrating the efficacy and safety of octreotide LAR in the treatment of patients with NET. The review highlights the importance of regular patient monitoring and clinical management.