What is the residual amount of Lanreotide (Somatuline) in the body after 6 months of treatment with 120 milligrams every 28 days?

From the Guidelines

After taking Lanreotide 120 mg every 28 days for 6 months, there would be minimal to no detectable amounts of the medication remaining in your body approximately 4-5 months after your last injection. Lanreotide has a half-life of approximately 23-30 days, meaning that half of the drug is eliminated from your body during this timeframe 1. After about 5 half-lives (roughly 4-5 months), less than 5% of the drug would remain in your system. The medication is primarily eliminated through the kidneys, with some excretion through the liver as well. While the drug achieves steady-state concentrations after about 3-4 injections when taken regularly, once you stop the medication, the elimination process begins. Some key points to consider when taking Lanreotide include:

• The licensed dosage of lanreotide Autogel is 60,90 or 120 mg every 4 weeks 1
• Patients should generally be started on lower doses with treatment up-titrated to achieve stabilisation 1
• In cases of breakthrough symptoms, rescue doses of subcutaneous octreotide can be used two or three times per day up to a maximum daily dose of around 1 mg 1 It's essential to discuss any concerns about stopping Lanreotide with your healthcare provider, as abrupt discontinuation could potentially lead to rebound symptoms depending on the condition being treated. The effects of somatostatin analogues, such as lanreotide, are demonstrable as biochemical response rates (inhibition of hormone production) in 30e70% of patients and as symptomatic control in the majority of patients 1. Long-acting formulations of somatostatin analogues, like lanreotide, have produced significant improvement in the quality of life of patients with neuroendocrine tumors and have comparable or better efficacy than short-acting octreotide 1.

From the FDA Drug Label

Lanreotide acetate showed sustained release of lanreotide with a half-life of 23 to 30 days. Mean serum concentrations were > 1 ng/mL throughout 28 days at 90 mg and 120 mg and > 0. 9 ng/mL at 60 mg. The steady- state trough serum lanreotide concentrations in patients receiving Lanreotide acetate every 28 days were 1.8 ± 0.3; 2.5 ± 0.9 and 3.8 ± 1. 0 ng/mL at 60 mg, 90 mg, and 120 mg doses, respectively. Pharmacokinetic data from studies evaluating extended dosing use of Lanreotide Injection 120 mg demonstrated mean steady-state, Cmin values between 1.6 and 2. 3 ng/mL for the 8- and 6-week treatment interval, respectively.

The amount of Lanreotide remaining in the body after taking it for 6 months, 120 mg every 28 days can be estimated based on the half-life of the drug, which is 23 to 30 days.

• After 6 months, the drug will have reached steady-state concentrations.
• The steady-state trough serum lanreotide concentrations for a dose of 120 mg every 28 days is approximately 3.8 ng/mL.
• Since the half-life of the drug is 23 to 30 days, it can be estimated that after 6 months, the amount of Lanreotide remaining in the body will be approximately 1.6 to 2.3 ng/mL at steady-state, based on the Cmin values for the 6-week treatment interval 2.

From the Research

Lanreotide Pharmacokinetics

• The pharmacokinetics of lanreotide Autogel were investigated in a study where patients with acromegaly were given 5 injections of lanreotide microparticles, 30 mg, followed by 3 injections of lanreotide Autogel, at doses of 60,90, or 120 mg every 28 days 3.
• Average minimum lanreotide concentrations (Cmin) at steady state were 1.949 +/- 0.619,2.685 +/- 0.783, and 3.575 +/- 1.271 ng/mL for 60,90, and 120 mg of lanreotide Autogel, respectively, showing a dose-proportional increase 3.
• The serum concentration of lanreotide required to lower GH to 2.5 ng/mL or less was estimated to be 1.13 ng/mL, with an EC50 of 0.206 ng/mL 3.

Lanreotide Half-Life and Accumulation

• Although the exact half-life of lanreotide is not provided in the given studies, the pharmacokinetics of lanreotide Autogel suggest that it has a prolonged release profile, allowing for dosing every 28 days 3.
• The accumulation of lanreotide in the body after repeated dosing is not explicitly stated in the provided studies, but the dose-proportional increase in Cmin values suggests that lanreotide may accumulate to some extent 3.

Lanreotide Elimination

• The elimination of lanreotide from the body is not directly addressed in the provided studies, but it is likely that lanreotide is eliminated through a combination of metabolic and renal pathways, as is common with somatostatin analogs.
• However, there are no research papers provided that directly assist in answering the question of how much lanreotide remains in the body after taking it for 6 months, 120 mg every 28 days.