Peptide education
Histrelin
Histrelin acetate · Supprelin LA · Vantas
Histrelin is a GnRH agonist delivered by an implant placed under the skin. Supprelin LA is labeled for children with central precocious puberty (CPP), while Vantas is labeled for palliative treatment of advanced prostate cancer.
The implant is placed and removed by a clinician, with treatment and monitoring matched to the product and condition.
Overview
Quick answer
Both implants contain 50 mg of histrelin acetate, but their labeled release rates and indications differ. Supprelin LA delivers approximately 65 micrograms per day; the Vantas label describes approximately 50 micrograms per day. Both labels call for removal after 12 months.
How does histrelin work?
Continuous delivery first stimulates the pituitary hormone pathway and then suppresses it. This lowers sex hormone production during treatment.
How long does an implant stay in place?
Both labels describe one implant for 12 months, followed by removal. A new implant may be placed when treatment continues.
What are the differences between the products?
Supprelin LA is labeled for central precocious puberty and releases approximately 65 micrograms of histrelin acetate daily. Vantas is labeled for advanced prostate cancer palliation and releases approximately 50 micrograms of histrelin acetate daily. The two labels describe different patient populations.
What happens when the implant is removed?
Removal is a procedure. The Supprelin LA label notes that an implant can be difficult to locate or may break during removal, making confirmation that all pieces were removed important.
Evidence
Evidence snapshot
In a 36-child open-label study, suppression of stimulated luteinizing hormone (LH) was reported through one year after insertion.
In a single-arm study, all 134 patients with a week-four testosterone measurement met the study's suppression threshold.
Implant-site reactions are common in the pediatric label's studies. Removal can sometimes require imaging or retrieval of broken pieces.
Claims
Common claims vs evidence
| Claim | Human evidence | Mechanistic evidence | Verdict |
|---|---|---|---|
| Supprelin LA and Vantas are identical because each contains 50 mg. | Their labels describe different indications and approximate daily release rates: 65 micrograms of histrelin acetate for Supprelin LA and 50 micrograms for Vantas. | Total implant content does not describe the entire product. | |
| The pediatric implant immediately lowers hormone levels. | The clinical study measured stimulated LH and sex steroid levels during follow-up. | The label describes a temporary rise in sex hormones after treatment begins, followed by suppression with continued exposure. | The initial and sustained effects occur at different times. |
| An implant can be left in place indefinitely. | Each referenced product label calls for removal after 12 months, with another implant placed if treatment continues. | Removal is part of the labeled treatment schedule. |
Bottom line
Main takeaway
A small implant provides continuous medicine, and a clinician removes it after the labeled interval.
The product, diagnosis, monitoring plan, and removal appointment all matter.
The pediatric and prostate cancer studies were single-arm studies in different populations with different endpoints.
Identity
What it is
Histrelin is a synthetic nine-amino-acid GnRH analog. Supprelin LA is a nonbiodegradable implant placed beneath the skin of the upper arm.
Vantas is a separate histrelin implant labeled for palliative treatment of advanced prostate cancer.
Use context
Routes, doses, and cycle patterns
Both products use an implant placed beneath the skin of the upper arm. Their labeled indications and daily release rates differ.
Human studies and product labels
Supprelin LA
- Purpose
- Treatment of central precocious puberty in children
- Context
- U.S. pediatric product label
- Route
- Subcutaneous implant in the upper arm
- Amount
- 50 mg histrelin acetate per implant, releasing approximately 65 micrograms per day
- Frequency
- One implant for 12 months
- Duration
- Remove after 12 months; another implant may be inserted to continue treatment
The label does not recommend use in children younger than two years.
Vantas
- Purpose
- Palliative treatment of advanced prostate cancer
- Context
- U.S. prostate cancer product label
- Route
- Subcutaneous implant in the upper arm
- Amount
- 50 mg histrelin acetate per implant, releasing approximately 50 micrograms of histrelin acetate per day
- Frequency
- One implant for 12 months
- Duration
- Remove after 12 months; another implant may be inserted to continue treatment
The label describes insertion and removal by a healthcare provider. A label alone does not establish current product availability.
What varies
- The Supprelin LA label calls for LH, follicle-stimulating hormone, and sex hormone tests one month after implantation and every six months thereafter, with height and bone age assessed every six to 12 months.
- The Vantas label calls for monitoring for an initial worsening of prostate cancer symptoms and periodic testosterone and prostate-specific antigen (PSA) measurements. It also calls for periodic blood glucose or HbA1c monitoring.
Research
Research evidence
Small, single-arm studies evaluated histrelin implants in children with central precocious puberty and in adults with advanced prostate cancer. The studies measured hormone suppression in different populations and cannot be combined into one outcome.
| Study / evidence area | Population | Design | Product context | Main outcome | Limitations | Weight |
|---|---|---|---|---|---|---|
| Histrelin implant in central precocious puberty | 36 children, including 20 without previous GnRH agonist treatment | Multicenter, open-label study over one year | 50 mg subcutaneous implant | Stimulated LH and sex hormone suppression were maintained during the study. | The study had no randomized comparator and does not determine an individual child's long-term outcomes. | Single-arm human study |
| Histrelin implant in advanced prostate cancer | 138 patients with prostate cancer, including 72 with elevated or rising PSA after definitive treatment for localized disease | Multicenter, open-label study | 50 mg subcutaneous implant | All 134 patients with week-four testosterone measurements reached the study's suppression threshold. | Testosterone suppression is a hormone endpoint, and the study had no randomized comparator. The FDA label describes a mixed disease history among participants. | Single-arm human study |
Cautions
Safety and unknowns
- Bruising, soreness, pain, or swelling at the implant site can occur. The pediatric label also describes difficult removal, implant breakage, and occasional extrusion.
- In children, the label reports psychiatric symptoms and convulsions and warns about severe skin reactions and increased pressure around the brain. Headache or visual changes warrant contact with the treating clinician.
- In prostate cancer treatment, the initial rise in testosterone can worsen symptoms. The Vantas label also discusses metabolic and cardiovascular risks.
- Supprelin LA is contraindicated in pregnancy and in patients with specified GnRH-related hypersensitivity.
- Vantas is contraindicated in patients with hypersensitivity to GnRH or GnRH agonist analogs. Its label also warns of possible fetal harm and says safety and efficacy have not been established in females.
- The Vantas label warns about severe skin reactions and possible QT interval prolongation. It advises clinicians to consider periodic electrocardiograms and electrolyte monitoring, particularly in patients with relevant heart conditions, electrolyte abnormalities, or other QT-prolonging medicines.
Product quality
Product identity and quality
Both referenced products are nonbiodegradable implants intended for clinical insertion and removal.
Product identity
Equal total histrelin content does not mean the two implants have the same release rate or indication.
Removal appointment
The labels call for removal after 12 months and describe possible difficulty locating or removing an implant.
Mechanism
How it is proposed to work
Continuous histrelin exposure quiets the pituitary signal that controls sex hormone production.
The first phase can briefly increase LH, follicle-stimulating hormone (FSH), and sex hormones before suppression develops.
The clinical aim differs between early puberty and advanced prostate cancer.
FAQ
Common questions
Are Supprelin LA and Vantas the same implant?
They have different labeled indications and release rates despite both containing 50 mg histrelin acetate. Their labels do not establish automatic interchangeability.
Does the implant dissolve?
Supprelin LA is nonbiodegradable and its label calls for removal after 12 months; a clinician may insert a replacement when continuing treatment.
Details
Technical details
Sources
References
- 1.
DailyMed. Supprelin LA histrelin implant prescribing information
U.S. label for the pediatric central precocious puberty implant.
- 2.
FDA. Vantas histrelin implant prescribing information
FDA label for the histrelin implant indicated for palliative treatment of advanced prostate cancer; labeling does not establish current supply.
- 3.
PubMed. Histrelin subdermal implant in central precocious puberty: multicenter trial
doi:10.1210/jc.2006-2479 PMID:17327379
Open-label pediatric trial measuring hormone suppression over one year.
- 4.
PubMed. Histrelin subdermal implant in advanced prostate cancer
doi:10.1016/S0022-5347(05)00649-X PMID:16515997
Open-label multicenter study of a 50 mg histrelin implant in advanced prostate cancer.