Histrelin

Histrelin (Supprelin LA, Vantas) is a real, FDA-approved GnRH agonist delivered as a once-yearly subdermal implant — the same active drug marketed under two different brand names for two very different patients, whose market fates have since diverged in a genuinely unusual way.

An implant, not an injection

Histrelin is a synthetic GnRH agonist nonapeptide, mechanistically identical to the other agonists this site covers (leuprolide, goserelin, triptorelin) — continuous stimulation eventually downregulates the pituitary GnRH receptor and suppresses sex-steroid production. What's different is delivery: histrelin is placed as a small subdermal implant in a brief office procedure, releasing a steady dose for a full 12 months before it needs to be replaced, rather than requiring a repeat injection every 1-6 months like the depot formulations of the other agonists.

One drug, two brands, two patients

The FDA approved histrelin as Vantas on 12 October 2004 for advanced prostate cancer, and separately as Supprelin LA on 3 May 2007 for central precocious puberty in children. Both are the same drug in the same implant technology — the two-brand structure exists because the two approvals cover different indications and patient populations, not because the drug itself differs.

A genuinely asymmetric outcome

Endo Pharmaceuticals discontinued Vantas around 21 September 2021, reporting to the FDA that ongoing manufacturing problems meant batches weren't meeting release specifications and no workable fix could be found — not a safety or efficacy issue, a production one. Because Supprelin LA uses the identical implant technology and remained in production, prostate cancer patients who'd relied on the far less expensive Vantas were left with only the significantly pricier Supprelin LA as a same-drug alternative — a real, reported access problem stemming from a manufacturing decision rather than any change in the drug's clinical picture.