Source: DGNews  |  Posted 2 years ago

By Chris Berrie

BARCELONA, Spain -- December 1, 2009 -- The new 6-month formulation of
triptorelin pamoate, a synthetic decapeptide gonadotropin-releasing hormone
analogue, is both safe and effective for induction and maintenance of
castration in patients with advanced prostate cancer.

This multicentre, open-label, noncomparative, phase 3 study was presented here
on November 27 by Eija Lundström, MD, Debiopharm SA, Lausanne, Switzerland, at
the 2nd European Multidisciplinary Meeting on Urological Cancers (EMUC).

“The triptorelin 1-month and 3-month formulations have already been marketed
for more than 20 years in the treatment of advanced prostate cancer,” said Dr.
Lundström; therefore, the main objective of this study was to evaluate the
efficacy of this new 6-month formulation for achieving and maintaining
castration levels of serum testosterone (<=1.735 nmol/L) 4 weeks following the
first injection in these patients. The range of secondary objectives included
changes in prostate-specific antigen (PSA) levels and safety.

The inclusion criteria were locally advanced or metastatic prostate cancer, as
staged at T3-4NxMx, TxN1Mx, or TxNxM1, or rising PSA levels after failed local
therapy (surgery or radiation). A serum testosterone of >5 nmol/L and an
expected survival >18 months also were required.

The 120 patients enrolled underwent 2 intramuscular injections (22.5 mg each)
of the triptorelin 6-month formulation, one on day 1 and the other on day 169
(after 24 weeks), with patient assessment through week 48. These assessments
included monitoring of serum testosterone, luteinising hormone (LH), and PSA
levels, plus adverse events (AEs) and serum triptorelin concentrations.

In all, 97.5% of the patients reached castration testosterone levels by day 29,
with 94.1% maintaining this from month 2 to month 9. These levels compared
favourably with the previous 1-month (92.7% castration; 94.2% maintenance from
month 2 to 9) and 3-month (97.7%; 94.4% maintenance) formulations of
triptorelin.

Serum LH levels to >1.0 IU/L were seen in 100% of the patients on first
triptorelin injection, but only 2.7% following the second injection on day 169.
Median relative decreases in PSA levels from baseline were 96.9% by month 6 and
in 96.4% by month 12.

In all, 14.2% of the patients experienced a serious AE, and the most common
drug-related AEs were hot flushes (72%), erectile dysfunction (10%), and
testicular atrophy (8%). Local tolerance was also good, with mainly mild
injection-site AEs seen in 6.7% of the patients.

Dr. Lundström concluded that “the efficacy and safety [of this new formulation]
are very similar to the existing formulations, meaning fewer injections and
more convenience.”

This study was funded by Debiopharm Group.

EMUC was co-organised by the European Association of Urology (EAU), the
European Society for Medical Oncology (ESMO), and the European Society for
Therapeutic Radiology and Oncology (ESTRO).

Presentation title: New Triptorelin 6-Month Formulation Shows High Level
of Efficacy and Safety in Patients With Advanced Prostate Cancer. Abstract P056