Results from the phase III study of Triptorelin pamoate 11.25 mg ( Decapeptyl 3 months ) administered subcutaneously in patients with locally advanced or metastatic prostate cancer were presented at the European Association of Urology ( EAU ) 14th Central European Meeting in Cracow, Poland.
The primary objective of the study was to assess the efficacy and safety profile of the sustained release Triptorelin pamoate 11.25 mg ( Decapeptyl 3 months ) formulation when administered by the subcutaneous route in men with locally advanced or metastatic prostate cancer.
This objective was met with castration levels of testosterone achieved in 97.6% [ 95% CI: 93.2-99.5 ] of men at week 4 and castration maintained in 96.6% of these men [ 95% CI: 91.6-99.1 ] at week 26.
Mean testosterone levels decreased to 18.4 ng/dl and 10.2 ng/dl at week 4 and week 8, respectively, and remained within this range until the end of the study.
Median time to achieve castration was 22 days.
For more than 90% of the patients, the level of testosterone was maintained below 20 ng/dl from week 8 up to the end of the trial.
Median Prostate Specific Antigen ( PSA ) levels were reduced by 64.2% and 96.0% at week 4 and week 26, respectively. PSA levels remained within the normal range ( 0–4 ng/ml ) from week 8 until the end of the study.
The efficacy results and safety profile of Triptorelin pamoate 11.25 mg administered by the subcutaneous route are consistent with the known efficacy and safety profile of Triptorelin administered by the intramuscular route.
This study is a multicentre, open-label, single-arm study of Triptorelin pamoate 11.25 mg given by the subcutaneous route twice ( at baseline and 13 weeks later ), in which patients from 14 centres were monitored for 26 weeks.
The co-primary endpoints were the proportion of patients with a castration level of serum testosterone ( less than 50 ng/dl ) at 4 weeks ( target greater than 80% achieving castration ), and of these, those still castrated at 26 weeks ( target more than 85% maintaining castration ).
Key secondary endpoints notably comprised: time to achieve castration; probability of testosterone levels remaining less than 50 ng/dl between week 4 and week 26; change in prostate-specific antigen ( PSA ) levels from baseline; proportion of patients with normal PSA levels at 26 weeks compared with baseline.
Decapeptyl is a peptide formulation for injection to be used mainly in the treatment of locally advanced or metastatic prostate cancer.
Additional indications developed subsequently include the treatment of uterine fibroids ( a benign tumour of muscle tissues in the uterus ), endometriosis ( proliferation of endometrial tissue, the mucous membrane that lines the uterine wall outside the reproductive tract ) after surgery or when surgery is not deemed appropriate, as well as early onset puberty and female infertility ( in vitro fertilisation ).
The active substance in Decapeptyl is Triptorelin pamoate, a decapeptide analogue of GnRH ( Gonadotrophin Releasing Hormone ), a hormone secreted by the hypothalamus, which initially stimulates the release of pituitary gonadotrophins ( hormones produced by the pituitary gland ), which in turn control hormonal secretions by the testicules and ovaries.
Administration of Triptorelin results in the suppression of the GnRH activity leading to hormonal castration in men and menopausal phase in women.
The formulations of Decapeptyl include a daily formulation, one-month, three-month and six-month formulations. ( Xagena )
Source: Ipsen, 2014