Population Council Projects

PROJECT
MENT^®

Several male methods under development at the Council have relied on MENT^®, a synthetic steroid that resembles testosterone. In contrast to testosterone, however, MENT does not have the effect of enlarging the prostate, a drawback that occurs with testosterone administered for therapy. A MENT implant and MENT transdermal gel and patch formulations are being developed for contraception and hormone therapy.

MENT implants
Delivering MENT acetate (MENT Ac) via one or more implants placed under the skin of the upper arm, this contraceptive aims to suppress sperm cell development without impairing sexual drive (libido). Early developmental work on the MENT Ac implant indicated that it might be appropriate both as a contraceptive in normal men and as hormone therapy in men with male-hormone deficiency (hypogonadal men). A recently completed one-year dose-finding study in normal men has shown that four implants suppress gonadotropin levels completely, leading to profoundly reduced sperm count. Eight of eleven men with four implants had zero sperm count which lasted in many subjects for several months until the implants were removed. In hypogonadal men, two MENT Ac implants were found to be adequate as therapy, and the men in the study preferred the implants to the standard therapy involving multiple injections of a testosterone derivative.

Other studies that combine MENT Ac implants with a synthetic progestin have been conducted. Long-term toxicology studies of MENT are also ongoing. (more)

MENT transdermal gels and patches
Laboratory tests show that MENT readily penetrates the skin. The delivery of a potent androgen through the skin into the blood stream is an effective way to avoid metabolism by the liver, thereby decreasing side effects of the hormone. Early studies in men indicated that MENT delivered via transdermal gel suppressed steroid sex hormones over a seven-day treatment period, and that the effect was reversible when the treatment ended. Preliminary studies conducted in hypogonadal men also show the gel to be safe for further development as a method of hormone therapy. (more)

Location

Chile, Dominican Republic, Germany, United Kingdom, United States

Duration

Ongoing

Population Council researchers

Narender Kumar, Frederick Schmidt,
Régine Sitruk-Ware, Irving Sivin

Non-Council collaborators

Richard Anderson, David T. Baird (MRC Reproductive Biology Unit, Edinburgh)

Horacio Croxatto (ICMER, Chile)

Eberhard Nieschlag (University of Munster, Germany)

Christina Wang (University of California, Los Angeles)

Donors

The Lita Annenberg Hazen Foundation

The George J. Hecht Fund

The William and Flora Hewlett Foundation