Intrinsa FDA Trials

Intrinsa has been the topic of many medical surveys so far, in order to establish whether it is worthy of FDA's approval or not. Generally speaking, the female subjects tested after being administered Intrinsa and compared with a placebo controlled group had sex 4 times more than usual in a 2-month period and reported more intensity and satisfaction of the sexual intercourse.

More specifically speaking, the NDA 21-769 submitted by P&G on June 21, 2004 for Intrinsa had as main support the Intimate SM1 and 2 trials conducted on surgically menopausal women also being administered estrogen.

The Intimate SM1 trial was conducted on 562 female patients. The results revealed a 74% increase in the frequency of satisfying sexual intercourse and 56% more sexual desire from baseline in women using Intrinsa. The testosterone patch was also proved to determine an average of 2.13 episodes of sexual intercourse in a month, while the placebo controlled female patients reported only .98 episodes in 4 weeks.

The Intimate SM2 trial was developed on 533 surgically menopausal women taking estrogen. The results indicated an increase in the frequency of total satisfying sexual performances of 51%. Every 4 weeks was registered a mean increase of 1.56 episodes of sexual intercourse, while the placebo controlled group reported an increase of only .73 episodes every 4 weeks.

Significant increases were also reported in sexual desire. After being treated with Intrinsa, female patients in the study were 49% more sexually driven than before, that is a 10,6 points increase compared to 4.3 points increase in the placebo patients. Visibly improved were also the orgasm pleasure, the level of responsiveness to sexual activity and the intensity of arousal.

The adverse reactions reported during the two medical surveys were comparable to the placebo controlled group. Most commonly blamed were headaches, upper respiratory infections and application site reactions. Intrinsa was worn on the abdomen by the female subjects in the two studies. The patch was effective as it released a controlled, relatively low dose of testosterone derived from natural, vegetal sources. The female patients involved in the surveys were on average 49 years old, developing stable couple relationships of approximately 19 years and experienced ovary removal surgery an average of 8½ years before surveys occurred. The testosterone patches were set to deliver 300 micrograms (mcg) of testosterone daily. The patches, in both groups were changed twice a week.

Intimate SM1 and 2 were conducted at the Women's Health Research Center and over 50 other centers in Australia, Canada and USA. Approximately 90% of the women involved in the surveys were recruited in the USA.

After analyzing the results of the surveys on the P&G Intrinsa, FDA Advisory Committee concluded that the improvements registered on patients using the testosterone patch weren't clinically meaningful. Moreover, FDA Advisory committee also outlined that possible risks derived from the long term combined use of testosterone and estrogen couldn't be revealed in surveys conducted on short terms. In other words the trials developed so far on Intrinsa associated with estrogen couldn't provide detailed information on the risks involved by hormonal therapy.

In addition, FDA specialists also state in their official report from December 2, 2004 that risks involved by adding testosterone to estrogen may be unexpected. Experts exemplify the increased jeopardy of breast cancer and cardiovascular disease generated by adding progesterone to estrogen and the unanticipated cerebrovascular condition induced by the treatment with equine estrogen.