BioSante Pharmaceuticals, Inc. (NASDAQ: BPAX), today announced successful completion of its principal LibiGel (testosterone gel) pharmacokinetic (PK) study. The top-line results indicate that LibiGel increases levels of free testosterone, bioavailable testosterone and total testosterone in the serum of postmenopausal women to within the normal ranges for younger, premenopausal women. LibiGel is in development for the treatment of female sexual dysfunction (FSD), specifically, hypoactive sexual desire disorder (HSDD) in postmenopausal women, for which there is no FDA-approved product.
“Significantly, none of the subjects in the LibiGel PK study had average testosterone concentrations above the normal range for younger, premenopausal women, a finding that may be a key component in the safety evaluation of LibiGel by FDA”
The LibiGel PK study was conducted as part of the required studies to be submitted in the LibiGel new drug application (NDA), which is anticipated by the fourth quarter of 2012. The PK study was conducted in 24 postmenopausal subjects for a total of 63 days, in the absence of estrogen therapy, as well as in the same women when treated with a transdermal estradiol patch and subsequently oral estrogen. There were no differences in blood levels of testosterone regardless of the absence or presence of estrogen therapy, whether transdermal or oral.
The data from the PK study showed that testosterone blood levels were similar on days 14, 21, 42 and 63 of the study, indicating that there was no buildup of testosterone blood levels with daily LibiGel treatment. Additionally, free and bioavailable testosterone returned to baseline levels within 36-48 hours after the last dose of LibiGel, indicating effective elimination after dosing is discontinued. The testosterone blood levels produced in this study were very similar to those seen in the BioSante LibiGel Phase II efficacy trial reported previously, and they were very similar to blood levels observed in transdermal testosterone patch studies, which also demonstrated efficacy in the treatment of HSDD. Importantly, in the LibiGel PK study, there were no measurable increases in blood levels of the most active estrogen, estradiol, which could have occurred as a result of the conversion of testosterone to estradiol. BioSante plans to present the full PK study results at an upcoming medical meeting.
"Significantly, none of the subjects in the LibiGel PK study had average testosterone concentrations above the normal range for younger, premenopausal women, a finding that may be a key component in the safety evaluation of LibiGel by FDA," noted Michael C. Snabes, M.D., Ph.D., senior vice president of medical affairs at BioSante. "This finding adds to our confidence that the results of our ongoing, long-term safety study of LibiGel will be favorable."
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