Biotech Watchlist: BioSante Pharmaceuticals and Antares Pharma

BioSante Pharmaceuticals, Inc. BPAX has just shared some additional data from its principal LibiGel (testosterone gel) pharmacokinetic (pK) study. Will that be enough to break shares away from down-trending resistance levels?

Top line data from this particular study were announced in late September and they indicate that LibiGel increases levels of free testosterone (the active testosterone component) 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.

The levels of free testosterone in the LibiGel pK study were similar to those seen in the BioSante LibiGel Phase II efficacy trial which ranged from 2.8 pg/ml to 3.6 pg/ml. These levels also were similar to those reported in the two pivotal testosterone patch (Intrinsa) studies which showed efficacy in treating HSDD in estrogen-treated surgically menopausal women, which were 4.0 pg/ml at 12 weeks and 3.1 pg/ml at week 24 and 4.0 pg/ml at week 24, respectively. In a recent publication, it was shown that serum testosterone concentrations in normally cycling 30-year-old pre-menopausal women range from 1.2 pg/ml to 6.4 pg/ml. However, generally, blood levels are not compared between studies because different studies performed at different times with different assays can produce varying testosterone blood levels.

LibiGel is a testosterone gel in Phase III clinical development for the treatment of women who suffer from female sexual dysfunction (FSD), specifically hypoactive sexual desire disorder (HSDD). The completed Phase III efficacy trials are double-blind, placebo-controlled trials that enrolled over 500 surgically menopausal women each for six-months of therapy, approximately half of whom were taking concomitant estrogen therapy and half of whom took no concomitant estrogen therapy. The completed efficacy trials were conducted according to an FDA-agreed special protocol assessment (SPA) agreement. LibiGel is absorbed quickly through the skin after applying a once-daily pea-sized topical application on the upper arm that delivers testosterone to the bloodstream evenly over time.

As we told our readers back in February, there are actually two companies in prime position to benefit from good news associated with clinical information about the LibiGel program: BioSante and their partner, Antares Pharma, Inc. AIS.

Both companies have a large stake in LibiGel and while BioSante has been pushing the product through development, many investors may not be aware that a patented FDA approved technology developed by Antares is a critical component in Libigel. The company’s Advanced Transdermal Delivery (ATD) Gel System offerd BioSante an ideal means to deliver testosterone in a controlled and reproducible way with a convenient to use dosage form.

Antares’platform allows LibiGel to be absorbed quickly through the skin after applying a once-daily, pea-sized topical application on the upper arm. The dose delivers testosterone to the bloodstream evenly over time.

The BioMedReports FDA Calendar and WorldWide RegulatoryCatalyst Tracker shows that back in March, Antares announced that their New Drug Application for Anturol Gel in patients with overactive bladder (OAB) was accepted for review the FDA. Anturol is an oxybutynin gel which also incorporates Antares' ATD Gel technology. The FDA has assigned Anturol is an oxybutynin gel Prescription Drug User Fee Act date of December 8, 2011, ten months from the official NDA filing. The PDUFA date is the target date for the FDA to complete its review of the NDA. 

Others are anticipating additional catalysts for the stock and feel it may be poised to move as well.

Disclosure: None