TesoRx licenses oral low-T drug to Aspen amid FDA crackdown

While the testosterone therapy field is under fire from government regulators, Menlo Park, CA-based TesoRx is licensing its oral-testosterone replacement therapy to a subsidiary of South African generics maker Aspen Pharmacare.

The Aspen Group's holding company, Aspen Global Incorporated, is fronting $15 million for the deal, which gives Aspen the rights to TSX-002, an orally delivered low-T therapy, in markets outside the U.S., EU, Japan, China and the Middle East. Under the agreement with TesoRx, Aspen will pay the specialty pharma company up to $80 million based on certain regulatory and commercial milestones in addition to potential royalty payments. 

TesoRx, which has tested TSX-002 in 150 patients, touts the drug as the first oral product that is a biologically identical form of the human hormone rather than than the modified testosterone molecules used by some of other products in development.

An oral low-T drug is an alluring prospect, since the topical gel-based products that currently dominate the $2.5 billion testosterone market are known to deliver abnormally high levels of the hormone. An oral product has eluded drug developers for years because of problems with poor absorption and rapid breakdown by the liver.

Low-T treatments have as of late come under scrutiny, and the FDA has been reassessing their safety in light of recent studies showing that testosterone therapy may do more harm than good, spurring elevated risks of heart attack and other adverse events. Other oral low-T drugs in development, such as Clarus Therapeutics' Rextoro and Repros Therapeutics' ($RPRX) Andoxal, are being watched with a close eye by federal regulators.

In September, a panel of FDA advisers voted in favor of restricting the use of testosterone products in the face of growing concerns that the drugs were being overprescribed to middle-aged men looking to boost their libidos. The drugs have been widely prescribed to men reporting low testosterone levels, but the FDA is now considering curbing their use to treat only specific medical conditions.

In the meantime, TesoRx plans to forge ahead with pivotal trials in 2015. Though the company reports that the drug has shown a favorable safety profile in all of its studies, it's unclear what it will take to win praise from the FDA.  

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