The United States Food and Drug Administration has approved Xiaflex (collagenase clostridium histolyticum), a drug to treat men suffering from Peyronie's disease.

Peyronie's (pa-ro-NEEZ) disease is characterized by a plaque or a fibrous scar tissue that develops inside the penis, leading to curved, painful erections.

The disease usually occurs in middle-aged men, but can also occur in young men. About 30 percent of all Peyronie's patients have hardened scar tissue somewhere else in the body such as hand or foot. A common example of scar build-up in limbs is the Dupuytren's contracture of the hand.

The drug is manufactured by Auxilium Pharmaceuticals and costs about $3,300 an injection. Full treatment cost is expected to reach $26,000 plus doctor's fee. Currently, physicians use a generic blood pressure drug to treat the problem, TheNew York Times reported.

FDA had earlier approved Xiaflex for the treatment of Dupuytren's contracture. The drug is a biologic medicine and is made of protein from an organism called collagenase clostridial histolyticum.

The drug works by breaking down the protein collagen. According to FDA, Peyronie's disease is treated in four treatment cycles with each cycle requiring two Xiaflex injection procedures and one penile modeling procedure conducted by a trained physician.

"Today's approval expands the available treatment options for men experiencing Peyronie's disease, and enables them, in consultation with their doctor, to choose the most appropriate treatment option," said Audrey Gassman, deputy director of the Division of Bone, Reproductive and Urologic Products in the FDA's Center for Drug Evaluation and Research, according to a statement.

The safety and efficacy of the drug was tested in lab studies conducted on over 800 men with penile curvature of atleast 30 degrees. Participants were put on either Xiaflex or placebo for 52 weeks. Study results showed that Xiaflex was more effective than placebo in reducing penile curvature. Most common side-effects of using the drug was pain and swelling in penis.

Auxilium shares were up 12 percent, closing at $21.64 at 4 p.m. New York time, Bloomberg reported.