Xiaflex, a new drug to treat clenched fingers could reach the markets soon.
Xiaflex, the experimental drug developed by US-based Auxilium Pharmaceuticals, Inc. has been recommeded for approval unanimously by the USFDA’s Arthritis Advisory Committee granting orphan drug status to the drug.
Xiaflex habeen voted for approval to treat Dupuytren’s contracture, the condition commonly known as clenched or curved fingers.
Depuytren’s contracture is a disorder of the tendons that lie beneath the skin of the palm. Collagen forms painful deposits in the palm of the hand that eventually grow into cords stretching from the palm to a joint of the finger. As the cords contract, they force the finger to curl.
Dupuytren’s contracture is progressive in nature. Typically, nodules develop in the palm as collagen deposits accumulate.
As Dupuytren’s contracture progresses, the collagen deposits form a cord that stretches from the palm of the hand to the base of the finger. Once this cord develops, the patient’s fingers contract and the function of the hand is impaired.
The most frequently affected parts of the hand associated with Dupuytren’s contracture are the joints called the metacarpal phalangeal joint, or MP joint, which is the joint closest to the palm of the hand and the proximal intra-phalangeal joint, or the PIP joint, which is the middle joint in the finger. The little finger and ring finger are most frequently involved.
Currently, there are no drugs approved to treat Dupuytren’s contracture. Surgery is the only effective treatment for Dupuytren’s contracture.
The incidence of Dupuytren’s contracture is highest in Caucasians, historically those of Northern European descent, with a global prevalence of three to six percent of the Caucasian population. Most cases of Dupuytren’s contracture occur in patients older than 50 years.
Xiaflex contains collagenase clostridium histolyticum, a combination of collagen-destroying enzymes isolated from Clostridium histolytica that are more effective than human collagenase at destroying the cords.
A study published two weeks ago in the New England Journal of Medicine on 308 patients showed that 64% of those receiving as many as three injections of the drug in each joint regained a nearly normal range of finger motion, compared with only 6.8% of those who received placebo injections.
The primary side effects were swelling and redness at the injection site. About 4% of the patients had contractures recur at an average of 7.4 months–about the same percentage who suffered a recurrence after surgery.
However, Xiaflex needs to be carefully injected into the affected joints.
Xiaflex has been designated as an orphan drug because of the limited market. The Orphan drug designation entitles Auxilium tax incentives for research and a seven-year monopoly on drugs for treating the condition.
“Xiaflex has the potential to provide an important new non-surgical treatment option for patients with Dupuytren’s contracture, a debilitating hand condition severely affecting patients’ quality of life,” said Armando Anido, chief executive officer and president of Auxilium.
US FDA Advisory Committee’s recommendation, although not binding, will be considered by the FDA in its review of the Biologics License Application that Auxilium has submitted for Xiaflex.
Auxilium studies Xiaflex in phase IIb of development for the treatment of Peyronie’s disease (a curving of the penis with a similar mechanism) and is in phase II of development for treatment of Frozen Shoulder syndrome (Adhesive Capsulitis).
Analysts predict that the eventual market for the drug to treat both conditions could be about $650 million per year.
Auxilium Pharmaceuticals, Inc. is a specialty biopharmaceutical company with a focus on developing and marketing to urologists, endocrinologists, orthopedists and select primary care physicians.
Auxilium markets Testim 1%, a topical testosterone gel, for the treatment of hypogonadism through its approximately 190-person sales and marketing team.
Xiaflex (collagenase clostridium histolyticum) has completed phase III clinical trials for the treatment of Dupuytren’s contracture, and the biologics license application is under review at the FDA for the treatment of Dupuytren’s contracture.
Auxilium’s transmucosal film product candidate for the treatment of overactive bladder (AA4010) and its fentanyl pain product using its transmucosal delivery system are in phase I of development.