AbbVie's FDA-approved Duopa gel for Parkinson's skates through yearlong study

Levodopa is often the drug of choice to mitigate the symptoms of Parkinson's disease, but getting the treatment into the bloodstream can be challenging because of the erratic muscle movement in Parkinson's patients' digestion systems. AbbVie's ($ABBV) gel-based Duopa is designed to improve absorption of levodopa in the small intestine, and researchers at the University of Kentucky recently demonstrated long-term safety and efficacy of the delivery method.

Approved in January for patients with advanced Parkinson's, AbbVie's treatment is delivered directly to the small intestine via an infusion pump. It is a levodopa-carbidopa intestinal gel (LCIG) meant to provide 16 hours of relief from symptoms, according to AbbVie, and over a period of 12 weeks it was shown to work better than immediate-release combinations of carbidopa and levodopa.

In the new Phase III study published in the Journal of Parkinson's Disease, researchers extended the treatment to a year, finding that LCIG's profile was consistent with results from the previous late-stage trial. Sixty-two of the original 66 patients continued on with the trial.

In Parkinson's patients, "off time" is that during which his or her symptoms are most prevalent. For the 52-week study, the patients maintained their improved off time from the previous study, which came in at almost two hours less than placebo. The most common complication was from device insertion with several other minor to moderate discomforts, according to the study.

The FDA approved Duopa as an orphan drug, as Parkinson's affects fewer than 200,000 patients in the U.S.

Several companies are vying for a spot in the Parkinson's market, though, with Impax Laboratories ($IPXL) peddling its approved oral Rytary, an immediate- and extended-release carbidopa and levodopa combo; Neuroderm's ($NDRM) still-unapproved version of the two drugs, which wrangled positive Phase IIa results this year along with a bump in the company's stock price; Civitas' inhaled levodopa-carbidopa treatment; and Cynapsus' thin-film strip.

"Due to the progressive nature of Parkinson's disease, it can be difficult to treat over time, especially in the advanced stages," National Parkinson Foundation CEO Joyce Oberdorf said in a statement back when Duopa was first approved. "Our organization is encouraged by the introduction of a new therapy that may provide another treatment option for affected patients and families."

- here's the study (PDF)