SOUTH SAN FRANCISCO (TheStreet) -- A Titan Pharmaceuticals (TTNP) device implanted just under the skin to release the anti-addiction medicine buprenorphine for six months prevented opioid abusers from relapsing equally as well as a daily buprenorphine, according to results from a phase III study announced Monday.
Titan and its partner Braeburn Pharmaceuticals believe positive results from the phase III study will be sufficient to satisfy the concerns raised by the U.S. Food and Drug Administration when the device, known as Probuphine, was rejected in 2013.
A resubmission to the FDA is on track for later this year, Titan said Monday. If approved in 2016, Probuphine, as it will be marketed, will be the first product to provide maintenance treatment of opioid addiction continuously for six months following a single procedure.
Titan shares closed Friday at 80 cents. By midday Monday, shares rose 13.6% to 90 cents.
Probuphine consists of matchstick-sized plastic rods embedded with buprenorphine. The rods are typically implanted just under the skin of the upper arm in an outpatient procedure. Once implanted, the rods release buprenorphine slowly over six months. Oral forms of buprenorphine are FDA approved to treat opioid addiction.
The phase III study enrolled opioid addicts receiving maintenance treatment of oral buprenorphine for at least three months. Half of the patients were implanted with Probuphine and switched to placebo tablets; the other half of patients were implanted with placebo rods and remained on oral buprenorphine.
After six months, 96.4% patients responded to Probuphine therapy compared to 87.6% of patients on oral buprenorphine, achieving the study's primary endpoint of statistical non-inferiority.
A patient was deemed a responder if at least four of six monthly urine tests came back free of opioids.
And 88% percent of Probuphine patients passed all six monthly urine tests, compared to 72% of oral buprenorphine patients. The difference was statistically significant. There were no differences between Probuphine and oral buprenorphine on symptoms of opioid withdrawal and cravings across the six-month study.
The overall safety profile was comparable between treatment groups, and the implant insertion and removal procedures were generally well tolerated.