Watson Pharmaceuticals Reports Results For Phase I Study For Gelnique

Gel does not impact cognition among healthy older adults

Watson Pharmaceuticals has posted findings of a double-blind study which demonstrate that Gelnique was comparable to placebo in its effect on memory tests and other cognitive functions in older healthy adult subjects when compared to immediate release oral oxybutynin treatments.

The study was a double-blinded, double dummy, phase I study of 152 older, healthy, non-demented adults (average age of 68 years) from five US centers, participants were randomised to one of three treatment arms for one-week of therapy: 1g Gelnique gel 10% once daily (Gelnique plus placebo oxybutynin immediate-release capsule; n=49); 5mg oral oxybutynin immediate-release three times daily (active OXB-IR capsules plus placebo Gelnique; n=52); or placebo (placebo Gelnique plus placebo OXB-IR capsules; n=51). After one week, participants were given a series of tests to assess cognitive and psychomotor functioning.

Results on the primary endpoint showed no significant treatment effect (p=0.273), as well as no significant differences versus placebo (Gelnique vs placebo, p=0.155; OXB-IR vs placebo, p=0.177). However, on another sensitive test of delayed recall measuring the participants' ability to recall the location of misplaced objects in a simulated house, there was a significant difference between treatment groups (p=0.029) with scores in the placebo and Gelnique groups both improving and performance in the OXB-IR group declining.

On the remaining tests of delayed recall and immediate recall, there were no significant treatment-related group differences. However, in an exploratory analysis of Reliable Change scores in the HVLT-Total Free Recall, 10 participants on OXB-IR showed a significant decline, compared to 6 subjects on placebo and 5 subjects on Gelnique.

On psychomotor scores, there were no significant treatment-related group differences on measures of psychomotor reaction time, or for any of the Memory Assessment Clinics Self-Report Questionnaire (MAC-S) variables.

Significantly more patients in the OXB-IR group vs Gelnique reported dry mouth (73.1% and 6.1%, respectively) and other treatment-emergent adverse events, such as headache (7.7% and 0%, respectively) and constipation (5.8% and 0%, respectively). The most common treatment-emergent adverse event was dry mouth; three people in the OXB-IR group discontinued treatment. There were no serious adverse events.

Scott MacDiarmid, director of alliance urology specialists for Bladder Control and Pelvic Pain Center, said: "Oxybutynin is a vital and effective treatment. That said, the potential for oral formulations to impact cognitive function is significant and weighs heavily on the treatment decisions I make on behalf of my OAB patients. Topically administered oxybutynin gel is an effective and easy-to-use treatment option with very few anticholinergic side effects. I am comfortable and confident prescribing Gelnique with the added peace of mind these data offer in terms of cognitive safety."