Sucampo Pharmaceuticals, Inc. has reported results of its double-blind, placebo-controlled phase IIa proof of concept study evaluating safety and efficacy of an intravenously (IV) administered compound of the company's proprietary ion channel activator programme in patients with lumbar spinal stenosis (LSS). A responder analysis of data from the trial revealed that patients receiving the ion channel activator experienced a statistically significant improvement in pain, as determined by improvements in the visual analog scale (VAS) score, versus placebo (94.4% versus 62.5%; p=0.035).

Improvements were also observed in the primary and other efficacy measures, including pain-associated quality of life measures for patients treated with the ion channel activator, although the extent of improvement was not statistically significant.

The ion channel activator was well-tolerated and was not associated with serious adverse events. Additionally, no worsening of any of the efficacy measures in the active group was recorded.

"These findings suggest that our proprietary ion channel activator could have the ability to target and treat several aspects of lumbar spinal stenosis. We are pleased that these preliminary data show that this compound has the potential to improve pain, one of the major aspects of LSS, in a patient population with the condition," said Ryuji Ueno, MD, Ph.D., chairman, chief executive officer, and chief scientific officer of Sucampo. "Based on the positive findings from this study, we will embark on an additional phase IIa study in 2014 to identify the appropriate endpoints and dosing regimen for the compound. We are encouraged that we can move forward to the next phase of clinical development for our ion channel activator, and we are committed to pursuing it in LSS, an underserved market with limited treatment options."

This multicentre, randomized, double-blind, placebo-controlled, dose-escalation study enrolled 51 hospitalized patients between the ages of 20 and 75 with a confirmed diagnosis of lumbar spinal stenosis.  Patients were administered 30 or 60 mcg of the ion channel activator or placebo twice daily for two weeks. Common adverse events included headache, diarrhea, injection site inflammation and feeling cold. No serious adverse events were observed. In addition, data from a previous phase I study demonstrated a favorable safety profile for the IV formulation of this ion channel activator.

Lumbar spinal stenosis is a common degenerative disease  which is caused by the narrowing of and diminished blood flow to the spinal cord, leading to pain, numbness and muscle weakness in the lower extremities. Current treatment options are limited to pain-killers and invasive surgery.

The (IV) compound of Sucampo's proprietary ion channel activator program is an investigational prostone compound in development as a potential treatment for severe lumbar spinal stenosis. Sucampo holds worldwide, exclusive rights to this compound. Sucampo is also developing an oral ion channel activator for potential treatment in mild to moderate lumbar spinal stenosis, among other indications under investigation. A Phase 1b study of the oral compound will begin in early 2014.

Sucampo Pharmaceuticals, Inc. is focused on the discovery, development and commercialization of drugs based on ion channel activators knows as prostones.