Elan Corporation announced that its recent Phase III trial for Prialt (ziconotide) met its primary endpoint in patients with severe chronic pain who had not achieved pain relief with other therapies including intrathecally delivered morphine.
In the double blind, placebo-controlled study, patients taking Prialt achieved statistically significant improvement at Week 3 in the Visual Analog Scale of Pain Intensity (VASPI) score, the most commonly used pain assessment scale for clinical trials. In the company's analysis, the treatment appears to be safe, efficacious, and well tolerated. Based on the positive results, the company expects to file an amendment to its New Drug Application (NDA) with the US Food and Drug Administration (FDA) in the second quarter of 2004 and to bring the treatment to market by the first quarter of 2005.
Prialt is the first in a new class of non-opioid analgesics known as N-type calcium channel blockers, administered intrathecally for the treatment of severe chronic pain. Elan submitted an application for approval for marketing Prialt in the European Union in May 2003.
Dr Lars Ekman, executive vice president and president, Research & Development, Elan, said, "We are very encouraged by these definitive findings with Prialt and believe that this is significant news for patients suffering with severe chronic pain, many of whom are not now adequately treated. This study fulfills the clinical requirement in response to the FDA's previous approvable letter, and upon submission, we anticipate a six month review for the amendment to the NDA."
The FDA had previously issued an approvable letter for Prialt, in which the agency had requested additional information. This trial was conducted in response to the FDA's clinical request and designed with their input, studying 220 patients with severe chronic pain to demonstrate the efficacy and safety of lower doses of Prialt and a slower titration schedule than was used in two previous Phase III studies. In this clinical trial, there were few serious side effects, with an incidence similar to placebo. These data will be presented at a major scientific pain meeting this year.
As a non-opioid analgesic for patients with severe chronic pain such as neuropathic pain or pain secondary to cancer, Prialt addresses a significant unmet medical need. About two million patients in the US with chronic pain fail to respond to existing comprehensive treatment. Of these, about 300,000 may be considered as potential candidates for intrathecal treatment, which could include Prialt. In order to make this treatment available to patients during the review process, a Treatment IND to make Prialt available on a limited basis to select pain centres in the US will begin in the first quarter of 2004.