Study of PL37 in Peripheral Neuropathic Pain of Diabetic Origin
Research type
Research Study
Full title
A 4 week phase 2a, multicentre, randomised, double-blind, placebo-controlled add-on study into safety, tolerability and efficacy of 200 mg t.i.d. of PL37 in patients with peripheral neuropathic pain of diabetic origin treated with pregabalin or gabapentin
IRAS ID
148925
Contact name
Bernhard Frank
Contact email
Sponsor organisation
Pharmaleads SA
Eudract number
2013-004876-37
Research summary
Neuropathic Pain (NP) is an unpleasant sensory and emotional experience that can have a significant impact on a person’s quality of life.
NP develops as a result of damage to, or dysfunction of, the system that normally signals pain. It may arise from a heterogeneous group of disorders that affect the peripheral and central nervous systems. Common examples include painful diabetic neuropathy, post-herpetic neuralgia and trigeminal neuralgia. People with neuropathic pain may experience altered pain sensation, areas of numbness or burning, and continuous or intermittent evoked or spontaneous pain.
NP is often difficult to treat, because it is resistant to many medications and/or because of the adverse effects associated with effective medications at therapeutic dosages. A number of drugs are used to manage NP, including antidepressants, anti-epileptic drugs (e.g. gabapentin and pregabalin), opioids and topical treatments such as capsaicin and lidocaine. Many people require treatment with more than one drug, but the correct choice of drugs, and the optimal sequence for their use, has been unclear. Pregabalin (Lyrica®) and duloxetine (Cymbalta®) effective in less than 1 in 4 patients, with 50% pain relief in only 25% of responder. Furthermore, they may induce unpleasant side-effects, which make their therapeutic margin narrow.
PL37 is the first compound of a novel pharmacological class christened DENKIs (for Dual Enkephalinase Inhibitors) compounds which inhibit the activity of enkephalin-degrading enzymes hence increasing half-life and local concentration of these potent natural analgesics, specifically where pain occurs, i.e. DENKIs work by enhancing the body’s natural pain control mechanism.
It appears that patients suffering from NP who are only partially relieved by gabapentin or pregabalin may significantly benefit from the addition of oral PL37 to their background medication. In this study, patients suffering from neuropathic pain of diabetic origin who have experienced significant but still inadequate pain relief despite being on the highest tolerated dose of pregabalin or gabapentin for at least three months, will receive either PL37 or placebo for a period of 4 weeks in addition to their pregabalin or gabapentin, to investigate if PL37 is effective and safe in reducing pain intensity.REC name
North West - Haydock Research Ethics Committee
REC reference
14/NW/0119
Date of REC Opinion
31 Mar 2014
REC opinion
Further Information Favourable Opinion