Spinifex Pharmaceuticals, an Australian pain drug development company, announces the presentation of new data from a study of EMA401 in a model of diabetic neuropathy. EMA401 is an angiotensin II type 2 (AT2) receptor antagonist currently in clinical development for a number of neuropathic pain indications.

The new data were presented at the 21st annual meeting of the Diabetic Neuropathy Study Group of the European Association for the Study of Diabetes, NEURODIAB, on the 11th September by Professors Norman Cameron and Mary Cotter of the University of Aberdeen.

Diabetic neuropathy is a side effect of diabetes that is characterized by the peripheral nerves not functioning properly. Patients present with symptoms that include pain but can also include sensory loss and reduced reflex. Diminished nerve conduction velocities resulting from damage to the peripheral nervous system have also been linked to other serious side effects of diabetes such as ulcers of the feet and legs which can ultimately lead to amputation.

In the new study, initiated by Spinifex Pharmaceuticals, EMA401 was shown to correct motor and sensory nerve conduction velocity (NCV) in an established animal model of diabetes. EMA401 also reduced pain and heat sensitivity and corrected sciatic nerve nutritive blood flow. EMA401 was effective at a dose of 1 mg/kg/day and no CNS side effects were observed, consistent with earlier studies at this and higher doses.

Spinifex Pharmaceuticals CEO Tom McCarthy said: “The discovery that AT2 receptor antagonists offer an innovative approach to the treatment of neuropathic and inflammatory pain was originally made by Professor Maree Smith at The University of Queensland and we have good earlier data on the impact of EMA401 on neuropathic pain in pre-clinical models. This new study we initiated with Professors Cameron and Cotter not only reinforces our earlier data on the impact of EMA401 on neuropathic pain but also confirms our hypothesis that EMA401 may treat the underlying nerve conduction velocity deficits that are the hallmark of diabetic neuropathy. This expands the range of potential indications for the compound and, importantly, provides a new therapeutic target for what is a particularly devastating form of neuropathy.”

Professor Norman Cameron said: “Inhibition of the renin-angiotensin system can reduce the development of diabetic complications including neuropathy but most attention has focussed on AT1 receptor-mediated mechanisms. This is the first study of the effect of an AT2 receptor antagonist on nerve function in an appropriate diabetes model. In showing EMA401 corrects aspects of neurovascular dysfunction the data suggests the AT2 receptor is a valuable new potential therapeutic target in diabetic neuropathy.”

Spinifex acquired the initial technology underpinning EMA401 from The University of Queensland and has conducted a comprehensive pre-clinical and early clinical development program. EMA401 has shown efficacy in a number of relevant models, good human safety and pharmacokinetics in phase I studies and the first of three phase II clinical trials will be initiated shortly.

Spinifex's clinical program for EMA401 is initially focused on neuropathic pain, an area of high unmet medical need. The market for neuropathic pain treatments is expected to continue to increase and is projected to reach US$ 6.2 billion by 2017. Despite this growth, current therapy needs to be improved as a significant proportion of neuropathic pain patients don't respond to current therapy and these treatments have dose-limiting side effects. As a result, EMA401 is being developed as a potential first-in-class oral treatment for neuropathic pain and related symptoms without central nervous system side effects.