Novartis International has agreed to acquire Spinifex Pharmaceuticals, a company focused on the development of new drugs for the treatment of chronic pain based in Stamford, Conn., and Melbourne, Australia, for an upfront cash consideration of $200 million plus undisclosed clinical development and regulatory milestone payments.

The acquisition is centered on Spinifex's lead candidate EMA401, a novel angiotensin II type 2 (AT2) receptor antagonist, being developed as a potential first-in-class oral treatment for chronic pain, particularly neuropathic pain, without central nervous system (CNS) side effects.

Neuropathic pain is defined by the International Association for the Study of Pain as that "caused by a lesion or disease of the somatosensory nervous system." These causes are diverse and include diabetes (painful diabetic neuropathy (PDN)), cancer or its treatment with therapeutic agents (e.g. chemotherapy induced peripheral neuropathy), viruses (e.g. postherpetic neuralgia (PHN)) and nerve trauma (peripheral nerve injury induced neuropathy). Current treatments for neuropathic pain do not relieve pain in all individuals or are not well-tolerated.

Positive results from Spinifex's phase II clinical trial of EMA401 in PHN, a painful condition that develops in some people following herpes zoster (shingles), have been published in The Lancet. Novartis will continue the development of EMA401 and is planning to initiate phase IIb clinical trials in patients with PHN or PDN. Novartis also intends to build on these two key indications and pursue a broad peripheral neuropathic pain (PNP) label for EMA401.

In addition to the upfront payment of $200 million from Novartis, Spinifex shareholders are eligible to receive payments contingent on future clinical development and regulatory milestones. The transaction is expected to close in H2 2015, subject to the receipt of clearance under the Hart-Scott-Rodino Act and customary closing conditions.