Targacept is taking another drug candidate into clinical trial, triggering a $6 million milestone payment from GlaxoSmithKline.

Just last week, Targacept (Nasdsaq: TRGT) reported one of its candidates being developed in partnership with GSK had failed.

However, on Monday, Targacept said compound TC-6499 had entered a Phase I clinical trial. It is a potential treatment for neuropathy, a painful condition that affects 15 million Americans. Major causes for neuropathy include diabetes and chemotherapy for cancer.

In preclinical studies, TC-6499 “demonstrated analgesic activity in multiple modesl of neuropathic pain,” Targacept said. The trial will test the safety and tolerability of TC-6499 on healthy patients.

“There is a clear need for effective treatments for neuropathic pain and the preclinical profile of TC-6499 is very encouraging,” said Hugh Cowley, GSK’s head of its Center of Excellence for External Drug Discovery.”

Targacept shares plunged last week when the company announced that compound, TC-2696, one of two key drug candidates Targacept identified as part of the development deal with GSK, had failed. The package with GSK is worth as much as $1.5 billion, according to Targacept.