LONDON, Aug. 14, 2013 /PRNewswire/ -- GW Pharmaceuticals plc (Nasdaq: GWPH, AIM: GWP, "GW") announced today that it has opened a Phase 3 Investigational New Drug (IND) application with the U.S. Food and Drug Administration (FDA) to conduct a pivotal efficacy and safety clinical program to evaluate Sativex® for the treatment of spasticity due to Multiple Sclerosis (MS). Sativex is currently approved in 22 countries outside the U.S. as a treatment for MS spasticity. The proposed U.S. Phase 3 program will be conducted under the agreement with GW's licensing partner for Sativex®, Otsuka Pharmaceutical Co. Ltd. Under the terms of GW's agreement with Otsuka, Otsuka is responsible for wholly funding the MS Phase 3 clinical program, as is the case with the current Phase 3 cancer pain program. As part of its MS spasticity IND application, GW requested feedback from the FDA on key features of the proposed single Phase 3 trial protocol. GW expects to work with the FDA over the coming months to incorporate FDA feedback and to finalize the protocol design, which may include a request for Special Protocol Assessment (SPA). GW expects the Phase 3 trial to commence in 2014. Cancer pain remains the initial target indication for Sativex in the U.S. and it is intended that MS spasticity would represent a future second indication for the U.S. market. GW and Otsuka are currently undertaking a Phase 3 clinical trial program for Sativex in cancer pain and results from two pivotal Phase 3 trials are expected in 2014. "With results from our U.S. Phase 3 program in cancer pain due next year, this new Phase 3 IND provides us with the opportunity to broaden the future U.S. market potential for Sativex to include MS spasticity. As such, this new IND represents an important extension of GW's and Otsuka's ambitions for Sativex in the U.S.," stated Justin Gover, Chief Executive Officer of GW. "We now look forward to working with the FDA to gain agreement on the required program to enable a future filing of an NDA for the MS indication."