Background	12 Months Ended
Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Background	Background We are an international biotechnology company focused in the field of regenerative medicine and operate in one business segment. Our operations consist of research, preclinical development and clinical development activities, and our most advanced program is in Phase 3 clinical development. We have incurred losses since our inception in 1995 and had an accumulated deficit of $373.0 million at December 31, 2018. We will require additional capital to continue our research and development programs, including progressing our clinical product candidates to commercialization and preparing for commercial-scale manufacturing and sales. At December 31, 2018, we had available cash and cash equivalents of $51.1 million. We believe that these funds, expected cash receipts primarily attributed to our collaboration with HEALIOS K.K. (“Healios”) and proceeds from our equity facility are sufficient to meet our obligations as they come due at least for a period of twelve months from the date of the issuance of these consolidated financial statements. In the longer term, we will have to continue to generate additional capital to meet our needs through new and existing collaborations and related license fees and milestones, the sale of equity securities from time to time including through our equity facility, grant-funding opportunities, deferring certain discretionary costs and staging certain development costs, as needed.

Background

We are an international biotechnology company focused in the field of regenerative medicine and operate in one business segment. Our operations consist of research, preclinical development and clinical development activities, and our most advanced program is in Phase 3 clinical development.

We have incurred losses since our inception in 1995 and had an accumulated deficit of $373.0 million at December 31, 2018. We will require additional capital to continue our research and development programs, including progressing our clinical product candidates to commercialization and preparing for commercial-scale manufacturing and sales. At December 31, 2018, we had available cash and cash equivalents of $51.1 million. We believe that these funds, expected cash receipts primarily attributed to our collaboration with HEALIOS K.K. (“Healios”) and proceeds from our equity facility are sufficient to meet our obligations as they come due at least for a period of twelve months from the date of the issuance of these consolidated financial statements. In the longer term, we will have to continue to generate additional capital to meet our needs through new and existing collaborations and related license fees and milestones, the sale of equity securities from time to time including through our equity facility, grant-funding opportunities, deferring certain discretionary costs and staging certain development costs, as needed.