Up to 220 participants will enter an open label extension (OLE) study during which all study participants will receive treatment for 12 weeks (84 days). Study participants will be followed for 16 weeks (112 days) post treatment-cessation and then the twice daily treatments will be re-introduced for the final 8 weeks (56 days).
This study seeks to establish the safety and efficacy of extended twice daily treatments for treating symptoms associated with PD. Only participants who completed the STEM-PD RCT trial are eligible for the OLE.