The increase in research and development expenses primarily reflects the following 437 million increase in manufacturing expenses primarily due to a continuing rampup of the Companys gene therapy programs 198 million increase in clinical trial expenses primarily due to increased patient enrollment for the Companys ESSENCE and MOMENTUM programs as well as certain startup activities for the Companys SRP9001 microdystrophin program 144 million increase in upfront milestone and other expenses primarily due to a 287 million increase of an accrued sublicense fee to Nationwide and 70 million of expense incurred as a result of milestone achievements in certain research and license agreements during the six months ended June 30 2021 offset by 93 million of expense related to sublicense payments accrued to Nationwide and 120 million of upfront payments as a result of the execution of certain research and license agreements during the same period of 2020 129 million increase in research and other primarily driven by an increase in sponsored research with academic institutions during the six months ended June 30 2021 80 million increase in facility and technologyrelated expenses due to the Companys continuing expansion efforts 78 million increase in preclinical expenses primarily due to an increase of toxicology studies in the Companys PPMO platforms 62 million increase in compensation and other personnel expenses primarily due to a net increase in headcount 36 million increase in stockbased compensation expense primarily driven by increases in headcount and changes in stock price 25 million increase in collaboration cost sharing with Genethon on its microdystrophin drug candidate 27 million decrease in professional service expenses primarily due to a decrease in reliance on thirdparty research and development contractors and 60 million increase in the offset to expense associated with a collaboration reimbursement from Roche primarily due to continuing development of the Companys SRP9001 microdystrophin gene therapy