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STOKE THERAPEUTICS Stoke Therapeutics Reports First Quarter Financial Results and Provides Business Updates May 10 , 2021 - Enrollment complete in single ascending dose ( SAD ) portion ( 10mg , 20mg , 30mg ) of Phase 1 / 2a MONARCH study of STK - 001 in children and adolescents with Dravet syndrome ; Interim analysis planned for the third quarter- - Enrollment and dosing ongoing in the 20mg multiple ascending dose ( MAD ) portion of MONARCH - - Company on - track to identify a clinical candidate for the treatment of autosomal dominant optic atrophy by year end - - As of March 31 , 2021 , Company has $ 267.7 million in cash , cash equivalents and restricted cash , anticipated to fund operations into 2024- BEDFORD , Mass .-- ( BUSINESS WIRE ) -- May 10 , 2021-- Stoke Therapeutics , Inc. ( Nasdaq : STOK ) , a biotechnology company dedicated to addressing the underlying cause of severe diseases by up - regulating protein expression with RNA - based medicines , today reported financial results for the first quarter of 2021 and provided business updates . " The momentum we are seeing with STK - 001 in the clinic is driven by high levels of interest from the Dravet community and our shared sense of urgency to advance a potential disease - modifying approach for the treatment of this devastating disease . The single dose portion of our Phase 1 / 2a MONARCH study in the U.S. is now fully enrolled up to the 30mg dose level and based on our progress , we now anticipate our first data readout from this single dose portion of MONARCH in the third quarter . We are also well underway with preparation to initiate a complementary study of STK - 001 in the United Kingdom in the coming months . Together , we believe these studies will provide meaningful data to inform future development of STK - 001 , " said Edward M. Kaye , M.D. , Chief Executive Officer of Stoke Therapeutics . “ In addition to clinical progress , we continue to advance our pipeline . We recently presented new preclinical data that provide additional confidence in our ability to upregulate OPA1 protein expression to treat the underlying cause of autosomal dominant optic atrophy ( ADOA ) , the most common inherited optic nerve disorder . We are on track with lead optimization efforts for the ADOA program and expect to demonstrate proof of mechanism for a third preclinical target using our TANGO approach by year end . " First Quarter 2021 Business Highlights and Recent Developments • The Company announced today , the completion of patient enrollment in the 10mg , 20mg , and 30mg single ascending dose ( SAD ) portion of the Phase 1 / 2a MONARCH study of STK - 001 in children and adolescents with Dravet syndrome . • Enrollment and dosing in the multiple ascending dose ( MAD ) portion of MONARCH is ongoing . • On March 30 , 2021 , the Company announced the authorization of its Clinical Trial Application ( CTA ) by the United Kingdom Medicines and Healthcare products Regulatory Agency ( MHRA ) to initiate a Phase 1 / 2a study ( ADMIRAL ) of STK - 001 for the treatment of Dravet syndrome in the United Kingdom . The planned ADMIRAL study complements the ongoing MONARCH study by evaluating multiple doses of up to 70mg of STK - 001 and represents a first step in the global clinical development of STK - 001 . • Dosing of patients is ongoing in SWALLOWTAIL , an open label extension ( OLE ) study designed to evaluate the long - term safety and tolerability of repeat doses of STK - 001 in patients who participated in the Phase 1 / 2a MONARCH study . • On May 4 , 2021 , the Company presented new preclinical efficacy data for TANGO antisense oligonucleotides ( ASO ) at The Association for Research in Vision and Ophthalmology ( ARVO ) . The new data demonstrated , for the first time , both OPA1 protein upregulation and improved mitochondrial function in human cells derived from autosomal dominant optic atrophy ( ADOA ) patients with different OPA1 mutations . OPA1 protein deficiency is the primary cause of ADOA , the most common inherited optic nerve disorder . Upcoming Anticipated Milestones • Enrollment and dosing in the Phase 1 / 2a study ( ADMIRAL ) of STK - 001 for the treatment of Dravet syndrome across multiple sites in the United Kingdom are expected to begin in the second half of 2021 . • As part of a planned interim analysis , the Company expects to report preliminary safety , pharmacokinetic , and cerebrospinal fluid ( CSF ) drug exposure data from the SAD portion of the Phase 1 / 2a MONARCH study of STK - 001 in the third quarter of 2021 . • A presentation of preclinical data supporting the Company's approach to treating ADOA with a TANGO ASO will be presented on May 11 , 2021 during the American Society of Gene and Cell Therapy ( ASGCT ) Annual Meeting . • In the second half of 2021 , the Company plans to initiate natural history data collection of people living with ADOA to better understand the natural progression of this disease and to support future clinical development of a TANGO ASO for the treatment of ADOA . • The Company remains on track to identify a clinical candidate for the treatment of ADOA by the end of 2021 . • The Company expects to demonstrate in vivo proof of mechanism and safety for a third TANGO ASO program by the end