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Scholar Rock Scholar Rock Reports Third Quarter 2021 Financial Results and Highlights Business Progress November 9 , 2021 - Phase 3 pivotal trial evaluating apitegromab in patients with non - ambulatory Type 2 and Type 3 SMA on track to initiate by year - end 2021 - Update from Part A of the DRAGON Phase 1 trial evaluating SRK - 181's ability to overcome primary resistance to checkpoint inhibitors being presented at the Society for Immunotherapy of Cancer ( SITC ) 36th Annual Meeting - Initiated Part B dose expansion portion of the DRAGON trial - U.S. patent issued providing additional product protection for SRK - 181 to May 2040 CAMBRIDGE , Mass .-- ( BUSINESS WIRE ) -- Nov . 9 , 2021-- Scholar Rock ( NASDAQ : SRRK ) , a clinical - stage biopharmaceutical company focused on the treatment of serious diseases in which protein growth factors play a fundamental role , today reported financial results for the third quarter ended September 30 , 2021 , and highlighted recent progress and upcoming milestones for its pipeline programs . " The DRAGON trial addresses two key questions ; first , can the selectivity of SRK - 181 for TGFẞ1 increase the therapeutic window for inhibition of this signaling pathway thereby enabling higher doses safely , and second , does SRK - 181 exhibit anti - tumor activity effective in overcoming resistance to checkpoint inhibitors in solid tumors . We are pleased with the results of Part A , as will be provided this week at the Society for Immunotherapy of Cancer ( SITC ) Annual Meeting , and we look forward to exploring the efficacy dimension of our therapeutic hypothesis in Part B , " said Nagesh Mahanthappa , Ph.D. , Interim CEO of Scholar Rock . " Building on the momentum from the first half of this year , we are also excited about the progress with apitegromab and are on track to initiate by year - end the Phase 3 pivotal trial evaluating its efficacy in patients with non - ambulatory Type 2 and Type 3 spinal muscular atrophy ( SMA ) . " Company Updates and Upcoming Milestones Apitegromab is a selective inhibitor of myostatin activation being developed as the potential first muscle - directed therapy for the treatment of spinal muscular atrophy ( SMA ) . • Additional Exploratory Responder Analyses and Pharmacologic Data from the TOPAZ Phase 2 Trial were Presented at Various Medical Congresses . In September 2021 , two posters were presented at the World Muscle Society Virtual Congress , including a late - breaker poster featuring an exploratory analysis evaluating time to achieving various thresholds of improvement in Hammersmith Functional Motor Scale Expanded ( HFMSE ) scores , which are consistent with the observed dose response in clinical efficacy . In October 2021 , a poster presented at the 25th World Congress of Neurology ( WCN ) described the positive correlation between the magnitude of target engagement and motor function improvements following apitegromab treatment . At the 50th Child Neurology Society Annual Meeting , additional exploratory responder analyses on Hammersmith scale scores were presented , including time to achieve different thresholds of improvement in HFMSE scores . • Phase 3 Trial Evaluating Apitegromab in Patients with Non - Ambulatory Type 2 and 3 Patients Remains on Track to Initiate by Year - End 2021. Scholar Rock is preparing to announce the design of the Phase 3 pivotal study later this month . The company is on track to initiate by the end of 2021 the randomized , double - blind , placebo - controlled Phase 3 trial evaluating apitegromab as add - on therapy for patients on either nusinersen or risdiplam with non - ambulatory Type 2 and Type 3 SMA . This patient population comprises an estimated two - thirds of the overall prevalence of SMA , and the greatest improvements in motor function ( as measured by HFMSE ) observed in the TOPAZ Phase 2 trial were in patients with non - ambulatory Type 2 and Type 3 SMA receiving apitegromab as add - on therapy to background nusinersen . SRK - 181 is a selective inhibitor of latent TGFB1 activation being developed with the aim of overcoming primary resistance to and increasing the number of patients who may benefit from checkpoint inhibitor therapy . • Update from Part A of the DRAGON Phase 1 Trial and Part B Dose to be Presented at the Society for Immunotherapy of Cancer ( SITC ) 36th Annual Meeting . A poster titled , " First - in - Human Phase 1 Trial of SRK - 181 : A Latent TGFẞ1 inhibitor , Alone or in Combination with Anti - PD- ( L ) 1 Treatment in Patients with Advanced Solid Tumors ( DRAGON trial ) " will be presented at the SITC meeting on November 12 , 2021. The poster will include initial clinical data from Part A of the DRAGON trial as well as the rationale for the identified Part B dose . The Company has initiated the Part B dose expansion portion of the trial , which consists of multiple cohorts , each enrolling up to 40 patients with various solid tumors who have demonstrated primary resistance to anti - PD- ( L ) 1 therapy . • U.S. Patent Issued Providing Composition of Matter Product Protection for SRK - 181 . In September 2021 , the United