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Scholar Rock Scholar Rock Reports Second Quarter 2021 Financial Results and Highlights Business Progress August 10 , 2021 - Phase 3 trial to evaluate apitegromab in patients with non - ambulatory Type 2 and Type 3 spinal muscular atrophy ( SMA ) anticipated to initiate by end of 2021 - DRAGON Phase 1 trial evaluating SRK - 181's ability to overcome resistance to checkpoint inhibitors continues to progress and on - track to advance to Part B dose expansion mid - year 2021 CAMBRIDGE , Mass .-- ( BUSINESS WIRE ) -- Aug . 10 , 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 second quarter ended June 30 , 2021 , and highlighted recent progress and upcoming milestones for its pipeline programs . " Scholar Rock has had significant momentum in the first half of the year with further demonstration of apitegromab's transformative potential to improve motor function for patients with SMA , as well as continued progression of dose escalation in the DRAGON trial evaluating SRK - 181's potential to overcome resistance to checkpoint inhibitors in solid tumors , " said Nagesh Mahanthappa , Ph.D. , Interim CEO of Scholar Rock . " I look forward to working closely with this exceptional team as we continue to advance our research and clinical programs to further elucidate the potential of our scientific platform and help make a difference in the lives of patients suffering from serious diseases . " 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 ) . • Positive Top - line Results and Additional Supportive Exploratory Analyses from the TOPAZ Trial were Presented at the Cure SMA Annual Conference . In June 2021 , positive top - line data from the TOPAZ Phase 2 trial ( NCT03921528 ) were presented by the lead principal investigator , Thomas Crawford , M.D. of Johns Hopkins Medicine . Treatment with apitegromab in conjunction with nusinersen in patients with Type 2 and 3 SMA led to meaningful motor function improvements of up to 20 points as measured by Hammersmith Functional Motor Scale Expanded ( HFMSE ) . The majority ( 74 % , 23/31 ) of non - ambulatory patients showed a clinical improvement , as defined by at least a 1 - point increase in HFMSE . Further evidence that improvements in motor function may be attributed to apitegromab was supported by a post - hoc analysis that showed no correlation between change in HFMSE and duration of prior maintenance nusinersen therapy . In addition , 7/35 non - ambulatory patients also showed major functional achievements as measured by World Health Organization ( WHO ) Motor Development Milestones , with one patient achieving two and one patient achieving three new WHO motor milestones . • Phase 3 Trial Evaluating Apitegromab in Patients with Non - Ambulatory Type 2 and 3 Patients Anticipated to Initiate by Year - End 2021. Subject to feedback from regulatory agencies , Scholar Rock intends to conduct a randomized , double - blind , placebo - controlled Phase 3 trial to evaluate apitegromab as an add - on therapy to nusinersen or risdiplam in patients with non - ambulatory Type 2 and Type 3 SMA . In the TOPAZ Phase 2 trial , non - ambulatory patients experienced the largest increases in motor function ( HFMSE scores ) following treatment with apitegromab as add - on to chronic maintenance nusinersen . Patients with non - ambulatory Type 2 and Type 3 SMA are estimated to represent approximately two - thirds of the overall prevalent SMA patient population . • Apitegromab Granted Fast Track Designation by the FDA for the Treatment of Patients with Spinal Muscular Atrophy . In May 2021 , the U.S. Food and Drug Administration ( FDA ) granted Fast Track designation for apitegromab , offering Scholar Rock eligibility to submit a rolling Biologic License Application ( BLA ) for apitegromab if relevant criteria are met . Fast Track designation is intended to facilitate the development and expedite the review of drugs to treat serious conditions and get new drugs to patients earlier . In addition to Fast Track designation , apitegromab had previously received Orphan Drug and Rare Pediatric Disease designations from the FDA as well as PRIME and Orphan Medicine Product designations from the European Medicines Agency for the treatment of SMA , all recognizing the unmet medical needs of patients with SMA . • Additional Potential Indications Identified for Apitegromab . Scholar Rock has identified multiple diseases for which selectively inhibiting the activation of myostatin may offer therapeutic benefit , including additional patient populations in SMA ( such as Type 1 SMA and ambulatory Type 3 SMA ) and potential indications outside of SMA . SRK - 181 is a selective inhibitor of latent TGFẞ1 activation being developed with the aim of overcoming resistance to and increasing the number of patients who may benefit from checkpoint inhibitor therapy . • Plan to Advance to Part B Dose Expansion Portion of the DRAGON Phase 1 Proof - of - Concept Trial Mid - Year .