Scholar Rock Holding Corporation provided recent corporate updates and highlighted upcoming priorities for its pipeline programs in 2022. 2022 Priorities: 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). Robust Enrollment of the Phase 3 SAPPHIRE Trial Evaluating Apitegromab in Patients with Non-Ambulatory Type 2 and 3 Patients.

Scholar Rock has initiated the SAPPHIRE study. The study design plans for approximately 156 patients aged 2-12 years old with non-ambulatory Type 2/3 SMA to be enrolled in the main efficacy population. Patients will be randomized 1:1:1 to receive for 12 months either apitegromab 10 mg/kg, apitegromab 20 mg/kg, or placebo by intravenous (IV) infusion every 4 weeks added on top of background SMN treatment.

Progress TOPAZ Long-Term Extension to Two Year Readout. As of January 6, 55 of 57 patients remain in the long-term extension trial of apitegromab in Type 2 and 3 SMA. Advance Development Activities to Include Patients with Type 1 and Ambulatory SMA.

SRK-181 is a potent and highly selective inhibitor of latent TGFß1 activation being developed with the aim of overcoming primary resistance to and increasing the number of patients who may benefit from checkpoint inhibitor therapy. Advance Progress in Part B of DRAGON Phase 1 Proof-of-Concept Trial. Based on the safety and pharmacokinetic data from Part A of the DRAGON Phase 1 trial, Scholar Rock has initiated the Part B dose expansion portion of the trial, which is evaluating SRK-181 dosed 1500 mg every three weeks (Q3W) in patients receiving an approved anti-PD-(L)1 therapy dosed Q3W and 1000 mg every two weeks (Q2W) in patients receiving an approved anti-PD-(L)1 therapy dosed Q2W.

Part B will enroll and dose patients in multiple proof of concept cohorts conducted in parallel, including; Urothelial carcinoma (UC); Cutaneous melanoma (MEL); Non-small cell lung cancer (NSCLC); Clear cell renal cell carcinoma (ccRCC); Other solid tumors. Each cohort is expected to enroll up to 40 patients with various locally advanced or metastatic solid tumors who have demonstrated primary resistance to anti-PD-(L)1 therapy. Early efficacy and safety data are anticipated in 2022.