Scholar Rock Presents TOPAZ Interim Analysis Data for Apitegromab in SMA
Scholar Rock recently shared 6-month interim analysis data from the TOPAZ Phase 2 clinical trial evaluating the potential of apitegromab, a highly selective inhibitor of latent myostatin, in improving motor function in patients with Types 2 and 3 spinal muscular atrophy (SMA). A this 6-month timepoint:
- Mean increases from baseline in Hammersmith scale scores were observed in all three cohorts.
- 67% of total patients achieved ≥1 point improvement in Hammersmith scores.
- A substantial proportion of patients in each cohort achieved a ≥3 point increase in Hammersmith scores.
- 35% of total patients achieved ≥3 point increase in Hammersmith scores.
The company expects to share top-line efficacy and safety data from the TOPAZ Phase 2 trial in the second quarter of 2021. A total of 58 patients were enrolled across the three cohorts of the TOPAZ clinical trial (NCT03921528). With the exception of one patient who discontinued early from the trial for reasons unrelated to the study drug, all patients completed the 12-month treatment period and elected to opt into the extension period. Top-line data from the 12-month treatment period will provide additional insights on apitegromab’s potential in improving motor function in patients with Types 2 and 3 SMA, including the potential for durability of effect and for further motor function increases observed from the 6-month interim analysis.
Apitegromab is a selective inhibitor of the activation of myostatin and is an investigational product candidate for the treatment of patients with SMA. Myostatin, a member of the TGFβ superfamily of growth factors, is expressed primarily by skeletal muscle cells. The absence of its gene is associated with an increase in muscle mass and strength in multiple animal species. Scholar Rock believes the inhibition of the activation of myostatin with apitegromab may promote a clinically meaningful improvement in motor function.
A Phase 2 clinical trial in patients with Types 2 and 3 SMA is ongoing (NCT03921528). The U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation (ODD) and Rare Pediatric Disease (RPD) designation to apitegromab for the treatment of SMA.