Scholar Rock reported on interim analysis results from their TOPAZ clinical trial to evaluate the safety and efficacy of SRK-015 in people with SMA Types 2 and 3.
SRK-015 is a muscle-directed therapy that aims to reverse or restrict the muscle atrophy and weakness experienced by SMA patients. The drug is an antibody that very specifically targets an important protein called myostatin.
TOPAZ is evaluating SRK-015, mostly in conjunction with SMN up-regulator therapy nusinersen, across three cohorts, using motor function scales to measure meaningful endpoints.
58 individuals with Type 2 and Type 3 SMA were recruited in January 2020. The key findings from the 6-month interim analysis include:
- Improvements in motor function, as measured by Hammersmith Scales, were observed in all three evaluated cohorts:
- Cohort 1 evaluated SRK-015 as a single therapy or in conjunction with nusinersen in individuals with ambulatory Type 3 SMA.
- Cohort 2 evaluated SRK-015 in conjunction with nusinersen in individuals with Type 2 or non-ambulatory Type 3 SMA.
- Cohort 3 evaluated SRK-015 in individuals with Type 2 SMA and had initiated treatment with nusinersen before 5 years of age.
- No safety and tolerability concerns for SRK-015 were identified from this interim analysis.
Scholar Rock believes that these findings demonstrate initial proof-of-concept of the therapeutic potential of SRK-015 in Types 2 and 3 SMA.