Scholar Rock Announces Encouraging Interim Data from the TOPAZ Phase 2 Trial of SRK-015

28 October 2020

Scholar Rock reported on interim 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 across three cohorts using motor function scales to measure meaningful endpoints. Most patients in the trial are also receiving the SMN-dependent therapy nusinersen as part of their normal therapeutic regime; the TOPAZ trial will therefore help to determine whether a combination of therapies can better treat SMA than nusinersen alone.

58 individuals with SMA Types 2 and Type 3 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 SMA Type 3.
  • Cohort 2 evaluated SRK-015 in conjunction with nusinersen in individuals with Type 2 or non-ambulatory SMA Type 3.
  • Cohort 3 evaluated SRK-015 in individuals with SMA Type 2 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 the therapeutic potential of SRK-015 in SMA Types 2 and 3.

Further information

About SRK-015
The press release
SRK-015 clinical trial updates