Scholar Rock reported on the recent progress and upcoming milestones for the TOPAZ Phase 2 clinical trial of SRK-015 in patients with Type 2 or 3 SMA, in the light of the COVID-19 pandemic.
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.
The company is committed to continuing the execution of the SRK-015 TOPAZ Phase 2 trial whilst having, as a primary focus, the safety and well-being of their patients, clinical investigators and employees. Despite uncertainty during these unprecedented times, Scholar Rock is planning for additional updates on the programme later this year.
Scholar Rock anticipates having interim efficacy and safety data from the TOPAZ Phase 2 Trial in the fourth quarter of 2020. COVID19-related restrictions have impacted patient access to clinical trial sites, which have led to missed or delayed doses or assessments (including efficacy) in some patients and has affected Scholar Rock’s ability to monitor trial data collected by sites. As a result, Scholar Rock now plans to report interim efficacy, safety, pharmacokinetic (PK), and pharmacodynamic (PD) results in the fourth quarter of 2020 for patients across the three cohorts who have progressed through at least six months of the treatment period. This is an approximately one quarter delay compared to the previous guidance of interim 6-month results in mid-2020.
As of 1st May 2020, the majority of patients have either completed, or are on track to complete, their 6-month visit for the interim efficacy and safety analysis. For patients who have had their 6-month visit impacted, Scholar Rock is working closely with clinical trial sites on scheduling, to minimise any additional delays in dosing and assessments.
Enrolment of the TOPAZ proof-of-concept trial was completed in January 2020. 58 patients with Type 2 or Type 3 SMA were enrolled across three cohorts:
- Cohort 1: 23 patients,
- Cohort 2: 15 patients,
- Cohort 3: 20 patients
To date, one patient (from Cohort 1) has discontinued the trial for reasons unrelated to the study drug. This occurred prior to the COVID-19 pandemic. As of 1st May 2020, 41 of 57 patients have completed the 6-month visit for the interim efficacy and safety analysis and 51 of 57 patients have completed the 5-month visit.
Approximately 70% of patients are enrolled in the U.S. and the remaining 30% of patients are enrolled in Europe (Italy, Spain, and the Netherlands). Top-line data for the 12-month treatment period are now expected in the first half of 2021 as compared to the previous guidance of the fourth quarter of 2020 and first quarter of 2021. There may be further impacts on the timing of future doses and assessments for patients in the trial, as the effects of the COVID-19 pandemic continue to evolve.