SHIELD Trial Results Announced for Symic Bio's SB-030 in Peripheral Vascular Disease
November 1, 2017—Symic Bio announced results from the phase 1/2 SHIELD trial evaluating SB-030, a locally administered therapeutic, in patients with peripheral vascular disease undergoing angioplasty. This is a first-in-human, prospective, randomized, single-blind controlled study of 67 patients.
According to the company, SB-030 demonstrated a positive safety profile, with no clinically meaningful difference observed in adverse events between treatment and control groups. In addition, treatment with SB-030 demonstrated the potential for improvements as compared with control across measurements of clinical efficacy in late lumen loss, target lesion revascularization, and primary patency rate.
Among per-protocol patients in the SHIELD trial at 24 weeks after treatment, SB-030 treatment demonstrated potential to improve angiographic measurements of vessel diameter relative to control, referred to as late lumen loss, with a 32% mean improvement that did not reach the level of statistical significance (P = .165).
The company noted that statistical assessment was impacted by a smaller than expected control arm, nonnormal data distribution, and a higher rate of bailout procedures in the control arm.
Bailout procedures, typically periprocedural stenting due to vasospasm, were required for 38% of patients in the control group as compared with 9% of patients in the SB-030 treatment group (P = .006). Nonparametric testing of the distribution of measurements in late lumen loss demonstrated a statistically significant difference between treatment and control groups (P = .018). SB-030 treatment also reduced the rate of target lesion revascularization by 22%. In addition, interim results from the extension phase of the study show promising trends for improved primary patency rate at 12 months. Safety assessments were confirmed by an independent medical monitor.
Andrew Holden, MBChB, one of the lead investigators in the SHIELD trial, commented in the company's announcement, "These results demonstrate clear potential for SB-030 in vascular disease, providing the first clinical proof of concept for this new mechanism. The promise of SB-030 in improving outcomes following vascular interventions is particularly striking given its unique mechanism of action and safety profile."
Symic Bio stated that these results support the company's plan to develop SB-030 as a first-in-class treatment to prevent vein graft failure following peripheral bypass graft surgery. The company intends to begin a phase 3 trial of SB-030 in the prevention of peripheral vein graft failure in 2018.
Michael Conte, MD, an investigator in the planned phase 3 study, stated, "The SHIELD trial provides clinically relevant data for SB-030 in patients with peripheral vascular disease. Loss of patency is associated with amputation in patients who undergo revascularization for advanced peripheral vascular disease. The outcomes observed in the SHIELD trial suggest a potential for SB-030 to improve vessel healing. Peripheral vein graft procedures are in serious need of innovative approaches to extend long-term patency, and SB-030 provides a technically and biologically attractive solution."