Fully 96 percent of the StrataGraft-treated burn sites across all patients did not require autografting.

Mallinckrodt plc’s StrataGraft (allogeneic cultured keratinocytes and dermal fibroblasts in murine collagen – dsat) may provide a much-needed alternative to autografting for patients with deep partial-thickness burns, a new study shows.

Fully 96 percent of the StrataGraft-treated burn sites across all patients did not require autografting, and 83.1 percent of patients with deep partial-thickness burns achieved durable wound closure by three months, according to Phase 3 clinical trial  As a reference, 86% of patients achieved durable wound closure of the autograft control sites. The significant reduction in use of autograft in patients treated with StrataGraft resulted in favorable outcomes in the secondary efficacy endpoints of donor site pain and donor site cosmesis (preservation or restoration of physical appearance), the study showed. Additionally, cosmesis at the StrataGraft and autograft treatment sites was clinically similar at 12 months.

StrataGraft contains metabolically active cells that produce and secrete a variety of growth factors and cytokines. StrataGraft is intended to be applied in appropriate aseptic conditions, such as the operating room, and can be sutured, stapled or secured with a tissue adhesive.

The data were published in Burns.

Safety results showed the most common treatment-emergent adverse event (TEAE) was pruritus at the treatment site, which occurred in 36.6 percent of patients and was causally related to StrataGraft treatment in 11 patients. All TEAEs related to StrataGraft treatment were mild to moderate in severity. Hypertrophic scarring (HTS) occurred at the StrataGraft treatment site in 12.7 percent of patients, and 4.2 percent of patients had HTS determined by the investigator to be causally related to StrataGraft treatment.

"Surgical advances have improved survival rates in patients with severe burns. However, new treatments are needed that can help reduce or eliminate autografting, as the need to harvest healthy skin tissue can lead to pain, itching, scarring and impaired function at the donor site," says James H. Holmes, IV, M.D., Co-Lead Investigator of STRATA2016 and Professor, Trauma Surgery, Wake Forest School of Medicine, in a news release. "We were encouraged to see in the Phase 3 trial that treatment with StrataGraft eliminated donor tissue harvest in all but three of the 71 study participants. Now that StrataGraft is approved, burn surgeons have an alternative biologic treatment option for patients with deep partial-thickness burns."

About the study

The open-label, controlled, randomized, multicenter Phase 3 clinical trial evaluated the efficacy and safety of a single application of StrataGraft in the treatment of deep partial-thickness thermal burns. The trial enrolled 71 patients at 12 burn centers across the United States. Eligible patients were age 18 years and older and had thermal burns comprising 3 percent to 49 percent total body surface area involving the torso or upper or lower extremities for which surgical excision and autografting were clinically indicated. The study design used an intra-patient comparator, in which two similar areas of burn injury on the same patient were randomly assigned to either StrataGraft treatment or autograft.

The co-primary endpoints were the difference in the percent area of the StrataGraft treatment site and the control autograft treatment site that was autografted by three months and the proportion of patients achieving durable wound closure of the StrataGraft treatment site without autograft placement at three months. Secondary endpoints assessed donor site pain, donor site cosmesis and treatment site cosmesis.

Mallinckrodt is currently conducting a StrataGraft continued access clinical trial (StrataCAT, NCT04123548) under an Expanded Access Program (EAP). The trial sites involved in the pivotal Phase 3 trial (STRATA2016, NCT03005106) have the opportunity to participate in this multicenter, open-label study. The company is planning to evaluate StrataGraft for the treatment of adults with full-thickness burns (also referred to as third-degree burns). Additionally, Mallinckrodt plans to conduct a study evaluating StrataGraft in the treatment of pediatric populations.