Pooled safety analysis of STRATA2011 and STRATA2016 clinical trials evaluating the use of StrataGraft® in patients with deep partial-thickness thermal burns.

OBJECTIVE: This analysis includes pooled safety data from 2 clinical trials (NCT01437852; NCT03005106) that evaluated the safety and efficacy of StrataGraft in patients with deep partial-thickness (DPT) burns. METHODS: The study enrolled 101 adult patients with thermal burns covering 3-49% of total body surface area. Patients were followed for up to 1 year. The pooled safety events included: adverse events (AEs), adverse reactions (ARs), serious AEs (SAEs), discontinuation, and deaths; immunological responses (reactivity to panel reactive antibodies [PRA] and human leukocyte antigen [HLA] class 1 alleles); and persistence of allogeneic DNA from StrataGraft. RESULTS: Eighty-seven (86.1%) patients experienced 397 AEs. Thirty patients (29.7%) experienced ARs; 16 patients (15.8%) experienced SAEs. The most frequent AEs were pruritus (n = 31; 30.7%), and blister, hypertension, and hypertrophic scar (n = 11 each; 10.9%); the most common AR was pruritus (n = 13; 12.9%). One patient discontinued the study; 2 patients experienced SAEs (unrelated to StrataGraft) leading to death. PRA and HLA allele reactivity was ≤ 25% at Month 3, with no persistent allogeneic DNA from StrataGraft. CONCLUSIONS: StrataGraft was well tolerated by patients, with a safety profile similar to autograft. StrataGraft may offer a safe alternative to autograft for DPT burns.

A phase 3, open-label, controlled, randomized, multicenter trial evaluating the efficacy and safety of StrataGraft® construct in patients with deep partial-thickness thermal burns.

OBJECTIVE: This phase 3 study evaluated StrataGraft construct as a donor-site sparing alternative to autograft in patients with deep partial-thickness (DPT) burns. METHODS: Patients aged ≥18 years with 3-49% total body surface area (TBSA) thermal burns were enrolled. In each patient, 2 DPT areas (≤2000cm2 total) of comparable depth after excision were randomized to either cryopreserved StrataGraft or autograft. Coprimary endpoints were: the difference in percent area of StrataGraft treatment site and autograft treatment site autografted at Month 3 (M3), and the proportion of patients achieving durable wound closure of the StrataGraft site without autograft at M3. Safety assessments were performed in all patients. Efficacy and safety follow-up continued to 1 year. RESULTS: Seventy-one patients were enrolled. By M3, there was a 96% reduction in mean percent area of StrataGraft treatment sites that required autografting, compared with autograft treatment sites (4.3% vs 102.1%, respectively; P<.0001). StrataGraft treatment resulted in durable wound closure at M3 without autografting in 92% (95% CI: 85.6, 98.8; n/n 59/64) of patients for whom data were available. The most common StrataGraft-related adverse event was pruritus (15%). CONCLUSIONS: Both coprimary endpoints were achieved. StrataGraft may offer a new treatment for DPT burns to reduce the need for autografting. CLINICAL TRIAL IDENTIFIER: NCT03005106.

Navigating the Regulatory Pathways and Requirements for Tissue-Engineered Products in the Treatment of Burns in the United States.

In the burn treatment landscape, a variety of skin substitutes, human tissue-sourced products, and other products are being developed based on tissue engineering (ie, the combination of scaffolds, cells, and biologically active molecules into functional tissue with the goal of restoring, maintaining, or improving damaged tissue or whole organs) to provide dermal replacement, prevent infection, or prevent or mitigate scarring. Skin substitutes can have a variety of compositions (cellular vs acellular), origins (human, animal, or synthetically derived), and complexities (dermal or epidermal only vs composite). The regulation of tissue-engineered products in the United States occurs by one of several pathways established by the U.S. Food and Drug Administration, including a Biologics License Application (BLA), a 510(k) (Class I and Class II devices), Premarket Approval (Class III devices), or a human cells, tissues, and cellular and tissue-based products designation. Key differentiators among these regulatory classifications include the amount and type of data required to support a filing. For example, a BLA requires a clinical trial(s) and evaluation of safety and efficacy by the Center for Biologics Evaluation and Research. Applicable approved biological products must also comply with submission of advertising and promotional materials per regulations. This review provides a description of, and associated requirements for, the various regulatory pathways for the approval or clearance of tissue-engineered products. Some of the regulatory challenges for commercialization of such products for the treatment of burns will be explored.

Determining clinically meaningful thresholds for innovative burn care products to reduce autograft: A US burn surgeon Delphi panel.

Reducing the amount of donor skin needed for definitive wound closure can improve outcomes in patients with severe burns. This Delphi Consensus Panel (DCP) aimed to achieve expert consensus on the percentage reduction in donor skin for autograft that constitutes a clinically meaningful benefit. A two-round DCP of fifteen US burn surgeons was conducted via a web-based survey platform. Fourteen panelists (93.3%) completed both rounds. In Round 2, consensus, defined as ≥70% agreement, was achieved for five of the seven consensus statements. All panelists agreed that a clinically meaningful reduction in the amount of donor skin required would facilitate wound management and decrease donor site morbidity experienced by patients. Furthermore, based on three treatment scenarios, consensus was achieved for a clinically meaningful reduction in the amount of donor skin required for autograft for the adult population in deep partial-thickness and full-thickness burns. Findings from this DCP indicate that an innovative cellular and/or tissue product that would reduce the needed amount of donor skin, by the identified thresholds, has the potential to improve the outcomes for patients with severe burn injuries in a meaningful way.

Healthcare resource utilization, treatment patterns, and cost of care among patients with thermal burns and inpatient autografting in two large privately insured populations in the United States.

The current standard of care for severe burns includes autografting; however, there is scarce knowledge regarding the long-term economic burden associated with thermal burns and inpatient autografting. The objective of this study was to characterize healthcare resource utilization, treatment patterns, and cost of care for thermal burn patients in two large privately insured populations in the United States who underwent inpatient autografting between 01/01/2011 and 06/30/2016. Patient demographics, clinical characteristics, healthcare resource utilization, and total cost were examined during baseline (one year before the initial hospitalization with autografting) and two-year evaluation period. There was a substantial economic burden on thermal burn patients who received inpatient autografts (HIRD® database [HIRD]: N=371, mean age=39.6 years, male=67.1%; MarketScan® database [MarketScan]: N=698, mean age=38.2 years, male=63.3%) in the year 1 evaluation period (HIRD: mean=$184,805; MarketScan: mean=$155,272), which was mainly driven by the initial hospitalization with autografting (HIRD: mean=$157,384 and MarketScan: mean=$131,470). The percentage of patients with burn-related healthcare resource utilization and average burn-related costs were considerably reduced in the year 2 evaluation period (HIRD: mean=$3020; MarketScan: mean=$1990). Consistent with previous studies, mean length of hospital stay (days) and mean total medical costs generally increased as the percentage of total body surface area burned increased.

Modulation of Cell Attachment, Proliferation, and Angiogenesis by Decellularized, Dehydrated Human Amniotic Membrane in In Vitro Models.

BACKGROUND: Decellularized, dehydrated human amniotic membrane (DDHAM) is an extracellular matrix devoid of cells, cell debris, and growth factors. This study examines the effect of cell attachment to the DDHAM and the induced cellular responses. MATERIALS AND METHODS: The cell types employed in this study were human dermal fibroblasts (HDF), human epithelial keratinocytes (HEK), and human dermal microvascular endothelial cells (HDMEC), all of which play critical roles in the wound healing process. Further, the DDHAM was compared to a dehydrated human amnion/chorion membrane (dHACM), which contains and releases biological entities including growth factors and cytokines. The HDF and HEK were cultured on the DDHAM and the dHACM, and cell imaging and proliferation assays were performed to evaluate cell attachment to and the ability to proliferate on the DDHAM relative to the dHACM. In addition, the effect of soluble factors released by the DDHAM and the dHACM on cell survival, attachment, and proliferation were examined. The authors also evaluated the effect of soluble factors produced by culturing cells on the DDHAM in in vitro functional assays, including cell survival and endothelial cell migration in a wound closure angiogenesis assay. RESULTS: The HDF and HEK cells readily attached to and proliferated on the DDHAM, while the dHACM did not support cell attachment and proliferation when cultured under the same conditions. Soluble factors secreted when HDF were cultured on the DDHAM enhanced both endothelial cell and keratinocyte survival and endothelial cell migration in a wound closure assay. CONCLUSIONS: Although DDHAM is only an extracellular matrix and serves primarily as a scaffold, it has sufficient cues to allow for cell attachment and proliferation. Further, the biological entities released as a consequence of cell attachment promote cell survival and migration.

Real-world Experience With a Decellularized Dehydrated Human Amniotic Membrane Allograft.

UNLABELLED: While randomized controlled trials (RCTs) are designed to evaluate efficacy and/or safety under controlled conditions, use of strict inclusion/ exclusion criteria are noted to exclude more than 50% of wound populations. Applicability of RCT outcomes to performance expectations in real-world wound populations raises questions about generalizing their results. The primary aim of this decellularized, dehydrated human amniotic membrane (DDHAM) Use Registry Study was to gain experience and observe outcomes with use of a DDHAM in uninfected, full-thickness, or partial-thickness wounds that, in the investigators' opinions, would benefit from such treatment. METHODS: Investigators were instructed to provide usual care regarding visit and application frequencies, concomitant therapies, and change in wound-care regimens. The only exclusions were patients with actively infected wounds or known hypersensitivity to DDHAM. Fifteen sites with practicing wound care clinicians of various specialties participated in this review, enrolling chronic wounds including venous, diabetic, pressure, collagen vascular, and arterial ulcers-all of various severities, durations, sizes, and previous treatments. Twenty-eight ulcers studied had failed 32 previous treatments with advanced biologic therapies. A total of 244 wounds were observed in this study, however, this review is limited to the 179 chronic wounds in 165 patients that were enrolled at 15 of the 19 participating centers. The 4 centers that enrolled acute wounds only were excluded. RESULTS: Results from the analysis of this very heterogeneous population demonstrated that during the usual course of an average of 8 weeks of wound management, patients experienced factors that significantly affected wound closure. These factors included wound infections, noncompliance with prescribed treatments (eg, compression, off-loading, and wound care), re-injury of the wound, and systemic comorbidities. Nearly 50% of chronic wounds (including those that failed previous therapy with advanced biologics) with an average baseline area of 3.1 cm2 achieved complete closure within a median of 6.3 weeks without product-related adverse experiences. CONCLUSION: Despite the challenges of uncontrolled factors that affect healing, this registry study demonstrated the safety and clinical benefit of DDHAM to support wound closure across a variety of chronic wound types and patient conditions in real-world environments.

The detection of anti-erythropoietin antibodies in human serum and plasma. Part I. Validation of the protocol for a radioimmunoprecipitation assay.

Rare cases of unexplained sudden severe anemia or red cell aplasia and resistance to recombinant human erythropoietin (rHuEPO) in patients with chronic renal failure (CRF) have been attributed to the development of anti-EPO antibodies. The development and validation of a radioimmunoprecipitation (RIP) assay to detect human anti-EPO antibodies in serum or plasma has been hampered by the lack of purified antibody to fully characterize and validate the assay. We have prepared an affinity-purified human antibody to EPO and used the antibody to characterize and validate a sensitive and reproducible RIP assay that can qualitatively measure anti-EPO antibody in serum or plasma samples. The lower limit of detection of the assay is 8 ng/ml of purified antibody. The threshold for detecting antibody is > or =0.9% cpm bound. The precision of the assay using purified antibody standards ranges from 5.8% to 15.3% and the precision of the assay using dilutions of the positive control ranges from 15.9% to 18.7%. EPO in the samples did not interfere with detection of the anti-EPO antibody except at high concentrations.

A meta-analytic approach to an integrated summary of efficacy: a case study of becaplermin gel.

This paper presents a case study involving a meta-analytic approach for an integrated summary of efficacy based upon four phase II and III clinical trials that comprised the basis for a Biologics License Application to the U.S. Food and Drug Administration for approval of becaplermin gel. There were substantial variations in observed response rates across the four studies that were of concern to regulatory agencies. Due to these variations and because there were various treatment combinations in the four trials, standard statistical methods for an integrated analysis of efficacy were problematic. A meta-analytic model that focused on the variations of concern was employed to permit a suitable integrated analysis. The resulting integrated analysis clarified response rate variability and provided accurate estimates of treatment effects based upon the four clinical trials. While this meta-analysis was viewed by neither regulators nor the sponsor as a confirmatory analysis, it was seen by both regulators and sponsor as strongly supportive of the efficacy of becaplermin gel.