# SUMMARY OF SAFETY AND EFFECTIVENESS DATA

## GENERAL INFORMATION 

**[Device Generic Name]{.underline}:** Interactive Wound Dressing

**[Device Trade Name]{.underline}:** DERMAGRAFT^®^

**[Applicant's Name and Address]{.underline}**: Advanced Tissue
Sciences, Inc.

10933 North Torrey Pines Road

La Jolla, California 92037-1005

**[Premarket Approval]{.underline}**

**[Application (PMA):]{.underline}** P000036

**[Date of Panel Recommendation:]{.underline}** Not applicable

**[Date of Notice of Approval]{.underline}**

**[of Application:]{.underline}** September 28, 2001

## INTENDED USE/INDICATIONS

DERMAGRAFT^®^ is indicated for use for the treatment of full-thickness
diabetic foot ulcers greater than six weeks duration which extend
through the dermis, but without tendon, muscle, joint capsule or bone
exposure. DERMAGRAFT^®^ should be used in conjunction with standard
wound care regimens and in patients that have adequate blood supply to
the involved foot.

## DEVICE DESCRIPTION

DERMAGRAFT^®^ is a cryopreserved human fibroblast-derived dermal
substitute; it is composed of fibroblasts, extracellular matrix, and a
bioabsorbable scaffold. DERMAGRAFT is manufactured from human fibroblast
cells derived from newborn foreskin tissue. During the manufacturing
process, the human fibroblasts are seeded onto a bioabsorbable
polyglactin mesh scaffold. The fibroblasts proliferate to fill the
interstices of this scaffold and secrete human dermal collagen, matrix
proteins, growth factors and cytokines, to create a three‑dimensional
human dermal substitute containing metabolically active, living cells.
DERMAGRAFT does not contain macrophages, lymphocytes, blood vessels, or
hair follicles.

The human fibroblast cells are from a qualified cell bank, which has
been extensively tested for animal viruses, retroviruses, cell
morphology, karyology, isoenzymes, and tumorigenicity. Reagents used in
the manufacture of DERMAGRAFT are tested and found free from viruses,
retroviruses, endotoxins, and mycoplasma before use. DERMAGRAFT is
manufactured with sterile components under aseptic conditions within the
final package. Prior to release for use, each lot of DERMAGRAFT must
pass USP Sterility (14‑day), endotoxin, and mycoplasma tests. In
addition, each lot meets release specifications for collagen content,
DNA, and cell viability. Maternal blood sera is tested for evidence of
infection with human immunodeficiency virus type 1 (HIV-1), human
immunodeficiency virus type 2 (HIV-2), hepatitis B virus, (HBV),
hepatitis C virus (HCV), syphilis, human T‑lymphotropic virus type 1
(HTLV-1), and found negative for the purposes of donor selection. During
subsequent screening of the fibroblast cell strain at various stages in
the manufacturing process, testing for these same viruses, as well as
Epstein-Barr virus (EBV) and human T-lymphotropic virus type 2 (HTLV-2),
is carried out and found to be negative.

DERMAGRAFT is supplied frozen in a clear bag containing one piece of
approximately 2 in x 3 in (5 cm x 7.5 cm) for a single-use application.

**IV. CONTRAINDICTIONS**

-   DERMAGRAFT is contraindicated for use in ulcers that have signs of
    clinical infection or in ulcers with sinus tracts.

```{=html}
<!-- -->
```
-   DERMAGRAFT is contraindicated for use in patients with known
    hypersensitivity to bovine products, as it may contain trace amounts
    of bovine proteins from the manufacturing medium and storage
    solution.

The warnings and precautions can be found in the DERMAGRAFT labeling,
which is available on the FDA web site at
*http://www.fda.gov/CDRH/pdf/p000036.pdf.*

**V. ALTERNATIVE PRACTICES AND PROCEDURES**

Alternative therapies include debridement of necrotic tissue, which can
significantly reduce bacterial colonization of the ulcer, and saline
moistened dressings. Excessive pressure at the ulcer site is alleviated
with the use of special pressure relieving inserts or orthotics.
Decisions of what treatments are necessary for ulcers are affected by
the results of a vascular evaluation of the patient. If vascular supply
is insufficient, surgical procedures may be necessary, including
arterial bypass grafting. If the vascular supply is sufficient, the most
common therapy for ulcers is debridement and wound dressing, as
described above.

**VI. POTENTIAL ADVERSE EFFECTS**

A total of 695 patients were evaluated in four clinical trials, 389
treated with DERMAGRAFT, and 306 treated with Control. Adverse events
that were reported in the pivotal 314-patient clinical trial at a
frequency of greater than 1% for patients treated with DERMAGRAFT are
presented in Table 1. Adverse Event data are also presented, combined,
from three previous studies.

**Table 1**

# Adverse Events Reported in Greater than 1%

**of Patients Treated with DERMAGRAFT**

+---------------------------+---------+---------+---------+---------+
| **Event**                 | **      |         | **P     |         |
|                           | Pivotal |         | revious |         |
|                           | Study** |         | St      |         |
|                           |         |         | udies** |         |
+---------------------------+---------+---------+---------+---------+
|                           | **DERMA | **Co    | **DERMA | **Co    |
|                           | GRAFT** | ntrol** | GRAFT** | ntrol** |
|                           |         |         |         |         |
|                           | ####    | ####    | **N =   | **N =   |
|                           | N = 163 | N = 151 | 226**   | 155**   |
|                           |         |         |         |         |
|                           | **n     | **n     | **n     | **n     |
|                           | (%)**   | (%)**   | (%)**   | (%)**   |
+---------------------------+---------+---------+---------+---------+
| Infection (study          | 17      | 27      | 63      | 43      |
| wound)^1^                 | (10.4)  | (17.9)  | (27.9)  | (27.7)  |
+---------------------------+---------+---------+---------+---------+
| Infection (non-study      | 17      | 14      | 33      | 22      |
| wound)                    | (10.4)  | (9.3)   | (14.6)  | (14.2)  |
+---------------------------+---------+---------+---------+---------+
| Accidental injury^2^      | 17      | 18      | 17      | 11      |
|                           | (10.4)  | (11.9)  | (7.5)   | (7.1)   |
+---------------------------+---------+---------+---------+---------+
| Skin dysfunction/Blister  | 16      | 20      | 38      | 31      |
|                           | (9.8)   | (13.2)  | (16.8)  | (20.0)  |
+---------------------------+---------+---------+---------+---------+
| Flu syndrome              | 15      | 9 (6.0) | 7 (3.1) | 8 (5.2) |
|                           | (9.2)   |         |         |         |
+---------------------------+---------+---------+---------+---------+
| Osteomyelitis (study      | 14      | 13      | 17      | 8 (5.2) |
| wound)                    | (8.6)   | (8.6)   | (7.5)   |         |
+---------------------------+---------+---------+---------+---------+
| Surgeries involving study | 13      | 21      | 35      | 13      |
| ulcer^3^                  | (8.0)   | (13.9)  | (15.5)  | (8.4)   |
+---------------------------+---------+---------+---------+---------+
| Wound enlargement/Skin    | 12      | 17      | 30      | 16      |
| ulcer (non-study wound)   | (4.0)   | (11.3)  | (13.3)  | (10.3)  |
+---------------------------+---------+---------+---------+---------+
| Cellulitis (study wound)  | 12      | 14      | 25      | 10      |
|                           | (7.4)   | (9.3)   | (11.1)  | (6.5)   |
+---------------------------+---------+---------+---------+---------+
| Cellulitis (non-study     | 10      | 7 (4.6) | 15      | 13      |
| wound)                    | (6.1)   |         | (6.6)   | (8.4)   |
+---------------------------+---------+---------+---------+---------+
| Peripheral                | 9 (5.5) | 7 (4.6) | 20      | 6 (3.9) |
| edema/Localized swelling  |         |         | (8.8)   |         |
+---------------------------+---------+---------+---------+---------+
| Pharyngitis/URI           | 7 (4.3) | 5 (3.3) | 13      | 11      |
|                           |         |         | (5.8)   | (7.1)   |
+---------------------------+---------+---------+---------+---------+
| Pain                      | 6 (3.7) | 5 (3.3) | 24      | 12      |
|                           |         |         | (10.6)  | (7.7)   |
+---------------------------+---------+---------+---------+---------+
| Lab test                  | 6 (3.7) | 5 (3.3) | 37      | 31      |
| abnormal-chemistry^4^     |         |         | (16.4)  | (20.0)  |
+---------------------------+---------+---------+---------+---------+
| Skin disorder^5^          | 5 (3.1) | 4 (2.6) | 0 (0.0) | 0 (0.0) |
+---------------------------+---------+---------+---------+---------+
| Osteomyelitis (non-study  | 5 (3.1) | 2 (1.3) | 10      | 6 (3.9) |
| wound)                    |         |         | (4.4)   |         |
+---------------------------+---------+---------+---------+---------+
| Wound enlargement/Skin    | 4 (2.5) | 8 (5.3) | 12      | 15      |
| ulcer (study wound)       |         |         | (5.3)   | (9.7)   |
+---------------------------+---------+---------+---------+---------+
| Urinary tract infection   | 4 (2.5) | 1 (0.7) | 7 (3.1) | 6 (3.9) |
+---------------------------+---------+---------+---------+---------+
| Diarrhea                  | 4 (2.5) | 5 (3.3) | 4 (1.8) | 3 (1.9) |
+---------------------------+---------+---------+---------+---------+
| Rash                      | 3 (1.8) | 2 (1.3) | 4 (1.8) | 4 (2.6) |
+---------------------------+---------+---------+---------+---------+
| Myocardial infarct        | 3 (1.8) | 0 (0.0) | 0 (0.0) | 4 (2.6) |
+---------------------------+---------+---------+---------+---------+
| Fever                     | 3 (1.8) | 0 (0.0) | 8 (3.5) | 3 (1.9) |
+---------------------------+---------+---------+---------+---------+
| Allergic reaction         | 3 (1.8) | 1 (0.7) | 1 (0.4) | 1 (0.6) |
+---------------------------+---------+---------+---------+---------+
| Rhinitis                  | 2 (1.2) | 1 (0.7) | 2 (0.9) | 2 (1.3) |
+---------------------------+---------+---------+---------+---------+
| Nail disorder             | 2 (1.2) | 3 (2.0) | 1 (0.4) | 3 (1.9) |
+---------------------------+---------+---------+---------+---------+
| Myalgia                   | 2 (1.2) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
+---------------------------+---------+---------+---------+---------+
| Joint disorder            | 2 (1.2) | 1 (0.7) | 1 (0.4) | 0 (0.0) |
+---------------------------+---------+---------+---------+---------+
| Headache                  | 2 (1.2) | 1 (0.7) | 3 (1.3) | 3 (1.9) |
+---------------------------+---------+---------+---------+---------+
| Gastrointestinal disorder | 2 (1.2) | 3 (2.0) | 0 (0.0) | 1 (0.6) |
+---------------------------+---------+---------+---------+---------+
| Chest pain                | 2 (1.2) | 1 (0.7) | 4 (1.8) | 5 (3.2) |
+---------------------------+---------+---------+---------+---------+
| Anemia                    | 2 (1.2) | 0 (0.0) | 4 (1.8) | 0 (0.0) |
+---------------------------+---------+---------+---------+---------+
| Bronchitis                | 1 (0.6) | 1 (0.7) | 7 (3.1) | 1 (0.6) |
+---------------------------+---------+---------+---------+---------+
| Eccymosis                 | 1 (0.6) | 0 (0.0) | 5 (2.2) | 0 (0.0) |
+---------------------------+---------+---------+---------+---------+
| Sinusitis                 | 1 (0.6) | 0 (0.0) | 4 (1.8) | 3 (1.9) |
+---------------------------+---------+---------+---------+---------+
| Neuropathy                | 1 (0.6) | 0 (0.0) | 4 (1.8) | 0 (0.0) |
+---------------------------+---------+---------+---------+---------+
| Nausea                    | 1 (0.6) | 2 (1.3) | 4 (1.8) | 1 (0.6) |
+---------------------------+---------+---------+---------+---------+
| Dyspnea                   | 1 (0.6) | 1 (0.7) | 4 (1.8) | 0 (0.0) |
+---------------------------+---------+---------+---------+---------+
| Vomiting                  | 1 (0.6) | 1 (0.7) | 3 (1.3) | 2 (1.3) |
+---------------------------+---------+---------+---------+---------+
| Sepsis/Septicemia         | 1 (0.6) | 1 (0.7) | 3 (1.3) | 0 (0.0) |
+---------------------------+---------+---------+---------+---------+
| Gastroenteritis           | 1 (0.6) | 0 (0.0) | 3 (1.3) | 1 (0.6) |
+---------------------------+---------+---------+---------+---------+
| Chills                    | 1 (0.6) | 0 (0.0) | 3 (1.3) | 3 (1.9) |
+---------------------------+---------+---------+---------+---------+
| Cataract                  | 1 (0.6) | 0 (0.0) | 3 (1.3) | 1 (0.6) |
+---------------------------+---------+---------+---------+---------+
| Angina pectoris           | 1 (0.6) | 0 (0.0) | 3 (1.3) | 3 (1.9) |
+---------------------------+---------+---------+---------+---------+
| Wound drainage            | 0 (0.0) | 0 (0.0) | 11      | 5 (3.2) |
|                           |         |         | (4.9)   |         |
+---------------------------+---------+---------+---------+---------+
| Cerebrovascular accident  | 0 (0.0) | 0 (0.0) | 7 (3.1) | 1 (0.6) |
+---------------------------+---------+---------+---------+---------+
| Congestive heart failure  | 0 (0.0) | 3 (2.0) | 6 (2.7) | 1 (0.6) |
+---------------------------+---------+---------+---------+---------+
| Cough increased           | 0 (0.0) | 2 (1.3) | 5 (2.2) | 2 (1.3) |
+---------------------------+---------+---------+---------+---------+
| Back pain                 | 0 (0.0) | 1 (0.7) | 5 (2.2) | 4 (2.6) |
+---------------------------+---------+---------+---------+---------+
| Peripheral vascular       | 0 (0.0) | 0 (0.0) | 4 (1.8) | 0 (0.0) |
| disorder                  |         |         |         |         |
+---------------------------+---------+---------+---------+---------+
| Retinal                   | 0 (0.0) | 0 (0.0) | 3 (1.3) | 1 (0.6) |
| disorder/Retinopathy      |         |         |         |         |
+---------------------------+---------+---------+---------+---------+
| Neoplasm^5^               | 0 (0.0) | 0 (0.0) | 3 (1.3) | 1 (0.6) |
+---------------------------+---------+---------+---------+---------+
| Lab test abnormal --      | 0 (0.0) | 0 (0.0) | 3 (1.3) | 2 (1.3) |
| urinalysis                |         |         |         |         |
+---------------------------+---------+---------+---------+---------+
| Cyst                      | 0 (0.0) | 0 (0.0) | 3 (1.3) | 1 (0.6) |
+---------------------------+---------+---------+---------+---------+
| Asthenia                  | 0 (0.0) | 0 (0.0) | 3 (1.3) | 0 (0.0) |
+---------------------------+---------+---------+---------+---------+

^1^ Infections include all local wound infections, regardless of
etiology (e.g. bacterial, fungal), not including osteomyelitis and
cellulitis.

^2^ Examples of verbatim codes included in this category are:
laceration, foreign body in eye, head injury, dislocation of hip, coccyx
fracture post fall, skin tear, and burn right index finger.

^3^ Surgical procedures to the study ulcer are defined as any procedure
(i.e., surgical debridement more extensive than required by protocol,
incision and drainage, revision, excision, or amputation) that occurred
during the course of the study.

^4^ Pilot study codes to "Lab Tests Abnormal" and does not distinguish
between Chemistry, Hematology, and Urinalysis.

^5^ None of the events reported under "Skin disorder" involved the study
ulcer. Under "Neoplasm", none of the events reported involved the study
leg for the DERMAGRAFT-treated patients.

## MARKETING HISTORY

DERMAGRAFT has only been available in the United States as an
investigational device under IDE G900155. DERMAGRAFT for the treatment
of diabetic foot ulcers was approved for sale in Canada in August 1997.
DERMAGRAFT was introduced in the United Kingdom in October 1997, and
several other European countries, New Zealand and Australia. As of this
submission, the device is available for commercial distribution in
Australia, Canada, Finland, France, Hong Kong, Ireland, The Netherlands,
New Zealand, Singapore, and The United Kingdom.

## SUMMARY OF PRE-CLINICAL STUDIES

This section provides summaries of preclinical tests performed on
DERMAGRAFT. Table 2 describes the non-clinical laboratory studies and
has been divided into the following categories: Development and
Characterization, Immunology, and Toxicology studies. The studies
reported here include a range of topics assessing safety, device
attributes, practical aspects of device delivery, and potential clinical
issues.

**Table 2**

**Pre-clinical Studies with DERMAGRAFT**

  ----------------------------------- -----------------------------------
  **Study**                           **Results/Conclusions**

  **Development and                   
  Characterization**                  

  Assessment of the in vitro aging of No significant loss of
  fibroblasts in DERMAGRAFT           proliferative capacity before 45
                                      doublings was observed and cells
                                      continued to grow for approximately
                                      60 doublings. Fibroblasts used in
                                      the manufacture of DERMAGRAFT are
                                      within a region of the cultural
                                      life span in which synthetic and
                                      proliferative activities may be
                                      expected to be consistent.

  Evaluation of DERMAGRAFT cell banks Flow cytometric analyses
  for the presence of other cell      (fluorescence activated cell
  types                               sorting \[FACS\]) did not detect
                                      the presence of keratinocytes in
                                      the fibroblast cell banks.

  Feasibility Study - Grafting of a   Results showed incorporation of the
  Cultured Skin Equivalent grown on   grafts into the wounds and complete
  mesh framework (Nylon) into full    epithelialization. Histologic
  thickness wounds in Rats            examination revealed keratinocytes,
                                      fibroblasts, collagen, adipocytes
                                      and smooth muscle fibers arranged
                                      in a natural configuration around
                                      nylon mesh fibers.

  DERMAGRAFT as a Dermal Replacement  Evidence of the safety and
  in Mini-Pigs to determine if the    biocompatability of a device
  device cultured with human          cultured with human fibroblasts was
  fibroblasts would incorporate       established in a porcine model with
  safely into full thickness wounds.  implants over six months.

  Athymic Mouse Studies to support    Evaluated the ability of the device
  DERMAGRAFT in the treatment of full to support healing and
  thickness burn wounds and evaluate  re-epithelialization of meshed,
  the viability of DERMAGRAFT with    split-thickness human cadaver skin
  respect to wound healing            placed on surgically excised wounds
                                      in mice. Percent epithelialization
                                      (healing) via histological
                                      evaluation, graft take and
                                      vascularization rated on data
                                      sheets and sent to outside agency
                                      for statistical analysis.
  ----------------------------------- -----------------------------------

+-----------------------------------+-----------------------------------+
| **Development and                 |                                   |
| Characterization (cont'd.)**      |                                   |
+-----------------------------------+-----------------------------------+
| Stimulation of Angiogenesis in    | Three dimensional fibroblast      |
| the Chick Chorioallantoic         | cultures induced vessel           |
| Membrane (CAM) assay              | development in the CAM to a       |
|                                   | greater extent than control.      |
|                                   | Capillary development is          |
|                                   | characteristic of VEGF induced    |
|                                   | angiogenesis. Preincubation of    |
|                                   | the fibroblast culture with       |
|                                   | anti-VEGF neutralizing antibody   |
|                                   | reduced the angiogenic activity   |
|                                   | to control values.                |
+-----------------------------------+-----------------------------------+
| Angiogenesis in the Aortic Ring   | Aorta rings co-cultured with      |
| Assay                             | DERMAGRAFT demonstrated a         |
|                                   | significant increase in the       |
|                                   | number of microvessels formed     |
|                                   | (p=0.028).                        |
+-----------------------------------+-----------------------------------+
| Stimulation \[^3^H\]-thymidine    | Medium conditioned from three     |
| incorporation in cultures of      | dimensional fibroblast cultures   |
| Human Umbilical Vein Endothelial  | stimulated \[^3^H\]-thymidine     |
| Cells (HUVEC)                     | incorporation in cultures of      |
|                                   | HUVEC. The stimulation of         |
|                                   | \[^3^H\]-thymidine incorporation  |
|                                   | appeared to be dose dependent.    |
+-----------------------------------+-----------------------------------+
| Stimulation of Endothelial Cell   | Results demonstrate DERMAGRAFT    |
| Chemokinesis                      | stimulates endothelial cell       |
|                                   | migration.                        |
+-----------------------------------+-----------------------------------+
| Stimulation of Endothelial Cell   | Medium conditioned by DERMAGRAFT  |
| Chemotaxis                        | stimulated HUVEC migration.       |
+-----------------------------------+-----------------------------------+
| Inhibition of Endothelial Cell    | Microvascular endothelial cells   |
| Apoptosis                         | when co-cultured with DERMAGRAFT  |
|                                   | continued to proliferate and did  |
|                                   | not undergo apoptosis.            |
+-----------------------------------+-----------------------------------+
| Expression of Angiogenic Growth   | VEGF and HGF mRNA was expressed   |
| Factors                           | in DERMAGRAFT. Also detected were |
|                                   | PDGF A-chain, TGFβ~1~,G-CSF and   |
|                                   | angiopoietin I.                   |
+-----------------------------------+-----------------------------------+
| Splice Variants of VEGF in        | Splice variants of VEGF           |
| Fibroblasts                       | corresponding to the diffusable   |
|                                   | and extracellular matrix-binding  |
|                                   | forms of VEGF were detected in    |
|                                   | RNA isolated from DERMAGRAFT via  |
|                                   | PCR technique.                    |
+-----------------------------------+-----------------------------------+
| Induction of Integrin α~v~β~3~    | Medium conditioned by DERMAGRAFT  |
|                                   | stimulated a significant increase |
|                                   | in the expression of Integrin     |
|                                   | α~v~β~3~ in HUVEC.                |
+-----------------------------------+-----------------------------------+
| Detection of Growth Factors by    | VEGF, HGF, TGFβ~1~, and G-CSF     |
| ELISA                             | were detected in pg to low ng     |
|                                   | concentrations by ELISA in medium |
|                                   | conditioned by incubation with    |
|                                   | DERMAGRAFT.                       |
+-----------------------------------+-----------------------------------+
| Bovine Serum Albumin (BSA)        | Quantification of the residual    |
| Content of DERMAGRAFT Rinsing     | amounts of manufacturing          |
| Study                             | materials after the device is     |
|                                   | thawed and rinsed according to    |
|                                   | the Directions For Use (DFU).     |
|                                   | Using a Fluorescent Enzyme Linked |
|                                   | Immuno-Assay (FELISA) specific    |
|                                   | for BSA, 4.6 μg/2"x3" device and  |
|                                   | 9.1 μg/4"x6" device residual BSA  |
|                                   | was detected.                     |
+-----------------------------------+-----------------------------------+
| Tearing Strength Properties of    | Evaluated the critical tearing    |
| DERMAGRAFT                        | force of mesh substrate and       |
|                                   | DERMAGRAFT at various times in    |
|                                   | culture and freezing at -70°C and |
|                                   | -140°C. The time period in which  |
|                                   | mesh substrate, seeded with       |
|                                   | fibroblasts, maintains a degree   |
|                                   | of tear strength and structural   |
|                                   | integrity is two to three weeks.  |
|                                   | Components of the mesh substrate  |
|                                   | maintain integrity during product |
|                                   | storage.                          |
+-----------------------------------+-----------------------------------+
| Effects of Sterilization on the   | Quantified the changes in tensile |
| tensile properties of the mesh    | properties of mesh substrate      |
| substrate.                        | subjected to different radiation  |
|                                   | sterilization methods E-beam and  |
|                                   | Gamma radiation at low (3.0) and  |
|                                   | high doses (6.0 mrad) and to EtO  |
|                                   | sterilization. Mesh substrate     |
|                                   | should maintain the same level of |
|                                   | mechanical strength throughout    |
|                                   | the DERMAGRAFT manufacturing      |
|                                   | process regardless of             |
|                                   | sterilization process.            |
+-----------------------------------+-----------------------------------+
| **Immunology**                    |                                   |
+-----------------------------------+-----------------------------------+
| Persistence                       | PCR testing of biopsies in venous |
|                                   | ulcers detected DERMAGRAFT cells  |
|                                   | in human patients up to 6 months  |
|                                   | after implantation.               |
+-----------------------------------+-----------------------------------+
| Response of DERMAGRAFT to         | In scaffold-based (DERMAGRAFT)    |
| γ-interferon                      | three dimensional fibroblast cell |
|                                   | cultures, γ-interferon caused     |
|                                   | little induction of CD40 and      |
|                                   | HLA-DR antigens whereas all cells |
|                                   | upregulated the expression of HLA |
|                                   | I antigen. Fibroblast cells grown |
|                                   | on collagen gel or in monolayer   |
|                                   | culture, in contrast, upregulated |
|                                   | both the expression of HLA I, HLA |
|                                   | II and CD40 antigens in response  |
|                                   | to γ-interferon.                  |
+-----------------------------------+-----------------------------------+
| Immunogenicity                    | Immunogenicity via histological   |
|                                   | assessment displayed no findings  |
|                                   | suggestive of an immune response; |
|                                   | The potential for DERMAGRAFT to   |
|                                   | elicit an immune response was     |
|                                   | evaluated by examining the        |
|                                   | baseline and terminal sera of     |
|                                   | patients enrolled in a clinical   |
|                                   | trial for DERMAGRAFT using        |
|                                   | Western Blot technique. No        |
|                                   | clinically significant antibody   |
|                                   | response to DERMAGRAFT was        |
|                                   | observed in patients treated with |
|                                   | up to 8 pieces of DERMAGRAFT.     |
+-----------------------------------+-----------------------------------+
| ####### Toxicology Studies        |                                   |
|                                   |                                   |
| **(sterilized plastics and        |                                   |
| polymeric components that have    |                                   |
| direct or indirect product        |                                   |
| contact)**                        |                                   |
+-----------------------------------+-----------------------------------+
| Cytotoxicity                      | No reactivity. Non-cytotoxic.     |
+-----------------------------------+-----------------------------------+
| Intracutaneous Reactivity         | No reactivity. Non-irritant.      |
+-----------------------------------+-----------------------------------+
| Systemic Toxicity                 | No reactivity. Non-toxic.         |
+-----------------------------------+-----------------------------------+
| ####### Toxicology Studies        |                                   |
|                                   |                                   |
| **(DERMAGRAFT)**                  |                                   |
+-----------------------------------+-----------------------------------+
| Genotoxicity assays:              | Pass. Non-mutagenic.              |
|                                   |                                   |
| Ames Mutagenicity                 | Pass. Non-mutagenic.              |
|                                   |                                   |
| Mouse Lymphoma Mutagenesis        |                                   |
+-----------------------------------+-----------------------------------+
| Tumorigenicity                    | Evaluation of tumor formation of  |
|                                   | end of production stage           |
|                                   | fibroblasts in nude athymic mice  |
|                                   | revealed the cells to be          |
|                                   | non-tumorigenic.                  |
+-----------------------------------+-----------------------------------+
| **Stability/Shipping Studies**    |                                   |
+-----------------------------------+-----------------------------------+
| Stability of the device when      | Stability testing via assays to   |
| stored at --70.                   | evaluate the product following    |
|                                   | real-time aging. The device when  |
|                                   | stored at -70°C meets             |
|                                   | requirements for sterility and    |
|                                   | product specifications for        |
|                                   | periods up to seven months.       |
+-----------------------------------+-----------------------------------+
| Validation study to verify that   | Three consecutive qualified       |
| the manufacturing process         | validation lots passed initial    |
| consistently produces DERMAGRAFT. | release criteria and established  |
|                                   | a minimum of three months         |
|                                   | acceptable stability. Long term   |
|                                   | testing results establish         |
|                                   | stability of the product for up   |
|                                   | to six months when stored at      |
|                                   | -75°C [+]{.underline} 10°C was    |
|                                   | obtained.                         |
+-----------------------------------+-----------------------------------+
| Safe shipping of DERMAGRAFT       | Thermal, impact and airfreight    |
|                                   | shipping tests were conducted to  |
|                                   | assure storage temperature        |
|                                   | requirements are maintained and   |
|                                   | all product release criteria are  |
|                                   | met with respect to sterility,    |
|                                   | viability, collagen and DNA.      |
|                                   | DERMAGRAFT can be safely shipped  |
|                                   | to domestic and international     |
|                                   | shipping destinations.            |
+-----------------------------------+-----------------------------------+

  ----------------------------------- -----------------------------------
  **Stability/Shipping Studies**      

  Product Equivalency for Commercial  Demonstrated that product evaluated
  Scale Manufacturing                 in pilot and first pivotal clinical
                                      studies (4"x6") is equivalent to
                                      commercial scale (2"x3") product
                                      determined by similarity of
                                      critical product characteristics
                                      and process trends.
  ----------------------------------- -----------------------------------

The fibroblast cells, from which DERMAGRAFT is manufactured, are from
human infant foreskin tissue. A comprehensive medical history of the
mother is taken and maternal serum is screened for the presence of
HIV-1, HIV-2, HTLV-I, Hepatitis B core antigen, Hepatitis B surface
antigen, Hepatitis C, non-A/non-B Hepatitis (detection via Alanine
Aminotransferase (ALT) activity), Cytomegalovirus (CMV), and Syphilis.
Additionally, the human foreskin fibroblasts used to form DERMAGRAFT are
derived from cell banks which are tested for the presence of HIV-1,
HIV-2, HTLV-I, HTLV-II, Hepatitis B, Hepatitis C, Herpes Simplex Virus
(HSV) Types 1 and 2, CMV, Epstein Barr Virus (EBV), Adenovirus,
Adventitious Viral Contaminants (*In Vitro* and *In Vivo* Assays), virus
particles by Electron Microscopy (EM), retrovirus by RT-PCR, mycoplasma,
bacteria, and fungi.

Karyological analyses of the fibroblast cells used in manufacture of
DERMAGRAFT revealed a limited number of chromosomal changes. These same
cells did not exhibit a transformed phenotype in *in vitro* nor in *in
vivo* tumorigenicity assays. Cell growth characteristics, i.e.,
morphology, cell doubling time, and substratum adherence, were monitored
and judged to be consistent through end of production stage cells.
Isoenzyme purity analyses and DNA marker identification evaluations
indicated that the cell bank was from a sole donor.

Product manufacture includes the use of bovine calf serum (BCS). The BCS
is provided with a certificate of analysis documenting the viruses
screened for in the serum and that it is obtained from a Bovine
Spongiform Encephalopathy (BSE)-free country. The sponsor, upon receipt
of BCS, tests the serum for sterility, endotoxin and mycoplasma. The
serum is functionally assessed by a growth promotion test.

To maintain cell viability the product is aseptically manufactured, but
not terminally sterilized. DERMAGRAFT is shipped after quarantine
pending results of sterility (14 day), endotoxin and mycoplasma testing.

IX. **SUMMARY OF THE RESULTS OF THE CLINICAL INVESTIGATION**

Advanced Tissue Sciences, Inc. has conducted 5 trials in the
investigation of DERMAGRAFT as a human replacement dermis in the
treatment of diabetic foot ulcers. Table 3 summarizes the clinical
experience of DERMAGRAFT.

**Table 3**

#### Summary of Clinical Trial Experience with DERMAGRAFT

+---------------+---+---+-----------------+-----------+---+---------+------------+
| **Protocol    |   | * |                 | **Length  |   | **N     | **Number   |
| Number**      |   | * |                 | of        |   | umber** | of Devices |
|               |   | D |                 | Fo        |   |         | Applied**  |
|               |   | e |                 | llow-up** |   | **of    |            |
|               |   | s |                 |           |   | P       |            |
|               |   | c |                 |           |   | atients |            |
|               |   | r |                 |           |   | Enr     |            |
|               |   | i |                 |           |   | olled** |            |
|               |   | p |                 |           |   |         |            |
|               |   | t |                 |           |   |         |            |
|               |   | i |                 |           |   |         |            |
|               |   | o |                 |           |   |         |            |
|               |   | n |                 |           |   |         |            |
|               |   | * |                 |           |   |         |            |
|               |   | * |                 |           |   |         |            |
+---------------+---+---+-----------------+-----------+---+---------+------------+
| DG-04-02-0293 | F |   |                 | 12 Weeks  |   | 50      | 177        |
|               | e |   |                 |           |   |         |            |
|               | a |   |                 |           |   |         |            |
|               | s |   |                 |           |   |         |            |
|               | i |   |                 |           |   |         |            |
|               | b |   |                 |           |   |         |            |
|               | i |   |                 |           |   |         |            |
|               | l |   |                 |           |   |         |            |
|               | i |   |                 |           |   |         |            |
|               | t |   |                 |           |   |         |            |
|               | y |   |                 |           |   |         |            |
+---------------+---+---+-----------------+-----------+---+---------+------------+
| DG-04-04-0694 | P |   |                 | 32 Weeks  |   | 281     | 925        |
|               | i |   |                 |           |   |         |            |
|               | v |   |                 |           |   |         |            |
|               | o |   |                 |           |   |         |            |
|               | t |   |                 |           |   |         |            |
|               | a |   |                 |           |   |         |            |
|               | l |   |                 |           |   |         |            |
|               | I |   |                 |           |   |         |            |
+---------------+---+---+-----------------+-----------+---+---------+------------+
| DG-04-04-0694 | S |   |                 | 32 Weeks  |   | 50      | 323        |
|               | u |   |                 |           |   |         |            |
|               | p |   |                 |           |   |         |            |
|               | p |   |                 |           |   |         |            |
|               | l |   |                 |           |   |         |            |
|               | e |   |                 |           |   |         |            |
|               | m |   |                 |           |   |         |            |
|               | e |   |                 |           |   |         |            |
|               | n |   |                 |           |   |         |            |
|               | t |   |                 |           |   |         |            |
|               | a |   |                 |           |   |         |            |
|               | r |   |                 |           |   |         |            |
|               | y |   |                 |           |   |         |            |
+---------------+---+---+-----------------+-----------+---+---------+------------+
| DG-04-07-0798 | P |   |                 | 12 Weeks  |   | 314     | 927        |
|               | i |   |                 |           |   |         |            |
|               | v |   |                 |           |   |         |            |
|               | o |   |                 |           |   |         |            |
|               | t |   |                 |           |   |         |            |
|               | a |   |                 |           |   |         |            |
|               | l |   |                 |           |   |         |            |
|               | I |   |                 |           |   |         |            |
|               | I |   |                 |           |   |         |            |
+---------------+---+---+-----------------+-----------+---+---------+------------+
| DG-04-08-0998 | T |   |                 | 20 Weeks  |   | 49      | 369        |
|               | r |   |                 |           |   |         |            |
|               | e |   |                 |           |   |         |            |
|               | a |   |                 |           |   |         |            |
|               | t |   |                 |           |   |         |            |
|               | m |   |                 |           |   |         |            |
|               | e |   |                 |           |   |         |            |
|               | n |   |                 |           |   |         |            |
|               | t |   |                 |           |   |         |            |
|               | I |   |                 |           |   |         |            |
|               | D |   |                 |           |   |         |            |
|               | E |   |                 |           |   |         |            |
+---------------+---+---+-----------------+-----------+---+---------+------------+
| TOTAL         |   |   |                 |           | 7 |         | 2721       |
|               |   |   |                 |           | 4 |         |            |
|               |   |   |                 |           | 4 |         |            |
+---------------+---+---+-----------------+-----------+---+---------+------------+

**FEASIBILITY STUDY**

From March 1993 to March 1994, a feasibility study (DG-04-02-0293) was
conducted to determine the most appropriate application regimen of
DERMAGRAFT for the treatment of diabetic foot ulcers. A total of
50 patients were enrolled at five sites in the 12 week trial. Patients
were masked and randomized to one of four treatment arms: one piece of
DERMAGRAFT applied to the wound weekly for a total of eight applications
(A), one piece of DERMAGRAFT applied to the wound every two weeks for a
total of four applications (B), two pieces of DERMAGRAFT applied to the
wound every two weeks for a total of eight applications (C), or control
treatment consisting of conventional therapy (D). In group A, 50% of the
patients achieved complete wound closure compared to 8% for the Control
group. Those patients randomized to treatment groups B and C were also
found to heal more often than those in the Control group. Further, there
was a dose dependent increase in wound closure.

**MULTI-CENTER TRIAL I**

From September 1994 to January 1997, a pivotal study (DG-04-04-0694) was
conducted to evaluate safety and effectiveness. A total of 281 patients
across 20 centers were enrolled in the 32 week trial. Patients were
masked and randomized to either one piece of DERMAGRAFT applied to the
wound weekly for a total of eight applications or to control treatment
consisting of conventional therapy. This study identified a specific
range of metabolic activity, as measured by MTT reductase activity which
determined the final metabolic release criterion that was utilized in
the subsequent supplemental and pivotal studies.

In the Intent-to-Treat analysis, 42 of the 139 DERMAGRAFT patients (30%)
and 40 of the 142 control patients (28%) healed at 12 weeks. Before 12
weeks of follow-up were obtained, 30 DERMAGRAFT and 16 control patients
were discontinued.

All the patients who completed the 12-week efficacy evaluation period of
the study or reached complete healing prior to Week 12 were considered
evaluable for the efficacy analysis. Patients who were discontinued from
the study prior to Week 5 of the efficacy period were deleted from the
analysis. 42 of the 109 evaluable patients from the DERMAGRAFT group
(39%) and 40 of the 126 evaluable patients from the control group (32%)
reached complete wound closure by 12 weeks.

For adverse events by week 12, there were 8 DERMAGRAFT patients and four
control patients with study wound osteomyelitis, 8 DERMAGRAFT patients
and 9 control patients with study wound cellulitis, 30 DERMAGRAFT
patients and 34 control patients with study wound infection, 11
DERMAGRAFT patients and 6 control patients had study wound-related
surgery.

**SUPPLEMENTARY STUDY**

In January 1997, a subsequent clinical trial was conducted to study
patients treated with DERMAGRAFT with a specific range of metabolic
activity, as measured by MTT reductase activity ( protocol number
DG-04-04-0694). Fifty patients were enrolled across 10 centers in the 32
week trial. Patients were not masked and all were treated with one piece
of DERMAGRAFT applied to the wound weekly for a total of eight
applications.

In an intent-to-treat analysis, 20 of 50 DERMAGRAFT patients (40%)
achieved wound closure at 12 weeks. Complete wound closure by week 12
data was observed in 51.3% of the evaluable patients. These
effectiveness analyses were based on patients with ulcers of any
duration.

TREATMENT IDE

The primary objectives of this study was to (1) gain experience on the
use of DERMAGRAFT; and (2) to expand health care provider access to
DERMAGRAFT while the pivotal trial for this device was conducted. This
study was an open label, multicenter study to evaluate the use of
DERMAGRAFT in patients with foot ulcers deemed to be of diabetic
etiology on the basis of a medical history and a physical examination.
Patient's wounds in this study were treated with up to 8 applications of
DERMAGRAFT, plus conventional treatment, (debridement, infection
control, a covering with Dermanet followed by either a saline moistened
gauze or foam dressing). It was up to the Investigator's discretion as
to which type of dressing (either foam or saline-moistened gauze) he/she
chose for the patient. However, the dressing type remained the same for
the patient throughout the course of the study. Patients were followed
for 20 weeks.

As of April 4, 2001, a total of 36 centers received IRB approval. Of
these, 22 centers actively recruited patients for enrollment, and 49
subjects had been enrolled into this trial. To date, one death,
unrelated to the use of DERMAGRAFT, was reported. There were no reported
unanticipated adverse device effects. A total of 383 devices have been
shipped, a total of 369 pieces implanted, and 14 pieces of product
returned to Advanced Tissue Sciences, Inc.

PIVOTAL STUDY

STUDY DESIGN

Patients were randomized to treatment with either DERMAGRAFT plus
conventional therapy or conventional therapy alone (debridement,
saline-moistened gauze, and pressure-reducing footwear). The criteria
for inclusion in the pivotal study were:

-   Patient is 18 years old or older.

```{=html}
<!-- -->
```
-   Patient has a current diagnosis of Type I or Type II diabetes
    mellitus.

```{=html}
<!-- -->
```
-   Patient\'s ulcer has been present for a minimum of two weeks under
    the current Investigator\'s care.

```{=html}
<!-- -->
```
-   Patient\'s foot ulcer is on the plantar surface of the forefoot
    (defined as distal to the Tarsal-Metatarsal joint and would include
    toes) or heel and is greater than or equal to 1.0 cm^2^ in size by
    the ulcer area grid method at Day 0 (the day of randomization). A
    wound that was greater than 1.0 cm^2^ at Screening but has healed to
    less than 1.0cm^2^ at Day 0 is [not]{.underline} eligible for this
    study.

```{=html}
<!-- -->
```
-   Patient\'s ulcer extends through the dermis and into subcutaneous
    tissue (granulation tissue may be present) but without exposure of
    muscle, tendon, bone, or joint capsule.

```{=html}
<!-- -->
```
-   Patient\'s wound (after debridement) is free of necrotic debris,
    exhibits no sign of clinical infection, and appears to be comprised
    of healthy vascularized tissue.

```{=html}
<!-- -->
```
-   Patient\'s Ankle-Arm Index by Doppler is [\>]{.underline} 0.7.

```{=html}
<!-- -->
```
-   The patient has adequate circulation to the foot as evidenced by a
    palpable pulse on the study foot (either dorsalis pedis or posterior
    tibial artery).

```{=html}
<!-- -->
```
-   If patient is capable of bearing children, she is using a medically
    accepted means of birth control, and she tests negative on a serum
    pregnancy test.

```{=html}
<!-- -->
```
-   Patient and caregiver are willing to participate in the clinical
    study and can comply with the follow-up regimen.

```{=html}
<!-- -->
```
-   Patient or his/her legal representative has read and signed the
    Institutional Review Board (IRB) approved Informed Consent form
    before treatment.

```{=html}
<!-- -->
```
-   Patient\'s study ulcer has been present (open) for \> 6 weeks at the
    time of the Screening visit. (note: This inclusion criteria was
    approved in February 2000 by the FDA. Enrollment for this study
    ended before this change could be implemented.)

The criteria for exclusion were:

-   Patient has clinical evidence of gangrene on any part of the
    affected foot.

-   Patient\'s ulcer is over a Charcot deformity of the mid-foot
    ("Rocker-Bottom Foot\") or over the tarsal bones-talus, distal
    calcaneous, navicular, and cuboid.

-   The patient\'s ulcer is due to a nondiabetic etiology.

-   Patient\'s ulcer has tunnels or sinus tracts that cannot be
    completely debrided.

-   Patient\'s ulcer has a total surface area that is greater than 20
    cm^2^.

-   Patient\'s ulcer has decreased in size by 50% or more during the
    screening period.

-   Patient\'s ulcer has increased in size by 50% or more during the
    screening period.

-   Patient has one or more medical condition(s) that in the opinion of
    the Investigator would make the patient an inappropriate candidate
    for this wound healing study.

```{=html}
<!-- -->
```
-   Patient has or has had a malignant disease (other than facial basal
    carcinoma) not in remission for five years or more.

-   Patient has severe malnutrition as evidenced by albumin \<2.0.

-   Patient has known alcohol or drug abuse.

-   Patient\'s random blood sugar reading is greater than 450 mg/dL .

-   Patient\'s urine ketones are noted to be \"Small, Moderate, or
    Large\".

-   Patient has a nonstudy ulcer on the study foot that is located
    within 7.0 cm from the study ulcer at Day 0.

-   Patient is receiving oral or parenteral corticosteroids,
    immunosuppressive or cytoxic agents, coumadin, heparin, or is
    anticipated to require such agents during the course of the study.

-   Patient has a history of bleeding disorder.

-   Patient has Acquired Immunodeficiency Syndrome (AIDS) or is know to
    be infected with Human Immunodeficiency Virus (HIV).

-   Patient has participated in another study and has been treated with
    an investigational product within the previous 30 days.

-   Patient has any elective osseous procedures to the study foot within
    30 days prior to the Screening visit.

-   Patient has previously been treated with DERMAGRAFT.

-   Patient\'s ulcer is accompanied by cellulitis, osteomyelitis, or
    other clinical evidence of infection.

-   Patient has any condition(s) which seriously compromises the
    patient\'s ability to complete this study.

TREATMENT PROTOCOL

Patients in the DERMAGRAFT group received up to 8 applications of
DERMAGRAFT over the course of the 12 week study. All patients received
pressure-reducing footwear and were encouraged to stay off their study
foot as much as possible. Total off-weighting (e.g., use of crutches and
wheelchairs) was not required by the study protocol.

STUDY ENDPOINTS

The primary effectiveness endpoint of this study was complete wound
closure by Week 12. Wound closure was defined as full epithelialization
without drainage.

The secondary effectiveness endpoints were:

-   Time to complete wound closure

-   Percent of wound closure by Week 12.

INTERIM ANALYSIS

A planned interim analysis was performed during the study that showed a
relationship between ulcer duration at the time of screening and
incidence of ulcer healing with DERMAGRAFT. Consequently, a modified
(after the interim analysis) statistical plan specified that (1) the
effectiveness analyses would be based only on the patients with ulcers
greater than 6 weeks in duration at the time of the screening visit and
(2) the primary endpoint would be analyzed using Bayesian statistical
methods. Bayesian methods provide for information obtained during the
initial part of a trial to be utilized prospectively in the latter part
of the trial to enable overall estimation of measures of effectiveness.
The effectiveness data are therefore based on the 245 patients with
ulcers of greater than 6 weeks duration. The safety analyses were
performed on all 314 patients who were randomized into the study.

PATIENT ACCOUNTING

For the population of patients with ulcers of any duration, 17% (27/163)
of DERMAGRAFT patients left the study prior to completing it. In the
control group, 21% (32/151) of patients did not remain in the study. For
the population of patients with ulcers greater than six weeks, 16%
(21/130) of DERMAGRAFT patients and 22% (25/115) of control patients
discontinued prior to completing the study, respectively.

Summaries of patient characteristics are provided in Table 5.

**Table 5**

**Summary of Pivotal Study Patient Characteristics†**

  ------------------------- --------------- --------- ------------ ------------
  **Parameter**             **Treatment     **N**††   **Median**   **Range**
                            Group**                                

  Age (years)               DERMAGRAFT      130       55.5         27.0 - 83.0

                            Control         115       54.0         31.0 - 79.0

  Ulcer Duration (weeks)    DERMAGRAFT      130       25.0         7.0 -- 208.0

                            Control         115       28.0         7.0 -- 999.0

  Ulcer Area (cm^2^)        DERMAGRAFT      130       1.6          0.8 -- 16.7

                            Control         115       1.4          0.5 -- 18.0

  Hemoglobin A1c (%)        DERMAGRAFT      129       8.5          4.6 -- 14.0

                            Control         114       8.5          4.7 -- 16.4

  Albumin (g/dL)            DERMAGRAFT      129       4.0          2.9 -- 5.1

                            Control         115       4.0          2.9 -- 5.0

  Ankle-Arm Index           DERMAGRAFT      128       1.0          0.6 -- 1.7

                            Control         114       1.1          0.6 -- 1.7

  Body Mass Index (kg/m^2^) DERMAGRAFT      130       30.8         18.6 -- 54.4

                            Control         115       31.5         20.9 -- 61.0
  ------------------------- --------------- --------- ------------ ------------

† All data obtained at Screening except for Ulcer Area that was obtained
at the Day 0 Randomization Visit.

†† Note: Due to missing observations/data, the "N" will vary.

ANALYSIS AND RESULTS

Effectiveness Results

##### Complete Wound Closure by Week 12

Complete wound closure by Week 12 was determined by the Investigator as
a wound that was completely reepithelialized and without drainage.
Closed wounds were seen for two consecutive weeks. If the wound had
reopened, then it was not considered healed. The Bayesian analysis
concluded that the probability that DERMAGRAFT plus conventional therapy
increased the chance of achieving wound closure in patients with ulcers
greater than 6 weeks in duration over and above that of conventional
therapy alone was 98.4%. Furthermore, there is a 95% probability that
the chance of achieving closure in patients with ulcers greater than 6
weeks duration ranges from 22% to 38% in the DERMAGRAFT group and 12% to
26% in the Control group.

##### Percent of Wound Closure by Week 12

Secondary endpoints in the study (percent of wound closure by week 12
and time to reach complete wound closure) were analyzed using
frequentist statistical methods.

By Week 12 the median percent wound closure for the DERMAGRAFT group was
91% compared to 78% for the Control group (p = 0.044; 2‑sided
Kruskal-Wallis test).

[Time to complete wound closure]{.underline}

The study also showed that ulcers treated with DERMAGRAFT closed
significantly faster than ulcers treated with conventional therapy (p =
0.040; 2-sided log rank test). Patients treated with DERMAGRAFT were 1.7
times more likely to close than Control patients at any given time
during the study (p = 0.044; 2-sided Cox's proportional hazards model).

Patients reported being ambulatory an average of 8 hours per day.

[Patient Demographics and Wound Closure]{.underline}

Summaries of patient characteristics and wound closure are provided in
Table 6.

Table 6

**Summary of Complete Wound Closure Results\
by Patient Category for Patients with Wounds\
of Greater than 6 Weeks Duration 1**

+---------------------------------+-----------------+-----------------+
| **Category**                    | **Number and    |                 |
|                                 | Percent of\     |                 |
|                                 | Wound Closure   |                 |
|                                 | by 12 Weeks**   |                 |
+---------------------------------+-----------------+-----------------+
|                                 | **DERMAGRAFT**  | **Control**     |
|                                 |                 |                 |
|                                 | **n/N (%)**2    | **n/N (%)**2    |
+---------------------------------+-----------------+-----------------+
| **Age (years)** 3               |                 |                 |
+---------------------------------+-----------------+-----------------+
| ≤55                             | 17/65 (26.2)    | 14/63 (22.2)    |
+---------------------------------+-----------------+-----------------+
| \>55                            | 22/65 (33.8)    | 7/52 (13.5)     |
+---------------------------------+-----------------+-----------------+
| **Albumin (g/dL)** 3            |                 |                 |
+---------------------------------+-----------------+-----------------+
| ≤4.0                            | 24/70 (34.3)    | 12/67 (17.9)    |
+---------------------------------+-----------------+-----------------+
| \>4.0                           | 14/59 (23.7)    | 9/48 (18.8)     |
+---------------------------------+-----------------+-----------------+
| **Alcohol Use**                 |                 |                 |
+---------------------------------+-----------------+-----------------+
| Yes                             | 6/37 (16.2)     | 5/28 (17.9)     |
+---------------------------------+-----------------+-----------------+
| No                              | 33/93 (35.5)    | 16/87 (18.4)    |
+---------------------------------+-----------------+-----------------+
| **Ankle-Arm Index** 3           |                 |                 |
+---------------------------------+-----------------+-----------------+
| > ≤1.1                          | 20/70 (28.6)    | 12/54 (22.2)    |
+---------------------------------+-----------------+-----------------+
| \>1.1                           | 18/58 (31.0)    | 9/60 (15.0)     |
+---------------------------------+-----------------+-----------------+
| **Body Mass Index (kg/m^2^)** 3 |                 |                 |
+---------------------------------+-----------------+-----------------+
| ≤31.1                           | 21/68 (30.9)    | 14/55 (25.4)    |
+---------------------------------+-----------------+-----------------+
| \>31.1                          | 18/62 (29.0)    | 7/60 (11.7)     |
+---------------------------------+-----------------+-----------------+
| **Diabetes Type**               |                 |                 |
+---------------------------------+-----------------+-----------------+
| Type I                          | 8/32 (25.0)     | 5/27 (18.5)     |
+---------------------------------+-----------------+-----------------+
| Type II                         | 31/98 (31.6)    | 16/88 (18.2)    |
+---------------------------------+-----------------+-----------------+
| **Gender**                      |                 |                 |
+---------------------------------+-----------------+-----------------+
| Male                            | 22/90 (24.4)    | 15/91 (16.5)    |
+---------------------------------+-----------------+-----------------+
| Female                          | 17/40 (42.5)    | 6/24 (25.0)     |
+---------------------------------+-----------------+-----------------+
| **Hemoglobin A1c (%)** 3        |                 |                 |
+---------------------------------+-----------------+-----------------+
| ≤8.5                            | 19/65 (29.2)    | 13/58 (22.4)    |
+---------------------------------+-----------------+-----------------+
| \>8.5                           | 20/64 (31.2)    | 8/56 (14.3)     |
+---------------------------------+-----------------+-----------------+
| **Mean Hours Non-Weight         |                 |                 |
| Bearing** 3                     |                 |                 |
+---------------------------------+-----------------+-----------------+
| ≤15.7                           | 15/54 (27.8)    | 13/58 (22.4)    |
+---------------------------------+-----------------+-----------------+
| \>15.7                          | 21/65 (32.3)    | 7/47 (14.9)     |
+---------------------------------+-----------------+-----------------+
| **Number of Ulcers on Study     |                 |                 |
| Foot**                          |                 |                 |
+---------------------------------+-----------------+-----------------+
| 1                               | 37/126 (29.4)   | 20/108 (18.5)   |
+---------------------------------+-----------------+-----------------+
| \>1                             | 2/4 (50.0)      | 1/7 (14.3)      |
+---------------------------------+-----------------+-----------------+
| **Race**                        |                 |                 |
+---------------------------------+-----------------+-----------------+
| Caucasian                       | 27/90 (30.0)    | 16/87 (18.4)    |
+---------------------------------+-----------------+-----------------+
| Non-Caucasian                   | 12/40 (30.0)    | 5/28 (17.9)     |
+---------------------------------+-----------------+-----------------+
| **Smoker**                      |                 |                 |
+---------------------------------+-----------------+-----------------+
| Yes                             | 8/27 (29.6)     | 4/17 (23.5)     |
+---------------------------------+-----------------+-----------------+
| No                              | 31/103 (30.1)   | 17/98 (17.3)    |
+---------------------------------+-----------------+-----------------+
| **Ulcer Area (cm^2^)** 3        |                 |                 |
+---------------------------------+-----------------+-----------------+
| ≤1.5                            | 24/60 (40.0)    | 15/63 (23.8)    |
+---------------------------------+-----------------+-----------------+
| \>1.5                           | 15/70 (21.4)    | 6/52 (11.5)     |
+---------------------------------+-----------------+-----------------+
| **Ulcer Location**              |                 |                 |
+---------------------------------+-----------------+-----------------+
| Forefoot or Toe                 | 33/112 (29.5)   | 20/102 (19.6)   |
+---------------------------------+-----------------+-----------------+
| Heel                            | 6/18 (33.3)     | 1/13 (7.7)      |
+---------------------------------+-----------------+-----------------+

^1^ Data observed at Screening except for Ulcer Area (obtained at the
day 0 randomization visit) and Mean Hours Non-weight Bearing (compiled
from patient diary information received from Study Weeks 1 through
Termination; patients were included if they turned in at least one diary
from any post randomization visit).

^2^ Note: For individual categories the N will vary based on available
patient information.

^3^ Cut-off values for each category are based on the overall median
value.

The healing results presented in Table 6 above are presented for general
information purposes only. Outcome data based on an analysis of one
demographic parameter in isolation may not be predictive of wound
closure, as multiple factors influence ulcer healing.

Table 7 represents the wound closure results according to the duration
of the ulcer.

**Table 7**

**Summary of Complete Wound Closure Results\
by Ulcer Duration**

+--------------------+------------------------+------------------------+
| **Ulcer Duration** | **Number and Percent   |                        |
|                    | of\                    |                        |
|                    | Wound Closure by 12    |                        |
|                    | Weeks**                |                        |
+--------------------+------------------------+------------------------+
|                    | **DERMAGRAFT**         | **Control**            |
|                    |                        |                        |
|                    | **n/N (%)**            | **n/N (%)**            |
+--------------------+------------------------+------------------------+
| \<6 weeks 1        | 13/33 (39.0)           | 15/36 (42.0)           |
+--------------------+------------------------+------------------------+
| 6 --26 weeks       | 19/68 (27.9)           | 11/55 (20.0)           |
+--------------------+------------------------+------------------------+
| \>26 weeks         | 20/62 (32.3)           | 10/60 (16.7)           |
+--------------------+------------------------+------------------------+

^1^ These 69 patients with ulcers less than 6 weeks in duration were not
included in the primary effectiveness analysis.

##### Ulcer Recurrence

In the previous multi-center controlled trial 139 patients were treated
with DERMAGRAFT and 142 patients were treated with control. All patients
were followed to week 32. Ulcer recurrence (defined as ulcers that
healed by week 12 and reopened on or before week 32) was 26% (11/42) for
patients in the DERMAGRAFT group and 22% (9/41) for patients in the
Control group. Among this group of patients that experienced recurrence,
the median time from healing to recurrence was 10 weeks for the
DERMAGRAFT group, and 7 weeks for the Control group. These results are
reflective of the entire study population, regardless of ulcer duration,
and include patients who received DERMAGRAFT that did not meet the final
metabolic release criterion.

After this study was completed, the metabolic release criterion for
DERMAGRAFT and the intended patient population were modified. Therefore,
a retrospective analysis was also performed on a subset of patients with
ulcer duration of greater than 6 weeks who received DERMAGRAFT that met
the final metabolic release criterion versus Control patients with ulcer
duration of greater than 6 weeks. Ulcer recurrence was 18.8% (3/16) for
patients in the DERMAGRAFT group and 20.7% (6/29) for patients in the
Control group.

Safety Results

Adverse events are displayed in Section VI for the five studies with the
product. The adverse event experience for DERMAGRAFT patients and
control patients were comparable for most adverse events.

### **Immunology and Persistence Studies** {#immunology-and-persistence-studies .unnumbered}

The potential for DERMAGRAFT to elicit an immune response was evaluated
by examining the baseline and terminal sera of patients enrolled in a
clinical trial for DERMAGRAFT using Western Blot technique. A comparison
of pre- and post-immune sera did not indicate an immunologic response to
DERMAGRAFT in patients treated with up to 8 pieces of DERMAGRAFT. In
investigating the persistence of the product in the wound bed, testing
using Y-chromosome \[male donor\] marker SRY, amplified by a nested PCR
technique revealed the presence of DERMAGRAFT cells from biopsies of
treated venous ulcers up to 6 months after treatment from a single piece
of DERMAGRAFT. Six of 10 patients evaluated at 2 months demonstrated DNA
from DERMAGRAFT cells. Three of 10 patients evaluated at 6 months
demonstrated DNA from DERMAGRAFT cells. In addition, biopsies of these
wounds were evaluated for histologic evidence of an immunologic response
to the product. This assessment found no histologic changes suggestive
of an immune response to DERMAGRAFT.

**X. CONCLUSIONS DRAWN FROM THE STUDIES**

These studies provide reasonable assurance of the safety and
effectiveness of DERMAGRAFT for the treatment of full-thickness diabetic
foot ulcers greater than six weeks duration.

The preclinical studies demonstrate that the device is composed of
biocompatible components.

The probability that DERMAGRAFT plus conventional therapy provided a
treatment benefit to patients with ulcers greater than six weeks over
and above that of conventional therapy alone is 98.4%. Furthermore,
there is a 95% probability that the percent of patients achieving wound
closure with DERMAGRAFT ranged from 22% to 38% and that the percent of
patients achieving wound closure with Control ranged from 12% to 26%.

Serious Adverse Events- No serious adverse events were attributed to
DERMAGRAFT. Of the 314 patients enrolled, 10.4% (17/163) of the
DERMAGRAFT patients developed an infection while 17.9% (27/151) of the
Control patients developed ulcer infection. Overall, 31/163 (19%) of the
DERMAGRAFT group developed infection, cellulitis, or osteomyelitis. In
the Control Group, 49/151 (32.5%) patients developed the same adverse
events. Thus, there was a lower rate of infection, cellulitis, and
osteomyelitis in the DREMAGRAFT treated group.

Immune Response- Analysis of DERMAGRAFT cells showed that there was no
antigens attributable to DERMAGRAFT cells.

## XI. PANEL RECOMMENDATIONS 

The application was not reviewed by the General and Plastic Surgery
Devices Panel.

## CDRH Decision 

Inspections of the sponsor\'s manufacturing facilities and sterilization
sites were completed on January 11, 2001 and were found to be in
compliance with the device Good Manufacturing Practice regulations.

The FDA worked with the sponsor to finalize product labeling.

FDA issued an approval order on September 28, 2001

## Approval Specifications 

Directions for Use: See product labeling.

Hazard to Health from Use of the Device: See Indications,
Contraindications, Warnings, and Precautions, Adverse Reactions in the
labeling.

Postapproval Requirement and Restrictions: See the approval order.