PRECLINICAL REVIEW MEMO

Composite Cultured Skin (CCS) was first used in Australia on RDEB
(*Recessive Dystrophic Epidemolysis Bullosa*) patients.

Ortec International Inc. introduced this product in the USA for the
first time in their clinical studies with burn patients via G920046.
Later the product was approved for several additional clinical studies:
G960200 (indicated for the treatment of Epidermolysis Bullosa patients),
G980037 (indicated for the treatment venous ulcer patients), G990063
(indicated for the treatment of donor sites in burn patients), G990204
(indicated for diabetic foot ulcers). Recently, the same device
(Orcel^TM^ Composite Cultured Skin has been approved for marketing under
a humanitarian device exemption (HDE) for EB patients (H990013).

In addition to the clinical studies referenced above, the subject
device, CCS was also approved for use in clinical studies for the
indication of donor sites in burn patients. For details regarding the
pilot study protocol, see G920046/S28, G920046/S29, G920046/30.

The pivotal study was conducted under the IDE, G990063.

The firm (Ortec International, Inc.) submitted this PMA seeking approval
of the subject device for the indication of donor sites in burn
patients. This PMA is being reviewed only for the safety and efficacy of
CCS for the following indication: For the management of split thickness
donor sites in burn patients. The data submitted in this PMA from other
studies (burn study, venous ulcer study, EB study, and diabetic foot
ulcer study) provide additional data supporting the safety of the
product.

# DEVICE DESCRIPTION AND PRECLINICAL STUDIES

The device under consideration is Composite Cultured Skin (CCS)
indicated for the management of split thickness donor sites in burn
patients.

CCS consists of a collagen matrix in which allogeneic human skin
(neonatal male foreskin) cells (i.e., epidermal keratinocytes and dermal
fibroblasts) are cultured in two distinct layers.

The collagen cross-linked sponge consists primarily of Type I bovine
collagen laminated on one side with a thin gel layer of acid soluble
bovine collagen. The collagen sponge is a component of the device and
such is not a stand-alone product and is not FDA-approved.

The fibroblast cells and keratinocyte cells are tested for human and
animal viruses, retroviruses, bacteria, fungi, yeast, mycoplasma,
karyology, isoenzymes and tumorigenicity. The final product is tested
for morphology, cell density and viability, sterility, mycoplasma, and
physical container integrity. The animal-derived reagents used in the
manufacture of the device are tested and found to be negative for
viruses, retroviruses, bacteria, fungi, yeast, and mycoplasma. The
bovine material used in the device is obtained from countries free of
BSE.

The device measures approximately 6 cm x 6 cm. A non-adherent mesh
(N-Terface) is placed on both aspects of the device to protect the
cells. The device is packaged in a plastic tray with protein-free medium
containing DMEM.

The human fibroblast cells and epidermal keratinocyte cells are obtained
from neonatal foreskin. The donor's mother's blood is tested and found
to be negative for the following infectious agents: HIV I, HIV II, HTLV
I/II, CMV, HBVsag, HBVab, Herpes 1 and 2, ALT and RPR.

The cell lines are tested (separately) for the following:

Growth and morphology evaluation, cytogenetic testing, isoenzyme
analysis, in-vivo tumorigenicity.

The cell lines (pooled) were tested for the following:

Sterility, mycoplasma, EBV (Epstein Barr Virus), HSV (Herpes Simplex
Virus), HBV, HIV I, HIV II, HTLV I/II and HHV-VI.

All the test results meet the acceptance criteria established for the
product.

The following table gives the final release criteria of the device:

Table 1

In-Process and Final Release Tests are:

  ---- ------------------------------------------- -----------------------
       **Test**                                    **Method**

  1    Appearance (excess growth/proliferation)    100% Visual inspection

  2    Dimensions                                  Linear Measurement

  3    Viable Cell Density                         Ortec TM 07-0004

  4    Cell viability                              Ortec TM 07-0004

  5    NHF Morphology (in-process)                 Ortec WI 09-0062

  6    NHK Morphology in-process                   Ortec WI 09-0062

  7    Endotoxin                                   Kinetic Chromogenic LAL

  8    Sterility, in-process                       USP Sterility

  9    Sterility Final product                     USP Sterility
  ---- ------------------------------------------- -----------------------

**Shelf Life of CCS Device:**

The sponsor submitted data supporting the shelf life of CCS (see
G990063). The data demonstrated that the subject device, CCS is stable
for at least 72 hours inside a temperature-maintained shipping
container.

**Mycoplasma Testing:**

Each lot manufactured is tested for mycoplasma.

**Cell Lines:**

In HDE H990013, the sponsor provided data in support of two cell lines
that will be used in product manufacture. They are **FS-143** and
**FS-145.**

In this PMA (P010016), the sponsor provides data for cell strain
**FS-148.**

Donor Mother's Blood Test results were also provided.

The following table gives presents type of tests performed on FS-148
NHK/NHF strain.

Note: NHK stands for normal human keratinocytes; NHF stands for normal
human fibroblasts.

Table 2

Cell Testing on FS -- 148 NHK/NHF Cells

+----------------------------------------------+-----------------------+
| **Test**                                     | **FS-148 NHK/ NHF**   |
+----------------------------------------------+-----------------------+
| **Keratinocytes & Fibroblasts (not pooled)** |                       |
+----------------------------------------------+-----------------------+
| Growth & morphology evaluation               |                       |
+----------------------------------------------+-----------------------+
| Cytogenetic Testing (Karyotype analysis)     | Pass (NHF)            |
+----------------------------------------------+-----------------------+
| Isoenyzme analysis                           | Pass (NHF)            |
+----------------------------------------------+-----------------------+
| In-vitro tumorigenicity (soft agar)          | Not tumorigenic       |
+----------------------------------------------+-----------------------+
| In-vivo tumorigenicity (nude mice)           | Not tumorigenic       |
+----------------------------------------------+-----------------------+
| # Keratinocytes & Fibroblasts pooled         |                       |
+----------------------------------------------+-----------------------+
| Sterility                                    | Sterile               |
+----------------------------------------------+-----------------------+
| Mycoplasma cultivable & non-cultivable       | Negative              |
+----------------------------------------------+-----------------------+
| In vitro virus - MRC-5, Vero & MDBK          | Pass                  |
+----------------------------------------------+-----------------------+
| EBV PCR                                      | Negative              |
+----------------------------------------------+-----------------------+
| HHV-6- PCR                                   | Negative              |
+----------------------------------------------+-----------------------+
| HBV PCR                                      | Negative              |
+----------------------------------------------+-----------------------+
| HIV-I PCR                                    | Negative              |
+----------------------------------------------+-----------------------+
| HIV II PCR                                   | Negative              |
+----------------------------------------------+-----------------------+
| HTLV- I/II                                   | Negative              |
+----------------------------------------------+-----------------------+
| HIV-1 co-cultivation & antigen capture       | Negative              |
+----------------------------------------------+-----------------------+

> Table 3
>
> The cytokine profiles

  -------------------------- --------------------------------------------
  **Cytokine**               **CCS Production**

  bFGF                       \+

  EGF                        \+

  GM-CSF                     \+

  IL-1a                      \+

  IL1b                       \+

  IL-6                       \+

  IFN-g                      \-

  KGF-1                      \+

  M-CSF                      \+

  PDGF                       \+

  TGF-a                      \+

  TGF-b1                     \+

  TGF-b2                     \+

  TNF-a                      \+

  VEGF                       \+
  -------------------------- --------------------------------------------

\+ Present

> \- Undetectable

The sponsor has developed a cryo-preserved version of the product called
Cryo-CCS. It should be noted that the fresh form of CCS is the only
product that was used in the treatment of donor sites patients.

Literature data Vogt, et al *Platic and Reconstructive Surgery,* 102,
117 (1998) on cytokine concentrations in human wound fluids are
available. The following are the data obtained from 16 patients:

IGF-1 (21-41 ng/ml)

EGF (3-63 pg/ml)

b-FGF (3- 60 pg/ml)

PDGF -- AB (40- 200 pg/ml)

IL-1a -- (10-200 pg/ml)

TGF-b -- (60 - pg/ml)

TGF-b2 (10 -- 30 pg/ml)

IGF-1 binding protein --1 (1-10 ng/ml)

IGF-1 binding protein --3 (1 - 300 ng/ml)

The growth factors IL-1a, TGF-b2, b-FGF and EGF are present in higher
concentrations in the subject device than in the patients' wound fluid
(literature values).

**Biocompatibility of Collagen Sponge:**

The following biocompatibility studies were conducted on the collagen
sponge:

Cytotoxicity, hemolysis, sensitization, acute systemic toxicity,
subchronic toxicity, mutagenicity, rabbit pyrogen test. All tests were
negative.