Gene Transfer for Recessive Dystrophic Epidermolysis Bullosa

The research project involves gene transfer into keratinocytes, which are the majority of the
cells in the outer layer of skin. In this gene transfer trial we plan to biopsy some skin
tissue, grow the cells in a skin cell culture (sterile dishes with special fluid that allows
cells to grow and multiply) and then infect the cells with a virus that we have genetically
engineered to insert the correct type VII collagen gene. The cells should then make type VII
collagen.

The process of inserting the correct type VII collagen gene into cells is called "gene
transfer." The virus used is called a "retrovirus." The virus is made so that it only
delivers the type VII collagen gene and it should not spread to other parts of the body.
During the study we will check for growth of the virus.

After cells have received gene transfer, we will grow the cells in culture into a sheet of
cells that look like a plastic film. We plan to graft the sheet to wounds. Grafting means we
will take cells from the culture and stitch them to the patient's skin.

Inclusion Criteria:

1. Clinical diagnosis of recessive dystrophic epidermolysis bullosa (RDEB)

2. 13 years old or older and willing and able to give assent/consent

3. Confirmation of RDEB diagnosis by immunofluorescence (IF) and electron microscopy (EM)

4. NC1[+] and mAb LH24 antibody staining negative

5. RDEB type VII collagen mutations in subject and carrier parents confirmed

6. At least 100 to 200 cm2 areas of open erosions on the trunk and/or extremities
suitable for skin grafting

7. Able to undergo adequate anesthesia to allow grafting procedures to take place.

Exclusion Criteria:

1. Medical instability limiting ability to travel to Stanford University Medical Center

2. The presence of medical illness expected to complicate participation and/or compromise
the safety of this technique, such as active infection with HIV, hepatitis B or
hepatitis C, as determined by hepatitis B surface antigen screening, detection of
hepatitis C antibodies, or positive result of hepatitis C polymerase chain reaction
(PCR) analysis.

3. Antibodies to type VII collagen associated antigens

4. Active infection in the area that will undergo grafting

5. Evidence of systemic infection

6. Current evidence or a history of squamous cell carcinoma in the area that will undergo
grafting

7. Active drug or alcohol addiction

8. Hypersensitivity to vancomycin or amikacin

9. Receipt of chemical or biological study product for the specific treatment of RDEB in
the past six months

10. Positive pregnancy test or breast-feeding

11. Clinically significant abnormalities (Grade 2 or higher on the National Cancer
Institute [NCI] toxicity scale) on laboratory tests performed prior to grafting,
except for the following specific exclusionary laboratory threshold results, subject
to approval or exemption by the EB physician:

- Albumin < 2.5 g/dL

- Leukocytes > 20K/uL

- Hemoglobin < 7.5 g/dL. Low hemoglobin will be treated at the discretion of the
investigators and the EB physician.

- Additional exceptions may be made at the discretion of the investigators and the
EB physician.

12. Clinically significant abnormalities (Grade 2 or higher on the NCI toxicity scale)
identified through medical history and physical examination on Day 0, with the
following exceptions:

- Anorexia, can enroll up to Grade 4 (inclusive)

- Constipation, can enroll up to Grade 2 (inclusive)

- Dysphagia, can enroll up to Grade 4 (inclusive)

- Keratitis, can enroll up to Grade 4 (inclusive)

- Bone pain, can enroll up to Grade 2 (inclusive)

- Additional exceptions may be made at the discretion of the investigators and the
EB physician.