A Phase I/II Study of KB103, a Topical HSV1-COL7, on DEB Patients

Inclusion Criteria:

   - Clinical diagnosis of the recessive form of dystrophic epidermolysis bullosa (RDEB).

   - Age

      1. Phase 1: 18 years old or older,

      2. Phase 2a: 5 years old or older,

      3. Phase 2b: 2 years old or older,

      4. Phase 2c: 2 years old or older.

   - Willing and able to give consent/assent

   - Confirmation of RDEB diagnosis by genetic testing, IF, and IEM

   - LH24 antibody negative (non-collagenous [NC] 2domain [NC2-]) and NC1 domain [NC1+]).
   (This criterion is applicable to the first 2 adults on the study (Phase 1). Subsequent
   subjects can be NC1+ or NC1-)

   - Confirmed RDEB COL7A1 mutations in subject

   - Wound that meets the wound size/surface area entry criteria:

      1. Phase 1: Two wounds up to 10 cm2; 1 randomized to B-VEC and 1 randomized to
      placebo

      2. Phase 2a and 2b: At least 3 wounds up to 20 cm2; 2 wounds randomized to B-VEC and
      1 randomized to placebo

      3. Phase 2c: At least 2 wounds up to 50 cm2; at least 1 randomized to B-VEC and 1
      randomized to placebo

   - Subjects, who are, in the opinion of the investigator, able to understand the study,
   cooperate with the study procedures, and are willing to return to the clinic for all
   the required follow-up visits.

Exclusion Criteria:

   - Medical instability limiting ability to travel to the investigative center

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

   - Serum antibodies to COL7 demonstrated on enzyme-linked immunosorbent assay (ELISA),
   indirect immunofluorescence microscopy, Western blot, or cell-mediated immunity to
   enzyme-lined ImmunoSpot® (subjects with negative results within 12 months of screening
   are eligible)

   - Active infection in the area that will undergo administration

   - Evidence of systemic infection

   - Known allergy to any of the constituents of the product

   - Current evidence or a history of squamous cell carcinoma in the area that will undergo
   treatment

   - Active drug or alcohol addiction

   - Hypersensitivity to local anesthesia (lidocaine/prilocaine cream)

   - Receipt of chemical or biological study product for the specific treatment of RDEB in
   the past 3 months

   - Specific wounds that have previously been administered investigational gene or cell
   therapy

   - Subjects who have taken systemic antibiotics within 7 days

   - Positive pregnancy test or breast-feeding

   - Clinically significant abnormalities as determined by the investigator