3
Dermagraft was healing more ulcers
than the control treatment. In
BSR's
opinion, this does not bode well for
Advanced Tissue Sciences, as it indi-
cates there are other underlying rea-
sons for the delay, despite the fact that
other countries have approved Derma-
graft for the treatment of diabetic foot
ulcers.
Even if Advanced Tissue Sci-
ences receives FDA approval to mar-
ket Dermagraft, they will have signifi-
cant competition.
Organogenesis and
Lifecell both have products on the
market. Organogenesis is marketing
Apligraf, an allograft tissue made
with two types of human skin cells -
epidermal keratinocytes and dermal
fibroblasts. Like Dermagraft, Apligraf
lacks specific cell types that might
cause the product to be rejected by the
patient. Apligraf is approved and
marketed in the U.S. for the treatment
of venous leg ulcers, and Organogene-
sis has applied to the FDA for mar-
keting approval for use on diabetic
foot ulcers. If Apligraf receives FDA
approval, it will make it extremely
difficult for Advanced Tissue Sci-
ences, as Organogenesis' partner No-
vartis markets Apligraf.
Although Lifecell's product Allo-
derm is not marketed for diabetic foot
ulcers, the potential to utilize this ma-
terial off-label is real. Alloderm is
comprised of human dermis, the un-
derlying layer of skin containing a
complex matrix of collagen, elastin,
blood vessel channels, and bioactive
proteins, which gives human tissues
their strength, volume, elasticity, du-
rability, and function. LifeCell has
developed methods of chemically
processing human dermis to gently
remove all cells while preserving un-
damaged the bioactive, structural der-
mal matrix. Lifecell's advantage is
that it lacks dermal cells and cellular
components, which avoids risks of
rejection or inflammation and pro-
vides the basis for complete tissue
reconstruction. Furthermore, LifeCell
owns patents on a process of freeze-
drying this cell-free matrix without
damaging its structure. Organogenesis
and Lifecell possess significant ad-
vantages and will make it difficult for
Advanced Tissue Sciences and
Ortec
International, which is developing
cultured skin grafts from human fore-
skin fibroblasts.
In addition to diabetic foot ulcers
there are other wounds to the skin,
such as burns, pressure sores and ve-
nous leg ulcers that are targets for
biotech companies. For burn victims,
the physician replaces a patient's
damaged skin with a thin layer of
healthy skin from another part of the
body. In the case of a severe burn,
however, a physician may determine
that there is not enough healthy skin
available to cover the affected area.
Individuals who are burned severely
over a large area of the body often die
within days after sustaining the in-
jury. A severe burn can destroy both
the epidermis and dermis, leaving the
skin unable to regenerate on its own
to cover the wound and protect the
underlying muscle and organs. To
address this market,
Genzyme Bio-
surgery (formerly Genzyme Tissue
Repair, Genzyme Surgical Products
and Biomatrix) offers Epicel cultured
epidermal autografts, the only form of
permanent skin replacement available
for patients with such life-threatening
burns. These epidermal grafts are
grown from a patient's own skin cells
and therefore are not rejected by the
patient's immune system. Starting
with a biopsy of healthy skin about
the size of a postage stamp, Genzyme
can grow enough skin to cover a pa-
tient's entire body surface in as little
as 16 days. Once the culturing proc-
ess has been completed, the skin
grafts are attached to a piece of surgi-
cal dressing material and delivered to
a burn center, where they are trans-
planted onto the patient. A 48-hour
shelf life allows these grafts to be
delivered anywhere in the U.S.,
Europe or Japan. Genzyme treats ap-
proximately 75 burn patients a year
with Epicel. Over 600 patients have
been treated worldwide since the
product was introduced.
Although tissue grafts are ex-
BioTech Sage Report, January 2001
