Background:
Fibroproliferative disorders (FPD) are common and serious disorders involving many human
tissues and are a leading cause of mortality and reported as high a 45% of annual deaths.
Hypertrophic scar (HTS) and keloids are the dermal equivalent of FPD and impose lower
mortality but great morbidity, particularly following burn injury. In the US, 1.25
million people are treated for burns annually, 50,000 requiring hospitalization. Although
the mortality rate for burn injury has improved, burn patients experience a prolonged
hospitalization (mean 26.2 days) and rehabilitation, requiring an average of 12.7 weeks
off work for patients with thermal injuries >30% of the TBSA. Much of the rehabilitation
relates to functional and cosmetic limitations imposed by HTS, including a reduction in
range of motion of the extremities and the intense pruritus and heat intolerance making
early return to work prohibitive, until remodelling of the HTS has occurred. Although
risk factors for HTS include sex, age, racial or genetic factors, and wound location, HTS
develops after prolonged inflammation of slowly healing burn wounds with a very high
frequency especially in deep dermal wounds independent of other factors in up to 75% of
burn patients. Unfortunately, HTS and keloid are known to respond poorly to current forms
of therapy, including pressure garments, topically applied silicone and intralesional
steroids, usually slowly over months or years, often incompletely. Advances in the
immunology of FPD including HTS and keloids, reveal many common features, such that novel
advances in therapy for these disorders may provide far reaching benefits to many
patients and military personnel suffering from severe scarring after burn injury.
Drug Information: NEFOPAM HCL has been found safe and effective for the reduction of
dermal scarring following standardized human dermal wounds of critical depth that
produces HTS in normal human volunteers. NEFOPAM HCl was first developed as a
non-narcotic analgesic drug and it is currently marketed primarily in Europe, New Zealand
and parts of Asia for oral, intramuscular or intravenous use for acute or chronic pain.
NEFOPAM HCl has over 30 years of human safety data. It is considered generally safe with
mild side effects including nausea, sweating, dry mouth and tachycardia. NEFOPAM
reformulated into a cream and topically administered has been shown to reduce the amount
of scar tissue formed during wound healing in mice and the red Duroc pig model of
hypertrophic scarring. Most recently, a phase I safety and efficacy study was conducted
in human volunteers using a standardized progressively deeper dermal wound (0-1.6 mm in
depth over 6 cm) made with a sterile jig in each hip, where normotrophic (negative
control) and HTS (positive control) develop in the superficial and deep regions of the
scratch. 24 patients have been studied over 104 days where the preliminary results
demonstrate that NEFOPAM cream has very few adverse side effects, low immunogenicity and
encouraging antifibrotic effects on the healing wounds.
Purpose/ Hypothesis:
To re-assess the safety, local tolerability and efficacy of NEFOPAM Cream in burn
patients when applied to bilateral deep dermal wounds using a standardized dermal scratch
model of hypertrophic scarring.
Objectives:
To assess the efficacy of NEFOPAM Cream versus placebo (vehicle) in reducing scar size
following artificially induced dermal wounds in each lateral hip region of burn patients.
To determine the efficacy on wound closure of NEFOPAM Cream versus placebo (vehicle) in
burn patients.
To assess the satisfaction of burn patients and investigators in the scar rating and
appearance after topical application of NEFOPAM Cream versus placebo (vehicle).
To determine the efficacy of NEFOPAM Cream versus placebo on the gene and protein
expression of fibrotic molecules including type I and type III collagen, β-catenin target
gene (AXIN-2), TGF- β1, and decorin, quantitative measures of collagen orientation index
(COI), immunohistochemistry of a-SMA (smooth muscle actin) and β -catenin in scar tissue.
Research Method/Procedures:
This study will be a double blind, placebo-controlled, randomized multicenter Phase II
study in which burn patients will be randomized to receive NEFOPAM Cream or placebo.
Qualifying subjects will be randomized to receive 2.0 mL of NEFOPAM Cream or placebo
(vehicle) on Day -1 on intact skin in an area on the upper hip not intended for the
incision. On Day 0 burn patients who are free of adverse events will enter the treatment
phase of the study.
Consenting burn patients requiring skin graft surgery will be scratch-wounded under
aseptic conditions on the lateral hip of each lower extremity while under local
anesthesia or general anesthesia for their wound debridement as previously described. To
create small standardized depth uniform wounds, a jig fitted with a sterile No.11
surgical scalpel blade will be used to create a wound that is 6 cm in length and from 0
to approximately 1.6 mm maximum depth into the deep dermis of the lateral hip
mid-distance between the anterior superior iliac spine and the lateral trochanter of the
hip. Two identical wounds will be made, one on each hip and subjects will be randomized
to receive treatment with NEFOPAM Cream or placebo on each wound. Wounds will be followed
until >90% re-epithelialized before the wounds will be cleaned and the cream will be
applied twice a day for the next 21 days. The wounds will be covered with an occlusive
dressing until Day 21 of treatment (Tegaderm ™). Once the treatment is completed and the
wounds are fully healed, the wound/scar will be left uncovered and treated with a
moisturizing cream (Glaxal™) if necessary.
Burn patients randomized to receive active treatment will have one wound treated with
NEFOPAM Cream (treatment wound site) and the other wound site treated with placebo
cream/vehicle (control wound site) according to the randomization schedule and dosing
instructions. All study team members and subjects will be blinded to all treatments.
Subjects will receive two applications of treatment to each wound per day for 21 days
after the wounds are 90% healed.
Wound evaluations will be performed daily through the treatment period. Digital
photography of the wound/scar will occur following wounding and on Day 6 (+/- 2), Day 13
(+/- 2), Day 20 (+/- 3), Day 27 (+/- 2), Day 48 (+/- 7) Day 76 (+/-14), Day 104 (+/- 15).
Modified VBSA and POSAS scale, vascularity and pigmentation via Mexameter® and ultrasound
evaluations of the scar will commence after the dermal scratch is completed and
thereafter when the wound is healed (defined as >90% epithelialization of the wound with
no exudate - approximately 1-3 weeks following wounding) and repeated on Day 20 (+/- 3),
Day 27 (+/- 2), Day 48 (+/- 7) Day 76 (+/-14), Day 104 (+/- 15).
Two punch biopsies will be performed on the maximally thick region of each scar on Day 28
and day 104 for immunohistochemistry analysis of a-SMA (smooth muscle actin) and
β-catenin, collagen orientation, and RT-qPCR analysis of type I and type III collagen,
the β-catenin target gene (AXIN-2), TGF- β1 and decorin.
Subjects may request that the scar be completely excised on or after D104 under local
anesthetic (1% xylocaine with epinephrine 1:100,000) and repaired using 4(0) monocril
suture in the subcuticular plain to produce a fine linear scar. Tissue removed from this
procedure will be used for immunohistochemistry analysis of β-catenin and RT-qPCR
analysis of type I and type III collagen, the β-catenin target gene (AXIN-2), TGF- β1 and
decorin.
Plan for Data Analysis:
All calculations and analyses will be performed using SAS version 9.4 or higher resident
on the HP Unix (HPUX B.11.11 or higher. The continuous data will be summarized via PROC
UNIVARIATE - mean, standard deviation, median, minimum, and maximum. The Safety
Population will be used for analysis of adverse events, tolerability reactions, clinical
evaluations, and laboratory tests. The ITT Population will be used for all other
analyses.
For any assessments that are not performed per hip (e.g. adverse event reporting),
results will be grouped by treatment (NEFOPAM 3.0% and placebo, placebo alone). For
assessments that are performed separately on each hip (e.g. tolerability, POSAS scale),
results will be grouped two ways: (1) By within-subject differences between hips grouped
by the 3 treatment groups; and (2) By overall group mean value by treatment applied.
Tolerability is assessed separately for each hip by the investigator using a 5-point
scale that ranges from 0 (No visible reaction) to 4 (Severe erythema with induration,
vesicles or pustules and/or erosion/ulceration). While Likert scales are ordinal in
nature, parametric methods are still robust and appropriate for analysis (43). Thus, for
the assessment of tolerability, an ANCOVA model will be used to compare the
within-subject difference between active and placebo hips (or, for placebo-only subjects,
between left and right hips) in average tolerability. The average tolerability for each
subject-hip will be calculated across all non-missing scheduled visits.