Efficacy of Human Recombinant Epidermal Growth Factors vs Conventional Therapy for the Treatment of Chronic Venous Ulcers: A Retrospective Case Series

Vascular ulcers are a challenge for health care professionals. Venous etiologies are most common, ranging from 80% to 90% of all ulcers^1,2; chronic venous insufficiency may originate from thrombosis, an alteration in the valve system, or a failure in the muscular pump, resulting in venous hypertension in the lower limbs.³ The prevalence of venous ulcers ranges between 0.10% and 0.30%, and 3 to 5 new cases are reported per 1000 people per year.⁴ These figures are doubled in population segments over 65 years of age.

Venous ulcers are also the most common type of chronic leg wound. Once they are triggered, like all chronic ulcers, they tend to have an insidious progress, are difficult to heal, and involve large areas of the surrounding skin.⁵ A review of the literature finds that 40% to 50% will remain active for 6 to 12 months, and 10% will reach progress for up to 5 years.⁶ According to some studies, venous ulcer care constitutes 50% of the total nursing time in primary care, thus having a high socioeconomic impact.⁷

Treatment of venous ulcers entails an arduous task for health care personnel, being frequently prolonged and, in many cases, proving difficult to appreciate progress. Also, the required treatment of the background pathology has an annual US estimated cost of $1.5 billion to $3.5 billion.⁸

For some authors, such as Borges,⁹ there is still doubt about the best treatment for venous ulcers. However, the management objectives must include the following pillars: promote healing, improve quality of life, and reduce adverse effects¹⁰ since active ulcers can become infected, causing an additional delay in the healing process.

The literature shows that compression therapy (3 or 4 layers of bandage) is the gold standard for healing ulcers of venous etiologies (type A recommendation).¹¹ However, 30% fail to heal after 1 year of treatment, becoming a complex and long-lasting pathology.¹²

Therefore, it should be taken into account that the initial response to treatment is a predictive factor of healing. It has been established that a decrease of approximately 15% of the surface of the wound after 1 or 2 weeks of treatment justifies continuing the established treatment.¹³ If this does not occur, the patient should be reassessed. It has been pointed out that to reduce the long-term impact in the patient’s healing process, as well as to contain costs, the use of adjuvant and advanced therapies should be considered since small-scale studies have demonstrated that initiating advanced therapy more quickly achieves better results than seen with traditional treatments. With a primary objective of reducing healing time, accelerating and modulating the healing process will minimize the risk of complications, reduce physical and emotional limitations in the patient, and decrease consumption of socio-health resources associated with significant labor costs.

Much progress has been made in the knowledge of biology in wound healing. The healing process has been found to be driven by a variety of soluble factors derived from cells, including the production of proinflammatory cytokines and proteolytic enzymes (metalloproteases, elastase, and plasmin) that destroy the extracellular matrix and inactivate growth factor.¹⁴ Moreover, understanding which of these molecules are overexpressed and which are in deficit and with low bioavailability, as is the case with the growth factor, it has been possible to develop medications, such as the recombinant human epidermal growth factor (rhEGF) nepidermin to repair, regenerate, and enhance new tissues in vascular wounds.

Nepidermin is a healing and stimulating agent that facilitates circumventing the biofilm barrier and is more efficient and safe for application in chronic ulcers.¹⁵ The rhEGF is typically administered perilesionally and intralesionally at a dose of 75 µg diluted in sterile water for injection, 3 times per week; the administrations are maintained until complete granulation of the lesion is achieved or up to 8 weeks.¹⁶

Among the experiences of nepidermin application in venous ulcers, a case series published in 2019 concluded that use of this drug reduced the healing time of chronic venous ulcers. In such cases, the time and number of vials that a patient would need for the treatment was determined; the average time of treatment was 5.6 weeks with 15.7 vials per patient.¹⁷ In another case report of a patient with a venous ulcer, 75 µg of nepidermin was applied 3 times per week for 8 weeks, achieving 95% granulation and 90% epithelialization at the end of therapy.¹⁸ It has been concluded that local intralesional administration of rhEGF promotes wound healing by correcting the expression of biological factors, which are altered in patients with ulcers, thereby reducing the release of reactive oxygen species and increasing serum levels of antioxidative capacity to improve the biochemical environment of the ulcer. Compared with the current standard of care for managing chronic venous ulcers, rhEGF is more effective, shows a shorter time to achieve complete healing of the lesion, and is well tolerated with an excellent safety profile.¹⁸

Consequently, this study was proposed to determine whether granulation and epithelialization of a chronic venous ulcer could be achieved more quickly by using intralesional nepidermin plus compression therapy vs topical hydrocolloid therapies plus compression therapy, thereby improving the patient’s health status in a shorter time.

The authors sought to determine the observed efficacy of rhEGF in a case series of patients with chronic venous insufficiency (Clinical-Etiology-Anatomy-Pathophysiology [CEAP] classification C6) plus compression therapy compared with conventional treatment with hydrocolloid gels plus compression therapy, measured in treatment time and progress of ulcer granulation. Other objectives included evaluating the number of cures and vials needed to fulfill the therapeutic goal, which was the closure of the venous ulcer.

The authors report this retrospective and descriptive case series of 48 patients with chronic venous insufficiency (CEAP classification C6) who were admitted to a wound clinic in Bogotá, Colombia, between January 2017 and December 2018. The review of the medical records determined the patients in the cohort by identifying those who met the established inclusion and exclusion criteria.

Inclusion and exclusion criteria
The medical records of patients admitted for wound management at the wound clinic were reviewed to identify who met the following inclusion criteria: diagnosis of chronic venous insufficiency (CEAP classification C6) as assessed by vascular surgery to define the type of treatment to be performed; ulceration progress greater than 4 weeks; ulcer length greater than 6 cm; ankle-brachial index greater than 0.9; adherence to conventional healing protocol with the use of hydrocolloids plus compression therapy according to nursing notes or facility protocol; and adherence to the protocol for application of the rhEGF Epiprot (Praxis Pharmaceutical).

The following were defined as exclusion criteria: presence of arterial ulcers or diabetic foot ulcers; ulceration progress less than 4 weeks; ulcer length less than 6 cm; history of malignancy; ankle-brachial index less than 0.9; presence of clinical signs of ulcer infection; and nonadherence to conventional healing protocols using hydrocolloids plus compression therapy or to rhEGF application protocols.

To evaluate the progress of the wounds, the Wollina index was used, which takes into account granulation criteria that are graded from 0 to 4, according to the percentage achieved in the wound; color, which is graded from 0 to 2; and consistency, which is graded from 0 to 1. The maximum score is 7; the higher the score, the better the condition of the wound.¹⁹

Methodology
The data corresponding to clinical- epidemiological factors, treatment, and outcomes associated with ulcer granulation and epithelialization were obtained from the patients’ clinical records through a research card and entered into a parameterized database per the variables for later analysis.

To maintain standardization of patients included in the case series, review of the histories for the time period of January 2017 through December 2018 had to demonstrate adherence to the protocol for either the application of rhEGFor conventional hydrocolloids and compression therapy.

Application protocol of rhEGF. The following requirements were to be verified: all patients were provided verbal and written information about the treatment that was to be performed; the number of 75 µg rhEGF vials prescribed and delivered by the patient’s health promotion entity (Entidades Promotoras de Salud) was applied; and the frequency of application of the drug was 3 times per week. In addition, adherence needed to be verified with the following drug application protocol: wash wound with 500 µL of normal saline solution; dry the wound with sterile gauze; measure foot pulse, capillary filling, and distal perfusion; take measurements of the length, width, and depth in the cephalocaudal direction of the lesion; assess the tissues of the lesion according to the TIME framework (viable tissue, signs of infection and inflammation, moisture balance/exudate, and perilesional edges); obtain photographic record; mix the 75 µg nepidermin vial in 5 µg of normal saline solution and syringe preload; apply rhEGF clockwise in an intralesional manner; cover the lesion with a sterile dressing; and apply a cotton bandage and elastic to the wound.

Conventional cure protocol with the use of hydrocolloids and compression therapy. The following requirements were to be verified: all patients were provided verbal and written information about the treatment that was to be performed; the number of cures requested by the specialist in external consultation was performed for each patient; and  the healing frequency was once every 5 days. Additionally, it was to be verified that the patients underwent the same healing process being managed at the Clínica de Heridas, which adhered to the following treatment protocol: wash the wound with 500 µL of normal saline solution; dry the wound with sterile gauze; measure foot pulse, capillary filling, and distal perfusion verification; take measurements of the length, width, and depth in the cephalocaudal direction of the lesion; evaluate the tissues of the lesion according to the TIME framework; obtain photographic record; apply the hydrocolloid gel on the wound; cover the lesion with a sterile dressing; and bandage the wound with a cotton bandage and elastic.

Since the study was retrospective, only clinical information was included in the data processing. This process was approved by the ethics committee of the wound clinic where the treatment of these patients was performed.

Stastistical analysis
For the present analysis of this study, each group was independently developed according to the type of treatment prescribed and administered and from the results of the chi-squared test.

For descriptive statistics, Microsoft Excel (Microsoft Corporation) was used to summarize data. The Friedman test was used to compare nonparametric variables when analyzing the granulation progress. The Student t test was used to compare parametric variables of patients treated with rhEGF.

For analytical statistics, the chi-squared test was used, considering the following aspects:

Definition of working groups: Working groups were classified as either exposed or nonexposed. Exposed corresponds to patients who received rhEGF injection plus compression as the treatment for a venous ulcer. Nonexposed corresponds to patients who received hydrocolloids plus compression as the treatment for a venous ulcer.

End condition definition: There were 2 possible end conditions. Healthy refers to patients who exhibited complete closure of the venous ulcer after 0 weeks to 8 weeks of treatment. Sick refers to patients who exhibited complete closure of the venous ulcer after more than 8 weeks of treatment.

Hypothesis.The null hypothesis was that no association exists between the use of rhEGF treatment and wound closure within 8 weeks of treatment. The alternative hypothesis was that an association exists between the use of rhEGF treatment and wound closure within 8 weeks of treatment. A 2 x 2 contingency table was made and the chi-squared calculated with a 95% significance level. The resulting P value was less than .05, rejecting the null hypothesis and supporting an association between the use of rhEGF venous ulcer treatment and wound closure within 8 weeks. For these calculations, StatCalc version 7.2.4 (Epi Info) was used.

The study population was composed of 48 patients, divided into 2 groups according to the type of treatment established for the venous ulcer. The majority of patients (> 60%) in both groups were female (Figure 1).

The average age of the rhEGF-treated group with was 62.4 years (range, 32–83 years). For the conventional therapy group, the average age was 69.4 years (range, 19–92 years). Figure 2 shows the age composition of the study population. In the group of patients aged 60 to 69 years, the predominant treatment was rhEGF. The group of patients aged 70 to 79 years constituted one-third of the population in the group that received conventional treatment.

Characteristics of the lesions: anatomical location
Ulcers are usually located anatomically on the lower and inner regions of the lower limbs. In this study, they were predominantly observed at the level of the internal and external malleoli; 75% and 83% were present at this location in the rhEGF and conventional therapy groups, respectively (Table 1).

In the group treated with rhEGF, 45.8% of patients had ulcers that had progressed 24 to 35 weeks before treatment. In the conventional therapy group, 33.3% had ulcers that had progressed for 60 weeks or longer (Table 2).

Weekly classification of the Wollina score and wound size between 2 management strategies
As shown in Table 3, from week 10 to week 12 of treatment, patients treated with rhEGF exhibited a significant improvement in the mean Wollina score¹⁹ from 0.3 ± 0.4 to 6.8 ± 0.6 (P < .000). The mean wound size at the beginning of treatment was 14 cm. At the end of treatment (week 12), wound closure was 100% in all patients in this group. Friedman X2r 185.54 two-way analysis further showed that rhEGF improved the granulation progress of ulcers, the value generated by this test were statistically significant (P < .001).

Patients who received conventional treatment exhibited a mean improvement in the Wollina score of 0.25 ± 0.4 to 4.1 ± 1.3, representing a 59% improvement (Table 4). Mean wound size at the beginning of treatment was 14.9 cm ± 5.8 cm. At 12 weeks of treatment, mean wound size was 9.3 cm ± 5.9 cm, demonstrating that complete closure of the ulcers under treatment was not achieved in the 12 weeks. In this patient group, the Friedman X2r 185.54 two-way analysis supported the observation that conventional treatment failed to close the venous ulcers within 12 weeks of management; the values generated by this test were statistically significant (P = .001).

Number of weeks vs treatments needed to achieve epithelialization
The number of vials of rhEGF used relative to the time taken for full wound closure is reported in Table 5. Of 24 patients in the group, 7 patients required up to 12 vials to achieve closure within 4 weeks, 11 patients required 12 to 24 vials to achieve closure within 5 to 8 weeks, and 6 patients required 12 to 24 vials to achieve closure within 9 to 12 weeks. No patients required more than 12 weeks to achieve complete wound closure (Figure 3).

Table 6 shows the number of treatment applications relative to the time taken for full wound closure in the group of patients receiving conventional therapy. Of the 24 patients, 4 patients required up to 19 applications to achieve closure in up to 16 weeks, 3 patients required 20 to 29 applications to achieve closure within 17 to 20 weeks, 5 patients required 30 to 49 applications to achieve closure within 25 to 28 weeks, and 6 patients required 40 to 69 applications and achieved closure after 29 weeks (Figure 4).

Results achieved
After treatment was administered to patients according to the determined group, wound closure was achieved in 100% of the intervened patients. In those treated with rhEGF, 71% of the patients achieved closure in 8 weeks or less, and the remaining percentage of wounds healed between 9 and 12 weeks. In comparison, 100% of the conventional therapy group required treatment for a minimum of 13 weeks and a maximum of 46 weeks (Figure 5).

To evaluate the association between application of rhEGF, and treatment time to reach wound closure, the chi-squared test was used. The resulting relative risk was 3.4 (95% confidence interval, 1.83–6.39; P = .000), confirming a 3.4-fold chance of closure in less than 8 weeks in patients who received rhEGF plus compression therapy vs patients who received hydrocolloid gel plus compression therapy for venous ulcer healing.

There were no allergic reactions or adverse events reported.

Aging of the population due to the increased life expectancy correlates to the increased number of people with chronic diseases.²⁰ Chronic venous insufficiency, which ultimately leads to the appearance of ulcers in its last phase, is the most frequently seen vascular disease, yet health care professionals and patients both seem to assume that it is a relatively benign pathology. Simultaneously, there is a sense of resignation that coexists among all who witness how this disease affects a patient’s quality of life.

According to the literature,²¹ these ulcers are more common in elderly patients, which is consistent with the data obtained in this study as patients in both groups were in their sixth decade of life or older. Additionally, these wounds often occur in the internal supramalleolar region but may also be on the external area or located slightly upward at the height of mid-calf, which was consistent with the findings of the present study. The highest number of patients in the 2 groups had lesions in the internal malleolus (62.5%). Likewise, the mean size of ulcers was 14.9 cm in the group of patients conventionally treated, compared with 14 cm in the group of patients treated with rhEGF. These 2 groups were balanced, which allowed determining the best response in the outcome of the cure per the treatment used.

Regarding the progression and chronicity of venous ulcers, the literature defines a chronic wound as one that requires extended periods of time for healing, not fully reaching closure for more than 6 weeks.²² Thus, these long periods of treatment can negatively impact patient quality of life. The high costs of therapy, which can be related to the divergences verified in professional practice, affect other services within the health system as well. More specifically, the multiple treatment options a medical professional can use to treat wounds, especially in relation to their expertise and knowledge, can impact the total cost. This chronicity is consistent with that seen in the patients in both groups of this case series, who had lesions that had progressed for more than 12 weeks. Approximately 45% of patients in the rhEGF group had a progression time of 24 to 34 weeks, and 41.3% in the conventional therapy group had a progression time of 48 weeks or more.

Formentini et al²³ found that one of the characteristics for an ulcer not to heal is the presence of episodes of local infection and/or need for antibiotic use. In this case series, active infection was not present at the time of admission to the study, as this was an exclusion criterion. However, it was not investigated whether the ulcer previously presented infectious processes. Two other studies mention this same point, adding that bacterial colonization is associated with the inactivation of growth factors, increased activity of metalloproteases, and altered proliferation and migration of epithelial cells.^24,25 Therefore, the intralesional and perilesional application of an epidermal growth factor that may be inactive in chronic venous ulcers is a therapeutic method that may provide a beneficial effect in promoting the healing phases.

In addition to local wound care and infection control, standard treatment is based on compression therapy. However, with conventional care alone, research has shown that up to 75% of patients do not achieve healing in an adequate time, extending progression times and affecting healing mechanisms. Moreover, considering that knowledge in the field is increasing and new products are becoming available, the use of advanced technologies that accelerate the healing process has been recommended for these patients.²⁰

Thus, when all conventional methods fail, there are alternative treatments for chronic, refractory, and/or complex ulcers. For example, the use of growth factors has been shown to have very encouraging results in reducing the cure time and the benefits that this entails in patients with diabetic foot ulcers.²⁶ While there are few observational studies describing in detail the use of this agent in venous ulcers, which makes it difficult to compare results, this shortage should be interpreted as a strength of this case series. This study evaluated patients in 2 different treatment groups with acceptable initial comparability in terms of sociodemographic characteristics and characteristics of progression, size, and location of the venous ulcer.  Patients treated with rhEGF compared with those receiving conventional therapy showed adequate healing of the ulcer in less time with use of 12 to 24 vials of rhEGF (Figure 6, Figure 7, Figure 8, Figure 9).

Overall, fewer patients in the rhEGF group (45%) required the maximum number of administrations (24 applications) vs 70.8% of the patients in the conventional therapy group (21–69 applications), and with no patient showing any adverse reaction.

The limitations of the study reflect those of retrospective studies. In addition, the divergence in weeks of wound progression between the 2 groups could have positively impacted the patients who received rhEGF. However, it should be noted that the homogenization of the injury size was similar. In addition, the costs generated by the therapies used were not taken into account and should be considered for future studies to evaluate cost effectiveness. Quality of life measurement scales also should be used to determine the benefit of each treatment with respect to the patient’s well-being.

The use of therapy with rhEGF plus compression was shown to produce total epithelialization of chronic venous ulcers in 12 weeks of treatment or less. This healing time was significantly superior to that seen with the use of conventional hydrocolloid gel and compression therapy.

Authors: Maria Teresa Cacua Sanchez, PhD; Luis Fernando Giraldo, APRN; and Jhon Alejandro Díaz, EPA

Affiliation: Centro de Cirugia Ambulatoria CCA  Bogota, Colombia

Correspondence: Maria Teresa Cacua Sanchez, PhD, Cirujano Vascular, Centro de Cirugia Ambulatoria CCA, Bogota Calle 89A No 20-57 , Bogota, Cundinamarca 1001000 Colombia; mcacua@gmail.com

Disclosure: The authors disclose no financial or other conflicts of interest.