Multicentric and Prospective Trial of Vulvovaginitis Treatment Comparing Propionibacterium Extract [Immunovag®] With Metronidazole Plus Clotrimazole [Meclon®]

1. Abstract Vulvo-Vaginal Infections [VVI] strongly interferes with the woman’s quality of life. Antibiotic treatments, alone or combined with an antifungal compound, are commonly and successfully used. Nevertheless, they can impair genital microbiota, with long-term disorders, such as a flare-up of genital disturbances due to changes of endogenous lactobacilli. Alternatively, probiotics have been proposed. This prospective multicenter double-arm study, performed in 72 premenopausal women diagnosed with VVI, whose etiology was Gardnerella Vaginalis (n=9), Candida Albicans (n=21), or Bacterial Vaginosis (n=42), was performed to compare the clinical efficacy of a short-term treatment with a vaginal gel containing the bacteria lysate obtained by Propionibacterium acnes [Immunovag®,

2. Introduction Vulvo-Vaginal Infections [VVI] are very frequent pathologies of the low genital tract, that require frequent gynecological consultations and when recurrent, may impact on woman quality of life [1]. Subjective symptoms include itching and burning of vagina and vulva, frequently associated with pain at intercourse. Watery or dense vaginal discharges (i.e., leucorrhea) grey, white or yellowish-white in color, and redness of vaginal mucosa [i.e., erythema] represent typical VVI signs [2]. Because of the impact of VVI on woman quality of life, many studies have tried to understand its causes and to define mechanisms to prevent it. The vagina has a complex ecosystem aimed to reduce growth of opportunistic or pathological bacteria [3-5]. It can be thought as an ecological niche in which different microorganisms dynamically adapt to the changes occurring in the vaginal fluid, epithelium or bacteria, to keep a balanced equilibrium [3-5]. Factors upsetting this equilibrium may predispose to different types of vaginal infections. Bacterial Vaginosis [BV], is an alteration of the vaginal microbiota in which lactobacilli are replaced by anaerobic bacteria [6-10]. Vulvo-Vaginal Candidiasis [VVC] is due to the excessive growth of Candida, a commensal of the vaginal microbiota [9-11]. Mixed flora vulvovaginitis and/or aerobic vulvovaginitis develops when several aerobic microorganisms come into play [12]. Is difficult to understand how to treat these different vaginal infections. Antibiotics alone, or in combination with antifungal agents, are considered the best treatment strategy. Metronidazole proved to be highly effective [13, 14, 15]. Yet the benefits of antibiotics come at the cost of an imbalance of the vaginal ecosystem. After the initial remission of symptoms, the induced reduction of vaginal lactobacilli may cause subsequent genital disturbance flare-ups. In addition, the development of sensitivity, allergy, and side effects, may limit the prolonged or repeated use of these therapies [15, 16]. Probiotic supplemented topically or systemically were proposed to avoid such limitations [17]. Potential therapeutic effects were obtained with bacteria lysate obtained by the mechanical fragmentation of Propionibacterium acnes [P. acnes] [18-20]. Indeed, in a large observational study, this treatment given alone improved symptoms and signs of VVI [19], with an efficacy that was like that of clyndamicine [18]. In addition, P. acnes lysate proved to potentiate the therapeutic effect of the antifungal agent fluconazole on VVC [20]. In the current study, the clinical efficacy of P. acnes lysate vaginal gel was compared to that of metronidazole, as antibiotic, associated with clotrimazole, as antifungal agent [Meclon®; Alfasigma S.p.A., Bologna, Italy].

3. Subjects and Methods Premenopausal women [age range 18-40] diagnosed with VVI were enrolled in this prospective multicentre double-arm study. Patients were recruited from the Gynaecological Departments of the University-Hospitals of Cagliari, Catania, Catanzaro, Genova and Modena - Reggio Emilia (Italy). The study was designed and conducted following the principles outlined in the Declaration of Helsinki and the Good Clinical Practices concerning clinical investigations of medical devices for human subjects. The study was conducted at the Obstetrics and Gynaecology Departments of the University-Hospitals of Cagliari, Catania, Catanzaro, Genova and Modena - Reggio Emilia (Italy). At the screening visit, subjective symptoms of VVI (i.e., vulvovaginal burning and/or itching, and/or dyspareunia) were rated on a visual analogic scale [VAS], ranging from 0 [absence of symptoms] to 10 (intolerable symptom). Women presenting scores between 4 and 8, for one or two of the above-mentioned symptoms, were invited to participate in the study. Concurrently, a gynaecological visit was performed to grade VVI signs, such as erythema and leucorrhea, according to the 10 VAS scale. Etiology of VVI was determined by a vulvovaginal swab for the identification of Gardnerella vaginalis [GV], Candida albicans [CA], and Trichomonas vaginalis [TV], and to determine Amsel criteria for the diagnosis of BV [18,21]. Only symptomatic women meeting the inclusion criteria were included in the study [inclusion and exclusion criteria are detailed in Table 1. Subsequently, women were randomly assigned to treatment with Immunovag® or Meclon®, daily vaginally administered for 5 or 6 days, respectively. Immunovag® [Depofarma S.p.A., Mogliano Veneto, Italy] is a vaginal gel based on hyaluronic acid, polycarbophil and P. acnes lysate, available in 35 ml tube with five disposal vaginal applicators of 5 grams each. Meclon® [Alfasigma S.p.A., Bologna, Italy] is a vaginal cream based on 20% metronidazole and 4% clotrimazole, available in 30 grams’ tube with six disposal vaginal applicators of 5 grams each. Post-treatment evaluation was performed after 10 days from treatment initiation. The same pre-treatment evaluations were repeated.

4. Statistical Analysis For sample size calculation, a 50% difference in terms of symptoms and signs between the two treatment groups was defined as clinically relevant. Considering this assumption, a sample size of 30 subjects in each group of treatment yields an alpha of .05 and a beta of .76 [22]. Statistical analysis of the results was performed using the Student’s t test for paired or unpaired data. Two-factor analysis of variance [ANOVA] for repeated measures was also used to analyze the data. Percentages were compared by the 2 test. Differences were considered significant for “p” less than .05. Statistical analysis was performed by the statistical software package Stat View 5.01 [SAS Institute Inc., Cary, North Carolina]. The results are expressed as mean ± standard error [SE].

5. Results Out of 100 women, only 80 subjects were enrolled, 5 women being excluded for the presence of TV, and 15 women for not giving the consent to participate to the study. Among enrolled women 74 suffered from vulvovaginal itching, 53 from vulvovaginal burning, 61 from dyspareunia. Seventy-fivewomen had vaginal leucorrhea, and 41 vulvovaginal erythema. Out of the 80 vaginal swabs, GV was present in 10 cases, and CA in 28 cases. The remaining 42 subjects were affected by BV, diag-nosed in accordance with the Amsel criteria [21]. In women with diagnosis of GV, Amsel criteria were present [21]. Eight subjects did not attend post-treatment evaluation. Accordingly, statistical analysis was performed only in women with the complete set of data, i.e. 72 women, of which 40 treated with Immunovag® and 32 with Meclon®. Prevalence of symptoms and signs of VVI were not significantly different between women assigned to the treatment with Immunovag® or Meclon®. A significant decrease in the prevalence of the symptoms such asitching (p=0.001) and burning (p=0.001) and the sign erythema (p=0.007) was observed in the 40 subjects treated with Immunovag®, independently from VVI etiology (Table 2). In women treated with Meclon® a significant decrease of the symptoms itching (p=0.001), and of the signsleucorrhea (p=0.006) and erythema (p=0.001) was observed (Table 2). The reduction in the prevalence of burning was more pronounced with Immunovag® (p=0.003) and that of Leucorrhea more pronounced with Meclon® (p=0.028) (Table 2). VAS values of symptoms and signs of VVI significantly decreased (p< 0.001), without anysignificant difference between treatments(Table 3). In women with a diagnosis of VVI by CA, VAS values of the symptoms and signs significantly decreased (p< 0.001) with no statistical difference between Immunovag® and Meclon® (Figure 1). Similarly, in women with a diagnosis of BV, VAS values ofsymptoms and signs significantly decreased (p< 0.001) with no statistical difference between Immunovag® and Meclon® (Figure 2). In women with a diagnosis of VVI by GV, VAS values of symptoms and signs significantly decreased (p< 0.001) with no statistical difference between Immunovag® and Meclon® (Figure 3).

6. Discussion The results of the present study indicate that in women with VVI the short-term clinical efficacy of Immunovag® and Meclon® are comparable in terms of symptoms and signs attenuation as well as in terms of VAS scores reduction of each symptom and sign. These observations are in line with our past experience related to the short-term treatment of VVI with Immunovag®. In a previous large study performed by our group on 592 women, Immunovag® administered for 5 days led to an average decrease of a 3 points [83% reduction] ofVAS scores of VVI symptoms [19]. Also in this considerably smaller study [n=40] VAS scores quantifying VVI symptoms, were reduced on average of 3 points [80% reduction] by Immunovag®. Such consistency, confirms the reproducibility of previous results, and corroborates the reliability of presented findings. The ability of the P. acnes-based product to compete in terms of efficacy on VVI with standard-of-care antibiotics was already demonstrated against clyndamicine [18]. In this study Immunovag® proved to be as effective on VVI than the association of metronidazole, another antibiotic, and clotrimazole, an antifungal agent. Metronidazole was expected to act as a potent therapeutic agent against BV and its combination with clotrimazole has certainly played a crucial role in the cases of CA positivity. Indeed, the efficacy of antibiotic and antifungal agents in treating infections is attributed to their well-establish capabilities of killing or inhibiting the growth of bacteria and fungi, respectively. Less clear is the mechanism of action of Immunovag®. The observed remission of VVI symptoms such as itching and burning sensations might be ascribed to two main factors: i] relevant antioxidant properties, eventually enabling the reduction of inflammation, have been recently associated to P. acnes fractions [23, 24]; ii] the presence of hyaluronic acid and polycarbophil, the two compounds that complement Immunovag® formulation, are thought to act as a hydrating protective barrier thanks to their moisturizing and mucoadhesive properties [25-27]. Therefore, while the two products share comparable clinical outcomes as VVI medications, the underlying mechanisms of action are completely different Such a difference can be understood as the root cause of the presence/absence of complications associated to the use of one or the other treatment. Indeed, while no side effects have been associated with the use of Immunovag®, general disorders and administration site disturbances, are experienced after using Meclon®, including irritative symptoms such as itching, allergic contact dermatitis, rash, and hypersensitivity to the compounds present in the formulation [15]. Moreover, as antibiotics natively act against bacteria, they inevitably affect also endogenous vaginal lactobacilli – key members of the vaginal ecosystem - leading, in turn, to long-term disorders [16]. Products containing strains of lactobacilli bacteria represent, indeed, another safe and efficient probiotic-based alternative or supplementation to antibiotic treatments. According to a recent systematic review [28] summarizing the clinical data associated to BV treatment with probiotic products containing lactobacilli, both local and systemic administration of such bacteria were associated to better performances with respect to placebo in several clinical trials, some of them including populations with large sample size. Differently, controversial results were reported about whether lactobacilli can improve metronidazole effects [29-35]. A direct comparison between the efficacy of metronidazole and probiotic products containing lactobacilli in treating BV still needs to be comprehensively addressed. Our study, by reporting a direct comparison between the perfor mances achieved with the sole use of a probiotic-based product [Immunovag®] and the ones obtained resorting to standard-of-care treatments [Meclon®], serves as another stepping stone towards the finding of a safe and efficient alternative strategy for VVI treatment. Nevertheless, limitations of the study such as the relatively small sample size of the population and the absence of follow-up visits need to be considered. The inclusion of VVI cases with different etiologies may have represented a confounding factor but, from another perspective, it may imply that the investigational product is indeed effective in treating a broad range of VVI. Future studies involving large sample size populations should be performed to draw solid conclusions regarding the ability of Immunovag® of matching Meclon® performances. Moreover, long follow-up times will be required to assess longer-term efficacy and safety of Immunovag® treatment.

7. Conclusion Within the limitations of the present study, the investigational device, Immunovag®, seems to be safe and effective in managing sign and symptoms of VVI with different etiologies. Notably, its performances are comparable to those of the active control, Meclon®, but avoiding the occurrence of side effects. These preliminary results should be confirmed by studies involving a greater number of subjects, longer follow-ups and, perhaps, less heterogeneous target populations. Nevertheless, in the light of the encouraging findingsreported in our study, we propose formulations such as Immunovag® as a valuable alternative to antibiotics and antifungal agents for VVI treatment

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Anna Maria Paoletti. Multicentric and Prospective Trial of Vulvovaginitis Treatment Comparing Propionibacterium Extract [Immunovag®] With Metronidazole Plus Clotrimazole [Meclon®]. Annals of Clinical and Medical Case Reports 2023