Efficacy of inosine pranobex oral therapy in subclinical human papillomavirus infection of the vulva: a randomized double-blinded placebo controlled study

A Review on Inosine Pranobex Immunotherapy for Cervical HPV-Positive Patients

The purpose of this review was to examine and summarize data for inosine pranobex (IP) immunotherapy in cervical HPV-positive patients. Persistent or recurring cervical human papillomavirus (HPV) infection is a major cause of cervical cancer. Self-clearance and blocking of cervical HPV infection depend on the status of the host immune system. Immunotherapy helps accelerate elimination of the infection. Host immunity is involved in the development of HPV infection. Several mechanisms of interaction between the virus and the immune system have been revealed; however, the mechanisms have not been completely elucidated. A properly functioning immune system impedes HPV progress and helps clear the pathogen from the body. IP has antiviral efficacy because it modulates both cellular and humoral immunities. IP has been on the market since 1971. Nevertheless, it has seldom been administered to treat cervical HPV infections. In this review, Google Scholar, PubMed/MEDLINE, Scopus, Cochrane Library, and Research Gate were searched for the period 1971–2021. Prospective controlled trials, observational and retrospective studies, and meta-analysis and reviews on immunotherapy against HPV cervical infection were explored. Prior studies showed strong clinical efficacy of combined and standalone IP therapy in reversing HPV-induced changes in the cervix, preventing disease progression, and clearing the pathogen. IP treatment enhanced host antiviral activity against HPV, delayed or stopped cervical oncogenesis, and rapidly removed HPV from the body.

Immunotherapy in patients with local HPV infection and high-grade squamous intraepithelial lesion following uterine cervical conization

OBJECTIVE

To establish the clearance of cervical human papillomavirus (HPV) infection following postoperative immunotherapy with inosine pranobex in women receiving surgical treatment of established high-grade squamous intraepithelial lesion (HSIL) of the uterine cervix.

MATERIALS AND METHODS

Over the six-year study period, 32 women with cervical HPV infection following electroconization (loop electrosurgical excision procedure) of the uterine cervix for established HSIL were randomly divided into two groups: I (n = 10) without and II (n = 22) with postoperative inosine pranobex immunotherapy. Follow-up after 24 and 48 months included cervical testing for HPV persistence and after 12, 24, and 48 months with cytology and colposcopy for dysplasia relapse (confirmed histologically).

RESULTS

Relapse monitoring in 32 women after 12 months revealed 1 and 0 HSIL positive in groups I and II, respectively; after 24 months an additional 3 patients in each group were positive; and after 48 months an additional 3 and 1 patients were positive in groups I and II, respectively (p < .05). The groups significantly differed (p < .05) with regard to clearing the most common high-risk HPV genotypes (HPV 16 and HPV 56).

CONCLUSIONS

Inosine pranobex immunotherapy in HPV-positive patients following cervical conization significantly increased the clearance of viral infection with high-risk genotypes and reduced relapse of HSIL.

Inosine Pranobex: A Key Player in the Game Against a Wide Range of Viral Infections and Non-Infectious Diseases

Inosine pranobex (IP), commonly known as inosine acedoben dimepranol, isoprinosine and methisoprinol, has been proven to positively impact the host’s immune system, by enhancing T-cell lymphocyte proliferation and activity of natural killer cells, increasing levels of pro-inflammatory cytokines, and thereby restoring deficient responses in immunosuppressed patients. At the same time, it has been shown that it can affect viral RNA levels and hence inhibit growth of several viruses. Due to its immunomodulatory and antiviral properties, and its safety profile, it has been widely used since 1971 against viral infections and diseases, among which subacute sclerosis panencephalitis, herpes simplex virus, human papilloma virus, human immunodeficiency virus, influenza and acute respiratory infections, cytomegalovirus and Epstein–Barr virus infections. Following an analysis of almost five decades of scientific literature since its original approval, we here summarize in vivo and in vitro studies manifesting the means in which IP impacts the host’s immune system. We also provide a synopsis of therapeutic trials in the majority of which IP was found to have a beneficial effect. Lastly, positive results from limited studies, suggesting the putative future use of IP in new therapeutic indications are briefly described. In order to support use of IP against viral infections apart from those already approved, and to establish its use in clinical practice, further well-designed and executed trials are warranted.

Funding: Ewopharma International.

Pharmacokinetic study of inosiplex tablets in healthy Chinese volunteers by hyphenated HPLC and tandem MS techniques

Inosiplex is a compound formulation composed of inosine and p-acetaminobenzoic acid (PABA) salt of N,N-dimethylamino-2-propanol (DIP). This study was to investigate the clinical plasma pharmacokinetic properties of DIP and PABA after single and multiple oral doses of inosiplex tablets in healthy Chinese volunteers. The established LC/MS/MS method for plasma DIP determination had a linear range of 0.02–10 µg/mL, and the HPLC method for plasma PABA determination had a linear range of 0.05–40 µg/mL. Linear pharmacokinetic characteristics were found with single oral doses of 0.5, 1.0 and 2.0 g. No obvious accumulation effects were observed for DIP and PABA.

Immunotherapy with isoprinosine as an adjuvant or independent method of treatment for patientswith papilloma viral infection

Isoprinosine (an immunotropic drug) has been well-known since the 1970s and is registered in most European countries. One of indications for its use is treatment of patients with papilloma viral infection. This article describes methods and efficacy of using Isoprinosine for such patients. The drug is administered as an adjuvant therapy in addition to destructive treatment methods or as a monotherapy. The literature review given in the article shows that the use of Isoprinosine increases the efficacy of destructive treatment methods, reduces the frequency of recurrences, normalizes the morphological picture of exocervix and endocervix, and results in the termination of the release of human papilloma virus from lesions.

Human papillomavirus: burden of illness and treatment cost considerations

The monetary and personal costs to society of human papillomavirus (HPV) infection are enormous. In order to make a comparison of different treatment methods we reviewed the entire literature on HPV treatment from January 1966 to December 2003 using MEDLINE, with particular reference to published meta-analyses, randomized controlled and comparative studies. Patient-applied therapies offer patients the possibility of convenient and, on the whole, pain-free treatment. Podofilox (podophyllotoxin) and salicylic acid for genital and extragenital warts, respectively, have the additional advantage of being the most cost-effective treatments and, on this basis, they are to be commended as appropriate first-line agents. The second-line treatment of choice for common warts is cryotherapy. For recalcitrant common warts possible options include inosine pranobex with cryotherapy or electrosurgery, imiquimod with paring and occlusion, intralesional bleomycin, or diphencyprone. Alternative first-line and second-line treatments for genital warts would be either some form of surgical removal or imiquimod. The first option may be the cheapest but this has to be balanced against a degree of post-operative morbidity. Limited data from comparative studies do not show any clear difference in efficacy between cryotherapy, trichloroacetic acid, scissor excision, electrosurgery, and laser surgery in the treatment of genital warts, and the cost effectiveness of these therapies is probably similar to that of imiquimod. Cryotherapy and trichloroacetic acid are relatively expensive and inconvenient for patients and should be reserved as third-line treatments with certain exceptions, such as cryotherapy for meatal warts. The duration of treatment is significantly related to the number of warts present, the area covered by the warts, and the length of time the warts have been present. For recalcitrant anogenital warts third-line treatment options that show promise include surgery in combination with imiquimod or cidofovir cream. For squamous intraepithelial lesions that cannot easily be excised or physically ablated current treatment options include imiquimod and fluorouracil cream. The latter is an inexpensive option but causes the greatest morbidity. It is hoped that cidofovir may be added to this list if it becomes commercially available, and that protective and therapeutic HPV vaccines will transform the management of HPV in the future.

Oral proliferative verrucous leukoplakia (PVL); open trial of surgery compared with combined therapy using surgery and methisoprinol in papillomavirus-related PVL

Proliferative verrucous leukoplakia (PVL) is a unique oral white lesion in which human papillomavirus (HPV) may play a role. PVL behaves far more aggressively than other forms of leukoplakia with a high rate of recurrence after surgical excision, and relentless progression to verrucous hyperplasia and to verrucous or squamous cell carcinomas. The treatment of PVL is usually by surgery, but there is often early recurrence. This study was an open trial of surgery in 25 patients with oral HPV-positive PVL, compared with combined therapy using surgery and methisoprinol in another group of 25 patients with oral PVL. Six months postoperatively there was a significant difference, with 18 recurrences in the patients treated by surgery alone compared to only two recurrences in the patients treated also with methisoprinol (isoprinosine or inosine pranobex), a synthetic agent with immunomodulatory properties and some antiviral activity against HPV. Eighteen months postoperatively there were no further recurrences in the patients treated by surgery alone but another two recurrences in the patients treated with methisoprinol. Overall, by 18 months follow-up, there were 18 recurrences in the group treated by surgery alone, compared with four in those also receiving methisoprinol. The use of this antiviral agent appeared to offer a significant enhancement to the surgical management of PVL.