Systematic review of intralesional cidofovir dosing regimens in the treatment of recurrent respiratory papillomatosis

Intralesional Cidofovir: A Systematic Review of Administration Protocols and Long-term Recurrence Rates in Adult and Juvenile Recurrent Respiratory Papillomatosis

OBJECTIVE

This is a systematic review aimed to explore Cidofovir administration protocols, recurrence rates, and long-term effectiveness for severe cases of recurrent respiratory papillomatosis (RRP). The primary goal was to identify current practices, determine the preferred protocol, and assess the adjuvant therapy's ability to prevent long-term papilloma recurrence in juvenile and adult-onset disease.

METHODS

The following databases were searched: Pubmed, Google Scholar (pages 1-10), EMBASE, Scopus, ISI (clarivate), Cochrane Library, and Journal Storage from 1996 to June 2022. Articles that reported the use of intralesional Cidofovir in RRP and reported remission/recurrence rates with follow-up were included in the review. The systematic review was registered through PROSPERO and contains the detailed protocol for the conduction of the review.

RESULTS

A total of 389 records were identified, 126 titles and abstracts screened, 45 studies fully read, and 30 studies met the inclusion criteria. Two hundred and fourteen adult-onset RRP (AORRP) and 126 juvenile-onset RRP (JORRP) cases were treated with Cidofovir across the included studies. There was no universal protocol for administering Cidofovir, with variations in concentration, treatment period, number and interval of injections, and follow-up duration. Most lesions showed human papilloma virus types 6 and 11. Recurrence rates varied, and other outcomes reported included remission rates, lesion reduction, surgical intervals, and side effects. Some studies demonstrated significant improvements in disease severity and extended intervals between recurrences after Cidofovir administration.

CONCLUSIONS

The analysis of 30 studies reveals the need for greater consistency in reporting treatment parameters and outcomes. The use of recurrence-free period as an outcome measure and the potential benefits of a concentration of 7.5 mg/mL are identified. Additionally, the importance of viral typing within papilloma lesions is emphasized. To further enhance understanding and establish optimal protocols, future research should focus on uniform reporting, including severity, dosage, interval, treatment duration, functional outcome, and related procedures.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022299549.

Efficacy of cidofovir versus bevacizumab in recurrent respiratory papillomatosis: A randomized, double-blind, placebo-controlled pilot study

OBJECTIVES

After surgical resection of papilloma, adjuvant therapy may be recommended for the control of recurrent respiratory papillomatosis (RRP). As the efficacy of adjuvant therapy remains unproven, the aim of this study was to compare the efficacy of cidofovir versus bevacizumab used as adjuvant therapies for the control of RRP.

METHODS

This randomized, double-blind, placebo-controlled pilot study was performed in a national respiratory disease referral centre. Patients with RRP were recruited prospectively and were divided into juvenile or adult RRP. Participants were randomly assigned to receive adjuvant therapy with cidofovir, bevacizumab or placebo. The study drug or placebo was administered after direct microlaryngoscopy with papilloma resection using cold instruments. The Derkay severity score and the Voice Handicap Index (VHI) were assessed at 3-6-week intervals, for a total of 3 visits. Follow-up included VHI and Derkay score assessments at 2-month intervals over the course of one year. Annual rates before and after surgical treatment were compared.

RESULTS

Five children and 11 adults were enrolled in the study. After one year, the group treated with cidofovir had a significant decrease in Derkay score (p=.027). No difference between treatment arms was observed in the annual surgery rate. There was a significant decrease in the VHI score in all treatment groups (p<.001), and no significant difference was observed between groups (p=.32).

CONCLUSION

While we observed a significant decrease in RRP severity with intralesional cidofovir, we were unable to provide proof of efficacy of intralesional bevacizumab.

CLINICALTRIALS

gov Identifier: NCT02555800.

Infantile recurrent respiratory papillomatosis: review of adjuvant therapies

BACKGROUND

Recurrent respiratory papillomatosis is a potentially life-threatening condition characterised by the growth of exophytic lesions within the larynx and trachea. The principal aim of management is maintenance of an adequate airway by surgical debulking. Several adjuvant therapies have been used to varying effect to reduce the burden of this disease and increase the interval between debulking procedures. The most severe cases present in children aged under three years, who are therefore most likely to need adjuvant therapies. The current evidence base on adjuvant treatments relating to children who present aged under three years has been reviewed.

METHODS

A literature review of articles in Cochrane, PubMed and Embase databases was carried out. Given the rarity of the condition in this age group, all the literature relates to case reports and case series.

RESULTS AND CONCLUSION

The following adjuvant therapies have been used in children who presented under three years of age: quadrivalent human papilloma virus vaccine, intralesional cidofovir, pegylated interferon, alpha-interferon, cimetidine and cetuximab.

Efficacy of cidofovir versus bevacizumab in recurrent respiratory papillomatosis: A randomized, double-blind, placebo-controlled pilot study

OBJECTIVES

After surgical resection of papilloma, adjuvant therapy may be recommended for the control of recurrent respiratory papillomatosis (RRP). As the efficacy of adjuvant therapy remains unproven, the aim of this study was to compare the efficacy of cidofovir versus bevacizumab used as adjuvant therapies for the control of RRP.

METHODS

This randomized, double-blind, placebo-controlled pilot study was performed in a national respiratory disease referral centre. Patients with RRP were recruited prospectively and were divided into juvenile or adult RRP. Participants were randomly assigned to receive adjuvant therapy with cidofovir, bevacizumab or placebo. The study drug or placebo was administered after direct microlaryngoscopy with papilloma resection using cold instruments. The Derkay severity score and the Voice Handicap Index (VHI) were assessed at 3-6-week intervals, for a total of 3 visits. Follow-up included VHI and Derkay score assessments at 2-month intervals over the course of one year. Annual rates before and after surgical treatment were compared.

RESULTS

Five children and 11 adults were enrolled in the study. After one year, the group treated with cidofovir had a significant decrease in Derkay score (p=.027). No difference between treatment arms was observed in the annual surgery rate. There was a significant decrease in the VHI score in all treatment groups (p<.001), and no significant difference was observed between groups (p=.32).

CONCLUSION

While we observed a significant decrease in RRP severity with intralesional cidofovir, we were unable to provide proof of efficacy of intralesional bevacizumab. Clinicaltrials.gov Identifier: NCT02555800.

Imaging of the rare cystic lung diseases

When discussing cystic lung diseases, a certain group of diseases tends to receive the majority of attention. Other less frequently discussed cystic lung diseases are also important causes of morbidity in patients. Etiologies include genetic syndromes, lymphoproliferative diseases, infections, exogenous exposures, and a developmental abnormality. This review article focuses on the clinical and imaging features of these other cystic lung diseases.

Efficacy of microsurgery in combined with topical-PDT in treating recurrent respiratory papillomatosis: compare JORRP with AORRP

Background: Recurrent respiratory papillomatosis (RRP) remains a challenging and frustrating disease to treat.Objective: To explore the efficacy of microsurgery in combined with Topical-PDT in treating recurrent respiratory papillomatosis.Materials and methods: Fifty patients with RRP were treated with microsurgery in combined with Topical-PDT. Medical document of each patient was retrospectively reviewed. Detailed clinical information, metrics of clinical course, and current results were evaluated.Results: Juvenile onset RRP (JORRP) might experience a more aggressive course than AORRP (adult onset RRP) with higher Derkay score (p < .01) and higher operation frequency per year (p < .01). Microsurgical excision combined with Topical-PDT every 25 days achieved "remission" of disease in 78% of patients, "clearance" of disease in 52%, and "Cured" in two patients. Each patient who achieved "remission" of disease, performed 6.82 ± 3.39 operations, and continued 8.93 ± 7.03 months of treatment duration. No statistically differences were found in these two aspects between JORRP and AORRP. A negative correlation between tracheotomy and the efficacy of microsurgery in combined with Topical-PDT was found (p = .025, Pearson's r = -0.3).Conclusions and significance: Microsurgery in combined with Topical-PDT might be a powerful method to treat RRP. Tracheotomy is a negative factor for this therapy.

Advances in Designing and Developing Vaccines, Drugs and Therapeutic Approaches to Counter Human Papilloma Virus

Human papillomavirus (HPV) is a viral infection with skin-to-skin based transmission mode. HPV annually caused over 500,000 cancer cases including cervical, anogenital and oropharyngeal cancer among others. HPV vaccination has become a public-health concern, worldwide, to prevent the cases of HPV infections including precancerous lesions, cervical cancers, and genital warts especially in adolescent female and male population by launching national programs with international alliances. Currently, available prophylactic and therapeutic vaccines are expensive to be used in developing countries for vaccination programs. The recent progress in immunotherapy, biotechnology, recombinant DNA technology and molecular biology along with alternative and complementary medicinal systems have paved novel ways and valuable opportunities to design and develop effective prophylactic and therapeutic vaccines, drugs and treatment approach to counter HPV effectively. Exploration and more researches on such advances could result in the gradual reduction in the incidences of HPV cases across the world. The present review presents a current global scenario and futuristic prospects of the advanced prophylactic and therapeutic approaches against HPV along with recent patents coverage of the progress and advances in drugs, vaccines and therapeutic regimens to effectively combat HPV infections and its cancerous conditions.

Recurrent respiratory papillomatosis: the role of cidofovir

Recurrent respiratory papillomatosis (RRP) is a rare condition that affects the respiratory system. It is caused by human papilloma virus (HPV) infection. Usually infection and papilloma growth is limited to 6-12 months duration; however, some patients have persistent disease, resulting in long-term symptoms and the need for recurrent intervention. Predominant symptoms include shortness of breath, reduced exercise tolerance and voice deterioration during flares. Current gold-standard management is through resection via microdebrider, CO2 laser, cryotherapy, electrocoagulation, Nd: YAG laser or pulse-dye laser. However, despite these therapies, approximately 20% of patients require adjuvant therapy. We discuss the use of intralesional cidofovir in the management of tracheal papillomatosis. Cidofovir's mechanism of action involves incorporating into the virus DNA chain and therefore, inhibiting the viral DNA polymerization process and hence replication.

The broad-spectrum anti-DNA virus agent cidofovir inhibits lung metastasis of virus-independent, FGF2-driven tumors

The FDA-approved anti-DNA virus agent cidofovir (CDV) is being evaluated in phase II/III clinical trials for the treatment of human papillomavirus (HPV)-associated tumors. However, previous observations had shown that CDV also inhibits the growth of vascular tumors induced by fibroblast growth factor-2 (FGF2)-transformed FGF2-T-MAE cells. Here, we demonstrate that CDV inhibits metastasis induced by FGF2-driven, virus-independent tumor cells. Pre-treatment of luciferase-expressing FGF2-T-MAE cells with CDV reduced single cell survival and anchorage-independent growth in vitro and lung metastasis formation upon intravenous inoculation into SCID mice. This occurred in the absence of any effect on homing of FGF2-T-MAE cells to the lungs and on the growth of subconfluent cell cultures or subcutaneous tumors in mice. Accordingly, CDV protected against lung metastasis when given systemically after tumor cell injection. Lung metastases in CDV-treated mice showed reduced Ki67 expression and increased nuclear accumulation of p53, indicating that CDV inhibits metastasis by affecting single cell survival properties. The anti-metastatic potential of CDV was confirmed on B16-F10 melanoma cells, both in zebrafish embryos and mice. These findings suggest that CDV may have therapeutic potential as an anti-metastatic agent and warrants further study to select those tumor types that are most likely to benefit from CDV therapy.

An overview of early investigational drugs for the treatment of human papilloma virus infection and associated dysplasia

INTRODUCTION

High-risk HPV (HR-HPV) related invasive cervical cancer (ICC) causes >270,000 deaths per annum world-wide with over 85% of these occurring in low-resource countries. Ablative and excisional treatment modalities are restricted for use with high-grade pre-cancerous cervical disease with HPV infection and low-grade dysplasia mostly managed by a watch-and-wait policy.

AREAS COVERED

Various pharmacological approaches have been investigated as non-destructive alternatives for the treatment of HR-HPV infection and associated dysplasia. These are discussed dealing with efficacy, ease-of-use (physician or self-applied), systemic or locally applied, side-effects, cost and risks. The main focus is the perceived impact on current clinical practice of a self-applied, effective and safe pharmacological anti-HPV treatment.

EXPERT OPINION

Current prophylactic HPV vaccines are expensive, HPV type restricted and have little effect in already infected women. Therapeutic vaccines are under development but are also HPV type-restricted. At present, the developed nations use national cytology screening and surgical procedures to treat only women identified with HPV-related high-grade dysplastic disease. However, since HPV testing is rapidly replacing cytology as the test-of-choice, a suitable topically-applied and low-cost antiviral treatment could be an ideal solution for treatment of HPV infection per se with test-of-cure carried out by repeat HPV testing. Cytology would only then be necessary for women who remained HPV positive. Although of significant benefit in the developed countries, combining such a treatment with self-sampled HPV testing could revolutionise the management of this disease in the developing world which lack both the infrastructure and resources to establish national cytology screening programs.

Recurrent respiratory papillomatosis: current and future perspectives

Although recurrent respiratory papillomatosis is a benign disease of the upper aerodigestive tract caused by infection with human papillomavirus, the disease process is unpredictable, ranging from mild disease and spontaneous remission to an aggressive disease with pulmonary spread and requirement for frequent surgical debulking procedures. It can present a protracted clinical course and cause potentially life-threatening compromise of the airways. Over recent decades, a number of alternative medical therapies to standard surgical treatment have been investigated, with modest outcomes overall. Currently, some additional therapies are being explored, together with novel surgical instrumentation that can help to avoid inevitable long-term stenotic complications, ultimately affecting quality of life. Hopefully, clinicians might soon be able to significantly improve the quality of treatment and outcomes for patients affected with recurrent respiratory papillomatosis, with human papillomavirus vaccination having a potentially important role.

Intralesional cidofovir as adjuvant for the successful management of aggressive respiratory papillomatosis in an infant

Recurrent respiratory papillomatosis (RRP) in young children is frequently characterized by a recalcitrant course and need for multiple surgeries. Periodic surgical debulking and ablation is the mainstay of therapy as a cure for RRP rarely occurs. Benefits of adjuvant treatment with local injection of cidofovir in aggressive cases of RRP have been reported in both children and adults. However, a consensus on initiation, dosage, or scheduling of this drug has not been established in the very young patient. Literature on successful remission in children less than 1 year of age is not available. One such case of an infant with aggressive RRP treated with local adjuvant cidofovir is described herein.