Scientific and clinical aspects of the use of cidofovir in recurrent respiratory papillomatosis

[Epidemiological features of laryngeal papillomatosis in adults in Moscow]

OBJECTIVE

To evaluate the incidence of laryngeal papillomatosis (LP) and LP recurrence in adults and to determine the risk factors for the development of LP recurrence in adults in Moscow. To solve the tasks set, a survey of patients carried out, including the collection of complaints and anamnesis, a standard examination of the ENT organs, an assessment of the condition of the larynx, and a histological examination.

MATERIAL AND METHODS

We conducted a retrospective analysis of the case histories of 299 patients with LP observed and treated at the Sverzhevsky Research and Clinical Institute of Otorhinolaryngology in the period 2010-2020.

RESULTS

On average, over the entire study period, the prevalence of PG was 17.80%. It was found that out of 299 patients, 69.6% (n=208) had a relapse of LP. Papilloma of the larynx were more often localized in the glottis. 275 (92%) patients had a widespread form of LP. LP recurrences were significantly more common in women and in patients with an existing cicatricle process in the larynx. The relapse rate was higher in non-smokers (73.5% vs 47.8%; p<0.001). Although the recurrence rate was higher in patients with non-voice occupations (70.6% vs. 52.9%), there was no statistically significant association between relapses and the vocal professions (p=0.125).

CONCLUSION

As a result of the study, a number of risk factors for laryngeal papillomatosis recurrent have been identified, and their study should be continued.

Bevacizumab as treatment option for recurrent respiratory papillomatosis: a systematic review

Purpose

To this day, there is no cure for recurrent respiratory papillomatosis (RRP). Multiple surgical procedures are performed to achieve symptom relief and prevention of airway obstruction. A promising drug for RRP is the vascular endothelial growth factor (VEGF) binding antibody bevacizumab. This chemotherapeutic agent has an angiogenesis-inhibiting effect which inhibits tumor growth. The objective of this review was to investigate the efficacy of bevacizumab as treatment option for RRP, and to explore the difference of its effects between intralesional and systemic treatment.

Methods

A systematic search was conducted in Cochrane, PubMed, and Embase. Articles were included if bevacizumab treatment was given intralesionally and/or systemically. The methodological quality of the studies was assessed using the CAse REport (CARE) guidelines.

Results

Of 585 unique articles screened by title and abstract, 15 studies were included, yielding a total of 64 patients. In 95% of the patients treated with systemic bevacizumab, the post-bevacizumab surgical interval was considerably prolonged. More than half of them did not need any surgical intervention during mean follow-up of 21.6 months. Treatment with intralesional bevacizumab showed a lower efficacy: in 62% of the patients, the post-bevacizumab surgical interval (mean, 1.8 months follow-up) was extended when compared to the interval before the treatment.

Conclusion

Systemically and intralesionally administered bevacizumab are effective treatment options for severe RRP. A systemic administration might be the treatment of first choice. Further prospective research with long term follow-up is advocated to elucidate this important topic.

The Antiviral Agent Cidofovir Induces DNA Damage and Mitotic Catastrophe in HPV-Positive and -Negative Head and Neck Squamous Cell Carcinomas In Vitro

Cidofovir (CDV) is an antiviral agent with antiproliferative properties. The aim of our study was to investigate the efficacy of CDV in HPV-positive and -negative head and neck squamous cell carcinoma (HNSCC) cell lines and whether it is caused by a difference in response to DNA damage. Upon CDV treatment of HNSCC and normal oral keratinocyte cell lines, we carried out MTT analysis (cell viability), flow cytometry (cell cycle analysis), (immuno) fluorescence and western blotting (DNA double strand breaks, DNA damage response, apoptosis and mitotic catastrophe). The growth of the cell lines was inhibited by CDV treatment and resulted in γ-H2AX accumulation and upregulation of DNA repair proteins. CDV did not activate apoptosis but induced S- and G2/M phase arrest. Phospho-Aurora Kinase immunostaining showed a decrease in the amount of mitoses but an increase in aberrant mitoses suggesting mitotic catastrophe. In conclusion, CDV inhibits cell growth in HPV-positive and -negative HNSCC cell lines and was more profound in the HPV-positive cell lines. CDV treated cells show accumulation of DNA DSBs and DNA damage response activation, but apoptosis does not seem to occur. Rather our data indicate the occurrence of mitotic catastrophe.

HPV vaccination as preventive approach for recurrent respiratory papillomatosis - a 22-year retrospective clinical analysis

BACKGROUND

Recurrent respiratory papillomatosis (RRP) is a rare, benign disease of the aerodigestive tract, especially the larynx, caused by infection with the human papillomavirus (HPV) types 6 or 11. Current management focuses on surgical debulking with microdebrider of papillomatous lesions with or without concurrent adjuvant therapy, e.g. Cidofovir®. This retrospective study evaluates the results of patients treated at a department of the university clinic between 1990 and 2012 and compares the results of the conventional treatment with a new treatment approach using adjuvant vaccination with Gardasil®.

METHODS

A retrospective Kaplan Maier analysis of n = 24 patients diagnosed and treated with RPR was performed. The records were reviewed for gender, age at the time of first manifestation of disease and time to recurrence.

RESULTS

Only n = 2 (15.4%) of the n = 13 vaccinated patients developed a recurrence of the disease after a mean time of 54.9 months (SD: 9.5 months). All patients who were not vaccinated (n = 11; 100%) developed a relapse after a mean time of 12.3 months (SD: 9.72 months).

CONCLUSION

We propose that adjuvant HPV vaccination with Gardasil® might have a preventive effect in RRP by occluding new papilloma formation.

Recurrent laryngeal papillomatosis with oesophageal involvement in a 2 year old boy: successful treatment with the quadrivalent human papillomatosis vaccine

Authors present a case report of a 2-year-old boy with recurrent laryngeal papillomatosis with oesophageal involvement due to human papilloma virus types 6 and 11, who needed surgical treatment every 4-6 weeks, altogether 11 times. After detailed immunological evaluation of basic immunological parameters, and in vitro detection of good responses to routine childhood immunization, a therapeutic vaccination has been decided with a 4-valent HPV vaccine. Following the third vaccine dose both laryngeal and oesophageal lesions disappeared completely, and for 2 years follow-up no papillomas could be detected. Vaccination could be a promising method in the treatment of RRP in children.

Clinical efficiency of quadrivalent HPV (types 6/11/16/18) vaccine in patients with recurrent respiratory papillomatosis

The aim of the study was to assess the clinical efficiency of quadrivalent HPV (types 6/11/16/18) vaccine in patients with recurrent respiratory papillomatosis (RRP). This was a prospective study of patients with RRP treated from January 2009 to July 2012 at the Ear, Nose and Throat Department of the Emergency County Hospital of Cluj-Napoca, Romania. Demographic characteristics, onset of RRP, HPV typing, use and number of cidofovir injections, number of surgeries for RRP per year, and use of human papillomavirus vaccine (types 6, 11, 16, 18) (recombinant, adsorbed)/Silgard® were considered from all the patients included in the study. Charts were reviewed for follow-up after diagnosis, after cidofovir, and after Silgard; all the statistical tests were applied at a significance level of 5%. The recurrences were observed within 27.53 ± 11.24 days after intralesional cidofovir injection. Thirteen patients with recurrence after cidofovir agreed and received Silgard® vaccine. 85% [54.44–99.41] of patients had no recurrences during 1-year follow-up. The recurrence of papillomas was observed in two patients (15%, 95% CI [0.59–45.56]), one with adult-onset RRP and one with juvenile-onset RRP. Both recurrences appeared after the first Silgard dose; one month after the third vaccine dose each patient underwent a new surgery for remaining papillomas with no recurrences at 1-year follow-up visit. Silgard® vaccination had a good effect and proved to be efficient in the treatment of our patients with RRR without appearance of recurrence in 85% of the patients during 1-year follow-up.

Treatment of paediatric laryngeal papillomas: web survey of British Association of Paediatric Otolaryngologists

Background and objective:

Recurrent respiratory papillomatosis is the most common benign neoplasm of the larynx in children. Intralesional injection of cidofovir may have some potential as an adjunctive treatment. There is no standardised protocol in the UK for the management of recurrent respiratory papillomatosis. This study aimed to investigate the management practices of surgeons treating paediatric recurrent respiratory papillomatosis in the UK.

Method:

A web questionnaire survey was sent by e-mail to all members of the British Association of Paediatric Otorhinolaryngology.

Results:

Out of 35 respondents, 23 were at that time treating children with recurrent respiratory papillomatosis. Nineteen respondents preferred to use a microdebrider, 12 preferred laser, and 5 preferred cold steel along with either laser or a microdebrider. Twelve surgeons used cidofovir for selected patients and 12 surgeons did not use cidofovir for any patients. Cidofovir was considered after 0–4 surgical procedures by seven respondents, after 4–6 surgical procedures by four respondents and after 6 surgical procedures by six respondents. Eleven respondents warned patients about the possible side effects of cidofovir and five gave no warning.

Conclusion:

There was no consensus as to when it would be appropriate to use cidofovir, indicating the need for cidofovir usage guidelines.

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

OBJECTIVE

Surgical management of recurrent respiratory papillomatosis (RRP) usually involves resection via microlaryngoscopy. Intralesional injection of cidofovir has been shown to be an effective adjuvant treatment, but remains unlicensed. United Kingdom General Medical Council guidelines recommend the prescribing doctor should "be satisfied that there is a sufficient evidence base and/or experience of using the medicine to demonstrate its safety and efficacy". This study reviews the published dosing regimens of intralesional cidofovir in the treatment of RRP in order to provide a precedent for those that wish to prescribe it.

METHODS

A systematic review of the literature was undertaken using Medline, EMBASE and CINAHL. Articles describing the use of intralesional cidofovir for RRP were reviewed. Information regarding cidofovir concentration, volume, total dose, number of treatments, interval between treatments, overall treatment period and follow up was extracted.

RESULTS

Fifty-one articles were identified. Concentration of cidofovir injected ranged from 0.0001mg/ml to 37.5mg/ml, with 5 to 7.5mg/ml being the most common. The volume of cidofovir solution injection ranged from 0.1 to 20ml. The total dose per injection ranged from 0.15 to 105mg. There was wide variation in dosing regimens with different intervals between endoscopies, number of injections and total doses delivered.

CONCLUSIONS

Based on this published literature, the precedent for prescribing intralesional cidofovir supports a concentration of 5 to 7.5mg/ml. Volumes up to 5ml per injection are routinely used. Total dose and frequency of cidofovir administration is highly variable. The need for repeat doses of cidofovir should be judged on an individual basis.

Next-generation treatment strategies for human papillomavirus-related head and neck squamous cell carcinoma: where do we go?

Oncogenic human papillomavirus (HPV) is currently recognised as a major risk factor for the development of head and neck squamous cell carcinomas (HNSCC). HPV is mostly detected in tumours arising from the oropharynx and more specifically from the tonsil. HPV-related tumours display clinical and molecular characteristics that are distinct from HPV-unrelated tumours, which are generally induced by alcohol and tobacco abuse. Detection of biologically active HPV in HNSCC has prognostic relevance, which warrants the separate classification of HPV-induced tumours and is a prerequisite for further optimisation of treatment protocols for this distinct group. Current guidelines for the treatment of oropharyngeal squamous cell carcinoma (OPSCC) have not incorporated specific treatment modalities for HPV-related tumours. The development of such treatment options is still in a preclinical phase or in early clinical trials. Recent data on treatment response of OPSCC have been obtained by retrospectively analysing HPV-status and indicate that patients with HPV-related tumours show a favourable prognosis, independent of the type of treatment. These patients may benefit from de-intensified treatment, which should be assessed in prospective clinical trials. The development and future use of new antiviral and immunomodulatory therapeutics may be instrumental in this approach to improve survival rates and decrease disease-and-treatment-related morbidity. In this review we will focus on present therapeutic HPV-targeting strategies and discuss future directions for de-intensified treatment of HPV-positive HNSCC.

Effectiveness of cidofovir intralesional treatment in recurrent respiratory papillomatosis

To present the results of recurrent respiratory papillomatosis (RRP) treatment with surgical excision and adjuvant anti-viral cidofovir intralesional use and to examine the correlation between the cidofovir effectiveness and the patient previous history of multiple larynx procedures, age, extension of lesion and dose. 32 patients with laryngeal papillomas were treated with cidofovir in our Department between I.2009 and I.2011. The number of previous RRP debulking procedures ranged from 1 to 100. The intensity of papillomatosis differed from one anatomic site and moderate growth to four or five localizations with heavy extension. The number of injections per patient varied from 1 to 7, and the total volume of 5 mg/ml solution varied from 2 to 33 ml. The injections were combined with laser debulking of the lesions. In disperse papillomata, the injections were administered in particular anatomical sites in 4–6 weeks intervals, in massive lesions injections were repeated in the same anatomical site in 2–4 weeks. Complete remission was observed in 18 out of 32 patients. 13 patients showed remission in a place of cidofovir injection. One patient did not react to the drug. In four patients, new changes in injection places appeared. In two patients, hepatic toxic side effects were observed. Intralesional cidofovir injection has been shown to be an effective and safe therapy for laryngeal papillomatosis and should be considered in those patients who experienced disease relapse.

Yet another ten stories on antiviral drug discovery (part D): paradigms, paradoxes, and paraductions

This review article presents the fourth part (part D) in the series of stories on antiviral drug discovery. The stories told in part D focus on: (i) the cyclotriazadisulfonamide compounds; (ii) the {5-[(4-bromophenylmethyl]-2-phenyl-5H-imidazo[4,5-c]pyridine} compounds; (iii) (1H,3H-thiazolo[3,4-a]benzimidazole) derivatives; (iv) T-705 (6-fluoro-3-hydroxy-2-pyrazinecarboxamide) and (v) its structurally closely related analogue pyrazine 2-carboxamide (pyrazinamide); (vi) new strategies for the treatment of hemorrhagic fever virus infections, including, as the most imminent, (vii) dengue fever, (viii) the veterinary use of acyclic nucleoside phosphonates; (ix) the potential (off-label) use of cidofovir in the treatment of papillomatosis, particularly RRP (recurrent respiratory papillomatosis); and (x) finally, the prophylactic use of tenofovir to prevent HIV infections.

Recurrent respiratory papillomatosis: an uncommon but potentially devastating effect of human papillomavirus in children

Human papillomavirus (HPV) causes disease not only in the genital tract, but also in the larynx. Within the larynx HPV 6/11 causes recurrent respiratory papillomatosis (RRP). RRP is relatively uncommon, yet it is devastating for the patient who requires many surgical procedures over years to control it. The cost of HPV-related genital tract disease is thought to be around £31 million per annum, whereas RRP costs in the region of £4 million annually despite RRP being comparatively rare. The HPV vaccination programme has brought great hope, although it is unfortunate that the current UK programme only targets high-risk HPV. Targeting both low- and high-risk HPV would have had additional benefits for the UK.

Mucosal Bridge and Pitting of the True Vocal Fold: An Unusual Complication of Cidofovir Injection

We describe a unique complication of intralaryngeal cidofovir injection and present the case of a patient with recurrent respiratory papillomatosis in whom both a mucosal bridge and a pit of the true vocal fold developed after intralaryngeal cidofovir injection. A 40-year-old man presented with laryngeal papillomatosis 19 years after being treated with surgery and adjuvant radiotherapy for leiomyosarcoma of the cervical esophagus. The patient underwent 5 papillomatosis excisions combined with subepithelial injections of cidofovir to the bilateral true vocal folds at a concentration of 5 mg/mL without any complications. He subsequently received 2 higher-dose cidofovir treatments 6 weeks apart because of a poor response to the previous treatments. Two months later, there was evidence of a large mucosal bridge along the free edge of the right vocal fold and a deep pit in the lateral aspect of the same vocal fold. We conclude that repeated high-dose intralesional injection of cidofovir may result in significant morphological changes to the vocal fold, most likely due to mucosal injury.