PO-0636: Safety profile support efficacy of gingival clonidine tablet to prevent severe oral mucositis in HNC

Pharmacological modulation of radiation-induced oral mucosal complications

Radiation-induced mucositis is a common toxicity, especially in patients with head and neck cancers. Despite recent technological advances in radiation therapy, such as intensity-modulated radiotherapy, radiation-induced mucositis is still causing treatment disruptions, negatively affecting patients' long and short term quality of life, and impacting medical resources use with economic consequences. The objective of this article was to review the latest updates in the management of radiation-induced mucositis, with a focus on pharmaceutical strategies for the prevention or treatment of mucositis. Although numerous studies analysing the prevention and management of oral radiation-induced mucositis have been conducted, there are still few reliable data to guide daily clinical practice. Furthermore, most of the tested drugs have shown no (anti-inflammatory cytokine, growth factors) or limited (palifermin) effect. Therapies for acute oral mucositis are predominantly focused on improving oral hygiene and providing symptoms control. Although low-level laser therapy proved efficient in preventing radiation-induced oral mucositis in patients with head and neck cancer, this intervention requires equipment and trained medical staff, and is therefore insufficiently developed in clinical routine. New effective pharmacological agents able to prevent or reverse radio-induced mucositis are required.

Comparison of the Systemic and Local Pharmacokinetics of Clonidine Mucoadhesive Buccal Tablets with Reference Clonidine Oral Tablets in Healthy Volunteers: An Open-Label Randomised Cross-Over Trial

INTRODUCTION

The clonidine mucoadhesive buccal tablet (MBT) is a novel delivery system resulting in high and sustained concentrations of clonidine in the oral cavity. In a phase II clinical trial, clonidine MBT reduced the incidence of severe oral mucositis (OM) compared to placebo in head and neck cancer patients undergoing chemoradiation. This study compared the pharmacokinetics (PK), safety and tolerability of clonidine MBT with a reference oral tablet (OT).

METHODS

This was a randomised, three-period, single-dose crossover study in 36 healthy subjects aged 18-50 years. Eligibility was assessed within 14 days of the first dose. IMP was administered in the fasted state on day 1 of each treatment period. PK samples were collected up to 24 h (saliva)/96 h (blood) for measurement of the clonidine concentration. Safety and tolerability were evaluated at specified times throughout the study. A washout period of at least 7 days was observed between administrations.

RESULTS

Clonidine MBT (50 and 100 µg) applied to the upper gum resulted in a dose-proportional increase in saliva (C _max and AUC_0-t ) and plasma (C_max and AUC_0-inf) clonidine levels. Clonidine MBT was considered to mimic a continuous release of clonidine in plasma, significantly decreasing the C _max and AUC and increasing the T _max when compared with the reference clonidine HCl tablets. Clonidine MBT exhibited high and prolonged concentrations in saliva where concentrations with the clonidine HCl tablet were negligible. Clonidine MBT exhibited a favourable safety profile with significantly fewer subjects reporting AEs (dry mouth and fatigue) and a reduction in blood pressure when compared to the reference clonidine HCl tablets.

CONCLUSION

Clonidine MBT is well tolerated and exhibits proportional saliva and plasma PK over the 50-100-µg dose level. The MBT results in higher saliva concentrations and lower systemic exposure than OT, which was associated with a trend towards fewer adverse events and less dry mouth, fatigue and hypotensive effect.

FUNDING

Onxeo SA.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT02548806.