Comparisons of successful and failed Phase III trials of drugs and biologicals tested for mitigation of oral mucositis in patients being treated with radiotherapy with or without concomitant chemotherapy for cancers of the head and neck

Abstract Oral mucositis (OM) remains a significant toxicity among patients being treated with radiotherapy (RT) alone or with concomitant chemotherapy (CRT) for cancers of the head and neck (HNC). Given its clinical significance as an unmet need and its potential commercial viability, the pharmaceutical industry has been actively pursuing an effective intervention. Despite this interest and activity, only a few agents have been studied in Phase III trials ( n = 6). The objective of this study was to identify common features that differentiate successful and failed Phase III OM trials. We used the United States Patent and Trademark Office Patent Public Search database to search patents with “oral mucositis” in the claims. We then searched ClinicalTrials.gov and PubMed to determine if Phase III or Phase II trial data for identified biologics/drugs had been published. We assessed each Phase III and Phase II trial for characteristics that may be associated with trial success or failure. We considered a study as a “success” if the primary endpoint reached statistical significance, and we considered a study as “failure” if the primary endpoint did not reach statistical significance. Of the three successful Phase III trials, one investigated avasopasem manganese (Galera Therapeutics) and two examined palifermin (Amgen). The three failed trials included those evaluating dusquetide (Soligenix), iseganan hydrochloride (IntraBiotics Pharmaceuticals), and clonidine (Monopar Therapeutics). We found that differences in the level of sponsor funding, patient inclusion criteria including radiation source and concomitant chemotherapy regimen, and concordance of primary efficacy outcomes between Phase II and Phase III trials influenced outcomes. To properly design clinical trials for OM in HNC patients, it is important that researchers and sponsors take note of specific study characteristics associated with success or failure, particularly with Phase III trials where the risks and costs are the highest.