I'm pretty sure he does not mean previously treated for OM as far as I am aware the Standard of Care is ice chips so it would be hard to find anyone who has not had ice chips. I believe he means treated for cancer previously.
LEGEND OF ABBREVIATIONS
B = Brilacidin, the antibiotic
K = Kevetrin, the oncology drug
P = Prurisol, the psoriasis drug
SAE = Serious Adverse Event
IND = Investigational New Drug