sooo sooo sorry jws80... whilst I have no experience with clinical trials for Oral cancer, I worked with clinical trials professionally.
there are differing stages for Clinical trials; thosein very early phase, and later phases ii or iii. ...those in the higher level phases have been tried previously with signs of success. Those that are in the earliest stages have not yet been tried on larger numbers of people and therefore may not demonstrate efficacy. If there is a clinical trial he is eligible to enroll in, it is valuable to weigh out the potential side effects vs the other conventional treatments such as the chemo. There are likely other members who have experience first hand with OC clinical trials and can possibly shed a better light on them for you than I.

positive energy your way!