I did think that it was a bit strange that they had only 3...

I did think that it was a bit strange that they had only 3 patients, so I guess this was the clarification on that:

"Four patients were enrolled in dose cohort 2 with three patients meeting the U.S. Food and Drug Administration (FDA) approved criteria for evaluation. The initial response data that has been provided at this time indicates that the 2nd dose cohort demonstrated local disease stability in two of the three patients."

It is common for patients to enroll in a study, only to be disqualified at a later stage. The reason for this is that the qualifying criteria are very strict, the fourth patient may have even passed away, or became too sick, developed another condition that precluded them, or perhaps dis-enrolled themselves from the program.

We should thank those who selflessly gave themselves to the trial during the safety stage, as there is little chance that the low-dose treatment will improve quality of life or expectancy.