That's a sample size and actuarial question.

No. Confounding variables are NOT fixed by using larger sample sizes.

As a trained epidemiologist, I regret that I have but one upvote to give.

Even if an abundance of patients with sufficiently similar terminal illnesses at sufficiently similar stages willing to forego their entitlement to other treatment or pain relief in the interests of medical science exists, I can't see "although several patients died during the trial the increase in death rate wasn't statistically significant and whilst possible side effects such as nausea and extreme fatigue were reported, these were also near-universal in the control group" as an advance in testing procedures...