Medical ethicist: Assuming there is a reasonable chance for a cure, it is acceptable to offer experimental treatments for a disease to patients who suffer from extreme symptoms of that disease.
Conclusion
It's never acceptable to offer an experimental treatment to patients who don't have any extreme symptoms of that disease.
Evidence
If a patient is showing extreme symptoms from a disease, then it's acceptable to offer an experimental treatment. Those patients are best able to weigh the tradeoffs of doing an experimental treatment.
Evaluation
The second premise is there to potentially hide the Necessary vs. Sufficient flaw. The author is performing an illegal negation: If a patient has extreme symptoms, then it's acceptable to offer experimental. thus, if a patient does not have extreme symptoms, then it's not acceptable to offer experimental.
Goal
Look for an argument that says, If you're of type X, then thing Y applies. Thus, if you're not of type X, then thing Y doesn't apply