It would be immoral/criminal to have a placebo gro

It would be immoral/criminal to have a placebo group that isn't using drugs approved for use. Approved drugs set the new standard for care. If leronilmab has statistically significant benefit over the standard, then it puts even more pressure on FDA to approve.

The extension of the above logic is that other drugs will have a hard time getting approval once leronlimab becomes the standard for care.