Another option is the complete rebuild of the curve. CURVES REBUILD CURVE This will enable the change of the amount of vertices of the curve to the change of Degree of the curve.
Rebuild curve is a rather complex command, and recommended only to use if necessary. It can be used to solve problems with existing curves, and gives high flexibility in its settings, therefore it is recommended to read the help file on the rebuild option, when wanting to use it. The example below shows a rebuild with curvature, where the area's with high curvature get more cv's, and an example with transforming a curve's degree.