transparency of an moving object

An object moves from point a to point b. In point a the transparency is 100%, until it reaches point b the transparency must be 0%.

You will need to change the material color alpha with something like this

yourMaterial.SetColor("_Color", new Color(R,G,B, A));

Change the A on update. Now make:

A = Mathf.Lerp(0, 1, T)

Where T is a function based on distance or distance traveled from pointA to pointB.
Hope you understend