Exit out of multipass shader

Hi, I have a multipass shader that is in the following format:

 Shader "ShaderLib/MultipassShader" {
     Properties {
         
     }
     Category {
         SubShader {
         Pass {
         
             CGPROGRAM
             #pragma vertex vert
             #pragma fragment frag
             
             VertexShaderOutput vert(appdata_base vi) {
                 ...
             }
 
             half4 frag(VertexShaderOutput vo) : COLOR {
                 ...
             }
 
             ENDCG
         }
         Pass {
 
             CGPROGRAM
             #pragma vertex vert
             #pragma fragment frag
             
             VertexShaderOutput vert(appdata_base vi) {
                 ...
             }
 
             half4 frag(VertexShaderOutput vo) : COLOR {
                 ...
             }
 
             ENDCG
         }
         Pass {
 
             CGPROGRAM
             #pragma vertex vert
             #pragma fragment frag
             VertexShaderOutput vert(appdata_base vi) {
                 ...
             }
 
             half4 frag(VertexShaderOutput vo) : COLOR {
                 ...
             }
 
             ENDCG
         }
         ...
         ...
         }
     }
 }

Is there a way to exit out of any pass (and bypass all the following passes), depending on some value I am reading from an input texture map?

Thanks!