Are my codes prone to open redirect attacks?

Hi, I would like to know if this set of codes is prone to open redirect attacks or not as I am task to solve the security issues of the application.

if (e.CommandName == "edit")
            {
                Response.Redirect("SumRInvAdd.aspx?prg=E&id=" + SumRInvID + "&bid=" + HttpUtility.UrlEncode(ddlBatchId.SelectedValue));
            }