I cannot find the telephone number for Amgen, which is out in CA. But I have Guilford's no. which is 410-631-6300. Call them and ask for Amgen's telephone no. Call Amgen and tel l them you want to sign up for GPI -l046 and woulfd they give you the name of the center closest to where you live. The only criteria that I know of is that you have had to be disagnosed within the last five years. I called and I could not sign up because I was diagnosed 16 years ago.