I've taken 6MP for about 8 years. Originally I was told that the drug takes 3 to 4 months to start working, longer than the 1 month Dr. Shen mentioned. While waiting for the drug to work I took steroids but I haven't had to take steroids since the 6MP started working.
Bottom line: no flares (fingers crossed) in 8 years so my advice is to hang in there. I hope it works for you too!