humira/methotrexate combination-alternatives

I have behcets disease which affects my joints, digestive system , skin and eyes, I have tried azothiaprin but was found to have a gene that means I was unable to break it down and became ill, I have since tried infliximab/methotrexate combination but found that my symptoms were being controlled for less time with each administration. I also started to become very breathless, both these drugs were stopped and I was given fortnightly injections of humira, the effects of which are not lasting above a week methotrexate was re-introduced and the breathlessness returned within days, I am still on the humira and am to be put on to another drug in combination with it in place of the methotrexate, I do not know what yet. I have been on 25mg of prednisolone also for approx 2 yrs now reducing am down to 13mg daily. Can you tell me what alternatives there are to the methotrexate to be used in combination with humira, and also if you think that the reduction in steroids is contributing to dramatic return of symptoms.