I'm really sorry that you have had such horrible relapses in such close succession. Your MS seems to be very aggressive.
I know that any of the DMDs take a minimum of 4 months to get underway and longer to reach full effect, but I also see that you are not seeing any slow down at all.
The Interferons work in a different way than Copaxone, so we can't presume that one of them won't work. Now, I have no real grounds for this, but I have gotten the impression from my neuro and remarks reported by other people's neuro's that Copaxone was not a favored med for disease that seemed pretty aggressive.
The interferons are three meds that each have a different dosing. The lowest dose per week is Avonex and the highest is Betaseron. My gut feeling is that B or R would be the next choice. One chemo med that is used off-label (meaning not approved) for MS are azathioprine.. In my reading azathioprine has not been shown to be superior to the approved DMDs for slowing relapses or slowing the rate of new lesion formation.
Mito is approved and is up for consideration when the assessment is SPMS. However, in addition to opening the patient up to severe infections, it also has direct cardiac toxicity. they dose the patient until they can measure the beginning of unacceptable level of decreased heart function. Then no more Mito - ever. So then a person still has MS AND heart damage. It would not be a choice of mine, at least not at my age. Personal opinion. It may have other redeeming qualities I haven't heard of yet.
Aza and Mito are problematic because they are true immune suppressants and have serious infections as possible side-effects. Mito also has direct cardiac toxcity that is not reversable. Mito is approved for Secondary Progressive MS.
You sound like you may be entering a secondary progressive phase, depending on how much improvement you see in symptoms between the relapses.
I am not up to date on what all the meds they use, alone or in combo, for SPMS.
Tysabri has the best track record here, in terms of slowing things down. I believe that some insurance companies require that a person with RRMS have failed two first line DMDs before they will approve Tysabri. So your teatment choices may depend on where your neuro places you on the spectrum of RRMS toward SPMS.
Then there are the more experimental therapies aimed at people with aggressive disease, like HiCy - High Dose Cyclophosphamide. Recently we had people reminding us of the good success that Johns Hopkins has had with this - but the study numbers are still small.
Sometimes the neuros choose to continue with the current med and do supplemental monthly Steroid infusions of 1 to 3 days. If the person is not yet in the range of when the med would expect to be helpful, this can tide them over.
I had a thread not too long ago called "Transitioning from RRMS to SPMS"
http://www.medhelp.org/posts/Multiple-Sclerosis/Transitioning-from-RRMS-to-SPMS-correction/show/1133638
I'm sorry I can't give more advice or info.
Quix