Of the four older disease-modifying therapies, aka the CRABs (Copaxone, Rebif, Avonex and Betaseron), the last three are in the class of drugs known as interferon beta. Interferon beta-based medications work very well for some people, keeping relapses at bay and (presumably) delaying disability.
However, the interferons have disadvantages:
- Flu-like side effects
- Rare side effect of depression
- Possible liver involvement and toxicity in some peopel
- Neutralizing antibodies develop in some people, rendering the interferon-based medication less effective
- Researchers recently discovered that 1/3 of people with MS (with higher levels of a certain immune component) may actually do WORSE on interferons than if they took nothing (read more: Interferons May NOT Be Good for Some People with MS)
One or more of the above factors may mean that certain people either cannot tolerate the interferons or have disease progression and relapses while on one of these drugs, which in many cases means they should switch to a non-interferon based medication.
Although many people think that failing to respond to one of the interferons means that they need to go straight to Tysabri, there is still one drug in the older group to consider - Copaxone.
Copaxone (glatiramer acetate) is a completely different class of drug, with completely different mechanisms of action and different side effect profiles.
A study conducted in Spain among 60 people with relapsing-remitting MS who were switching from an interferon showed the following results:
- 21 patients were switching because the interferon was not effective in preventing relapses. These patients went from having an average of 1.39 relapses per year on the interferon to .52 relapses per year on the Copaxone. [Note: I found this interesting, as many experts think that Copaxone does not reach full effectiveness for at least 9 months. Therefore, it would be expected that the relapse rate in subsequent years would be even lower.]
- 39 patients discontinued interferons because of intolerable side effects and switched to Copaxone. Among these patients, the relapse rate was the same on interferons (0.35 relapses per year) and Copaxone (0.36 relapses per year).
While Copaxone certainly does have some drawbacks (daily injections and side effects like lipoatrophy and immediate post-injection reaction), it is good to know that there is still an option for people not responding to the interferon-based meds who do not feel ready to switch to Tysabri for many possible reasons.
BOTTOM LINE: I guess I thought most people knew that Copaxone was worth a shot if they failed to respond to an interferon-based med or could not tolerate the side effects. However, it seems like I get many e-mails from people whose docs switch them around on the interferons, then give up and put them on Tysabri. Of course, some people may want to head to Tysabri right away upon a disagreeable experience with an interferon or in the case of rapidly-progressing MS. Needless to say, this is a decision to be made with your neurologist after weighing all the factors.
What about you? Have you been on an interferon and switched to Copaxone? Have you been on Copaxone and switched to an interferon? What about those of you who have switched off of a CRAB to Tysabri? Please share any experiences in the comment section to help the rest of us make sense of all of this.
Source: Oreja-Guevara C, et al "Characteristics of switching from interferon beta to glatiramer acetate in non respondent relapsing remitting multiple sclerosis" AAN 2010; Abstract P06.162.