Switching

Switching-2-glatiramer acetate

Last updated on November 28th, 2024 at 01:45 pm

Possible reasons to switch

  • Glatiramer acetate (GA) has one of the best safety records in pregnancy.
  • GA is relatively well tolerated in the short term and is not immunosuppressive.
  • Following an adverse event on another DMT, for example persistent lymphopaenia.
  • GA has no monitoring requirements.

Reasons for caution

  • Adherence can be a problem in the long term, owing to injection fatigue.
  • Long-term use of GA leads to lipoatrophy (loss of fatty tissue under the skin).
  • Its impact on preventing end-organ damage (brain volume loss) is only modest.

GA-20 to GA-40 switch

People with MS may decide to switch between GA preparations because of local skin reactions. GA-40 is administered only three times per week and has demonstrated better tolerability than the daily GA-20 formulation.

Lack of efficacy

I would not recommend switching between GA preparations because of a lack of efficacy or perceived lack of efficacy. If you have had a suboptimal response to one GA preparation it would make sense to switch classes. In general, I tend to escalate treatment rather than switch to another moderate efficacy DMT; vertical escalation rather than horizontal switching.

Other DMTs

Provided the baseline screening bloods are fine and there are no specific contraindications, I see no reason why GA can’t be used after any of the other licensed DMTs. However, if you are switching due to a suboptimal response, I would recommend a more efficacious DMT. There is reasonable real-life data that shows switching upwards (escalation) gives a better overall response rate than switching to a similar efficacy DMT (horizontal switching). I suspect that most people with MS who switch to GA will do so for family planning reasons, because GA has one of the best safety records in pregnancy. Another reason to switch may be an adverse event on another DMT, for example a persistent lymphopaenia.

Special circumstances

The presence of other specific comorbidities may make it difficult to switch from certain DMTs to GA. These could include generalised urticaria or a known allergic reaction to GA in the past.