Variations on the theme. Which will you choose?


Why is this important? You can get a leading brand or a generic at the fraction of the cost, they both contain more of less the same stuff, but come in different packaging but with different prices. What do you do?

Well the same issue comes with MS drugs and they do the “Aldi/Hoffer” approach i.e. the same lemondade in the same bottle but a different label and one costs £1.50, the other at £0.32. For example two products are made by the same manufacturer, especially as some have their own generics arms. Now we have fingolimod, siponimod, ozanimod, and ponesimod, which are you going to take?….The brand with the most information? The original, The latest? The one clearing the longest or shortest, the cheapest? or the most expensive?, as Quality costs? As NDG pointed out we have at least four companies making Brutons tyrosine kinase inhibitors, but before that. Next up we have the dimethyl fumarate me-toos. The active ingredient of di(two)methyl fumarate is mono(one)methyl fumarate so you can use one of two agents that make monomethyl fumarate or go straight for monomethyl fumarate. They deliver as much monomethyl fumarate so again, what do you chose? The product you know about or a new Me-Too? The choice is yours. I

Pharmacokinetics and Bioavailability of Monomethyl Fumarate Following a Single Oral Dose of Monomethyl Fumarate or Dimethyl Fumarate. Lategan TW, Wang L, Sprague TN, Rousseau FS. CNS Drugs. 2021. doi: 10.1007/s40263-021-00799-9.

Background: Dimethyl fumarate [DMF]. Drug name removed) is an approved product for the treatment of relapsing forms of multiple sclerosis. Monomethyl fumarate (MMF. Drug name removed) is the only active metabolite of DMF and is responsible for its therapeutic efficacy.

Objective: The objective of this study was to determine whether two MMF capsules each containing 95 mg of MMF is bioequivalent to one DMF capsule containing 240 mg of DMF, a prodrug of MMF.

Methods: This was a single-dose, open-label, randomized, two-way crossover study evaluating two treatments over two periods with a washout interval between treatments. Fifty healthy subjects were randomized to receive a single dose of the test drug MMF 190 mg as 2 × 95 mg delayed-release capsules or the reference drug DMF 240 mg as a 1 × 240-mg delayed-release capsule. Blood samples were obtained prior to dosing and at prespecified time points through 24 h post-dose to determine plasma concentrations of MMF. The pharmacokinetic parameters of MMF were calculated including maximum observed concentration, time to reach maximum observed concentration, apparent half-life of the drug in plasma.

Results: The mean ratios (90% confidence interval) of the test drug MMF vs the reference drug DMF were 104.84% (95.54-115.05) maximum observed concentration, respectively. Two capsules of MMF was safe and generally well tolerated. The most common adverse event for both products was flushing, 60% and 51%, for MMF and DMF respectively.

Conclusions: Based on the statistical analysis results of the pharmacokinetic parameters of MMF, a single oral dose of two MMF 95 mg capsules is bioequivalent to a single oral dose of one DMF 240 mg capsule.

I was at a meeting not so long ago where the issue of me-toos was addressed and there was little interest, so the new versions are going to have to do something more interesting, be better, be much safer, but maybe in the COVID era they offer something different. I guess we have to see the sales figures to see where thoughts lie.

CoI: Multiple. None considered relevant

Disclaimer: Please note that the opinions expressed here are those of the author and do not reflect the positions of the Barts and The London School of Medicine and Dentistry nor Barts Health NHS Trust or Queen Mary Univeristy of London.

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  • In some countries (markets for the pharmas), you get better support (insurance, follow-up, attention and a smile on the face) from doctors prescribing drugs from the big guns. (My friend was treated terribly by her neuro’s assistant because she insisted on switching from Teri to Rituximab).

    I think it would be sensible to start with the original for at least 6 months and if tolerating the treatment well, consider move on to the generics.

  • For small molecules, if there is a generic, I will buy the generic (thank good for generic sildenafil vs the original…). Have not so far had to decide on biosimilars, really.

    Also, le- vs teriflunomide… Is the former even used for MS?

    And arguably, Mavenclad vs injectable cladribine?



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