There has been lot of discussion about reference (originator) natalizumab and biosimilar natalizumab and some people have been claiming that the biosimilar, after they were switched, does not work as well and they have been quite vocal causing some places to switch back.
This switch was dictated by NICE because they had done a deal with the biosimilar manufacturer to get a better price.
https://www.nice.org.uk/guidance/ta1126/chapter/3-Committee-discussion#costs
However, the manufacturers of the reference were quite canny and they have pushed the use of subcutaneous natalizuamb and this can now be given at home and so they government does not have to collect the 20% value added tax (sales tax) levied on hospital given drugs, which they pay for. However because the money comes from different budgets NICE sees it as a saving so now they have said you can either use reference orginator natalizumab i.e Tysabri if it is used subcutaneously or biosimilar natalizumab i.e Tyruko as an infusion they say that one should not use originator natalizumab infusion….So those vocal about the switch from Tysabri to Tyruko, who were switched back may be switched to subcutaneous Tysabri if the letter of the NICE-law is followed….
The subcutaneous Tysabri is given as a 300mg injection every month, compared to 300mg infusion every 4 weeks. There have been studies of extended interval dosing of intravenous Tysabri to every 6 weeks. I suspect there isn’t the data on extended interval dosing for subcutaneous (under the skin) administration. However with subcutaneous administration, less antibody reaches the circulation we have seen with ocrelizumab they give more antibody i.e. 920mg under the skin compared to 600mg i.v. to get a similar effect. Natalizumab under the skin gives 30% less antibody in the circulation [Moskorova D et al. Analysis of serum natalizumab concentrations obtained during routine clinical care in patients with multiple sclerosis: A cross-sectional study. Mult Scler Relat Disord. 2025;94:106298]. It will be interesting to see the perception of the comparison, the available data suggests they are the same, but so did the difference between biosimilar and referernce natalizumab. It will be interesting to see how this changes use in different NHS trusts where some use more infusions than subcutaneous delivery. Yes, I do know which places do what. It is public data you could know too.
In the UK the list price is lhttps://bnf.nice.org.uk/drugs/natalizumab/medicinal-forms/
300mg in 15ml is £1,017 (Tyruko) and £1,130/15ml infusion or per 2ml (Tysabri) so NHS cost is (£1,017 + £203.4 = £1,220.4) or £1,130 + 226 = £1356 so £136 saving for Poundland UK PLC). However subcutaneous tysabri (£1,130) at home is £90 cheaper than intravenous biosimilar. However people are probably stated on treatment in hospital so the saving advantage may be lost.
Now the real prices are top secret….what a SH1-show created to save a few quid. They learned and with anti-CD20 depletion they allowed people to stay on their treatment rather than being forced to change.
Please don’t panic yet but spare a thought for the neuros who have to dealt with the ditacts
But, with such dictacts coming it could be good for the generic manufacturers of cladribine, If the price drops which it should once the cladribine patents expire, which iminent.
Source: multiple-sclerosis-research.org