“Whatever choice you make makes you. Choose wisely” – Roy T Bennett, The Light in the Heart.
Unfortunately, you can’t pick your race or whether you get MS, nor whether you have to deal with both. Racial differences in treatment response for health conditions is not a novel concept. When I was a trainee I was taught that it was harder to control blood pressures in African-Americans than in Caucasian individuals, with poorer response to B-blockers and ACE inhibitors. To date this remains one of the most widely studied racial differences in response to medicines.
This April at AAN 2021, the NYU School of Medicine presented preliminary work demonstrating a difference in response to anti-CD20 therapies between African-American and Caucasian individuals with MS/NMO. They studied B-cell repopulation rates in 168 MS/NMO patients (71% female) treated with either rituximab or ocrelizumab.
Their main finding was that B cells repopulated faster in African-American individuals than Caucasians (unfortunately, I’m not able to show you their slides as it’s still unpublished work) – 76% versus 33% at 6-12 months, respectively. The B-cell subset composition was no different between the two groups, suggesting that this is purely an efficacy thing.
So what does this mean? It is likely that anti-CD20 treatments aren’t as effective in African-Americans than in Caucasians. We may have to do more frequent anti-CD20 dosing or higher total dose in this population to have the same effect as in Caucasians.
It should be noted that these are findings from a single study and a pooled analysis of the Phase III ocrelizumab clinical trials asking the same questions would be helpful.AAN2021
Disclaimer: Please note that the opinions expressed here are those of the author NDG 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 University of London.