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BTK Inhibitors – The Next Big MS Therapy?

BTK Inhibitors – The Next Big MS Therapy?

Is orelabrutinib one of the next big MS therapies? Biogen is betting at least $125 million that it is.

Orelabrutinib is an experimental oral BTK inhibitor (BTKi). BTKi’s are designed to selectively block an enzyme that’s important for the activation of B-cells and microglia. Some of those immune cells drive the abnormal immune responses that characterize MS. Researchers hope the medication will lower inflammation and slow progression of all forms of MS, as Multiple Sclerosis News Today‘s Marta Figueiredo noted.

Orelabrutinib was developed as a cancer drug, but it began a Phase 2 clinical trial in March to judge its safety and efficacy as a treatment for relapsing-remitting MS. Biogen has bought the rights to globally distribute the medication as an MS drug. According to a Biogen press release, if certain development and sales goals are met, Biogen will pay up to an additional $812.5 million to InnoCare Pharma, the Chinese company that developed the medication, plus royalties.

Other BTK inhibitor tests underway

Orelabrutinib isn’t the only BTK inhibitor in the research pipeline. Sanofi has tolebrutinib (previously known as SAR442168), Roche is studying fenebrutinib, and EMD Serono (Merck KGaA outside North America) is investigating evobrutinib. All are in Phase 3 trials.

Small and selective

The big deal about BTK inhibitors seems to be that they can selectively target B-cells, wiping out those that harm the immune systems of people with MS while leaving normal B-cells alone. (Disease-modifying therapies such as Ocrevus (ocrelizumab) and rituximab wipe out all of the B-cells, leaving a greater chance of infection.)

“That’s important. That’s what you want,” Peggy Kendall, an allergist and immunologist at Washington University School of Medicine, told the journal Nature Biotechnology.

BTK inhibitors are small molecules. According to University of California, San Francisco neurologist Stephen Hauser, also quoted in Nature Biotechnology, this fact allows them to get into parts of the nervous system that other antibodies have a tough time reaching.

Hauser even used the “C-word,” telling the journal’s Elie Dolgin that if small-molecule therapies can “knock out the adaptive inflammation that’s overactive in the nervous system, I think we can really cure MS.”

Could that really happen?

That’s a pretty powerful prediction. No wonder several pharmaceutical companies have their research eyes on BTK inhibitors and are willing to pay big bucks to carve out a piece of this pie. I’m not a scientist or a doctor, so I can’t judge whether or not “we can really cure” is just hyperbole. But let’s hope that working with BKT inhibitors at least leads us in that direction, and that the cost of developing them won’t push their price tag into the stratosphere.

(A version of this post first appeared as my column on the MS News Today website.)

(Featured image by Michal Jarmoluk from Pixabay.)