I have not dealt much with medications for MS in this blog but plan to do so in the near future; however, the approval of Ocrevus requires comment. In the authors opinion, this is the biggest advance in therapy since the first interferon was approved in 1993. This is a block buster drug. It is an infusion with two initial infusions followed by one every 6 months. Its effectiveness is up there with natalizumab (Tysabri), daclizumab (Zinbryta) and alendronate (Lemtrada) but without many of the risks. It is not free of risk, very few drugs are but it has much less risk than other drugs that are this effective. There are two cases of progressive multifocal leukoencephalopathy (PML) but this is and will be a rare event. It occurred in someone who had been on natalizumab (Tysabri) and we don’t yet have background information on the other patient. It remains likely that it will continue to be a rare event.
Ocrelizumab also has been approved for primary progressive MS, the first drug approved for that purpose. Some of the other drugs should have been approved (for example beta interferons have a similar effect in progressive MS but because, like ocrelizumab, it did not improve walking it was not approved as it didn’t change the Kurtzke score which at that level is entirely dependent on walking. It did improve hand function as shown by the 9-hole peg test and cognition as shown on the paced auditory serial addition test (PASAT) but at that time the FDA only accepted the Kurtzke scale and wouldn’t accept any drug that didn’t improve disease progression on that scale. It has advanced and will now accept at least one other measure, the MS Functional Composite scale.