Should I switch to teriflunomide?
Please don’t panic! The coronavirus or COVID-19 pandemic is a problem but needs a calm and considered public health approach, which is happening in the UK. At the moment the general public, including pwMS, are overreacting.
Another patient emailed me yesterday to inform me they are going to stop their ocrelizumab and asked what the consequences will be. In the short-term very little, but if you decide to stop ocrelizumab it may provide an opportunity to test a hypothesis.
The treatment effect of ocrelizumab lasts many months and probably years after stopping the treatment. In the phase 2 ocrelizumab extension study, the group of patients who had been treated with ocrelizumab had no disease activity 18 months later. The latter is what underpins one of our proposed treatment arms in the ADIOS study and suggests that anti-CD20 could be used in a similar way to IRTs (immune reconstitution therapies), i.e. alemtuzumab, cladribine and HSCT.
What about safety? B-cells and b-cell responses don’t return immediately after stopping ocrelizumab. They take about 6-12 months to reconstitute. The B-cells that return are not memory B-cells, but initially naive cells that later mature with memory B-cells taking several years to reappear. The bigger issue is circulating immunoglobulin levels. With time as more patients develop hypogammaglobulinaemia on anti-CD20 therapies, the serious infection risk will go up. This is clearly seen in the Swedish rituximab data (see below), which shows that by 6 years approximately 50% of rituximab-treated patients have had a serious infection. This will almost certainly occur with ocrelizumab and ofatumumab and the other emerging anti-CD20 therapies.
Therefore stopping ocrelizumab, rituximab, ofatumumab or another anti-CD20 is not going to reverse your immune defects overnight; it will take months and possibly years to have a fully functional and reactive B-cell and plasma cell repertoire. Some argue that you can reverse these defects with immunoglobulin replacement therapy. Yes and no! Yes, in terms of broad-spectrum population-type immunity, but no in terms of antibodies against new infectious agents such as COVID-19. For the latter to be covered you would need immunoglobulin from COVID-19 exposed survivors. I suspect Chinese medical entrepreneurs will be working on this strategy already. Organism-specific, in this case, COVI-19 specific, hyperimmune globulin therapy is a well-trodden path and may yet prove to be an effective treatment strategy in managing high-risk COVID-19 infected patients as an emergency.
The latter may be relevant in the context of COVID-19 as the pandemic will play out over months to years. Similarly, if a COVID-19 vaccine is developed you may want to be in a position to maximise your benefit from any future vaccine by not being on an anti-CD20 or other immunosuppressive therapy.
What should you do if you want to derisk your immunosuppression, increase your vaccine responsiveness and keep your MS in remission? This is where the immunomodulators will see a resurgence, in particular teriflunomide. I have hypothesised in the past that teriflunomide is the ideal maintenance therapy post-induction with an anti-CD20; I called this the iTeri study. My grant application for the iTeri study was rejected by Genzyme-Sanofi; I suspect because the patent-life of teriflunomide was too short to make this study worthwhile. However, the iTeri data may emerge spontaneously from real-life data as a result of the COVID-19 pandemic. Let’s say 5,000-10,000 pwMS derisk their treatment from an anti-CD20 onto teriflunomide the data will emerge from registers on how good teriflunomide in keeping these people in remission.
Please be aware that I have always referred to teriflunomide as the dark horse DMT; COVID-19 may prove to be the stimulus that allows teriflunomide to run free outside its small paddock.
Gustavo Luna et al. Infection Risks Among Patients With Multiple Sclerosis Treated With Fingolimod, Natalizumab, Rituximab, and Injectable Therapies. JAMA Neurol 2019; Oct 17 (online)
Importance: Although highly effective disease-modifying therapies for multiple sclerosis (MS) have been associated with an increased risk of infections vs injectable therapies interferon beta and glatiramer acetate (GA), the magnitude of potential risk increase is not well established in real-world populations. Even less is known about infection risk associated with rituximab, which is extensively used off-label to treat MS in Sweden.
Objective: To examine the risk of serious infections associated with disease-modifying treatments for MS.
Design, setting, and participants: This nationwide register-based cohort study was conducted in Sweden from January 1, 2011, to December 31, 2017. National registers with prospective data collection from the public health care system were used. All Swedish patients with relapsing-remitting MS whose data were recorded in the Swedish MS register as initiating treatment with rituximab, natalizumab, fingolimod, or interferon beta and GA and an age-matched and sex-matched general population comparator cohort were included.
Exposures: Treatment with rituximab, natalizumab, fingolimod, and interferon-beta and GA.
Main outcomes and measures: Serious infections were defined as all infections resulting in hospitalization. Additional outcomes included outpatient treatment with antibiotic or herpes antiviral medications. Adjusted hazard ratios (HRs) were estimated in Cox regressions.
Results: A total of 6421 patients (3260 taking rituximab, 1588 taking natalizumab, 1535 taking fingolimod, and 2217 taking interferon beta/GA) were included, plus a comparator cohort of 42 645 individuals. Among 6421 patients with 8600 treatment episodes, the mean (SD) age at treatment start ranged from 35.0 (10.1) years to 40.4 (10.6) years; 6186 patients were female. The crude rate of infections was higher in patients with MS taking interferon beta and GA than the general population (incidence rate, 8.9 [95% CI, 6.4-12.1] vs 5.2 [95% CI, 4.8-5.5] per 1000 person-years), and higher still in patients taking fingolimod (incidence rate, 14.3 [95% CI, 10.8-18.5] per 1000 person-years), natalizumab (incidence rate, 11.4 [95% CI, 8.3-15.3] per 1000 person-years), and rituximab (incidence rate, 19.7 [95% CI, 16.4-23.5] per 1000 person-years). After confounder adjustment, the rate remained significantly higher for rituximab (HR, 1.70 [95% CI, 1.11-2.61]) but not fingolimod (HR, 1.30 [95% CI, 0.84-2.03]) or natalizumab (HR, 1.12 [95% CI, 0.71-1.77]) compared with interferon beta and GA. In contrast, use of herpes antiviral drugs during rituximab treatment was similar to that of interferon beta and GA and lower than that of natalizumab (HR, 1.82 [1.34-2.46]) and fingolimod (HR, 1.71 [95% CI, 1.27-2.32]).
Conclusions and relevance: Patients with MS are at a generally increased risk of infections, and this differs by treatment. The rate of infections was lowest with interferon beta and GA; among newer treatments, off-label use of rituximab was associated with the highest rate of serious infections. The different risk profiles should inform the risk-benefit assessments of these treatments.