Ocrelizumab concentration and antidrug antibodies are associated with B-cell count in multiple sclerosis

The ocrelizumab wearing-off phenomenon is associated with reduced immunomodulatory response and increased neuroaxonal damage in multiple sclerosis

OBJECTIVE

The wearing-off phenomenon is common in people with multiple sclerosis (MS) treated with ocrelizumab. We aim to evaluate the presence and severity of wearing-off to ocrelizumab in relation to demographic and MS clinical variables, immune profiling, and a marker of neuroaxonal damage (plasma neurofilament light chain (pNfl)).

METHODS

This cross-sectional study included MS patients treated with ocrelizumab from at least 1 year. Wearing-off questionnaire and blood samples were collected between 21 and 23 weeks after the previous ocrelizumab infusion. Lymphocyte subpopulations were evaluated on peripheral blood using flow cytometry. PNfl was evaluated using fully automated chemiluminescent enzyme immunoassay.

RESULTS

We included 106 people with MS (age 49.5 ± 11.6 years; females 42.3%; wearing-off 57.6%). On regression models, wearing-off was associated with higher pNfl, CD8, CD3, and CD3CD27 lymphocytes. Most frequent wearing-off symptoms were cognitive, sensory, and balance problems; wearing-off started < 1 week (9.4%), 1-4 weeks (10.7%) or > 4 weeks (10.7%) before infusion; 44.8% of the complaints were moderate to severe. Severity of wearing-off was associated with higher pNfl and CD8 lymphocytes.

CONCLUSIONS

Wearing-off is common in people with MS treated with ocrelizumab, and is associated with reduced immunomodulation (higher T lymphocytes) and increased neuroaxonal damage, suggesting reduced treatment response.

Evaluating the Therapeutic Potential of Ublituximab in the Treatment of MS: Design, Development and Place in Therapy

B cells are critical to the pathogenesis of multiple sclerosis (MS), an autoimmune disease of the central nervous system. B cell depletion using anti-CD20 monoclonal antibodies (mAbs) has proven to be an extremely successful treatment strategy, with profound suppression of both clinical and radiological evidence of focal inflammatory disease. Several anti-CD20 mAbs are now licensed for use in MS, with ublituximab being the latest to gain regulatory approval. The unique properties of each of the anti-CD20 mAb may result in nuanced differences in timing, duration and depth of B cell depletion, with the potential for such differences to have a clinical relevance to both drug efficacy and adverse effects. In this review, we summarize the design, development, and current place in MS therapy for ublituximab.

Extended interval dosing with ocrelizumab in multiple sclerosis

BACKGROUND

This study investigates clinical and biomarker differences between standard interval dosing (SID) and extended interval dosing (EID) of ocrelizumab therapy in multiple sclerosis (MS).

METHODS

This is a prospective, double-arm, open-label, multi-center study in Denmark. Participants diagnosed with MS on ocrelizumab therapy >12 months were included (n = 184). Clinical, radiological, and blood-based biomarker outcomes were evaluated. MRI disease activity, relapses, worsening of neurostatus, and No Evidence of Disease Activity-3 (NEDA-3) were used as a combined endpoint.

RESULTS

Out of 184 participants, 107 participants received EID (58.2%), whereas 77 participants received SID (41.8%). The average extension was 9 weeks with a maximum of 78 weeks. When comparing EID to SID, we found higher levels of B-cells, lower serum concentrations of ocrelizumab, and similar levels of age-adjusted NFL and GFAP in the two groups. No difference in NEDA-3 between EID and SID was demonstrated (hazard ratio: 1.174, p = 0.69). Higher levels of NFL were identified in participants with disease activity. Body mass index correlated with levels of ocrelizumab and B-cells.

CONCLUSION

Extending one treatment interval of ocrelizumab on average 9 weeks and up to 78 weeks did not result in clinical, radiological, or biomarker evidence of worsening compared with SID.

Cross-Reactivity of Antibodies to Rituximab with Other Therapeutic Anti-CD20 Antibodies

One reason for a lack of response to rituximab as well as infusion-related anaphylactic adverse events is the development of antidrug Abs to rituximab. Besides rituximab, a number of other therapeutic Abs targeting CD20 are nowadays available as alternatives. In this study, we investigated the potential cross-reactivity of (human) anti-rituximab Abs to three other anti-CD20 mAbs: ofatumumab, obinutuzumab, and ocrelizumab. In 25 cases of anti-rituximab Abs, cross-reactivity was examined using both direct binding assays and inhibition immunoassays. Although no cross-reactivity was observed to ofatumumab or obinutuzumab, 8 of 25 samples also showed reactivity toward ocrelizumab in at least one of the two assays. Furthermore, in three cases of anti-ocrelizumab Abs, cross-reactivity to rituximab was observed in an inhibition immunoassay, albeit not in a direct binding assay. Our results suggest that obinutuzumab or ofatumumab are safe anti-CD20 alternatives in case of the presence of anti-rituximab Abs. It is advisable to proceed cautiously if switching from rituximab to ocrelizumab (or vice versa) is considered in case these alternatives may not be available.