Favorable findings
Two other late-breaking posters at the meeting provided updates regarding antibody responses among patients receiving S1Ps. There has been concern that S1Ps may blunt antibody responses to COVID vaccinations.
The concern is in regard to their unique mechanisms of sequestering circulating lymphocytes, particularly the older, nonselective S1P receptor modulator fingolimod, said the author of one of the studies, Daniel Kantor, MD, president emeritus of the Florida Society of Neurology and founding president of the Medical Partnership 4 MS+.
“It appears the issues with fingolimod might relate to the level of white blood cell sequestration, [which is] greater in fingolimod than the newer S1P receptor modulators, and/or the result of S1P4 receptor modulation, which is not seen with the newer, selective medications,” Dr. Kantor said in an interview.
In a prospective observational trial of patients with relapsing MS, among 30 participants who were treated with ozanimod, the mean increase in IgG antibody titer 4 weeks after either of the two available mRNA vaccines was 232.73 AU/mL versus a mean increase of 526.59 AU/mL among 30 non–ozanimod/DMT-treated patients.
To date, only three patients in the study were taking ocrelizumab; for those patients, the mean increase in IgG titers was 0.633.
Despite the lower antibody titers in the ozanimod-treated patients, which Dr. Kantor noted are generally regarded as protective, all but one of the patients had positive results on T-Detect, which was indicative of vaccine protection.
“In this study, [relapsing] MS patients treated with ozanimod had an antibody and T-cell response to the mRNA COVID-19 vaccines,” he reported. “This trial is ongoing, with 48 weeks of follow-up expected in December 2022.”
Ponesimod results
In the other S1P modulator-related late-breaking study, Janssen Research and Development reported on antibody responses of patients who were treated with the S1P drug ponesimod in the phase 2 AC-058B202 study.
The median exposure to ponesimod at time of vaccination was 10.7 years (range, 9.8-11.8 years). There were 134 patients in the study. Of those, both prevaccination and postvaccination blood samples from 49 patients were tested for spike antibody concentrations.
Among those participants, 40 (81.6%) met the definition of response to the COVID-19 vaccination, defined as seroconversion in the case of negative prevaccination antibody testing or a fourfold antibody concentration increase in the case of a positive prevaccination antibody result.
Of the 38 antibody-negative participants, 33 (86.8%) achieved seroconversion post vaccination.
A total of 20 participants reported having had prevaccine COVID, while 17 had postvaccination COVID.
None of the cases were serious, severe, or fatal, and none led to permanent treatment discontinuation.
“In patients with RMS on ponesimod, the majority (> 80%) appear to develop a measurable SARS-CoV-2 humoral response after COVID-19 vaccination,” the authors, led by Janice Wong, of Janssen Research and Development, wrote.
“Further investigations on the efficacy and safety of COVID-19 vaccination in MS patients on ponesimod are warranted,” they added.
In a final study from Genentech, of 4848 patients with MS who were fully vaccinated during the Delta and Omicron waves, 1.3% had a COVID-related hospitalization. In addition, rate of severe SARS-CoV-2 infections was very low (0.6%); there were fewer than 10 infections in each subgroup of DMTs. These patients included 585 (17%) who were treated with ocrelizumab, 238 (7%) who were treated with S1P receptor modulators, 33 (1%) who were treated with interferons, 1,004 (29%) who were treated with other DMTs, and 1,574 (46%) for whom no DMTs were recorded.
“We can conclude from this study that the characteristics of people with MS with more severe COVID-19 outcomes resemble those observed in the general population,” such as in those who are older or have higher rates of comorbidities, Preeti Bajaj, team lead of HEOR, Neuroscience, at Genentech, said in an interview. “We believe [ocrelizumab] treatment decisions should be made between a patient and their treating neurologist or other medical professional based on a benefit-risk assessment specific to the individual patient.”