The case report was presented online as part of the 2020 American Academy of Neurology Science Highlights.
PML, an opportunistic infection of the brain caused by reactivation of the John Cunningham (JC) virus, has occurred with rituximab, another anti-CD20 therapy, in rare cases. Eight other cases of PML diagnosed after ocrelizumab initiation are considered carry-over cases related to prior treatment with natalizumab or fingolimod,, the manufacturer of ocrelizumab. No other PML cases have been associated with ocrelizumab alone.
The case without prior MS treatment was in a 78-year-old man. He presented with 2 weeks of progressive visual disturbance and confusion, said, chief of neurology at the Zucker Hillside Hospital in Glen Oaks, N.Y., and professor of neurology and psychiatry at the Donald and Barbara Zucker School of Medicine at Hofstra/Northwell in Hempstead, N.Y.
The patient had a right homonymous hemianopia. “MRI revealed an enlarging non-enhancing left parietal lesion without mass effect,” reported Dr. Gordon and colleagues. “CSF PCR revealed 1,000 copies/mL of JCV, confirming the diagnosis of PML. Blood work upon diagnosis revealed grade-2 lymphopenia ... and negative HIV serology.”
“The patient’s symptoms progressed over weeks to involve bilateral visual loss, right facial droop, and dysphasia,” they said. “Ocrelizumab was discontinued and off-label pembrolizumab treatment was initiated.” The patient did not respond to therapy and became bedbound, Dr. Gordon said in an interview. The patient received palliative care and died. An autopsy is pending.
“PML occurrence may have been multifactorial, due to a combination of the immunomodulatory function of ocrelizumab, possible immune senescence, and preceding mild lymphopenia,” Dr. Gordon and coauthors said. “This case emphasizes the importance of a thorough discussion of the risks and benefits of ocrelizumab, especially in patients at higher risk for infections, such as the elderly.”
The patient, who was Dr. Gordon’s patient for 20 years, had monitored updates in drug development and had looked forward to starting ocrelizumab, the first therapy approved for primary progressive MS, when it became available after its approval in 2017. The patient was concerned about progressively worsening gait impairment and related falls caused by MS.
Antibodies indicated that the patient had prior exposure to JCV, but Dr. Gordon considered the risk of PML to be relatively small. Prior to treatment, the patient’s absolute lymphocyte count was normal or indicated mild lymphocytopenia, which Dr. Gordon did not consider clinically significant. The patient received ocrelizumab for 2 years without incident.
In anfor health care professionals about ocrelizumab and PML prepared in February 2020, Genentech says the patient’s age and low absolute lymphocyte count are confounding factors, which distort “the assessment of association between exposure to a drug and an adverse event.
“As of January 31, 2020, no unconfounded PML cases associated with ocrelizumab therapy have been reported,” according to the document. “Out of more than 150,000 patients treated globally (clinical trials and post-marketing experience), there have been nine confirmed, confounded cases of PML in patients treated with ocrelizumab, of which eight were carry-over cases from a prior DMT.”
The prescribing information for the drug notes that no cases of PML were identified in ocrelizumab clinical trials, but that PML has been observed in patients treated with other anti-CD20 antibodies and other MS therapies. In addition, PML “has been associated with some risk factors (eg, immunocompromised patients, polytherapy with immunosuppressants).
“At the first sign or symptom suggestive of PML, withhold ocrelizumab and perform an appropriate diagnostic evaluation,” the prescribing information says. “MRI findings may be apparent before clinical signs or symptoms. Typical symptoms associated with PML are diverse, progress over days to weeks, and include progressive weakness on one side of the body or clumsiness of limbs, disturbance of vision, and changes in thinking, memory, and orientation leading to confusion and personality changes.”
“It is important for people to recognize that this is at least a possibility,” Dr. Gordon said. Any change in clinical symptomatology may warrant imaging, and CSF testing may be warranted if an MRI raises concerns about PML, he said.
Dr. Gordon has received research support from MSD (Merck), Eisai, AbbVie, and Janssen.
SOURCE: Sul J et al. AAN 2020. .