Literature Review

Biosimilar equal to natalizumab for relapsing remitting MS



An agent biologically similar to the humanized monoclonal antibody natalizumab is as effective and safe as the original reference drug for relapsing remitting multiple sclerosis (RRMS) – and has a similar level of immunogenicity, new research shows.

The investigators noted that these phase 3 trial findings are the final stage in the regulatory approval process.

“There will be a biosimilar that with respect to all parameters – efficacy, side effects, immunogenicity – doesn’t differ from the original drug and will probably be an option to consider to reduce treatment costs in MS,” said lead investigator Bernhard Hemmer, MD, a professor in the department of neurology, Technical University of Munich (Germany).

The findings were published online in JAMA Neurology.

Potential cost savings

Disease-modifying therapies (DMTs), particularly targeted biologics, have revolutionized the treatment of MS, including RRMS. Natalizumab, which was the first targeted biologic therapy approved for RRMS, is very effective and widely used, Dr. Hemmer said.

However, this and other DMTs are costly. Biosimilars, which are medicines clinically similar to an already marketed reference biologic medicine, can address this issue. In the areas of rheumatology and oncology, biosimilars have already demonstrated significant cost savings and improved treatment access.

The biosimilar natalizumab (biosim-NTZ), developed by Polpharma Biologics, is the first biosimilar monoclonal antibody therapy to be developed for MS.

Health authorities such as the Food and Drug Administration require comparative phase 3 studies to confirm there are no clinically relevant differences between a proposed biosimilar and its reference medicine.

The new multicenter, phase 3, double-blind, randomized trial – known as Antelope – included 264 adult patients with RRMS at 48 centers in seven Eastern European countries. Most study participants were women (61.4%), and their mean age was 36.7 years.

All study participants were randomly assigned to receive intravenous infusions every 4 weeks of 300 mg of biosim-NTZ or reference natalizumab (ref-NTZ) for a total of 12 infusions.

At week 24, 30 patients were switched from ref-NTZ to biosim-NTZ for the remainder of their infusions. Including such a population is required by regulatory agencies to ensure switching patients from a drug they’ve been taking to a new biosimilar does not introduce any concerns, said Dr. Hemmer.

Comparable efficacy, safety profile

The primary efficacy endpoint was the cumulative number of new active brain lesions on MRI.

At baseline, 48.1% of the biosimilar group and 45.9% of the reference drug group had at least one gadolinium-enhancing lesion. In addition, 96.9% of the biosimilar group had more than 15 T2 lesions, compared with 96.2% of the reference group.

At week 24, the mean difference between biosim-NTZ and ref-NTZ in the cumulative number of new active lesions was 0.17 (least square means, 0.34 vs. 0.45), with a 95% confidence interval of –0.61 to 0.94 and a point estimate within the prespecified margins of ± 2.1.

The annualized relapse rate for biosim-NTZ and ref-NTZ was similar at 24 weeks (0.21 vs. 0.15), as well as at 48 weeks (0.17 vs. 0.13). For Expanded Disability Status Scale scores, which were similar between treatment groups at baseline (mean, 3.4 vs. 3.2), change at 24 and 48 weeks was minimal and similar in both groups.

The safety profile was as expected for patients with RRMS receiving natalizumab. There were few adverse events of special interest, with similar proportions across all treatment groups.

The overall adverse-event profile for patients who switched from ref-NTZ to biosim-NTZ was similar to patients continuing ref-NTZ treatment and did not indicate any new or increased risks associated with switching.

Rates of treatment-emergent adverse events (TEAEs) were similar, at 64.9% for biosim-NTZ, 68.9% for ref-NTZ, and 73.3% for the switch group. The most-reported TEAEs among all treatment groups were nervous system disorders and infections and infestations.

Progressive multifocal leukoencephalopathy (PML), a rare and potentially fatal demyelinating disease of the central nervous system, is associated with some DMTs – notably ref-NTZ. It is caused by infection with the John Cunningham virus (JCV) (also referred to as human polyomavirus), the researchers noted.

As per the study protocol, no participant had a JCV-positive index of more than 1.5 at baseline. Proportions of patients positive for anti-JCV antibodies were similarly distributed between treatment groups throughout the study.


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