Humira Biosimilar Shows Promise Treating Rheumatoid Arthritis

Pfizer recently announced positive results from the REFLECTIONS B538-02 clinical trial of an investigational biosimilar.

The drug, PF-06410293, is a monoclonal antibody that is a potential biosimilar of adalimumab (Humira). The experimental drug demonstrated equivalent efficacy as evident by the American College of Rheumatology 20 (ACR20) response rate at 12 weeks, according to a press release from Pfizer.

The clinical trial evaluated the safety, efficacy, and immunogenicity of the biosimilar compared with the reference product. Both drugs were administered in combination with methotrexate.

Included in the trial were 597 patients with moderate to severe rheumatoid arthritis (RA) who previously had an inadequate response to treatment with methotrexate monotherapy.

The primary endpoint was an equivalent ACR20 response at week 12, which was achieved, according to the press release.

This latest drug is Pfizer’s second investigational inflammatory biosimilar, and their third biosimilar overall to report positive results over the past 4 months, according to the press release. Pfizer’s biosimilar pipeline contains 8 different molecules in advanced development, with multiple drugs still in the earlier stages of development.

Adalimumab has been approved in the United States and in the European Union for the treatment of RA, juvenile idiopathic arthritis, psoriatic arthritis, ankylosing spondylitis, adult and pediatric Crohn’s disease, ulcerative colitis, plaque psoriasis, hidradenitis suppurativa, and uveitis.

In September 2016, adalimumab-atto (Amjevita), a biosimilar of adalimumab, became the fourth biosimilar to be approved. However, the FDA did not indicate that adalimumab-atto was interchangeable for adalimumab.

Despite the positive results seen in the current study, approval and marketing of this biosimilar is still a long way off. The manufacturer of adalimumab, AbbVie, went to great lengths to ensure that adalimumab-atto would be kept off the market, likely due to a large portion of the manufacturer’s revenue being generated from the drug.

AbbVie employed delay tactics by filing a lawsuit that alleges Amgen’s biosimilar, adalimumab-atto, infringes on multiple, valid patents. The company alleges that Amgen is infringing on 61 adalimumab patents, but they are only including 10 in the current lawsuit.

This new proposed biosimilar created by Pfizer may face similar legal challenges.

“Today’s announcement builds on Pfizer’s robust biosimilar pipeline which has now delivered positive top-line data results for 3 of our proposed biosimilars,” said Sumant Ramachandra, MD, PhD, MBA, head of Research and Development at Pfizer Essential Health. “As the leading global biosimilars company, we continue to advance our commitment to expand access to high-quality treatment options for patients living with chronic, debilitating conditions, such as those in inflammation. Inflammation remains one of the core research areas for Pfizer, spanning over 60 years and including a number of assets in various stages of development.”