FDA Authorizes Phase II Study for Natrunix in Rheumatoid Arthritis Patients

XBiotech Believes its Drug Candidate Natrunix Could Revolutionize Arthritis Treatment

AUSTIN, Texas, May 22, 2023 (GLOBE NEWSWIRE) -- XBiotech Inc. (NASDAQ: XBIT) today reports that the FDA’s Division of Rheumatology has authorized the Company to initiate a Phase II clinical study to test Natrunix as a treatment for Rheumatoid Arthritis.

The randomized, double-blind, placebo-controlled, trial will examine the effectiveness of Natrunix to treat rheumatoid arthritis compared to placebo in subjects already receiving stable but inadequate treatment with methotrexate (MTX). A total of 210 patients will be randomly distributed in equal numbers into three groups: including two different Natrunix dosages and a placebo group. Change in disease severity will be assessed at multiple time points according to the American College of Rheumatology (ACR) grading scale. Subjects will also be assessed for reduction in pain, number of tender or swollen joints as well as overall disease activity. The study concludes after subjects have received 12 cycles of therapy and follow-up.

Natrunix is a preparation using a monoclonal antibody indistinguishable from a naturally occurring antibody present in a healthy human. With billions of different antibodies circulating in the blood of healthy humans, identifying a single antibody molecule is technically challenging. Not a single antibody therapy marketed today or in the past was actually derived from a natural human antibody.

The Phase II study in rheumatoid arthritis is the culmination of XBiotech efforts to pioneer therapies derived from natural human immunity. XBiotech’s core proprietary technology enables identification of rare antibodies present in human donor blood that could be used to naturally treat disease, including the candidate therapy Natrunix for the treatment of arthritis. XBiotech also has antibodies to treat infectious disease, such as influenza, Ebola, COVID, Shingles and others.

Natrunix specifically targets and neutralizes a substance—interleukin-1α (IL-1α)—that is produced by the human body and is involved in many disease conditions. In chronic illness, such as rheumatoid arthritis, IL-1α can be a key part of the disease process. IL-1 can mediate the breakdown of joint synovium, bone remodelling, pain, and inflammation in the rheumatoid joint.

There are over 86,000 academic manuscripts and 6,600 review articles describing interleukin-1 (IL-1), making this substance among the most studied subjects in medicine. There are several marketed therapeutics targeting “interleukin-1” (including KINERET, ARCALYST and ILARIS). Yet the term interleukin-1 actually refers to two different molecules—IL-1α and IL-1β—that are produced at different times and places and play very different roles in disease. Remarkably, Natrunix is the only product candidate that exclusively targets and neutralizes the activity of IL-1α, or the “missing-link,” for the treatment of arthritis.