Nektar Therapeutics has started a Phase 1 clinical trial of its biologic therapy NKTR-358 for inflammatory disorders and autoimmune diseases like multiple sclerosis.
NKTR-358 is a first-in-class regulatory T-cell stimulator designed to correct the immune system dysfunction associated with these disorders. It targets regulatory T-cells, or Tregs.
Other immunosuppressant therapies suppress the entire immune system. By stimulating the growth and activation of Tregs selectively, NKTR-358 decreases the side effects of immunosuppressive therapy.
Treg dysfunction has been implicated in many autoimmune disorders, including multiple sclerosis, Crohn’s disease, lupus, and rheumatoid arthritis, Nektar said.
Primate studies have shown that NKTR-358 increases Treg functioning. In particular, it restores the body’s ability to distinguish between its own molecules and invaders.
In addition, NKTR-358 reduced markers of disease progression in a mouse model of systemic lupus erythematosus (SLE), Nektar said.
“NKTR-358 has the potential to be a first-in-class key resolution therapeutic in immunology,” Jonathan Zalevsky, PhD, vice president of biology at Nektar, said in a press release.
“Data from non-human primate studies show that NKTR-358 drives proliferation and increased functional activity of Regulatory T cells (Tregs). Suboptimal Treg numbers and their lack of activity underlie many autoimmune diseases, including lupus, Crohn’s disease, psoriasis, rheumatoid arthritis and multiple sclerosis. As the first potential medicine to restore appropriate Treg levels and function, NKTR-358 could address a critical unmet need for patients with serious and debilitating immune disorders.” Zalevsky added.
The Phase 1 clinical trial that is under way will assess single ascending doses of NKTR-358 in around 50 healthy participants. The goal is to define a range of doses that can be used in new clinical trials. The drug’s safety and pharmacokinetics — or how it behaves in the body — will also be accessed.
A second trial evaluating NKTR-358 in patients with SLE is planned for the second half of 2017.
NKTR-358 is being developed as a once- or twice-monthly self-administered injection, Nektar said.
Estimates are that more than 23 million Americans have an autoimmune disease, which represents almost 8 percent of the population. More than 80 types of autoimmune diseases have been identified, and their prevalence is rising.