Monkey Peptide Reverses Joint Disease!

Certain monkeys and their powerful peptides could hold great promise for reversing joint disease.

New work from the University of Southern California (USC) has found that in a rat model, a peptide found only in Old World monkeys—θ-defensin 1 (RTD-1)—totally reversed rheumatoid arthritis. Co-author Michael Selsted, M.D., Ph.D., chair and professor of pathology at the Keck School of Medicine, USC, told OTW, “There is a significant unmet need for more effective and safer drugs for treatment of rheumatoid arthritis (RA).”

“RTD-1 is the prototype of a family of small cyclic peptides (θ-defensins), the only circular proteins in the animal kingdom,” said Dr. Selsted in the November 16, 2017 news release. “Previous studies have shown that RTD-1 modulates lethal inflammation in animal models of infection, and we predicted that RTD-1’s protective mechanism in those models would translate to rheumatoid arthritis, a disease in which chronic inflammation produces irreversible joint damage.”

As Keck Medicine wrote in the news release, “To test their hypothesis, the researchers administered RTD-1 to rats with arthritis for 11 days and observed whether the treatment had any anti-arthritic effects. Within 24 hours of the first administered dose, RTD-1 had significantly reduced arthritis progression. At the end of the treatment, rats that received RTD-1 also had markedly lower arthritis severity scores as compared with rats that had not received RTD-1.”

“Next, RTD-1 was tested in rats with severe arthritis. The research team found that RTD-1 produced a rapid reduction in arthritis severity within 48 hours of treatment, with complete resolution of clinical disease in all treated rats by day 15. RTD-1 was then compared to two gold standard treatments for rheumatoid arthritis—methotrexate and etanercept—in rats with severe arthritis. The team found that RTD-1 treatment resulted in greater disease resolution than methotrexate or etanercept. RTD-1 also achieved the highest rate of complete disease resolution of the three treatments.”

Dr. Selsted commented to OTW, “Treatment of animals with evolving or severe autoimmune arthritis with RTD-1 resulted in rapid arrest and resolution of disease that was superior to current RA drugs. Based on the preclinical efficacy of RTD-1 in treatment of autoimmune arthritis in rats, we are will shortly launch safety studies that we expect will allow for human trials of this first-in-class drug in 2018.”

The study, “Suppression and resolution of autoimmune arthritis by rhesus θ-defensin-1, an immunomodulatory macrocyclic peptide,” appears in the November 16, 2017 edition of PLOS ONE.