California-based, Proteolix has announced that selective immunoproteasome inhibitor PR-957 was shown to block disease progression in rheumatoid arthritis in a dose dependent manner, and completely eliminate visible signs of disease at the highest dose. The study was published in Nature Medicine.
PR-957 is a highly selective, small molecule inhibitor of the immunoproteasome.
The anti-inflammatory effect induced by PR-957 was rapid and long-lasting, lowering expression of multiple inflammatory mediators, including TNF-a and IL-6. Disease regression was evident 24 hours after dosing and a complete amelioration of disease was achieved with a single dose.
When compared to anti-TNF-a therapy (etanercept), PR-957 mediated a more rapid resolution of clinical symptoms, including joint inflammation, and was more effective than etanercept in a model of aggressive arthritis.
John Scarlett, President and CEO of Proteolix, said: “The research published today in Nature Medicine provides a strong rationale for clinical development of PR-957 in rheumatoid arthritis and other inflammatory and autoimmune diseases.”
“Proteolix has now discovered and developed carfilzomib, a proteasome inhibitor in late Phase 2 clinical trials for the treatment of multiple myeloma, PR-047 as an oral proteasome inhibitor also targeted in oncology, and now PR-957 as a strong drug candidate for the treatment of autoimmune disorders. This demonstrates the company’s unique discovery and development capabilities, as well as its leadership in the field of proteasome inhibition,” he added.