CARLSBAD, Calif., March 13, 2013 /PRNewswire/ -- Isis Pharmaceuticals, Inc. (NASDAQ: ISIS) announced today that ISIS-CRP Rx selectively reduced severe elevations in C-reactive protein (CRP) in humans. Data from a Phase 1 clinical study showed that ISIS-CRP Rx produced statistically significant, dose-dependent reductions in CRP response following an endotoxin challenge, which produces immune responses similar to those seen with bacterial infections. In this study, significant reduction of the endotoxin-induced CRP response was achieved in the healthy volunteers treated with ISIS-CRP Rx, with no changes in other important immune modulators, such as TNF-alpha, IL-6, and other cytokines and chemokines. Selective reduction of CRP could offer a safer approach to treating patients who have chronic inflammatory diseases, such as rheumatoid arthritis, by potentially lowering the risk of infections, a common side effect of other anti-inflammatory drugs, such as TNF-alpha inhibitors. A Phase 2 study of ISIS-CRP Rx in patients with rheumatoid arthritis is currently underway with data anticipated in the middle of this year.
"The study illustrates the considerable specificity of antisense technology to target a single component of a complex immunologic response," said Dr. Paul Ridker of the Brigham and Women's Hospital and the Harvard Medical School. "Thus, the approach shown to be effective here provides an opportunity to evaluate the role of CRP in different inflammatory disorders."
"This study is the first clinical demonstration of selective blunting of severe increases in CRP. The fact that reductions in CRP can be achieved without affecting any other key inflammatory markers supports a potentially valuable profile for CRP inhibition in inflammatory diseases. The selectivity of ISIS-CRP Rx could translate into significant therapeutic benefit, especially in patients who, due to their disease, need to selectively reduce inflammation without suppressing critical immune system functions," said Richard Geary, Ph.D., senior vice president of development at Isis.
The Phase 1 study was a randomized, placebo-controlled, dose-response study designed to assess the effects of ISIS-CRP Rx pretreatment on CRP levels following an endotoxin challenge in 30 healthy subjects. ISIS-CRP Rx was administered six times over the course of 22 days (days 1, 3, 5, 8, 15 and 22) at a dose of 400 mg or 600 mg. At day 26, all subjects were administered an endotoxin challenge. Key inflammatory markers were measured just prior to and after the challenge. In this study, ISIS-CRP Rx blunted severe increases in CRP levels by 63% (p=0.0011) in the 600 mg cohort and 36% (p=0.023) in the 400 mg cohort compared to placebo subjects at the time of peak CRP response (24 hours post challenge). No changes in other inflammatory markers were observed. Subjects receiving placebo had a mean baseline level of CRP of 1 mg/L and experienced robust, acute increases of CRP levels of greater than 30 times normal levels after the endotoxin challenge, which returned to baseline after 72 hours. ISIS-CRP Rx was well tolerated with no serious adverse events observed and no dose limiting toxicities."ISIS-CRP Rx is the first drug to selectively reduce CRP protein in humans. CRP levels are frequently elevated in many inflammatory diseases, and patients with chronic elevation of CRP have increased disease burden and worse outcomes. As such, we believe that ISIS-CRP Rx could provide patients with therapeutic benefit in numerous diseases with large commercial opportunities," said Stanley T. Crooke, M.D., Ph.D., chief executive officer and chairman at Isis. ISIS-CRP Rx is currently being evaluated in a Phase 2 study in patients with rheumatoid arthritis, an autoimmune disease where CRP is chronically elevated. In these patients, the degree of CRP elevation correlates with the severity of inflammation. ISIS-CRP Rx is also being evaluated in a Phase 2 study in patients with atrial fibrillation, a condition that involves an irregular and often rapid heart rate. In patients with atrial fibrillation, elevated levels of CRP are associated with an increase in the severity of atrial fibrillation episodes. By selectively lowering CRP in these diseases, ISIS-CRP Rx could provide significant therapeutic benefit to these patients. Isis plans to report data from the rheumatoid arthritis study in the middle of this year and from the atrial fibrillation study in the first half of 2014. "Our Phase 2 program is designed to show benefit in diseases where elevated levels of CRP are predictive of disease severity, like atrial fibrillation and rheumatoid arthritis. If positive, data from one or both of these studies will be evidence of the large potential of this drug in a variety of inflammatory diseases and conditions," concluded Dr. Crooke.