Isis Pharmaceuticals is to cut back on its ambitions for antisense candidate ISIS-CRP Rx after it dropped investigations for the drug in the treatment of rheumatoid arthritis (RA).
The company announced last week that ISIS-CRP Rx failed to prove it was significantly more effective than placebo in improving the signs and symptoms of RA during a phase II study.
This was despite ISIS-CRP Rx achieving mean reductions of up to 67 percent in C-reactive protein (CRP) – a protein associated with inflammation which ISIS-CRP Rx is designed to inhibit.
However, this still wasn’t enough to show the drug was effective as the placebo group “demonstrated a higher than expected response in both symptom score and CRP reduction”.
Dr Richard Geary, senior VP of development at Isis put a positive spin on the trial, saying that the company was able to better understand the drug and that it could lower CRP activity.
“The study accomplished its goals,” he said. “We are pleased with the consistency of CRP lowering across all of our clinical studies, but we are disappointed that we did not see a greater impact on RA symptoms in these patients”
Dr Geary also confirmed that Isis was still testing ISIS-CRP Rx in other diseases, including an ongoing phase II study in patients with atrial fibrillation – a condition that involves an irregular heart rate that commonly causes poor blood flow to the body.
“CRP is strongly associated with the presence and severity of many diseases, including numerous inflammatory and cardiovascular diseases,” he explained.
Isis is evaluating the effect of lowering CRP on the frequency and duration of atrial fibrillation. Data is expected in the first half of 2014.