By Lisa Seachrist
San Diego-based Idec Pharmaceuticals started a multicenter Phase II clinical trial testing its primatized, non-depleting anti-CD4 monoclonal antibody clenoliximab (IDEC-151) in combination with methotrexate as a treatment for moderate to severe rheumatoid arthritis (RA).
The study is the third Phase II trial testing the drug as a means for regulating helper T-cell function and quieting the out-of-control immune response. Because the antibody doesn't destroy T cells, it is less likely to interfere with normal immune function. Previous studies tested the drug as a monotherapy.
"CD4 has been shown to play a role in models of arthritis, multiple sclerosis and transplantation rejection," said IDEC's chief scientific officer, Nabil Hanna. "By blocking the CD4 on helper T cells we hope to see the induction of a long-lasting tolerance. We hope to deliver a brief period of treatment followed by a prolonged clinical benefit."
The clinical study will include approximately 130 patients with moderate to severe RA who will receive either clenoliximab plus methotrexate or methotrexate alone. Hanna said the company will be looking for both prolonged benefit and significant improvements in the measures of disease.
The American College of Rheumatologists uses an arthritis measure indicating improvement of disease measures called the ACR. An ACR 20 - an improvement of 20 percent over baseline - is routinely considered the minimum to show a therapy has a benefit. Hanna said the company will be looking to see how many patients clear the higher hurdles of ACR 50 and ACR 70 with clenoliximab therapy.
"We are coming into a market where there are other therapies," Hanna said. "We would like to see more dramatic results or a more prolonged effect with our product."
IDEC's stock (NASDAQ:IDPH) closed Monday at $142.75, up $5.75.