BioWorld International Correspondent

LONDON - Celltech Group plc announced positive results from the first Phase III trial of CDP 870 in rheumatoid arthritis, a trial that was conducted by former partner Pfizer Inc.

The 247-patient study of the tumor necrosis factor-alpha inhibitor, in combination with methotrexate, compared to methotrexate plus placebo, reached its primary endpoint with a "highly statistically significant" number of CDP 870 patients achieving a 20 percent reduction in symptoms at 24 weeks. A significant response was seen in week one of the study and was maintained up to 24 weeks.

Celltech CEO Goran Ando told a teleconference audience, "The results are extremely robust."

"The CDP 870 group was separated out from the methotrexate-only group at one week, and this was maintained from week one to week 24," he said. "That adds to the robustness of the pharmacological activity that was shown."

Shares in Slough, UK-based Celltech (NYSE:CLL) gained $1.02 on the news Wednesday to close at $17.24.

The side effect profile was consistent with that seen in Phase II and with other TNF-alpha inhibitors, and there were no safety concerns. None of the patients contracted tuberculosis or any other opportunistic infection during the trial. A majority of treated patients have gone into an open-label follow-up study.

Ando said the Phase III data will be sent today to the four companies Celltech has short-listed as prospective partners for CDP 870. "We will ask them for term sheets and select a partner for contractual discussions." He expects to compete that process by the end of the second quarter. "This is achievable despite the complexity of agreeing terms," he said.

There were 18 secondary endpoints in the study, but Celltech intends to present the data at a conference and publish them in a journal, and so Ando declined to give any further details. However, he did say, "There is nothing in our view in the data we have not given that compromises [the results]."

The U.S. and European study recruited patients with moderate to severe RA. Ando highlighted the fact that the mean disease duration was 10 years and all patients were heavily pretreated, which he said indicated the severity of the disease was quite high. All the patients were already prescribed methotrexate and most were also taking another disease-modifying anti-rheumatic drug and other drugs.

Ando said differing patient groups made it impossible to relate the CDP 870 study to published studies in the two marketed TNF-alpha inhibitors, Humira and Enbrel. "It is difficult to compare across, and I think it would be inappropriate."

Celltech received the data on Tuesday, and Ando said there had not been time to go into the details to see if CDP 870 offers any advantages over Humira and Enbrel. "We will spend a lot of time in the months to come to understand the finer points of CDP 870's action."

Celltech believes it has an advantage over existing treatments because CDP 870 is administered monthly and the company has developed a low-cost manufacturing process.

A second Phase III monotherapy study will conclude in the third quarter. A third study - to assess the impact of CDP 870 on disease progression - will start after Celltech signs a marketing partner.

Ando said last month that he expects the new partnership for CDP 870 to be at least equivalent in value to the previous $280 million one with Pfizer. That relationship ended in December after Pfizer tried to renegotiate the terms.